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[edit] Computing

[edit] December 2

[edit] rundll

Can you change the rundll without reinstalling windows? —Preceding unsigned comment added by 152.31.162.62 (talk • contribs)

Yes, you can change it, e.g. by using a hex editor in another OS on the computer. But almost all changes you do to it, will make Windows malfunction. Exactly what do you mean by "change"? --Andreas Rejbrand (talk) 01:11, 2 December 2009 (UTC)

It's just a file (albeit a system one), so you can certainly change it. But why would you want to? If you think it's infected with a virus, you need a more thorough clean than just changing this file. And if you're simply worried because you see lots of "rundll" instances in the Windows task manager, that's not necessarily an indication of a problem (lots of things use rundll to work, most of them benign). If you're worried about the safety and security of your system, a virus and spyware scan is in order. If you're getting crashes in rundll, they're probably really crashes in some program that's just using rundll. And if rundll appears implicated in your system being entirely non-operational, it may be time for a restore to a safe restore point. -- Finlay McWalter • Talk 01:15, 2 December 2009 (UTC)

[edit] Rundll

Can you change the rundll on a computer. I got rid of some viruses but the rundll is still looking for them and I don't want to reinstall if I don't really have to —Preceding unsigned comment added by 152.31.162.62 (talk) 01:11, 2 December 2009 (UTC)

OK. You most likely do not want to change the system component rundll32.exe. Perhaps the unwanted software is located in autostart? Run msconfig and see if you find anything. --Andreas Rejbrand (talk) 01:15, 2 December 2009 (UTC)

[edit] Briefcase Blues

I'm using a briefcase as a simple way to back up my documents and pictures onto my iPod. Should be pretty simple, right? It all works fine for the Pictures folder, as well as a third folder, but the Documents folder just doesn't work. Nothing appears under its status (as in "up-to-date" or "needs updating"), and when I click "Update this item," only the "Please wait while Briefcase checks your files" window opens up briefly, then disappears. I try "Update all items," but apparently 2 gigabytes isn't enough memory to handle it all. I could go through and manually update the items within, but it doesn't let me update the subfolders, saying I should update the parent folder. This leaves me unable to back up anything I created after having made the Briefcase. What should I do?--The Ninth Bright Shiner 01:13, 2 December 2009 (UTC)

Briefcase has a spotty reputation for doing weird things (but not as spotty as Roaming Profiles, another of MS's not-quite-good synchronisation solutions). Personally I wouldn't trust briefcase, but instead use rsync. rsync works the same way (at least for a one-way sync, like you're doing) and is generally extremely reliable and weirdism free. -- Finlay McWalter • Talk 02:14, 2 December 2009 (UTC)

Sounds good, I'll look into it. Thanks! But one more problem...how should I dispose of radioactive waste the old Briefcase file? Just delete it...right? I don't want it to voraciously claim any more of my files, not after the Calgary pictures incident...--The Ninth Bright Shiner 02:27, 2 December 2009 (UTC)

[edit] Contextual search

Is there any search engine that can make contextual searches, i.e. intersect the set of results with the set of pages on a particular topic? I just tried the Google search "rings in GAP", because I want to find out more about rings as they are used in GAP. But most of the matches are irrelevant, not about mathematics at all. It would be nice with a search syntax like "rings in GAP topic:mathematics", so that all returned pages are (likely) about mathematics. It would also be good if you could restrict the matches to be case-sensitive, so that only "GAP" is matched, and not e.g. "gap". --Andreas Rejbrand (talk) 01:20, 2 December 2009 (UTC)

This page from Google tells you how to get more out of your search, but doesn't say how to get the results you describe. Astronaut (talk) 13:49, 2 December 2009 (UTC)

Over at Bing, they provide a different set of controls and advanced search options. Astronaut (talk) 14:01, 2 December 2009 (UTC)

[edit] Easiest way to copy short clips from a DVD

I want to copy short clips from a DVD to an avi or mp4. Technologically speaking, what's the quickest and easiest way to do this? (using WinXP :( ) --Alecmconroy (talk) 03:33, 2 December 2009 (UTC)

(edit conflict)You need to first rip & decrypt the DVD onto your hard drive before you can do anything with the DVD. Try DVD Decrypter. If you are questioning the legality of this, it is not illegal to decrypt and rip the DVD if you do not utilize the decrypted data for commercial profit (that's piracy). DVDs are licensed for private home viewing; this is a different form of private home viewing.  Buffered Input Output 12:28, 2 December 2009 (UTC)

The DMCA (in the USA) makes it pretty clear that using the above method is illegal, and the media companies seem to agree. As I'm hoping not to start a debate about this very hot topic, I personally like to think ripping DVDs for personal use falls under the Fair Use exception. This may or may not hold up in court. I don't know of any cases where this was argued, but if there are any it would bring more merit to my views as well as the views of many consumers. Unfortunately circumventing the DRM using DVD Decrypter and other similar programs is the only way of doing what you want to do... aside from videotaping your TV screen :P Caltsar (talk) 20:14, 2 December 2009 (UTC)

They will never find out unless you're dumb and tell them, or start selling or distributing your decrypted dvds —Preceding unsigned comment added by 82.44.55.75 (talk) 20:34, 2 December 2009 (UTC)

Interestingly enough, shortly after posting here I read something about a guy in Denmark who turned himself in for doing just that. I'm hoping this sets some precedent for the US laws to be set right in the near future. Caltsar (talk) 15:53, 3 December 2009 (UTC)

The legal question is separate from the technical one. The easiest technical way is to use something like HandBrake, which makes ripping DVD chapters really easy. --Mr.98 (talk) 21:03, 2 December 2009 (UTC)

[edit] SIGHUP udevd on new USB device

Sometimes when I connect a USB storage device to my ubuntu laptop, udev doesn't acknowledge it nor does it mount manually, even though the device shows up in /dev/disk/by-id just fine. The only way I know of to fix this is to send SIGHUP to udevd. Is there any way I can have a SIGHUP sent automatically when I plug in a USB device? NeonMerlin 12:25, 2 December 2009 (UTC)

A hacky fix (rather than actually fixing whatever is causing your problem) would be to watch /dev/disk/by-id with inotify and SIGHUP whenever that sees a change. inotify has a nice utility which makes it useful from shellscripts - I'd guess you'd just do (in pseudo shellscript) something like:

   while true:     inotifywait /dev/disk/by-id     kill -HUP $udev_pid 

I can confirm that inotify does indeed work inside /dev. You may benefit from a sleep 1 between the inotifywait and the kill, to make sure the kernel has everything up before forcing udev to look at it. -- Finlay McWalter • Talk 14:31, 2 December 2009 (UTC)

[edit] What are normal CPU and motherboard temperatures?

My second-hand old computer has five fans in it, including the CPU fan and the power-unit fan. In other words its got three case fans. It is very noisy. I've disconnected one of the case fans, and I'm wondering if I could disconnect one or two more without harm, to reduce the noise. My previous old computer only had a power-unit fan and a CPU fan as far as I recall, and worked OK. The current temperatures are Motherboard 34 degrees C, CPU 27 or 28 degrees C, HDD 26 degrees C, fanin0 2812rpm, and fanin1 3125rpm. As its winter with the central heating off the room temperature is only 19 degrees C. Are the computer temperatures good? Would disconnecting one or two more case fans be advisable? Thanks 89.242.106.49 (talk) 13:59, 2 December 2009 (UTC)

I'd normally be reluctant to disable fans, but those temps seem quite low. You might also want to consider other noise reduction strategies, like placing the computer in a compartment of a wooden shelf (should be open in the back to allow cooling). If you don't have such a compartment, you could make something like that yourself out of Styrofoam sheets. StuRat (talk) 06:22, 3 December 2009 (UTC)

Many times case fans are the standard 80mm type and are easily replaced with far quieter temperature sensitive versions. Check out your favorite online retailer of computer parts (NewEgg is one in the US that comes to mind) many have a wide variety at a low price. This solution would keep your hardware safe and the ambient noise down. --Jmeden2000 (talk) 21:27, 3 December 2009 (UTC)

[edit] What computer systems are bank accounts located on?

I've been wanting to ask this question for a long time. Bank accounts must nowadays physically exist on some sort of computer systems. But what sort? They must be pretty incredibly reliable, otherwise people would get very upset when a computer failure causes them to lose money. How does it actually work? JIP | Talk 20:20, 2 December 2009 (UTC)

Traditionally most would be on mainframes. Eg the IBM mainframe. Graeme Bartlett (talk) 21:04, 2 December 2009 (UTC)

I know that the ATMs for the Nationwide Building Society run XP. I once had one BSOD on me while I was making a withdrawal.--80.176.225.249 (talk) 23:54, 2 December 2009 (UTC)

NCR ATMs all used to run OS/2; I believe a lot of current ones run Windows 2000. -- Finlay McWalter • Talk 00:35, 3 December 2009 (UTC)

I believe many nowadays may use Windows XP editions#Windows XP Embedded not Windows 2k, but I'm not sure. Others may use Windows CE. These things tend to have a long lifecycle so it's difficult to say, Windows XP Embedded or CE or some other version of Windows Embedded (including Vista Embedded) is obviously what Microsoft would suggest [1] but it doesn't mean they're using it. [2] [3] [4] [5]. Windows 2k and even some version of 9x has been used in the past I believe. Nil Einne (talk) 03:35, 3 December 2009 (UTC)

Tandem Computers was a big supplier for bank back-office equipment, because they had a lot of technology for seamless failover. That behaviour was subsequently adopted by the post-mainframe suppliers (IBM, Sun, HP, SGI, and latterly by Microsoft) whose equipment dominates now (using essentially what they sell as internet servers). The traffic volumes really aren't that high (when compared with things like World of Warcraft or Google), and the database is readily shardable. Electronic banking still works, at a procedural level, pretty much like manual banking (with paper ledgers) - there is no need for a constantly consistent global state, as they perform a reconciliation at the close of business. So they have a bunch of logically and physically separate machines doing redundant transaction logging (so they can always replay the day after hours to rebuild a consistent view), and they run multiple failover groups (at multiple geographically distinct sites, with multiple redundant connections between them). While Sun et al hardware is both very reliable and fault-tolerant, the real redundancy comes from having lots of everything, and lots of wires between them all keeping everyone up to date. -- Finlay McWalter • Talk 00:35, 3 December 2009 (UTC)

Whitney National Bank uses IBM's i OS for its core systems - this story has a lot of detail[6]. The National Bank of Greece apparently uses z/OS and OS/390[7] which run on IBM mainframes. If you search IT news sites you'll find a lot of stories about what banks are buying and using. IBM mainframes with IBM operating systems seem very common. --Pleasantman (talk) 12:54, 3 December 2009 (UTC)

Banks in South Africa use a variety of platforms and systems, but the mission critical systems like the transactional ones use Oracle databases on "high availability" / clustered (such as RAC) platforms. The redundancy is either provided by Oracle themselves or vendors such as EMC who provide solutions such as BCV. I know someone at one bank that monitors the national Cisco network on which the ATM's are connected. These things are also redundant and fault tolerant at the core, but when remote points fail then operations people and engineers run around like headless chickens trying to sort them out. HA solutions are normally hosted by companies like IBM. The company I work for has HA systems at an IBM site a few hundred metres underground, so if the entire district is bombed, the company's systems are still operational. Further backups are sent offsite to another location 40 kilometres away "just in case". We have many copies of our core databases on warehouse setups as well, so it's almost impossible to lose data for more than a day. Sandman30s (talk) 10:47, 4 December 2009 (UTC)

[edit] PS3 60GB & PS3 slim 120GB hard drive swap.

I have an original 60GB PS3 and a new 120GB PS3 slim. I successfully backed up my 60GB data using the Backup tool in the PS3 System menu to a large USB thumb drive. I swapped hard drives and the old PS3 powered up fine. It said that the drive contained a different system and needed to be wiped. So it wiped the drive and then restored the backup from the thumb drive. The "fat" PS3 works great and I have about 112GB of storage now.

However, when I put the 60GB drive into the PS3 slim, it will start up, but says that it can't find any system files. It asks that I hold down the start and select buttons to restart the system. I do that and it brings me back to the same warning. I thought it would go through the same auto format procedure, but it's isn't. I can't get to the XMB to format the internal drive. Any ideas how to fix? --70.167.58.6 (talk) 22:41, 2 December 2009 (UTC)

I found the answer here [[8]] --70.167.58.6 (talk) 15:52, 3 December 2009 (UTC)

[edit] December 3

[edit] How to prevent automatic re-directing on a website?

A website was created using a service, Moodle. However, the service provider was later switched to WetPaint. But, whenever the administrator tries to view the new website on their laptop they are unable to, and all that shows up is a generic 'demo page' for Moodle. The new website works fine on all other computers. Deleting cookies and setting firefox to alert you when re-directs take place haven't fixed this. The same thing happens with IE. Does anyone have any ideas on how to fix this? Thank you. —Preceding unsigned comment added by 60.234.239.245 (talk) 00:38, 3 December 2009 (UTC)

Do you mean "view the new website" that you are going to yourwebsite.com and it is going to the wrong place? If so, and you have set up the DNS correctly, then it probably means that whatever local DNS server your computer is connecting to is just not updated, and probably will in a day or two. Sometimes this kind of thing takes a day or so to percolate through the system. But how long has it been? --Mr.98 (talk) 03:14, 3 December 2009 (UTC)

On the laptop, go to Start --> Run... --> cmd --> ipconfig /flushdns. Then, try again. The DNS Helper Service caches DNS resolutions, which can become out of date. If that doesn't work, then try typing net stop "DNS Client".--Drknkn (talk) 03:37, 3 December 2009 (UTC)

[edit] Maximized embedded flash video minimizes when I click elsewhere

I have a dual-screen setup (Windows 7, GeForce 9600 GT with 2 BenQ 16:9 monitors if that matters...) and I like to use the right screen for video.

Unfortunately, when I go full-screen on many embedded video clips (like ones on CNBC.com - which uses Adobe Flash Player 10 in Google Chrome)on one monitor, then click anywhere on the other monitor, the video goes back to it's original size.

It would be nice if I could watch a video like that full-screen on one monitor, while surfing the internet on the other. Any ideas?NByz (talk) 02:24, 3 December 2009 (UTC)

I don't have a solution, but can offer a work-around. I had a similar problem using full-screen mode on one screen of a two-screen setup. My solution was to simulate full-screen mode by dragging the corner of the window off the edge of the screen. This is easiest if the screen layout is offset, like so:

 +-----+ |     |+-----+ |     ||     | +-----+|     |        +-----+ 

I have CRT monitors, so I can also adjust the horizontal and vertical scaling and panning, so that I don't see the window edges. With most LCD monitors you lose this ability, unfortunately, so you might have to settle for leaving two adjacent sides of the window still showing. StuRat (talk) 06:11, 3 December 2009 (UTC)

Try this — Matt Eason ^{(Talk • Contribs)} 11:54, 6 December 2009 (UTC)

[edit] How people look up information

I am trying to find statistics on how people look up information - by library, internet, buying books etc. In other words how people try to find information to answer something. I can't think of a way to phrase the search query or find to find any relevant statistics. I am writing a paper and need to substantiate the claim that people prefer to use Wikipedia, search engines, google, online databases etc as opposed to going to a library for their information retrieval needs. I know this is true.. but I need statistics to back it up. And don't know how to find them. Thanks for any help. —Preceding unsigned comment added by Baalhammon (talk • contribs) 03:26, 3 December 2009 (UTC)

You can search for prior research using Google Scholar. Surely somebody has collected statistics on exactly what you are working on. Some helpful search terms might include "information retrieval" or "information systems". I found Interaction with Texts: Information Retrieval as Information-Seeking Behavior, which has some helpful conceptual overviews and may lead you to exactly what you're looking for. Nimur (talk) 04:31, 3 December 2009 (UTC)

I appreciate the heads up - but I already have a conceptual understanding of the topic, I need hard statistics. I wouldn't be posting here unless I already looked using those keywords - what comes up is exactly what you linked to, theoretical papers. I need statistics that demonstrate how many users use Wikipedia, search engines, online databases, other web 2.0 technologies versus library visits. I think its obvious to most people that this is true.. but without the data I can't make the claim in good conscience. —Preceding unsigned comment added by Baalhammon (talk • contribs) 05:53, 3 December 2009 (UTC)

The reason people don't go to the library is that it requires a trip. However, there are other sources of info at home that might offer more competition for the internet; like dictionaries, the Bible, medical texts, and even asking a family member. Are you including these ways to "find stuff out" ? StuRat (talk) 06:02, 3 December 2009 (UTC)

[edit] Remastering an MP3

OK, so I have a Shirley Temple song on my playlist. Since it was a bit messed up (i.e. audio levels, static, etc.), up to how much extent can it be restored or remastered using software? Blake Gripling (talk) 06:43, 3 December 2009 (UTC)

There's a lot of audio editing software that can remove static and let you adjust levels. Audacity is free and may do the job, but for more demanding work there are many commercial packages too, such as Adobe Audition. See also List of free software for audio, Category:Digital audio workstation software. You'll have to experiment to see how well it can be fixed, as this will depend on the type of noise and how badly it is degraded. --Pleasantman (talk) 13:02, 3 December 2009 (UTC)

Note that this is a non-trivial task... it will probably not be easy unless there is a uniformly wrong thing (e.g. total song wrong volume, or wrong pitch). Otherwise it will take a lot of careful manipulation, and even then might not sound much improved (I find trying to improve audio often leads to it getting pretty swampy, even if it is something that should theoretically be easy, like removing a constant humming noise). --Mr.98 (talk) 22:27, 3 December 2009 (UTC)

Removing an unknown noise signal is a theoretically hard statistical signal processing problem. The trouble with these sorts of interfering sounds is that they come from real noise sources - so the sort of theoretical approximations like constant frequency hum, or gaussian distribution noise, or smoothly varying amplitude, are all out the window. From the standpoint of looking at a waveform, the conventional assumption that it is a mere "superposition" of the desired music with an additive noise source becomes less useful in practice, (since the noise source has virtually no useful descriptive parameters). Approximating the noise so it can be subtracted out requires many assumptions about the noise shape; alternatively, you can work on a few seconds of the audio at a time and tune your parameters manually. As has been noted above, this kind of manual remastering will require a lot of time and effort tweaking parameters, even if you have very sophisticated tools. The end result may still be noisy. Conversely, sometime a simple equalizer or level adjustment is all you need to improve the quality - and those operations are fairly straightforward one-shot processes. Nimur (talk) 15:12, 5 December 2009 (UTC)

[edit] return

In a function in C, one uses return value to return a value back to main. What happens when there is no value following return? Does it return nothing or all the values?

for example:

 main()  ... void printfunction(char file[])  ...   printf("\n\nThe file reversed:\n");   for(count2=0;count2<=count;count2++)     printf("%c",original[count-count2]);     return; } 

-- penubag  (talk) 09:10, 3 December 2009 (UTC)

As the declaration of the function says, it returns a void - i.e. nothing. If you were to try to use the return value:

     retval = printfunction(filname); 

then you would get a compile error. --Phil Holmes (talk) 09:39, 3 December 2009 (UTC)

If the return type of a function is void, it does not return a value, and the only valid return-statement is on the form return;. Otherwise, the return-statement must contain an expression convertible to the function's return type. In any case, the function main shall have a return type of int. If your program does not match these requirements, anything can happen. decltype (talk) 09:43, 3 December 2009 (UTC)

Ahh, I see. So it has the same effect as return void or not having anything?-- penubag  (talk) 10:08, 3 December 2009 (UTC)

Well yes, except that "return void;" is not valid. So for a function with void return type, "return;" simply ends execution of that function and returns to the calling function. decltype (talk) 10:29, 3 December 2009 (UTC)

It may be worth saying that you don't need to put a return at the end of a void function; if you simply hit the end of the function body (the last }) you'll exit the function just fine. You use return in a void function when you want to exit it other than at the end (which some, but not all, programmers think is a bad thing: see for example [9]). (You can also return early from a function that returns a value; you must supply each return statement with a value, though they need not be the same.) --Tardis (talk) 16:13, 3 December 2009 (UTC)

Yes, if you follow the Single-Entry Single Exit methodology, you are unlikely to have any return statements at all in your void functions. There could still be one at the very end, but I believe most people would consider it redundant. decltype (talk) 15:02, 4 December 2009 (UTC)

From what I can remember, main() is legal in pre-ANSI C, but not necessarily in ANSI C. int main() is legal in both, void main() is illegal in both. ("Illegal" meaning "causes undefined behaviour", meaning it might work all perfectly under some particular operating system, but there's nothing whatsoever guaranteeing it won't make the entire computer explode under another operating system.) main() has three standard return values: 0, EXIT_SUCCESS and EXIT_FAILURE, of which the first two mean the same thing. Any other return value is implementation-dependent. Falling off main() without returning anything counts as returning 0, but main() is the only function guaranteed to do that. For any other function returning anything other than void, falling off the function without returning anything causes undefined behaviour. JIP | Talk 20:56, 3 December 2009 (UTC)

What does "all the values" mean? Also, it's not at all the question you were asking, but it's probably important: your array original probably has length count. Yet the first time through the loop what you try to print is original[count], which is a bad thing. --Tardis (talk) 16:13, 3 December 2009 (UTC)

Thanks for this! -- penubag  (talk) 20:36, 5 December 2009 (UTC)

[edit] Symbols, colors, fonts won't copy into email

I'm reposting this question from Vchimpanzee, who asked some follow-up questions after the thread was archived. I've added a question to VChimpanzee for more detailed info. --NorwegianBlue ^talk 15:55, 3 December 2009 (UTC)

Referring back to this question:[10]

I now find myself unable to copy and paste this information into emails. Is this something new in Internet Explorer 8?

I do recall warnings that I was telling the computer to do something unsafe and that was stopped, but I hardly see where just the symbols would cause a problem. I do remember video or something else moving and I was told don't use Explorer. I stay away from Firefox and use plain text when possible, but copying the symbols manually is such a pain. Vchimpanzee · talk · contributions · 20:43, 24 November 2009 (UTC)

No. The problem is not IE8. Probably, your email client is set to using just plain text. If you switch to using html, it should work (at least sort-of-work). See E-mail#Plain_text_and_HTML. --NorwegianBlue ^talk 21:14, 25 November 2009 (UTC)

I'm not sure what that means. I just go to the web site of the email service and sign in (#Webmail in the above article). It doesn't seem to matter what computer or what address, but there is a problem with this now.

I'd rather do plain text but sometimes don't because copying the symbols is a pain.Vchimpanzee · talk · contributions · 21:28, 27 November 2009 (UTC)

Update: while I couldn't see the text with the symbols and fonts, it did go through.Vchimpanzee · talk · contributions · 20:47, 2 December 2009 (UTC)

To get a more specific answer, it would be helpful if you stated which email client you use, or, if you use a webmail service, which service you use (gmail, yahoo etc). It would also be helpful if you provided a link to a web page with contents that you want to copy and paste into your email. --NorwegianBlue ^talk 15:55, 3 December 2009 (UTC)

[edit] Fun Ti 83 Calculator programs

What are some cool TI 83 calculator programs?Accdude92 (talk to me!) (sign) 18:03, 3 December 2009 (UTC)

• [11]. --Michael White^T·C 18:36, 3 December 2009 (UTC)

ticalc.org is the most comprehensive site to find programs. I remember playing a multiplayer Bomberman type game back in high school. I think it required MirageOS which can be a little tricky to work with. Caltsar (talk) 18:39, 3 December 2009 (UTC)

[edit] Wonderful Special Effects on Wordpress

Just have a look at this wordpress blog. See the wonderful "snowfall". How can I do same on my own wordpress ?

 Jon Ascton  (talk) 18:11, 3 December 2009 (UTC)

The first google hit for "wordpress snowflakes" answers the question, but unless your blog is about falling snowflakes I'd file this under "blink tag". --Sean 18:59, 3 December 2009 (UTC)

Like this http://www.sjbaker.org ? Well, go to [12] - copy the javascript from that paste into your own web page right below the BODY tag at the top of the file. Then find the place where it says "var snowsrc=" ...and delete the URL and change it to just "snow.gif". Then make a small GIF image of a snowflake (or just a white circle - like I did) with a transparent background and place that into a file in the same directory as your web page...and you're done! (If you're feeling super-lazy, you can steal http://www.sjbaker.org/snow.gif - which I hereby release under the GFDL and Creative commons yadda yadda yadda (yes, it's a 16x16 pixel white circle, created with all of my very best, professional graphics skills so it's a valuable contribution to society...enjoy!) SteveBaker (talk) 19:14, 3 December 2009 (UTC)

(Revised: I made a spinning snowflake - it's even more annoying than the circles!) SteveBaker (talk) 20:17, 3 December 2009 (UTC)

[edit] Function templates with Microsoft cl.exe compiler

With the following lines of code:

 template <class T> T max(T x, T y) {     return (x > y) ? x : y; }; 

For the line T max(T x, T y), I get the error c2027 stating "use of undefined type 'T'." I've tried putting "typename" in front of all possible permutations of the Ts on that line, but to no avail. What format does the Microsoft compiler require for function templates? 20.137.18.50 (talk) 19:52, 3 December 2009 (UTC)

I'm guessing a little here, but they are probably guarding against pathological cases. Declared in the manner you describe, the size of the return type (and the parameter type, which needs to be copied) could be near infinite, which could cause problems. If you declare it to return a T&, it should work per this KB article, assuming I'm reading it right. —ShadowRanger ^(talk|stalk) 21:33, 3 December 2009 (UTC)

That KB article is about code like template<class T> foo() {...}, which is not legal C++, not template<class T> T foo() {...}, which is legal. -- BenRG (talk) 23:19, 3 December 2009 (UTC)

I know, but as it happens, it documents a perfectly legal version of the function they are trying to write. As such, I was speculating that the difference involved might be the source of the problem. Seeing your post below, I'm guessing that the problem is completely different (possibly related to an error in the code using it, as opposed to the code declaring it), but the C++ compiler is doing its usual thing of providing useless error messages. —ShadowRanger ^(talk|stalk) 23:22, 3 December 2009 (UTC)

The code is legal C++ and should work. And it does for me (Microsoft C++ version 15.00.21022.08 for x86). Is this part of a larger program? The error might be caused by an instantiation of the template rather than the template itself.

Incidentally, the semicolon after the close brace is not necessary and most people would consider it unidiomatic. It is legal, though. -- BenRG (talk) 23:15, 3 December 2009 (UTC)

I'm trying to make pclaf.obj using pclaf.cpp and pclaf.h at http://web.engr.oregonstate.edu/~budd/Books/oopintro2e/info/slides/chap19/slide1.htm by typing C:\>cl /c pclaf.cpp when I get the error. 71.161.61.41 (talk) 00:16, 4 December 2009 (UTC)

The problem (and I feel silly for not guessing this earlier) is that min and max are already defined as macros in an included header, so the compiler is seeing something like template <class T> T (T x > T y ? T x : T y) { return ... }. You can work around this by #undefing them before defining the templates. This is very old code, predating the ISO C++ standard, and would need a fair amount of cleanup to compile under recent versions of Microsoft C++ (which, unlike earlier versions, adhere pretty closely to the standard). -- BenRG (talk) 00:55, 4 December 2009 (UTC)

Thanks! 71.161.61.41 (talk) 00:58, 4 December 2009 (UTC)

Actually, the stray semicolon makes the program ill-formed, assuming that max is in the global namespace, and not a class member function template. A few compilers actually do diagnose it (most don't). decltype (talk) 15:26, 4 December 2009 (UTC)

An aside: you only need to stick "typename" in when the compiler might guess wrong about whether a template-parameter-qualified name is a value or a type. "T::foo" could require "typename" because the compiler doesn't know if foo is like "typedef int foo;" or "static void foo() {}" in class T. It defaults to interpreting as a value, so if it's a type you'll need to say so with "typename T::foo". Since your example doesn't contain any scope resolution operators (double colons) at all, you would never need "typename". --Sean 16:08, 4 December 2009 (UTC)

I was surprised to see we didn't have a typename article, so I added one. --Sean 18:42, 4 December 2009 (UTC)

[edit] Why School and Library Computers Don't Suffer Often from Viruses

Why do the computers at schools and libraries don't suffer from viruses and malware as much as personal computers despite their high traffic? All of these public computers I have used erase everything stored on the computer when rebooted; could this be one of the reasons? Would setting up a personal computer like this (one that erases everything when shutdown) effectively eliminate all malware/viruses? 128.84.178.36 (talk) 20:04, 3 December 2009 (UTC)

Not all, no. If you get infected while logged in and then create some documents which also become infected, and send them via e-mail, or whatever, you'd still be propagating the malware. The hard disk wipe does help a lot, though. When the hard disk gets wiped at the end of a session, the malware gets wiped, too. Trouble with doing this on your home PC would be that you could no longer change its configurations, add programs, store any documents locally. Tempshill (talk) 20:10, 3 December 2009 (UTC)

Most malware these days isn't viruses, and mostly gets onto machines because someone let them (they fell for a scam and downloaded and ran something they shouldn't, or ran some program emailed to them under a deceptive guise). Machines set up as kiosks generally take some simple security measures with this in mind:

• the ordinary user is an unprivileged account (and not an admin), and that account has its abilities heavily curtailed using the system security policy
• the administrator is a professional, and is hopefully either very experienced or pretty well qualified
• anti-virus and anti-spyware software are kept up to date
• there usually isn't an email client (or it's disabled); users use webmail (which is generally less likely to transmit malware effectively to the machine).

So, for the merely incompetent users such a machine mostly gets, these sensible security measures are mostly sufficient. They do the blank-and-restore thing as an additional protection, and for protection against local users with malicious intent. For a single-user home machine, blank-and-restore is overkill, and if you're technical enough to set that up properly, you're technical enough not to get malware in the first place. -- Finlay McWalter • Talk 20:13, 3 December 2009 (UTC)

(ec) Another major reason they are probably not often infected is their rigorous policy that users do not log in with accounts that have administrator rights, so system files can't get infected. Most home and small business users just blindly use admin accounts all the time. Tempshill (talk) 20:15, 3 December 2009 (UTC)

This is the crux of the difference between almost all home run computers, and computers that follow basic security guidelines. A current version of Windows with the latest security patches and a properly restricted user account is resistant to almost all viruses/malware. Antivirus tools are little more than a safety net for haphazard users with too much privilege on the system. It cannot be stressed enough, if you want to stop problems before they start, give users only enough privilege to log in and do exactly what they need to do. Also, one more comment about the flush-at-reboot approach, this is obviously more final (especially if you boot up from unwritable CD or DVD and the hard drive is completely wiped) and it doesn't have to be impractical. There are "live CD" boot images for many major operating systems that are easy to obtain, can be customized, and include a lot of features. If the original question was asked with the intention of building a more robust computer for, say, a less computer fluent family member that won't require constant support to remove malware and correct configuration mixups, this may be a good approach to take. --Jmeden2000 (talk) 21:18, 3 December 2009 (UTC)

It's likely that most schools and libraries enjoy the services of one or several professional computer experts in a dedicated I.T. Department who are specifically employed to set up the computers and the network they're on securely, to install the best available security programs, to keep those programs fully up to date, and to actively monitor the network for problems, external attacks, etc: certainly that's the case in the commmercial companies with comparable equipment that I've worked at. 87.81.230.195 (talk) 00:35, 6 December 2009 (UTC)

When I was in college, my school's computer lab was staffed by students. They weren't the most knowledgeable people in the world.

Anyway, one of the lab computers we'd remote-desktop into got a really bad virus. We weren't administrators, and the system ran a fully-patched version of Windows Server 2003. It spread to three other computers. Removal of adminship will stop many viruses, but some will still be able to infect the computer using buffer overflows or by running under the system account at startup. I read about an exploit the other day that allows you to give yourself administrative privilages in a Vista machine. In later years, the lab used machines with Windows Vista and Windows Server 2008 and I never saw those machines become infected.--Drknkn (talk) 04:40, 6 December 2009 (UTC)

[edit] How can I tell what Bluetooth profile a USB dongle supports

I found a USB Bluetooth adapter behind my desk. How can I tell what class and profile it supports? There's no manufacturer name. --70.167.58.6 (talk) 20:13, 3 December 2009 (UTC)

If you plug it into a Linux machine and type lsusb it will show you the device's manufacturer and model number, give you something to put into Google to find info on the device. I think in Windows there's something similar in the DeviceManager (I'll get back to you on that). -- Finlay McWalter • Talk 20:17, 3 December 2009 (UTC)

Hmm, the Windows Device Manager (on 7 at least) has lots of USB properties for installed devices, but none reports the useful info that lsusb does. -- Finlay McWalter • Talk 20:29, 3 December 2009 (UTC)

Right-click any device and select properties. From this page select the details tab and then just scroll through the "Property" choices to find the information you want. The most useful ones are "Hardware Ids", "Bus relations" and "Device Instance Path" (which between them will tell you the manufacturer/model (if it's actually saved in the USB hardware) and Googling the Device ID will usually give you more information. ZX81 ^talk 20:51, 3 December 2009 (UTC)

So yeah, I'm using a Mac, so none of those options are available. Looking through Wikipedia, I found a photo of it. It's the exact one listed in the Bluetooth entry here [13] --70.167.58.6 (talk) 18:57, 4 December 2009 (UTC)

[edit] CSS "tabs"/indents

So I'm trying to make a page that looks something like this:

...and so on. Except, I'd like (for a variety of reasons), to do it without tables. Is there any way to get this kind of tab-like behavior? Indents don't seem to help much, because I can't separate the date and first line. Putting a margin-right on the date doesn't work because the lengths of any individual date can vary (e.g. "May 5" is fewer characters than "February 5" and so it looks incorrect). In Microsoft Word, this would be accomplished with tabs, but I don't see any obvious CSS equivalents.

Any thoughts? --Mr.98 (talk) 21:06, 3 December 2009 (UTC)

Make each date block a float:left div, each of the right "column" another float:left div, and do a clear:left between the row. -- Finlay McWalter • Talk 21:08, 3 December 2009 (UTC)

Like this:

Of course in practice you'd use CSS classes and a stylesheet (which I can't readily do on Wikipedia), making your html very simple.-- Finlay McWalter • Talk 21:12, 3 December 2009 (UTC)

That's clever, but it doesn't quite work for what I'm doing. One of the reasons I'm trying to avoid using a table is because I'm floating an image to the right of all this text (I know, how complicated can I make this? I swear it's not really that complex a layout visually!), and doing that with all of these other floats makes some weird things happen if the "some information" text is long (which it is in some cases)—it'll float the DIVs near the image in weird ways, like this:

Bleh. Any other ideas? :-/ --Mr.98 (talk) 21:23, 3 December 2009 (UTC)

OK! I figured it out. If I don't make the info floating, and instead just give it a margin-left of the right size, then the above works OK. Great! Thanks. --Mr.98 (talk) 22:04, 3 December 2009 (UTC)

I figured out a way with floating: http://mcwalter.org/unlinked/css_table/index.html (with stylesheet at http://mcwalter.org/unlinked/css_table/fin.css). -- Finlay McWalter • Talk 22:09, 3 December 2009 (UTC)

A definition list is good for data pairings. ¦ Reisio (talk) 05:27, 6 December 2009 (UTC)

[edit] domain cloaking, etc.

I run a page at a URL like http://myuniversity.edu/dept/ . It is hosted by the university in question. Unfortunately the university's IT department is pretty backwards and the web options are pretty artificially constrained. I would like to have the hosting provided by a commercial host, like bluehost.com or dreamhost.com or whatever. The problem is, I need the URL to look the same (it still needs to be http://myuniversity.edu/dept/) and it needs to be seamless (that is, if you go to myuniversity.edu/dept/aspecificpage.html, it would have to work correctly and still appear to be at myuniversity.edu).

What specifically would the university IT people have to do in order to make the .edu domain point to the commercial host servers? How technically difficult would this be (especially considering that ONLY the "/dept/" directory would point to these servers—the rest of the university's pages would obviously still be hosted on university servers)? This is normally consider "domain cloaking", I believe, but I don't really know how it works on the back-end, or how it would work in the case of a single directory on a domain (and not the whole domain).

Does anyone know what this would involve? Goofy half-solutions (e.g. loading all the pages via AJAX or something) are not really acceptable possibilities. --Mr.98 (talk) 21:11, 3 December 2009 (UTC)

I can almost guarantee that your university will not change their DNS records for you which is required to do what you ask. The only other options are to do half-solutions that can be quite a pain and aren't really adequate. Framing a site is a popular one in this case. The cleanest way I can think of to show the other URL is legit is to have a link on your .edu page that says something like "due to technical restrictions, this department's homepage is located at x.url." Of course, University policy can be pretty backwards even when this is taken into account so ask about this first. You could also possibly get funds to set up your own server for the department where your options are less constrained by the normal IT department. I am, of course, assuming that this is a site for a full department at the university. Caltsar (talk) 21:32, 3 December 2009 (UTC)

Framing and linking offsite won't work, no... it will look pretty cheesy and the whole goal is to not look cheesy. ;-)

If I know exactly what the DNS requirements are (e.g., what exactly they will need to do), I have a good chance of getting them to do it (not because they care a wit about me, but because the person I work for is pretty close with the head of their IT department and can get things pushed through if need be), but I will need to know exactly what is to be done (because the IT people will not know how to do it and won't want to bother with it otherwise). (Oh, if only the IT department didn't see the need to do everything in-house in the first place...) --Mr.98 (talk) 21:42, 3 December 2009 (UTC)

DNS doesn't have anything to do with directories, and can't be used to make just one directory appear on a different server. A Reverse proxy, if supported by the webserver on myuniversity.edu, can forward requests to /dept/ to a third server, making it seemless from the browser's point of view.82.75.185.247 (talk) 22:54, 3 December 2009 (UTC)

OK... blah. Reverse proxies look like a lot of work. Hmm. Dang. --Mr.98 (talk) 00:23, 4 December 2009 (UTC)

Another option is to actually host your own server at something like "yourserver.yourschool.edu", which is a lot easier than getting a subdirectory of another web host to point to your machine. Would that be an acceptable solution? Nimur (talk) 22:38, 4 December 2009 (UTC)

[edit] Copying URLs to clipboard

I am using WinXP and IE8.

I would like to be able to highlight some text on a webpage (or just indicate the whole page) and have all the explicit URLs there copied to my clipboard while the rest of the text is ignored: is there any quick way to do this please rather than copying each URL individually? I only want to copy the visible URLs, I do not want to copy any weblinks where the text of the URL is not visible to the eye.

Second question, is there any quicker way to copy a visible URL to the clipboard other than highlighting it, right clicking, and choosing 'copy' from the menu? 89.242.105.246 (talk) 21:19, 3 December 2009 (UTC)

2nd question: You don't have to highlight the URL; just right-click it. Tempshill (talk) 21:41, 3 December 2009 (UTC)

2nd question: Alt+D, Ctrl+C. --Andreas Rejbrand (talk) 22:31, 3 December 2009 (UTC)

Just to clarify, 89.242.105.246 seems interested in gathering addresses spelled out in text, but not interested in clickable links on the page. The only solutions I can think of involve writing a script or program.

Here's an AutoHotkey script that lets you select text, then press F12 to put just the URLs on the clipboard. (In this script, a URL is considered to be text that begins with http:// or https:// )

 F12::     Send ^c   ClipWait   cb := Clipboard . " "     out := ""   currentpos := 1     Loop   {       matchpos := RegExMatch(cb, "(https?://.+?)\s", url, currentpos)       if (matchpos = 0)       break       out .= url1 . "`r`n"     currentpos := matchpos + StrLen(url1)     }     Clipboard := out   return 

For example, with this script loaded, I clicked on this page, pressed Ctrl+A, F12, and the clipboard contained

 http://jblevins.org/projects/markdown-mode/) http://192.168.1.1/ http://www.sjbaker.org http://www.sjbaker.org/snow.gif http://web.engr.oregonstate.edu/~budd/Books/oopintro2e/info/slides/chap19/slide1.htm http://mcwalter.org/unlinked/css_table/index.html http://mcwalter.org/unlinked/css_table/fin.css). http://myuniversity.edu/dept/ http://myuniversity.edu/dept/) http://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Computing" 

--Bavi H (talk) 04:34, 4 December 2009 (UTC)

Thank you very much. I've installed AutoHotKey and run the script. However unfortunately on closer inspection many of the URLs I want to copy only make visible a shortened version of themselves on the webpage, putting in dots where parts of the URL has been skipped, while the underlying URL that I want to copy is complete. Is there any quick and easy way to mass-copy these URLs into the clipboard please? Thanks. 92.29.42.147 (talk) 13:59, 4 December 2009 (UTC)

I misunderstood and thought you wanted to gather mainly plain text addresses that aren't clickable links. But it sounds like you're interested in the addresses of clickable links, but only certain kinds.

Here's a way you can see the addresses of all the links on a page in Internet Explorer 8: Click on the Tools button, then click on Developer Tools. In the Developer Tools window, click on the View menu, then click Link Report. This will open a new tab that shows the address of every link on the page. This might make it easier to copy the addresses you want normally or with the AutoHotkey script above. --Bavi H (talk) 04:07, 5 December 2009 (UTC)

Thanks, I tried that, Unfortunately that produces lots of URLs, and it is difficult to identify the ones I want. Perhaps I should have a go at extending your script myself. Is there any way to identify the underlying URL (in the source code) that the visible URL refers to please? Or to filter all the URLs in the source code and only copy those that include a particular text string? Thabks again. 92.27.148.85 (talk) 12:55, 5 December 2009 (UTC)

AutoHotkey uses the plain-text version of the clipboard, so it can't access the addresses of links you select on a normal webpage. However, if you select text on the Link Report list, then the text of the link (which AutoHotkey can access) is the same as the address of the link. So you can select all the text on the Link Report, then run the script to get a list of all the addresses on to the clipboard. Here are some ideas to make that list more useful:

• If you sort the list, that might make it easier to identify the addresses you want. Add the line Sort, out right before Clipboard := out
• Read the AutoHotkey help file pages "RegExMatch()" and "RegEx Quick Reference" to learn how to change the filter in the script.

--Bavi H (talk) 17:48, 5 December 2009 (UTC)

Also, here's a completely different idea. I know installing another web browser is a large step to take. But in Opera, you can go to Tools, Links to see a list of links on the page. (It looks like this: opera links.gif.) You can click on the column headers to sort (or unsort) the list by name or address, and you can type in the little search box to filter the list. Then you can Shift+click or Ctrl+click to select multiple links you want, then use Copy (Ctrl+C; Edit, Copy; or right-click, Copy) to copy just the addresses. --Bavi H (talk) 18:24, 5 December 2009 (UTC)

[edit] Sensitive Data What to do ?

Well, is there some way I can hide my important .doc, .txt and picture files. Of course I know about "hide" command but anyone can tick the "show hidden files" option and see them. I mean no one can see them no matter how hard they try. Or a part of my harddisk becomes inacessible to anyone but me...?

 Jon Ascton  (talk) 22:24, 3 December 2009 (UTC)

You could create a TrueCrypt volume on your disk. To anyone else, this will just be a single file containing data that appear to be random. If you click on the file, you will be prompted for a password to mount the disk. After having given the password, the volume looks just like a second hard disk for the remainder of the session. You could save and edit your sensitive data there. The safety of the data, will of course depend on the strength of the password you choose. --NorwegianBlue ^talk 22:36, 3 December 2009 (UTC)

Bruce Schneier's advice in this regard is here. -- Finlay McWalter • Talk 22:58, 3 December 2009 (UTC)

[edit] Sony 16GB S Series Walkman Video MP3 Player -- Windows 2000 support

I may soon get a "Sony 16GB S Series Walkman Video MP3 Player" (model NWZ-S545). However, my operating system is Windows 2000, which Sony's "Content Transfer" program claims to not support. I'd personally prefer not to use Content Transfer anyway, but I want to be able to use the player. A review online says that when you use a different operating system, it accesses the player as a USB mass storage device, which I assume I'd greatly prefer over having to use Sony's middle-man program on my old, slow computer.

Does anyone have this player, and use or have access to Windows 2000? If so, can you tell me whether I'll be able to properly get my files onto it (hopefully just as a regular removable storage device)? For the record, I have nothing that is DRM-protected, so that's no issue. Also, if I have to use MediaMonkey to transfer, I can do so. ---4.251.126.53 (talk) 22:39, 3 December 2009 (UTC)

If the MP3 player is USB Mass storage device compliant then it means that when you plug it into a Windows 2000 computer (or newer) then it will operate like a USB pen drive, so you will we able to simply copy over music files in the same way you would copy over other files to a USB pen drive. Depending on the player's configuration you may have to copy them to a specific folder on the player, but otherwise you won't need any software to copy of your files at all. Rjwilmsi 20:17, 5 December 2009 (UTC)

The review that I read said that when using Windows, you have to access the device in MTP mode. I'm not too familiar with that, as I've never gone above Windows 2000. One of their complaints in the end summary was that they were forced to use MTP. However, they said that in other operating systems it uses UMS. The reason I'm confused is because W2K doesn't even have an MTP mode, so I'd assume that the computer would just treat it as mass storage by default... but I don't know. --4.251.126.205 (talk) 21:08, 5 December 2009 (UTC)

[edit] December 4

[edit] Funny shapes in scanned images

Like many other scanned images I've seen, this picture (taken from a Google Books scan of an 1890s book) has funny shapes that presumably comes from the scanning process. Not all Google Books images have these shapes uniformly, as you can see at this image, but most seem to have them to some extent. What causes these shapes to appear? Nyttend (talk) 01:07, 4 December 2009 (UTC)

It's Moiré fringing - cause by the beat frequency between the halftoning grid in the original image and the pixels in the camera/scanner. Scanning the image at much higher resolution - and using appropriate filtering to down-size the image can get rid of this - but sadly, it's a common artifact in amateur scanning. SteveBaker (talk) 02:23, 4 December 2009 (UTC)

Some scanning software has an option called "Descreening" which is designed to reduce this effect. --Phil Holmes (talk) 09:27, 4 December 2009 (UTC)

[edit] Anonymous

I don't know if this is the right sort of question for the reference desk, but what are your views on the internet group Anonymous, are they a serious threat, or are they like a little brother whining for attention? Thank you for your time.

Americanfreedom (talk) 05:49, 4 December 2009 (UTC)

I would say that your suspicions are correct - it's not the right sort of question for the Reference Desk as any answer other than linking the Wikipedia article would be a forum discussion. And since you linked the relevant article yourself, you imply that you've already read it, meaning there's probably nothing else to do or say here, so let's just move along shall we? 218.25.32.210 (talk) 09:14, 4 December 2009 (UTC)

Anonymous is a joke. A bunch of fake hackers pretending to exist in an unstructured collective, which is actually highly structured. Anonymous never was an never will be a part of the hacking scene. The war on Scientology is naive and immature —Preceding unsigned comment added by 82.44.55.75 (talk) 22:09, 4 December 2009 (UTC)

@88.44.55.75 Anon: I have scored your comment out to avoid a debate, according to the guidelines, Wikipedia:Reference_desk/Guidelines#What_the_reference_desk_is_not. We're here to answer factual questions, not discuss. --81.101.121.181 (talk) 16:00, 5 December 2009 (UTC)

[edit] Spell check in MS Word

I am proof checking a document of about 250 pages, created by someone else in Word 2003. I can see with the naked eye that it contains many spelling errors (not just matters of style such as labour/labor, but things like advnatage instead of advantage). Yet when I run spell check none of these errors are picked up. I get a message telling me that spell check is complete, but that text marked in some particular way (I forget the detail) has not been checked. How can I force Word to check ALL the document? I have spent ages with the online help routine and can't find any clue about this.

Thanks for any help. Maid Marion (talk) 08:49, 4 December 2009 (UTC)

Try Tools, Language, Set Language and check that "Do not check spelling or grammar" isn't checked. --Phil Holmes (talk) 09:25, 4 December 2009 (UTC)

Thanks Phil, but this made no difference - I still get the same result. Having done it again, I can now tell you all what the exact message is: Text marked with 'Do not check spelling or grammar' was skipped. But presumably there should not be any such text now that I have followed Phil's suggestion? Maid Marion (talk) 11:17, 4 December 2009 (UTC)

I think you need to look for Tools, Spelling & Grammar, Options, Recheck Document ... this forces a recheck of words previously marked to be ignored - which may be your issue. It's worth double-checking all the options on the Options list, lest any of them have silly configurations. Also check the the language of the document is set appropriately - CTRL-A, Tools, Language, Set Language. --Tagishsimon (talk) 11:30, 4 December 2009 (UTC)

Should have said - select all the document before you set the checking options. --Phil Holmes (talk) 12:00, 4 December 2009 (UTC)

Thanks to both of you, but none of this seems to solve the problem. Not to worry - I guess I'll just have to rely on old-fashioned 'manual' proofreading. 86.146.15.100 (talk) 16:13, 4 December 2009 (UTC)

Hey - don't give up! I think there are some "features" in the way Word allows you to change the language. On my system, either selecting all, or selecting more than about 5 pages mean that the change doesn't "stick". (You can check by selecting the "undo" down-arrow and see that you can't undo the change, since it hasn't been made). Try selecting less text (including some you know is wrong) and change the setting. I think this will work. --Phil Holmes (talk) 16:30, 4 December 2009 (UTC)

Perhaps you could create a new Microsoft Word document and copy/paste the entire contents of the first one into it? That might enable you to bypass oddities in the old document that are causing this problem. Do you have significant formatting in the document? If you simply have text, or if text formatting isn't used very much, you could copy the text into Notepad and then into a new Word document; while that would get rid of good formatting, it would guarantee that there was no odd formatting in the text itself. Nyttend (talk) 18:14, 4 December 2009 (UTC)

... and you might just check that the mis-spelt words have not been accidentally included in a user dictionary (e.g. Custom.dic). Go to Tools --> Options --> Spelling & Grammar ... and tick the box "Suggest from main dictionary only". Dbfirs 13:46, 5 December 2009 (UTC)

Isn't the 'Do not check spelling or grammar' setting a per-paragraph style setting? You might need to select all the text and flick that setting back and forth a few times to make it propogate the change across all the styles. However, copying it all to a new document is a good idea and will let you impose a consistant set of styles across the whole document; and it might reduce the size of the .doc file as well. Astronaut (talk) 16:20, 5 December 2009 (UTC)

Apologies if this is obvious to you, but don't rely just on Spellcheck; it won't flag words that have been misspelled as another valid word, or some grammar mistakes - you really need to read the whole thing yourself line by line, paying attention to meaning, and possibly also to consistency of punctuation and layout (parts of what are sometimes called "house style"). As a former professional editor and proofreader, I can confirm that proof checking requires much more concentration and mental effort than ordinary reading. Checking on screen is strangely harder than on paper, so consider printing the material out if you haven't already. You may find it helps to hold a ruler under each line to deliberately slow your reading speed down and thus avoid accidentally skimming over mistakes without noticing them. Watch out for errors in larger-print, like chapter titles - they're easy to miss. Proof checking a 250-page document is not a trivial task - I'd guesstimate it to be at least 30 hours or so of hard work. Good luck! 87.81.230.195 (talk) 00:25, 6 December 2009 (UTC)

[edit] Animation

To make an animation, I used Photoshop CS4 on a Macbook and created pictures frame by frame. Is there any software that can link all these images together to make a gif animation?--153.20.24.68 (talk) 09:03, 4 December 2009 (UTC)

Yes. Photoshop CS4 can make animated GIFs: File --> Save for Web. That's assuming you used the animation palette to make the frames -- which you did, right?--Drknkn (talk) 09:27, 4 December 2009 (UTC)

Put in a more helpful way: in CS4, go to Window > Animation. In the lower-right corner of the window created will be a button that, when you hover your mouse over it, says "Convert to Frame Animation." If you click that, it'll make a frame of animation with whatever you have visible, labeled "1". If you create a new frame (labeled "2"), whatever layers you enable in that will be the second frame. And so on. Once you have all of these frames set up (and the timings between the frames what you want them to be), then you can Save as Web, and save it as an Animated GIF. --Mr.98 (talk) 14:02, 4 December 2009 (UTC)

convert *.gif w00tpie.gif ¦ Reisio (talk) 05:30, 6 December 2009 (UTC)

[edit] Google Search

Suppose there is a url as: "www.somesite.com\someDir1\someFile.jar". Now, suppose I need to find all the links from the web that point to the files located under someDir1. How do I do that (using google or any other engine)? 218.248.80.113 (talk) 12:49, 4 December 2009 (UTC)

First of all, the directory separator in Internet URLs is "/", not "\" as in Windows. To answer your question, I think that you can use "search terms link:www.somesite.com/someDir1" in Google, but I am not sure. Perhaps it will only find links to the exact page "www.somesite.com/someDir1". --Andreas Rejbrand (talk) 13:30, 4 December 2009 (UTC)

The "link:<URL>" method appears not to be working very well in Google, I must say, though. --Andreas Rejbrand (talk) 13:33, 4 December 2009 (UTC)

[edit] Font ID request

In this picture the font used for "THE 50 BEST Ice-cream parlours", as well as the bolded names of the winners below. A heavier weight can be seen here... I tried WhatTheFont to no avail! Thanks! ╟─TreasuryTag►senator─╢ 17:11, 4 December 2009 (UTC)

It looks at first glance like something in the Myriad family. --Mr.98 (talk) 17:21, 4 December 2009 (UTC)

Very close, but not quite: the tops of the 'y' slope differently, and the horizontal stroke of the 'n'... :( ╟─TreasuryTag►directorate─╢ 17:24, 4 December 2009 (UTC)

It is very similar to both Congress Sans Light and PTL Maurea, although there are subtle differences (in at least the 'a' and 'e' and slightly in 'r'). -- Finlay McWalter • Talk 17:54, 4 December 2009 (UTC)

Hmm, they're exactly the same two that MyFonts suggested for the first image :P ╟─TreasuryTag►UK EYES ONLY─╢ 17:56, 4 December 2009 (UTC)

Closer still is Agilita Light. -- Finlay McWalter • Talk 18:22, 4 December 2009 (UTC)

Or Linotype Trade Gothic Roman. -- Finlay McWalter • Talk 18:31, 4 December 2009 (UTC)

Whitney ¦ Reisio (talk) 06:25, 6 December 2009 (UTC)

[edit] so, my laptop is completely destroyed, again.

The screen comes up as just lots of strange coloured lines, I think I can sort of see the desktop through them, and still open files on it, but in a strange blured and barely visible way, and many times over across the screen space. Is there any way of getting everything off? Can I plug it into another screen somehow and still use that, can I plug something in and copy all my files over onto that, and would I have to select everything on the desktop to copy over, as I can't see which is which, would that even work? Is there anything I can do to make it look better and easier to work with?

my sister's laptop, which is the same, had a grafics problem a few days ago, though I am not sure mine has the same problem, if it is, if the grafics driver has broken down, what do I do then? Would I have to send it to the mechanics, or can I fix it myself?

148.197.114.158 (talk) 18:38, 4 December 2009 (UTC)

My guess is that's its the connections between the body of the laptop and the screen. It'll probably work if you get a screen from a desktop and plug it into the VGA plug on your laptop.

I tried that, there doesn't seem to be anywhere the right shape for the plug though. I think my laptop is too new. Or the screen too old. 148.197.114.158 (talk) 19:05, 4 December 2009 (UTC)

If you told us the type of laptop it was, we could probably tell you what kind of plug it would be. --Mr.98 (talk) 19:56, 4 December 2009 (UTC)

It's... one of those ones that fold in half. It says Medion on the top, beyond that i don't know though. Whichever plug it might be though, it seems I don't have one, and if I did I'm not sure the other end of the wire would plug in anywhere. It seems incompatible for any wire from any screen I have ever seen. Perhaps there is some other way?148.197.114.158 (talk) 22:36, 4 December 2009 (UTC)

Should be a model number on the bottom or someplace. You should have a Video Graphics Array or a Digital Visual Interface connector. If your display uses VGA, you can get an adapter from DVI. In the worst case, the hard drive can be removed and an adapter cable for USB attached to connect it to another PC so you can recover the data. ---— Gadget850 (Ed) ^talk 02:54, 5 December 2009 (UTC)

I think the problem could be a problem with the screen, a problem with the graphics card, or a problem with the graphics drivers. If you can see the BIOS screen before any sign of the operating system, then it is graphics drivers which are faulty (to test that theory further, try booting from a CD - perhaps a Linux Live CD - which will use a different graphics driver). Assuming you are using Windows, you can press F8 to force the computer to bring up a menu where you can select "safe mode" which will let you delete the existing graphics driver and install a new one.

The other two possibilities will require a repair. If you connect an external monitor (there is usually an external VGA interface on laptops) and the problem is gone it means the screen is faulty. If the problem is still there then graphics card is faulty. You can visit Medion Support if you click here, which provides various options including emailing them and calling their hotline (open 7 days a week). This page describes how to find your laptop (or notebook) ID number which you will need. If it is out of warranty, you will have to pay for a repair which could be very expensive.

One thing to note is that laptop repair usually make no guarantees about keeping your data, especially if sending it away. Ask their advice about whether you can simply remove the hard drive before sending it for repair, or whether you should back up your stuff. Btter still, try to get them to do a "on-site" repair (I had a similar sounding problem with my laptop about a year ago; the on-site repair was quick and efficient, and free because it was under warranty). Astronaut (talk) 14:20, 5 December 2009 (UTC)

That sounds like good advice, only trouble is I have no idea what a BIOS or a Linux live is, and I can't actually get into safe mode or back anything up, because I can't see the screen well enough to know what I am doing on it. And my laptop doesn't have a VGA interface. It seems to have one of those DVI things, though I have never seen a plug for one of those anywhere. I think I will take it back home, see what my parents think, we should be able to work something out, and at least everything on it seems to still be there, somewhere. It was a lot worse last time. 148.197.114.158 (talk) 13:06, 6 December 2009 (UTC)

[edit] Excel Formula Help

I’m looking for some help with an Excel formula. I think I’m pretty savy with Excel, but just cannot seem to figure this one out. THANKS for any solutions.

In Column A, I have text in each row that’s one of: TR, Plunge, SW, Central, or KCM.

In Column B, I have a dollar amount in each row (i.e. $15.00). The amount varies.

I want a formula that does this:

If Column A contains TR or Plunge, then sum the amount for that row, found in Column B.

Example:

So with the formula, it would automatically scan Column A, see the Plunge and TR, then add the $50, $45 and $35 and show the total of $130.

Thanks for any suggestions! Rangermike (talk) 20:31, 4 December 2009 (UTC)

I think SumIf is probably what you want. It only takes one criteria (annoying, of course), but since your criteria is so simple you could easily use two of them. e.g. =SumIf(A1:A5, "Plunge", B1:B5)+SumIf(A1:A5, "TR", B1:B5). --Mr.98 (talk) 20:49, 4 December 2009 (UTC)

An alternative would be to use column C and enter the formula =IF(OR(A2="TR",A2="Plunge"),B2,0) and then sum the resulting figures. --Phil Holmes (talk) 10:57, 5 December 2009 (UTC)

[edit] December 5

[edit] HP Laserjet M1120 vs Linux

Short and sweet ('s 2 am here and I'm dying): does anyone have any experience with HP's all-in-one M1120 on Linux (I'm running Zenwalk Linux specifically). Broader: which all-in-one, if any, would you guys/gals recommend? I know I will prefer a laser printer over an ink jet printer, and I'd like to have a scanner. Xeros machine functionality would be nice, but I'll live without it. No networking/fax/misc magical powers are really necessary. Thanks for your input, friends. Cheers, Ouro (blah blah) 00:35, 5 December 2009 (UTC)

The open printing database quotes one person who says printing and scanning work (on Ubuntu at least) out of the box. -- Finlay McWalter • Talk 02:15, 5 December 2009 (UTC)

[edit] C

Two questions about C programming:

1. When I run a compiled C program from the terminal using the "exec" command, the terminal closes when the program finishes. How can I get it to stay open?

2. Consider the following code:

 void main(void) {   // some lines of code   check();         // Line A   // some lines not calling check()   check();         // Line B   // more code } 

If no key was pressed between lines A and B, check() returns a one-item list containing 0. If a key was pressed, check() returns a list of values corresponding to the keys pressed, in the order that they were pressed. Furthermore, check() does not cause any break/pause/etc in the execution of the program.

Are there any functions that can be used to create check()?

If it's pertinent, I use Code::Blocks and GCC. 72.197.202.36 (talk) 00:39, 5 December 2009 (UTC)

1. Don't use exec, or exec a command followed by a pause command of some sort (which really means you've spawned a new shell anywasy, so you may as well skip exec and just do program && pause && exit. Exec means the program replaces the shell, and when the program goes, so will the shell.
2. A non-blocking single character read would work, but real input handling is OS dependent. You'd need to give more details. —ShadowRanger ^(talk|stalk) 00:44, 5 December 2009 (UTC)

For question 2, consider using keyboard hooks for a Windows system.--TParis00ap (talk) 04:28, 5 December 2009 (UTC)

[edit] Can I use a RAID controller without any RAID?

I am trying to buy a cheap older computer to work as a data server in my house, and I already have a couple of large SATA drives already filled with data. I am looking at a Dell Dimension 8400 because the specs say it can take four SATA drives, and I think I'll buy another someday. When reading the manual it talks about RAID configurations 0 and 1, which both sound very nice, but if I understand them correctly neither is what I want. I want to keep the data on the drives (neither will have the OS), and I'd like to be able to a) remove them easily with everything working fine and b) take them to another computer, possibly as an external drive. So can I use a RAID controller in this manner? Thanks for your help. mislih 00:48, 5 December 2009 (UTC)

What you describe is called a JBOD ("just a bunch of disks"). That page you linked doesn't seem to mention RAID, so I guess that the machine doesn't come with one, and that you intend to install a PCI RAID (from someone like Adaptec), right? Every RAID controller I've ever used had a JBOD mode; but I'd check the specs of the specific RAID controller you're thinking about before buying one. Note that you can get a PCI SATA expansion card (that doesn't do hardware RAID) for a bit less than a RAID card (and, perhaps confusingly, you can still do RAID anyway, just with the OS and the CPU doing the work). -- Finlay McWalter • Talk 01:45, 5 December 2009 (UTC)

No, I picked this machine because it has four SATA ports on the motherboard as shown in the page I linked to above. When I read the manual is where it talks about RAID (the pdf I linked to is a pretty big). From other reading, I think it means the motherboard has 'fakeRAID' built in. Are you saying I can I run it in JBOD mode and get seperate disks? mislih 02:22, 5 December 2009 (UTC)

p22 talks about turning "RAID On", and talks about machines being delivered without that configuration. So that seems to me to be a pretty strong implication that, with RAID off, it's just a JBOD. -- Finlay McWalter • Talk 02:30, 5 December 2009 (UTC)

Thanks for the help! mislih 04:19, 5 December 2009 (UTC)

[edit] adding Wikipedia search engine to my page

I would like to add Wikipedia search engine to http://sovietdream.com/researches/ , so that client would be taken to Wikipedia separate result page after entering search words to, that engine in my page. Could I get html code of such search engine? —Preceding unsigned comment added by 78.58.207.25 (talk) 08:50, 5 December 2009 (UTC)

my email - [redacted] —Preceding unsigned comment added by 78.58.207.25 (talk) 08:54, 5 December 2009 (UTC)

email removed to avoid questioner suffering spam. Question reformatted. --Phil Holmes (talk) 10:52, 5 December 2009 (UTC)

Here is the basic template used on most Wikipedia pages. It is pretty straightforward to modify; all I did was all the full en.wikipedia URL to the "action" value to make it portable.

 <form action="http://en.wikipedia.org/w/index.php" id="searchform"> 	<input type='hidden' name="title" value="Special:Search"/> 	<input id="searchInput" title="Search Wikipedia" accesskey="f" value="" name="search" /> 	<input type='submit' name="go" class="searchButton" id="searchGoButton"	value="Go" title="Go to a page with this exact name if one exists" />&nbsp; 	<input type='submit' name="fulltext" class="searchButton" id="mw-searchButton" value="Search" title="Search Wikipedia for this text" /> </form> 

Enjoy. --Mr.98 (talk) 15:21, 5 December 2009 (UTC)

[edit] Problem with MediaWiki code which I copied over to swfanon.wikia.com

Hey,

I copied {{Article issues}} over to the Star Wars Fanon Wiki: http://swfanon.wikia.com/wiki/Template:Mult_issues. I also copied over any other needed templates: {{DatedAI}}, {{Ambox}}, {{Ambox/core}} and {{ns0}}. Now, on Mult_issues/test, I cannot seem to get any of the parameters (which are all new, replaced ones, and no originals) to show up. Have I deleted a crucial bit of code? Or am I still lacking a certain template? Neither the Sysop nor I can figure out what's wrong with it. I hope you guys can do a better job ;-)

Thanks in advance, :-),--213.168.119.120 (talk) 09:30, 5 December 2009 (UTC)

Wikipedia has a lot of MediaWiki Extensions. Often, the more complicated templates on Wikipedia are deeply interwoven into these kinds of software modifications. All of them are freely available, and you can compare which sets are installed on Wikipedia's MediaWiki Version Information and the corresponding page on your wiki. I can't see any of the obvious ones missing (ParserFunctions is often missing on third-party wikis). All this is still hinging on the hunch that the trouble is based on a missing extension, which may not be the case, but it's what I would check first. Nimur (talk) 14:50, 5 December 2009 (UTC)

And they are often dependent on markup in MediaWiki:Common.css and code in MediaWiki:Common.css. See m:Help:Transwiki. ---— Gadget850 (Ed) ^talk 15:42, 5 December 2009 (UTC)

The last link should probably be MediaWiki:Common.js. --Andreas Rejbrand (talk) 17:15, 5 December 2009 (UTC)

[edit] Find the center of a triangle in Blender

In Blender, I want to add a vertex at (I think) the circumcenter of a triangle. That is, a location equidistant to the three other points. Selecting the three points and choosing snap->cursor to selection doesn't do the job: it moves the cursor to (I think) the centroid, the average of the three points, instead. Any idea how to get my desired kind of center? This would be useful for constructing polyhedrons and probably for other things. 93.97.21.17 (talk) 11:19, 5 December 2009 (UTC)

I don't use Blender, but the circumcenter is indeed equidistant from the three vertices, and can be constructed by drawing the perpendicular bisectors of the three sides. Does Blender have a routine for this? Dbfirs 13:26, 5 December 2009 (UTC)

If it does not, Blender supports Python scripting, so you can write your own routine. The math would be fairly simple to compute the circumcenter; the hardest part would be locating the API to access the current vertices and get their coordinates. That would be the list() routine to get your object name, followed by the getData() routine to get its mesh and vertices. We have a WikiBook on Blender Scripting which walks through an example of getting vertex information. In addition, the official manuals and tutorials are available from the Blender website. Nimur (talk) 14:58, 5 December 2009 (UTC)

That is a most useful-looking wikibook, thanks for the link. 213.122.21.216 (talk) 15:53, 5 December 2009 (UTC)

[edit] Force no redirects when searching

Hello all. I have attempted to solve this myself but I am not very good at these things. When I type a URL into my address bar (I use Firefox) and I make a typo, I get automatically redirected to Bing search for the typoed URL. 99.99% of the time what I want is to simply go back to the address bar and fix the letter I omitted or typed wrong and hit enter and I have no use for the search results. However, I can't do this since the URL has been changed to Bing's search URL. Is there a way to only go to exactly where I typed without being redirected (in the case of typos, I guess to nowhere with my browser saying the page cannot be found) so that the address in the URL is never changed for me. Thanks in advance.--68.160.242.48 (talk) 15:56, 5 December 2009 (UTC)

There are several things which might redirect you. Your ISP may redirect bad DNS lookups to a search URL - there's not much that can be done about this (though you can override the default DNS with an alternate public service). More likely problems which might be causing this are due to your browser - I find these "fixups" very irritating. (I am often on a private network with valid URLs like http://nimur. When I type "nimur" into my URL bar, I do not want a "keyword search," I want Firefox to go to the correct server). You can disable these irritating "auto-fixup" features by disabling "search from the address bar" and other "url fixup" options in Firefox. You can also download ClumsyFingers addon, which disables several shortcuts (like "ctrl-enter" to automatically append ".net" and other DNS changes). There may be some other specific tweaks for your browser to make sure that you get a true "Server not found" error message, rather than a redirect to a different computer, when you mistype a DNS name or URL. Note the important distinction between a typo that results in a host not found, and a 404 error.Nimur (talk) 19:22, 5 December 2009 (UTC)

[edit] Assigning a string to a variable in C

With out doing it when I declare the variable, how can I assign a string to a variable?

For example:

 #include <stdio.h> #include <string.h> #define STRSIZ 20   typedef struct inventory{       char product_cat,    /* Catergory of each product */            depart_name[STRSIZ],  /*Name of department*/ 	  product_name[STRSIZ],   /* Name of the product */       meat_type,              /* type of meat */ 	  plants,	  /* fruit or veggie */ 	  aisle_side,  /* side of asile */ 	  nonfood_cat; /*category of nonfood item*/       int cost_item;    /* Cost of item in cents */       int packaging_date,  /* Date of packaging */ 	  expiration_date, /* Date of expiration */ 	  aisle_number; } any_product;   int main (void) {   struct inventory any_product;   char pad; /*absorbs stray \n from buffer */     printf("Enter product category (M,P,D,C,N,Q): ");   scanf("%c", &any_product.product_cat);   printf("%c\n", any_product.product_cat);   scanf("%c", &pad); /*absorbs stray \n from buffer */     switch (any_product.product_cat)      {      case 'm':      case 'M':           printf("Meats\n");           any_product.depart_name = "Meat department";    ... 

The last assignment doesn't work. How can I make it so it does? -- penubag  (talk) 20:41, 5 December 2009 (UTC)

Use strcpy, like this:

          strcpy(any_product.depart_name, "Meat department"); 

of course, you want to be sure the text never exceeds 19 characters in length.

I can see several improvements that could be made, but I assume this is something in an early stage of development so I'll leave it to you to learn. Astronaut (talk) 21:03, 5 December 2009 (UTC)

Thank you much! Please tell me what can be improved. -- penubag  (talk) 21:58, 5 December 2009 (UTC)

Here are three recommendations. First, never use scanf() unless you absolutely need to process freeform input. The fact that it does not distinguish between space and newlines for most purposes can be very confusing when you use it interactively. Instead, use fgets() to read in one line (of convenient size; allow for several hundred characters) and then use sscanf() to examine that line and see if it has the form you expect.

Second, when you #define the maximum size of something, make it the maximum size of the string and add 1 to get the array size. So instead of

  #define STRSIZ 20  char depart_name[STRSIZ]; 

write

  #define STRSIZ 19  char depart_name[STRSIZ+1]; 

Then STRSIZ tells you the actual maximum size of the string, which is more self-documenting and may also be useful if you find yourself needing to do arithmetic on it.

Third, learn the difference between declaring a struct template and typedeffing the type. Your first declaration did both at once. If you are going to refer to your struct types in the style "struct inventory", then you don't need to use typedefs. Typedef defines an alternate name for a type, which allows you to not use the keyword "struct" all the time. Personally I think that is a bad approach when working with structs, but some programmers prefer it. In this case you have (presuambly accidentally) typedeffed the name "any_product" to be a synonym for "struct inventory". This would have allowed you, when you wanted to declare the variable "any_product", to write "any_product any_product;"! In practice, most programmers who use typedefs for structs use the same name as the struct tag, so they write "typedef struct inventory inventory;" or "typedef struct inventory { (template here) } inventory", and then declare "inventory any_product;".

Hope this helps. --Anonymous, 09:26 UTC, December 6, 2009.

[edit] How do I play a movie DVD in my computer?

I cannot get a movie DVD in my DVD drive to play, neither with Windows Media Player nor with VLC. What do I need to do to view the movie please? I have WinXP. 92.27.148.85 (talk) 21:18, 5 December 2009 (UTC)

In order to play a DVD you need a DVD drive and the computer has to have the necessary software to interpret the DVD drive. Without those, VLC and Windows Media Player will not be of any use for playing a DVD. To start with the obvious, do you have a DVD player, rather than a standard CD player? Usually it tells you that it is a DVD player on the front of the drive. Falconus^{p t c} 21:48, 5 December 2009 (UTC)

Try reading the top bit again please - it says "in my DVD drive". 92.27.148.85 (talk) 22:48, 5 December 2009 (UTC)

VLC contains the necessary software; it does not need an external codec to decode a DVD. -- Finlay McWalter • Talk 22:42, 5 December 2009 (UTC)

I tried trying to start it with VLC but nothing happened. 92.27.148.85 (talk) 22:48, 5 December 2009 (UTC)

VLC has a menu option (it's in "tools" on my machine) called "messages". Open that and retry to open the disk (using VLC's Media->open_disk option). The messages screen should display whatever VLC thinks is the error. Also try to play one of the (large) .VOB files on the disk by opening it in VLC. -- Finlay McWalter • Talk 22:53, 5 December 2009 (UTC)

Thanks, did that. The message box says "main error: ES_OUT_RESET_PCR called main error: ES_OUT_RESET_PCR called libmpeg2 error: invalid picture encountered" 78.146.29.54 (talk) 23:57, 5 December 2009 (UTC)

It thinks the DVD files are corrupt (that they don't contain proper MPEG streams). Does this happen with all DVDs? -- Finlay McWalter • Talk 23:59, 5 December 2009 (UTC)

I've tried another DVD, and this time it plays, in a manner of speaking, but the image is very very very corrupted, nearly all garbage. The message box says: "main error: ES_OUT_RESET_PCR called main error: ES_OUT_RESET_PCR called libmpeg2 error: invalid picture encountered spudec error: overflow in SPU next command sequence libmpeg2 error: invalid picture encountered libmpeg2 error: invalid picture encountered libmpeg2 error: invalid picture encountered" with the last comments repeated many times. I am in the UK where PAL is used rather than NTSC. I do not know if that makes any difference to the DVD encoding. The previous DVD was "widescreen" according to the box. The other more recent DVD that I tried gives more information on the box: PAL 16:9, DVD-5, Region 2. I suppose the 16:9 proprtion means that was wide-screen as well.

When I tried to run the DVDs with Windows Media Player I got an error message saying "Windows Media Player cannot play the DVD because a compatible DVD decoder is not installed on your computer." This lead to a webpage which said (edited): DVD Playback Options for Windows......install a compatible DVD decoder (also known as a MPEG-2 decoder) before continuing with......Playing a DVD......Playing video files that were encoded with the MPEG-2 codec (.mpeg, .mpg, and some .avi files) To purchase a compatible DVD decoder, visit Plug-ins for Windows Media Player."

Update: I've tried another DVD, this time 4:3 format. It will not play in Windows Media Player, giving the same error message as above. It does play imperfectly in VLC, with some garbage on screen, very choppy sound, and I have not figured out how to get past the opening menu. Thanks Update 2: Despite uninstalling VLC and re-installing the latest version, I still get the same problems. 89.243.153.124 (talk) 13:37, 6 December 2009 (UTC)

You may have to clean your laser lens in the drive, it may have dirt or fluff on it. Graeme Bartlett (talk) 20:48, 6 December 2009 (UTC)

[edit] huawei

i'm posting this questions after 7 hours of thorough googling. i received a modem from my bro that had been locked. he's in another country and i'm in Kenya and i would want to unlock it so as to use the networks available in my country. It's a Huawei E160 3g modem and here guys are charging heavily for unlocking modems yet they've downloaded the software from the net for free. Anyway anyone who knows a site i can download the unlocker preferrably for free ,i've already changed it's dashboard but i need the unlock code. The one at nextgenserver.com is givin a mscoree.dll or something error message when i run it. please assist. —Preceding unsigned comment added by 212.49.88.34 (talk) 22:29, 5 December 2009 (UTC)

Two idle google clicks of my own make me think it's asking you to install .NET, as per [14]... 81.131.30.94 (talk) 04:52, 6 December 2009 (UTC)

[edit] December 6

[edit] Why ALU division is slow

I'm making slides about why integer division in an ALU is slow. To be complete, I've been Googling to see if there are any reasons I haven't included and I see many websites/papers that claim that one of the reasons for the slowness is that you have to check in each iteration to see if you are done. In addition/multiplication, the number of iterations is known from the start. I find that a bit strange. How can it take more iterations than bits in the dividend? -- kainaw™ 01:42, 6 December 2009 (UTC)

Could it be because of the added complexity of calculating fractions or remainders? I don't know that much about how the logic systems keep track of things, but if you were dividing 12 (1100) by 8 (1000), the answer would be 1.5 (0001.01). Any other odd divisions would end up with more bits. Maybe that's not how it works, I don't know for sure since my digital logic education didn't get that far (I'm more of an RF guy). —Akrabbim^talk 04:16, 6 December 2009 (UTC)

For integer division, 12/8=1. Each step of the process, be it restoring or non-restoring, produces at least 1 bit of the answer. Since the maximum answer for 4-bit division is 4 bits, it will iterate a maximum of 4 times. By your answer, I wonder if a lot of sites are confusing integer with float division. -- kainaw™ 04:24, 6 December 2009 (UTC)

After I shut down my computer last night, I realized that even floating point division has a distinct number of iterations. For example, SRT division begins with k padded zeros. The number of zeros (k) is how many shifts will be needed to complete the division. So, even if there is confusion between integer and float division, the number of iterations is still known before the iterations begin. Therefore, I think it is just nonsense being copied and pasted throughout the Internet that one reason for division to be slow is that you don't know the number of iterations before you begin. -- kainaw™ 16:24, 6 December 2009 (UTC)

Division isn't important so why bother spending a lot on it? The division algorithms that are used are fast enough so it isn't a bottleneck and that's good enough. Just a little extra speed on addition or multiplication is more worthwhile. I don't see any great problems about making it almost as fast as a multiplication if it really was important. Dmcq (talk) 18:56, 6 December 2009 (UTC)

That is a horrifying over-simplification. Some computer graphics algorithms such as texture-mapping have to compute at least a couple of divide operations for every single pixel that's drawn. The speed of division can be a critical bottleneck and computer graphics people spend a lot of effort to minimize the number of them. SteveBaker (talk) 03:55, 7 December 2009 (UTC)

(It's been a long time since I thought about this!) Isn't it because multiplication can be done in parallel? For a 16x16 bit multiplier:

• Take 16 differently wired multiplexers - each one selects between a zero and the first operand shifted up 0,1,2,3,4,5,6,7,8,9,10,11,12,13,14 and 15 times (that's just wiring up the inputs of the mux'es - no actual math is required).
• Use the 16 bits of the second operand to switch the 16 multiplexers (a 0 selects the 0 input of the mux - a 1 selects the shifted version of the first operand.
• Add the 16 outputs using a cascaded 16-way adder.

I don't think there is a similar algorithm for division - you have to know the result of each bit before you can calculate the next bit - so a 16 bit division requires anything up to 16 steps. SteveBaker (talk) 00:46, 7 December 2009 (UTC)

Floating point is a lot like integer math - remember, you can simply add or subtract the exponents then multiply the mantissae using integer math. There is a bit more messing around for the corner cases (denormalised numbers, etc) - but it's not that hard. SteveBaker (talk) 00:49, 7 December 2009 (UTC)

[edit] Non-linear stretching for HDTVs

Some widescreen televisions offer a non-linear stretch mode for displaying 4:3 images on the entirety of the 16:9 display without losing any (or at most very few) lines at the top and bottom edges and without the unpleasant effect of uniform stretching (especially on people). Unfortunately, there seems to be no standard name for this technique. Widescreen display modes calls it "wide zoom", but I suspect that name may instead refer to a stretch that differs in x and y (say, 16/12=133% in x and 120% in y, losing 1/12=8.3% of the lines in the image and distorting an on-screen square to an aspect ratio of only 110.8%). Other names seem to be Just, Horizon, Smart Stretch (which seems to be Sharp's name for it), Panorama, or TheaterWide — but I've seen written elsewhere that TheaterWide is another non-uniform x-y stretch. So:

1. Do all of those names really refer to non-linear stretches?
2. What is the name of the non-linear stretch mode (if any) for Samsung, Sony, and LG televisions?
3. What other brands support an equivalent option (and under what names)?
4. Do Blu-Ray players exist that can apply such a stretch if the TV can't? Can they apply it to upconverted DVDs and for BDs?
5. Are there any significant quality differences between implementations?
6. How does the notional aspect ratio of a DVD play into this? Some movies, like Willy Wonka & the Chocolate Factory, were actually shot in 4:3, but their DVDs were released early enough that (I believe) they are expanded (linearly, surely) on the disc to 16:9, with the expectation that a DVD player connected to a 4:3 TV will undo the stretch. Having that movie stretched non-linearly and then recompressed linearly to 4:3 would obviously lose.

Thanks in advance for responses even to a few of these many questions! --Tardis (talk) 04:17, 6 December 2009 (UTC)

[edit] Make apps running outside a VM visible within it?

In Windows, is it possible to set up a virtual machine so that selected apps running outside the VM have their memory mapped into the VM and are visible to apps running within it? (The only practical use for doing so that comes readily to mind is a future-proof way to defeat Warden -- run Warden in a VM, and let it see only Blizzard games and Windows system processes. Running the games themselves inside the VM would probably slow them down.) NeonMerlin 08:35, 6 December 2009 (UTC)

Surely not. I don't think it violates the rules of thermodynamics, but trying to get the guest OS to imagine it has a process running when it really doesn't sounds far too complicated to be feasible. --Tardis (talk) 16:01, 6 December 2009 (UTC)

Your best bet is to forget that one machine is "virtual" and make the applications visible to each other via a network service. Both the host and the virtual PC can operate as either server or client, and can communicate to eachother via an IP or TCP/IP-based protocol. Depending on your needs, you might find OpenMPI very helpful for dealing with such tasks, especially if you are writing the software. In general, though, this categorically excludes shared memory programming, which is what you are seeking (mapping the memory space of one computer across a different computer). You could switch to a different operating system like Altix, which makes network-based shared-memory "transparent", but this is not possible on Windows or most linuxes. Further, it has huge performance obstacles - and since you're already virtualizing the system... well, why would you virtualize and then attempt to share memory? Anyway, re-reading your post, it sounds like your goals are very specific, and I think this approach is not going to work. You stand a better chance at running a proxy server and intercepting the network traffic, modifying it, and re-transmitting "clean" network traffic - but this has its own set of challenges. Nimur (talk) 20:19, 6 December 2009 (UTC)

Yes it's possible, see Windows_Virtual_PC#Windows_XP_Mode —Preceding unsigned comment added by 82.44.55.75 (talk) 20:43, 6 December 2009 (UTC)

Warden examines other processes, and mmaps their memory (our article says it only mmaps the wow process itself, now at least). You can subvert this without a VM (indeed, a VM seems like an unnecessary burden). It's generally possible to intercept kernel calls, and to give Warden fake (i.e. okay) copies of pages (ones you've patched) when it tries to mmap. Or you could just patch warden yourself. Of course warden will have some protections against that, but that can only go so far. With a bit of work you'll succeed in being able to change the Wow process without warden noticing. But when Blizzard figure it out (which they will if you post the program onto some public forum, or when they change warden to be more devious, which I guess they do very often) they'll break your hack (they'll look for your hack, they'll run extra checks). So starts a war of randomly-named polymorphic code (much like the war between virus checkers and polymorphic viruses that seek to disable them). Eventually they gain an advantage because they can persuade (i.e. pay) Microsoft to sign a Vista/win7 kernel module, which you can't, and which you can't patch. You can still subvert that by rootkitting the entire machine, to overcome Windows' signed-kernel-code restrictions. That works unless a given machine will not boot a patched kernel, verified using the Trusted Computing infrastructure. -- Finlay McWalter • Talk 20:47, 6 December 2009 (UTC)

Of course Blizzard have another trick up their sleeve. Warden doesn't (or need not) disable WoW even if it sees a given cheat. They can just keep a log of all the accounts that uses one, and then every six months or so close all those accounts for a TOS breach. That will piss off the regular users of the cheat no end (because even with the cheat they've spent/wasted countless hours on their character); it won't inconvenience the goldfarmers (who you'd expect would be the biggest users of cheatware) as they're smart and will roll accounts over quickly regardless (in part because of Blizzard's existing anti-goldfarming measures). -- Finlay McWalter • Talk 20:53, 6 December 2009 (UTC)

[edit] Web

What was the very first Web site? jc iindyysgvxc (my contributions) 10:26, 6 December 2009 (UTC)

According to this page by Tim Berners-Lee it was http://nxoc01.cern.ch/hypertext/WWW/TheProject.html. That page is no longer active but there is an archived version. -=# Amos E Wolfe ^talk #=- 10:34, 6 December 2009 (UTC)

Keep in mind that the World Wide Web is only a small part of the overall Internet. Tim Berners-Lee started serving HTML pages in around 1989, and so earns the claim as the first "Web Site", but there are other internet and non-internet events which predate that. History of the Internet is a good overview. Nimur (talk) 15:33, 6 December 2009 (UTC)

[edit] OOP/philosophy terminology concordance?

Do any dictionaries exist for translating between object-oriented programming terms and their equivalents in philosophical ontology? NeonMerlin 13:19, 6 December 2009 (UTC)

Probably not. And if there was, would it be very long, or very interesting? I doubt it. Which is probably why there isn't one. --Mr.98 (talk) 22:29, 6 December 2009 (UTC)

[edit] ip address

A while ago I asked what the technical risks of someone knowing your ip address were, like hacking etc. Now I'm wondering what other issues might come from someone malicious knowing and wanting to cause trouble, for example someone randomly harvesting ips from Wikipedia recent changes and reporting them to the respective ISPs as having violated their TOS, hosting / posting illegal material, violating copyrights etc. All of the accusations are baseless, but would an ISP terminate a customer if someone were to go around reporting random ips? —Preceding unsigned comment added by 82.44.55.75 (talk) 18:11, 6 December 2009 (UTC)

Probably not. ISPs themselves have very limited liability for things like that. As a consequence, they don't get much out of enforcing requests other than hassles. They will comply with legitimate legal requests (e.g. a subpoena for info on the real human behind an IP address) but I doubt most would do anything just because some company asked them to—the ISPs themselves have very little to gain in doing so. --Mr.98 (talk) 20:06, 6 December 2009 (UTC)

Simply complaining to an ISP is not sufficient for them to take action against anyone. Usually, a subpoena or court order is required before the ISP will do anything; the barrier to obtaining one of these is sufficiently high that it is nearly impossible to get one frivolously, let alone to get them in bulk for many IPs without any actual cause. Nimur (talk) 20:16, 6 December 2009 (UTC)

Ok, thank you. @ Mr.98, I wasn't even thinking of something as large as a company making reports, I was thinking of just a random person with nothing better to do collecting ip addresses and reporting them to a page like this, out of spite or boredom or something. Anyway, thank you for the helpful answers :) —Preceding unsigned comment added by 82.44.55.75 (talk) 20:26, 6 December 2009 (UTC)

Again, the ISPs have basically no liability for user activity (at least in the U.S.A.), and get their money by keeping users, not kicking them off. They would have to be extraordinarily stupid to actually pay attention to random letters alleging bad behavior and actually act on them in a way that hurts their own economic interests. It doesn't mean it's not possible, but I doubt it could be a serious problem in any way. It would be an extremely unproductive way of trying to make trouble. --Mr.98 (talk) 22:28, 6 December 2009 (UTC)

[edit] Synching two computers

I have a desktop with Windows Vista and a laptop with Windows 7 and I would like to set it up so that if I change/add/delete a file on one computer, that the change will be made on the other computer as well so I don't have to use a flash drive to move files back and forth all the time. Is there an easy way to do this? I would be willing to spend a small amount of money if I need some sort of hardware to do this. In case this info is helpful/necessary, my network is an unsecured wireless network as my apartment provides this for free. And, I have a Seagate external hard drive which automatically backs up my desktop computer, but I believe it can only be hooked up to one computer at a time. Thanks. StatisticsMan (talk) 20:18, 6 December 2009 (UTC)

A one way sync (just changes on one machine to the other) is quite easy - rsync is easy and very good. Personally I'd tunnel that over ssh (particularly because you're on an insecure connection); you can get easy to setup ssh client and server from OpenSSH. A two way sync (where a change on either machine is propagated to its counterpart) is more challenging - rsync's counterpart Unison (file synchronizer) will do that. For any two-way scheme (including those from Microsoft) you'll run into "conflicts", where the same file has been changed on two different machines - it's just the same problem as a MediaWiki edit conflict, and like those you're left to resolve the conflict manually (usually you end up with two versions of the conflicted file). -- Finlay McWalter • Talk 20:23, 6 December 2009 (UTC)

You can try something like Jungle Disk. For US$4 a month, you get 10 GB (you can purchase additional space at a rate of US$0.16 per GB). You can install the Jungle Disk clients on both your machines, and it will keep them in sync in real time. This may not be ideal if you have a lot of data because it will sync it via the Internet. It has the added benefit of letting you access the data from anywhere that you have internet access, and keeps an offsite backup. - Akamad (talk) 02:41, 7 December 2009 (UTC)

[edit] December 7

[edit] Science

The Wikipedia Reference Desk covering the topic of science.
WP:RD/S all #eee #f5f5f5 #eee #aaa #aaa #aaa #00f #36b #000 #00f science Wikipedia:Reference desk/Science Science WP:RD/S

[edit] December 3

[edit] Medical experiment that went terribly wrong

Resolved.

I remember reading a news story from a few years ago about a medical experiment that went terribly wrong. My memory is foggy but I'll try as best I can to explain what I remember. The researchers were testing an experimental drug. It was the first trial on humans. The test subjects had a terrible reaction to the drug. I can't recall if any of the test subjects died, but a couple might have. I remember that part of the controversy was that the scientists administered the drug to the test subjects back to back, rather than waiting to make sure that the first person didn't have a negative reaction. They may have violated medical protocols. This happened maybe 2 or 3 years ago. It recieved some mainstream media attention. Again, my memory is foggy, but I think I read about it at BBC News. Does anyone know what I'm talking about? A Quest For Knowledge (talk) 05:16, 3 December 2009 (UTC)

Sounds a lot like the trials of TGN1412 — Zazou 05:34, 3 December 2009 (UTC)

• I think you've got it. It happened in England in March 2006; six patients got the drug at 10-minute intervals and it only took an hour before they began suffering one after the other. Nobody died, but they were all severely affected. --Anonymous, 08:28 UTC, December 3, 2009.

Presuming this is what you mean, and it sounds to me like it is, while the 10 minutes interval thing generated a lot of controversy amongst other things and did seem like a dumb thing to do to many, I don't believe it was a violation of protocols or particularly unusual. In fact, as this ref suggests [15] for example, giving sufficient time for a reaction to be observed is a new recommendation arising from the trial Nil Einne (talk) 10:40, 3 December 2009 (UTC)

They gave systemic doses of a previously untested drug instead of giving it topically to begin with. It was a drug designed to boost the immune system, they gave it to healthy patients, and it resulted in a cytokine storm. This was definitely predictable and as an immunologist noted "not rocket science". Fences&Windows 14:40, 3 December 2009 (UTC)

Maybe but that doesn't mean it violated the protocols of the time which was the point I was addressing. To put it a different way, they may have screwed up badly, but it doesn't mean they ignored established protocols, more that perhaps they didn't think properly whether the protocols were appropriate in the specific instance. On the other hand this [16] does suggest it's normal to try hazardous agents on one patient first so it may not have been uncommon as the earlier ref. However it isn't peer reviewed. There is of course still research ongoing as a result of the case. E.g. [17] [18] Nil Einne (talk) 15:44, 3 December 2009 (UTC)

The protocol-design issue is basically this: when you don't anticipate any problems, how long do you wait for problems to develop before you decide that it's enough? When they chose 10 minutes, they were probably imagining that the only possible rapidly manifesting problem would be something like anaphylactic shock, which comes on faster than that. In retrospect that was clearly a bad idea. But what if they'd waited an hour, only to find that after six hours people started getting sick? What if they'd waited a day, only to find that it took a week? With no data on the sort of problems to be expected, it really is a judgement call. Of course, if Fences is correct that this sort of reaction was to be expected, that's a different story. But that's not how it was reported in newspapers at the time, and I'm no immunologist, so I can't comment. --Anonymous, 08:55 UTC, December 5, 2009.

Perhaps the X-linked severe combined immunodeficiency gene therapy trial? Or less likely the gene therapy trial that killed Jesse Gelsinger. 75.41.110.200 (talk) 06:40, 3 December 2009 (UTC)

Yes, that's it. Thanks! A Quest For Knowledge (talk) 23:44, 3 December 2009 (UTC)

[edit] Butterfly sensation from infatuation.

There's a girl I've recently become infatuated with and I think she reciprocates my affections at least to some degree. Sometimes, I'll go many minutes without thinking of her and then suddenly, in a flash, I'll remember her-- infectious laughter, her supple contour, her stellar character, her daring wit, & her infinite, limpid, brown eyes... Accompanying these thoughts, I often experience a sinking sensation in my stomach or heart -- butterflies, I think it's sometimes called. What is the cause of this delicious sinking feeling? What are the biological and physical reasons for it? —Preceding unsigned comment added by 66.210.182.8 (talk) 05:41, 3 December 2009 (UTC)

Wikipedia has an article on everything. Looking at that article, it seems that the main component is due to anxiety, possibly due to adrenalin. Vimescarrot (talk) 09:52, 3 December 2009 (UTC)

and good luck! --pma (talk) 13:31, 3 December 2009 (UTC)

Well, we really ought to have an article on the neurobiology of love; there is enough of a literature. In the absence of an article, here is a pointer to a recent paper with a lot of information, a bit technical though. Looie496 (talk) 17:22, 3 December 2009 (UTC)

Also Esch, Tobias; George B. Stefano (2005). "The Neurobiology of Love". Neuroendocrinology Letters 3 (26). http://www.nel.edu/pdf_/26_3/260305R01_15990719_Esch--Stefano_.pdf.  Fences&Windows 23:25, 3 December 2009 (UTC)

And a video about how the key to love is oxytocin. Fences&Windows 23:29, 3 December 2009 (UTC)

This would somewhat overlap the existing article on limerence. 67.117.130.175 (talk) 06:58, 4 December 2009 (UTC)

[edit] Physical fallacies

Hi, I posted this question about speed of light calculations few months ago. Is there an article discussing such physical fallacies? If yes, can anyone volunteer to explain where the wrong use of physical laws was made in that website? I think such information should have the same interest as has been done to mathematical fallacy article.--Email4mobile (talk) 09:26, 3 December 2009 (UTC)

It seems to me you got a good answer last time. What else do you want to know? Second the paragraph "Variable Speed of Light" is not true. Not at all. It's completely contrary to the theory of relativity. And third scientists have NOT confirmed the existence of Dark Energy. Why do you want to learn anything at all from a website that does not understand science? If you want to theorize on changes to science go for it. But don't think for a second that what they say is correct by current theories. Unlike some, I don't mind speculating on changes to current thinking (historically the accepted scientific thinking of the day has been wrong quite often, I see no reason to believe we are in a unique period today) - but it's always important to note when your speculations differ from current understanding. Ariel. (talk) 11:07, 3 December 2009 (UTC)

I agree with Ariel, it is usually pretty pointless entering a scientific discussion with fundamentalists. The fundamentalist position starts from the premise that all truth emanates from their holy book (of whatever religion). It is intolerable to them that anyone else can obtain "truth" from another source, hence the strong desire to "prove" that their holy reference manual contains that truth, though it was previously somehow overlooked by everyone. I guarantee that no-one has previously interpreted that passage in the Koran as meaning the speed of light until long after science came up with an accurate measurement of it. Science starts from a radically different position, and mutually incompatible with the fundamentalist view. The scientific position is that truth (the laws of nature) is the simplest possible interpretation consistent with the experimetal results. This means that science will modify its laws in the light of new evidence. The fundamentalist can never do this, contradictory evidence will only cause the reasoning to become ever more contrived in order to make the holy book remain true.

I like the postulate on that site that Angels travel at the speed of light. If that is true, it means they are inside our own light cone and exist in our universe, not in some other ethereal existence. In principle then, they are scientifically detectable - but it is strange that no experiment, so far, has found them. SpinningSpark 14:03, 3 December 2009 (UTC)

Perhaps, but then we have never found any dark matter either. Googlemeister (talk) 14:22, 3 December 2009 (UTC)

Angels are photons, God is a singularity, and Satan is the heat death of the universe. Fences&Windows 14:31, 3 December 2009 (UTC)

That analogy doesn't work. In christian and jewish versions of the story, Satan is an angel who "turns to the dark side". I don't see how the heat death of the universe is also analogous to a photon. The information content of a singularity is restricted to it's mass and maybe it's spin...doesn't bode well for something that's supposed to be all-knowing and therefore containing an infinite amount of information!

Anyway - these kinds of websites are nonsense. It's very easy to come up with similar nonsense - it doesn't prove anything - the best you can do is ignore them. You can find approximate coincidences in ratios of numbers everywhere - it doesn't prove anything. Precise relationships are more interesting - but even then may not mean much. Let's look at one "fact" from that page:

"But 1400 years ago it was stated in the Quran (Koran, the book of Islam) that angels travel in one day the same distance that the moon travels in 1000 lunar years, that is, 12000 Lunar Orbits / Earth Day. Outside the gravitational field of the sun 12000 Lunar Orbits / Earth Day turned out to be the local speed of light!!!" - Well, how far does the moon travel in 1000 "lunar years"? What the heck is a "lunar year" anyway? If it's the time it takes the moon to orbit the sun - then that's almost exactly the same as a regular year - and the distance the moon travels over that time (relative to the earth) is 1.022km/s x 1000 x 365.25 x 24 x 60 x 60 = 32,251,000,000km - the distance light travels in a day is 1,079,000,000 km/hr x 24 = 25,896,000,000 km. So these supposed angels are travelling at about 25% faster than the speed of light. I'm not sure what the gravitational field of the sun has to do with it - the speed of light is constant and the sun's gravity can't change that, it can distort time a bit - but nothing like 25%. Now, you might consider the distance travelled by the moon relative to the sun...that's a bit tougher to calculate but it's got to be a lot more than it moves relative to the earth - so that just makes the situation worse. So this guy has an error of 25% in his calculations - that's simply not acceptable in any kind of scientific argument. The errors in our measurements of the speed of light and the speed of the moon are tiny TINY fractions of a percent. So this argument must be incorrect...period. SteveBaker (talk) 17:43, 3 December 2009 (UTC)

Not really related, but satan in jewish thought is NOT an angel that went to the dark side. Stan is more akin to a prosecutor, who works for god, has no free will! Ariel. (talk) 20:19, 3 December 2009 (UTC)

While I agree with Steve's overall sentiment, he is a bit overzealous with regard to numerical accuracy in astrophysics. For a lot of parameters, 25% error is acceptable in astrophysics... for example, look at some of the tolerances on the parameters of a typical exoplanet, CoRoT Exo B, as documented by the ESA. Its density is quoted with a 30% error bar. I've seen much more speculative numbers with worse uncertainty in other publications. Stellar physics publications are lucky if they can estimate some numbers to within a factor of 10. But these parameters are not the speed of light, which is well known to better than one part in a billion. In general, a "high level of accuracy" is context-specific. In any case, the above argument is making an outlandish claim, so a greater burden of proof is in order. While I can stomach a 50% uncertainty about whether an exoplanet is iron- or silicate-core, I don't have the same tolerance for the "angels are photons" argument. Because those claims are much more unbelievable, I would expect a much higher standard of accuracy before giving them even the slightest little bit of credibility. I guess my point can be summarized as follows: the above claims are false - but not simply because the numerical error is very large. Numerical error is acceptable, if the scientific claims are qualitatively correct. The above claims about "lunar years" are simply wrong, so it's useless to even bother analyzing their accuracy. Nimur (talk) 17:52, 3 December 2009 (UTC)

No, I'm not being overzealous. Errors that big are acceptable only when the data you're working from has error bars that big. The error bar on the speed of light is a very small fraction of a percent - and so is the speed of the moon, the length of a year and all of the other things that made up that calculation. The numbers I calculated for the distance travelled by the moon over 1000 years and the distance travelled by light in a day are accurate to within perhaps one part in a thousand. The discrepancy between them is 25%!! There is no way that those numbers back up that hypothesis - and no respectable scientist would say otherwise. Since our confidence in the speed of the moon, etc is very high - the hypothesis that the Koraan is correct about the nature of angels is busted. It flat out cannot be true. (Well, technically - the number "1000 years" has unspecified precision. I suppose that if the proponents of this theory are saying "1000 years plus or minus 50%" and therefore only quoting the number to one significant digit - then perhaps we have to grant that it is possible (not plausible - but possible). But I'm pretty darned certain that the proponents of this theory would tell us that when this holy book say 1000 - it means 1000.0000000000000000000000...not 803.2 - which would be the number required to make the hypothesis look a little more credible! Hence, probably, the necessity of muddying the water by dragging the sun's gravitational field into the fray - the hope being that anyone who tries the naive calculation above can be bamboozled into accepting the result as being 100% correct once general relativity has been accounted for...but sadly, that's not the case because none of the bits of the solar system involved are moving anything like fast enough relative to each other and the sun's gravitational field simply isn't that great.) SteveBaker (talk) 18:26, 3 December 2009 (UTC)

For the purposes of establishing the actual facts of this claim, I looked up the quoted passage and got;

He regulates the affair from the heaven to the earth; then shall it ascend to Him in a day the measure of which is a thousand years of what you count. (The Adoration 32:5)

I was going to post just the quote and leave it at that. However, I was intrigued by the lack of mention of the moon in the passage, or indeed, in the entire book (or chapter or whatever the Koran calls its subdivisions). Apparently we must read "the measure of what you count" as meaning a lunar year. So looking a bit further I found this;

To Him ascend the angels and the Spirit in a day the measure of which is fifty thousand years. (The Ways of Ascent 70:4)

Sooo, to be consistent we must interpret that the same way and now have angels travelling at 50C, and if the interpretation that angels travel at the speed of light or slower is to be maintained we must conclude that the Koran would have the speed of light to be at least 1.5x10¹⁰. I think that pretty much rules out the Koran as a potential reliable source for Wikipedia purposes. SpinningSpark 19:07, 3 December 2009 (UTC)

At the core of the issue, it's difficult/impossible to assess the scientific merits of an unscientific line of reasoning. This theory, and others like it, are very inconsistent, are not based on empirical observation, and do not draw logical conclusions from experimental data. Therefore any assertions that it makes are categorically unscientific. It doesn't matter what the error-bars are on its numeric results. A lot of numerology finds exact values via convoluted procedures. That "accuracy" does not mean the methods are sound or scientific. In the same way, the inaccuracy of the above numbers is irrelevant - the method is simply wrong. Nimur (talk) 19:09, 3 December 2009 (UTC)

Also, I object to SpinningSpark's comment, "that pretty much rules out the Koran as a potential reliable source for Wikipedia purposes." The Koran is a reliable source for information about Islam'. It is a very reliable source for Wikipedia's purposes when those purposes are related to Islam. It'd be hard to find a more reliable source for our article about Islam, for example. But, the Quran is not a scientific book, and sourcing scientific claims from it would be invalid. Since this is the science desk, we should never source our references from the Quran or any other "holy book;" nor should we source scientific claims from history books, poetry books, or other non-scientific references. However, that doesn't mean that these are unreliable sources - it's just the wrong source for the Science Desk or science-related issues. Nimur (talk) 19:16, 3 December 2009 (UTC)

Quite so, I had intended to qualify that with "...for scientific articles" or some such, but typed the more general "Wikipedia" instead. SpinningSpark 19:32, 3 December 2009 (UTC)

On second thoughts, no you cannot use the Koran as a reliable source about Islam, at least not on its own. The only thing it is a reliable source for is what the Koran says. SpinningSpark 09:03, 4 December 2009 (UTC)

The issue is not that people believe the Quran - that's entirely their own problem - it's that some people are attempting to portray what it says as somehow reliably relevant and applicable to modern science. Plainly, it's not...or at least not as that website explains it. But if he can't get his science right and he can't quote the Quran accurately then it's really no use to anyone. SteveBaker (talk) 19:44, 3 December 2009 (UTC)

A lunar year is 12 lunar months, which is about 354 days. That makes it a little closer than your calculation gave, but not by much. --Tango (talk) 22:37, 3 December 2009 (UTC)

Well, I'm an Arab and Muslim too; though I don't believe for any reason to connect between religion and Science. Unfortunately many Muslims believe. I'm afraid to say the one who tried to prove this fallacy was originally a professor as I heard. If I were just an engineer then how could I convince so may people who are spreading such information not only in that website but in the schools and universities. How can they believe me such information are totally mess unless I can verify that from reliable sources and I believe in Wikipedia because it either gives reliable sources or proofs. On the one hand, I still believe this problem is not just in Muslim countries but almost all religions have some extremist who would like to convince others by any means. Anyhow thank you very much for this wonderful interaction.--Email4mobile (talk) 20:38, 3 December 2009 (UTC)

I agree - it's certainly not just the Quran that makes these kinds of error. The Christian bible says that Pi is 3 and that bats are a species of bird. This is what happens when you try to take written material that's several thousands of years old and apply it to everything we've learned in the meantime. The fact is that we shouldn't expect this stuff to be halfway reasonable - the problem isn't the books - it's that people are still trying to apply it to modern situations. SteveBaker (talk) 00:53, 4 December 2009 (UTC)

Steve, I know you're not a big fan of the Bible, fine, but don't say nonsense about it. Nowhere does it say pi is 3. It says someone made a "molten of sea" that was 10 cubits across and 30 cubits round about. From there to "pi==3" there are a couple of large logical jumps. --Trovatore (talk) 00:59, 4 December 2009 (UTC)

The argument Steve mentions has indeed been made, but its main flaw (it seems to me) is to assume that exactly 10 and 30 (i.e. 10.0 and 30.0) cubits were meant. If the figures were actually rounded to the nearest cubit, which seems perfectly reasonable in the context, then the description is entirely consistent with the true value of pi: for example, 9⅔ and 30⅓ would come very close at 3.138. 87.81.230.195 (talk) 02:16, 4 December 2009 (UTC)

But that's the point! Did they mean 1000 lunar years or did they mean 1000 lunar years to one significant digit just like the "molten of sea" thing? If they really meant 803 lunar years - rounded to the nearest 1000...then this is indeed a valid "prediction" of the fastest speed anything can possibly move. But was it ever intended as a prediction of relativity? My bet is no. No more than the Bible is talking about geometry of circles. We're generally lead to believe that the words in these books are to be taken "as gospel". But we can't judge that by modern standards. Nobody measured the speed of an angel or the circumference of the "molten of sea" thing to modern precision levels. We must avoid dual-standard here. It's precisely as wrong to claim that the Quran predicts the speed of light as it is that the Bible predicts the value of pi - neither of those things were ever intended by the original authors - it's just modern hindsight trying to extract miracles where there is nothing but simple literary verbiage that's been blown out of all proportion. (Although it is pretty clear on that bat==bird thing - and on a whole bunch of other biological 'oopsies' in the dietary laws.) SteveBaker (talk) 04:08, 4 December 2009 (UTC)

What's the error with the bat bird thing? You define bird as creature with feathers. The bible doesn't, it defines the word in hebrew that is commonly translated as bird, as flying creature. During creation for example it even says flying creature[19][20]. And a bat flies, so what's the problem? And complaining about the basin is really stupid, since that part isn't even the word of god - it was a person recording what he saw - the basin was a physical object. You can't argue with that any more or any less than any other ancient document. And for the record the speed of light thing is nonsense. Ariel. (talk) 05:02, 4 December 2009 (UTC)

There seems to be some cherry picking going on here. My King James bible says,

And God said, Let the waters bring forth abundantly the moving creature that hath life, and fowl that may fly above the earth in the open firmament of heaven. (Genesis 1:20)

The American Standard Version does not say flying creature either. SpinningSpark 13:58, 4 December 2009 (UTC)

Back to Steve: A Lunar year is a year in the lunar calendar, i.e. in this case likely the Islamic calendar. It consist of 12 lunar months, i.e. 354 or 355 days, depending on how the fractions work out. That's how the original author arrives at the 12000 (12 months times 1000 years). So the error is about 3 percentage points worse than your result. --Stephan Schulz (talk) 20:50, 3 December 2009 (UTC)

Yes, Stephan, I think I've already mentioned that in the previous discussion but not sure it SteveBaker noticed that. To me I've accepted this step of calculations but was surprised when he again used another kind of conversions to achieve cos(26.92952225^o) in order to reach 0.01% error. That was the point I wanted to swallow, but couldn't understand how (See the details here).--Email4mobile (talk) 21:02, 3 December 2009 (UTC)

Apart from that other verse talking about 50,000 years a day, let's first verify the 1000 years a day calculation, Spinningspark.--Email4mobile (talk) 21:21, 3 December 2009 (UTC)

[edit] Lines of little circles of light on camera

How come when a camera shoots something very bright like a brief shot of the sun, you often see little circles, usually as if they were strung together along a line? 20.137.18.50 (talk) 12:56, 3 December 2009 (UTC)

See lens flare. Gandalf61 (talk) 13:01, 3 December 2009 (UTC)

It's caused by light reflecting back and forth between the surfaces of the lenses. Cameras with high quality lenses don't do it nearly so much. The dots you see in the 'flare' aren't always circles - sometimes they are pentagonal or hexagonal. In this photo they seem to be 7-sided. SteveBaker (talk) 17:16, 3 December 2009 (UTC)

Fixed your link. APL (talk) 17:22, 3 December 2009 (UTC)

Almost certainly images of the leaves of the lens aperture. See bokeh. --Phil Holmes (talk) 09:54, 4 December 2009 (UTC)

[edit] Rainbow ham?

What I'm talking about

What causes the rainbow color that I sometimes see in ham and other cured meats? This says it's a "chemical reaction" (not telling much more), this says it's birefringence, which is a nicer word, but our article on birefringence doesn't mention this effect at all. (If it is birefringence, this is probably one of the most common effects of birefringence encountered in the typical life of citizens of the western world. Probably deserves a mention.) Staecker (talk) 17:35, 3 December 2009 (UTC)

A lot of cured meats are soaked in a brine, saline solution, or other liquid to add volume and flavor to them. The birefringence or other optical effects are often the result of these saline liquids suspended in the interstitial spaces of the meat. Nimur (talk) 17:46, 3 December 2009 (UTC)

There are several possibilities - one is that we're seeing an "oil on water" effect because oils from the meat are mixing with water - another is that we're seeing some kind of Dichroism effect - yet another is some kind of coherent scattering - similar to the thing that makes the colorless scales of a butterfly's wing show up in such vivid, iridescent colors. There are a lot of related effects and this could easily be any one of them - or even some complicated combination of them. Without some kind of expert study - I don't think we should speculate. SteveBaker (talk) 18:07, 3 December 2009 (UTC)

We can, however, point to prior research, e.g. Prediction of texture and colour of dry-cured ham by visible and near infrared spectroscopy using a fiber optic probe, Journal of Meat Science, 2005. Virtually everything that can possibly be observed, and many things that can't, has already been studied and published somewhere. Nimur (talk) 18:10, 3 December 2009 (UTC)

Darn! How did I miss that? I'm such an avid reader of the Journal of Meat Science! SteveBaker (talk) 19:38, 3 December 2009 (UTC)

[edit] Does such a disease exist?

Is there a disease where the neurons of the brain spontaneously form synapses with all their neighboring neurons at an accelerated rate, essentially forming one very deeply interconnected mess? 20.137.18.50 (talk) 18:27, 3 December 2009 (UTC)

Never heard of anything like that. If there were a mutation that did that, it seems likely to me that it would be fatal at a pretty early stage of embryonic development. Looie496 (talk) 20:41, 3 December 2009 (UTC)

Relevant articles are Synaptogenesis and Synaptic pruning. Landau–Kleffner syndrome and continuous spikes and waves during slow sleep syndrome, related to epilepsy, both involve too much synaptogenesis during childhood due to electrical activity that strengthens the synapses.[21] Fences&Windows 23:12, 3 December 2009 (UTC)

There is a great variety of proteins that participate in axonal guidance and/or affect synaptogenesis. See, for example, FMR1, Thrombospondin, semaphorins, and Amyloid precursor protein. I am not familiar with the specific pathology you refer to, though. --Dr Dima (talk) 00:48, 4 December 2009 (UTC)

[edit] cheesewring stones

It does not say in the article, but is the Cheesewring a natural formation, or is it man made like Stonehenge? Googlemeister (talk) 20:26, 3 December 2009 (UTC)

Looks natural to me. In southern Arizona there are hundreds of rock formations that look like that -- made of sandstone rather than granite though. Looie496 (talk) 20:37, 3 December 2009 (UTC)

The article states "Geological formation" which implies natural rather than man made source. In Southwestern Utah there are formations called Hoodoos (you've seen them in the old Wile E. Coyote cartoons). Geology + psychology is capable of some remarkable looking formations. I remember taking some college friends to Northern New Hampshire to see the Old Man of the Mountain (RIP), and they kept asking "No really, who carved that? Was it the Indians?" I kept trying to tell them it was just a natural formation. Other fun natural formations which have been mistaken for manmade include the Giant's Causeway in Ireland, the Pingos of northern Canada, the Badlands Guardian of Alberta, the Cydonia face on Mars, etc. --Jayron32 21:07, 3 December 2009 (UTC)

Apparently we are lucky that it still exists. Looie496 (talk) 21:22, 3 December 2009 (UTC)

For interest, there is currently an artist in the UK who makes somewhat similar, though smaller, piles of rocks on public beaches, often featuring apparently impossible balancing. Google-searching turns up the name Ray Tomes who has done something similar but I don't think he's the artist I have previously encountered. 87.81.230.195 (talk) 02:00, 4 December 2009 (UTC)

I think you might be referring to Andy Goldsworthy. Richard Avery (talk) 10:30, 5 December 2009 (UTC)

Idol rock

Speaking of apparently impossible balancing, I have seen a lot of amazing stuff in Utah, but nothing as amazing as the picture on the right. Looie496 (talk) 17:52, 4 December 2009 (UTC)

Yes, the strength of that Millstone grit at Brimham Rocks is remarkable. This shape is supposed to be a result of natural sand-blasting of the somewhat softer layer at the base. Mikenorton (talk) 13:26, 5 December 2009 (UTC)

The Cheesewring is a rather extreme example of a tor, a type of rock outcrop that typically forms in granite. They are a result of weathering, which has acted particularly on pre-existing sub-horizontal joints to produce the unlikely shape (see Haytor for a less extreme example). Mikenorton (talk) 11:06, 4 December 2009 (UTC)

[edit] North Korea's closed-circuit speaker system

In this article and at least one other at the Wall Street Journal, they say that the North Korean authorities notified the citizenry of the replacement of the North Korean won by means of "a closed-circuit system that feeds into speakers in homes and on streets, but that can't be monitored outside North Korea."

Speakers in homes? Really? Do we have a Wikipedia article on this system? Is this cable TV but without the TV? How many homes are equipped with this technology? I have a raft of questions. Tempshill (talk) 21:54, 3 December 2009 (UTC)

Is this science? Anyhow... from the New York Times: "Every North Korean home has a speaker on the wall. This functions as a radio with just one station -- the voice of the Government -- and in rural areas speakers are hooked up outside so that peasants can toil to the top 40 propaganda slogans. Some of the speakers are hooked directly into the electrical wiring, so that residents have no way of turning them off; they get up when the broadcasts begin and go to sleep when the propaganda stops. In some homes, however, the speakers have a plug, and people pull the plug when they want some quiet."[22] Just like in 1984. Something similar but less scary in Australia: "loudspeakers are sprouting like mushrooms on Sydney streets, peering down from the tops of traffic lights. The State Government has begun to put in place a permanent public address network that will, in some unspecified emergency, tell people what to do."[23] Fences&Windows 22:47, 3 December 2009 (UTC)

You might find this: [24] link interesting. It has a photo of a similar hard wired radio(?) in russia. Ariel. (talk) 00:03, 4 December 2009 (UTC)

Back in the 70s and 80s -- and probably well before that -- there was a ubiquitous contraption called "radiotochka" (radio spot) in the USSR households. IIRC the radio signal was transmitted via the electric wires of the power grid and not by air. I do not know how the signal was modulated, but I am pretty sure it was separated in frequency from the 50 Hz AC current the wires were carrying. There was only one station. Yes, it was government-controlled, but so was the TV, anyway; and it could be turned off or unplugged any time you like, of course :) . I doubt it that it transmitted anything back, but in principle I guess it could double as a bug for the bolsheviks to eavesdrop on you. --Dr Dima (talk) 00:08, 4 December 2009 (UTC)

(I haven't seen Ariel's post when I edited mine, but I didn't get the EC screen either. Weird.) anyway, Ariel, yes, that's it in the picture. It had one station only, though, not three; or maybe it had three in some places. Or maybe the other two were added after I emigrated :). --Dr Dima (talk) 00:13, 4 December 2009 (UTC)

Would you mind creating an article on it? It's ok if you don't know everything about it, just get it started and put in what you do know. (I know nothing about it. But maybe I can ask the person who posted the photo to contribute.) Ariel. (talk) 00:34, 4 December 2009 (UTC)

Last time I've seen a radiotochka was about 20 years ago. I do not think my memory from back then is accurate enough for me to write a Wikipedia article about it now. Sorry. --Dr Dima (talk) 01:07, 4 December 2009 (UTC)

I don't think it's that weird. The software is getting better and better at resolving edit conflicts. It's obviously fairly annoying for editors when you make extensive edits to a page (or even fairly minor but spread out ones) and have an edit conflict then have to resolve that then try again and have another conflict etc. Particularly a problem for high traffic pages. I'm not sure but it's also possible that this page is treated like an article and the software is more fussy on talk pages in recognition of the fact that edit conflicts could in some instances lead to confusing discussions. This is of course the kind of thing that people don't tend to notice since unless you actually get an edit conflict, you may not realise people have edited while you were editing. But to use an example I just encountered see [25]. I didn't actually look at the time when I started editing but I'm pretty sure it was before the 2 Madman2001 edits maybe even before the Derlinus. These where not that hard to resolve for the software, but I strongly suspect several years ago I would have gotten an EC Nil Einne (talk) 07:09, 5 December 2009 (UTC)

Incidentally, there was a similar device in use in the 1950's in the US. It was to be used for civil defense, and would also get the signal through the electrical wiring. It would be always left on to sound the alarm in an emergency (even if the homeowners had the radio and TV turned off). It never really caught on, though, and the plan was canceled after a few years. StuRat (talk) 05:44, 4 December 2009 (UTC)

That US device was on a History's Mysteries segment I saw a week or two ago. Clever device, tested and worked for transmitting an alarm. But the system was scrapped when they recognized that there was just the alarm, no ensuing instructions on how to respond to the situation. DMacks (talk) 07:34, 4 December 2009 (UTC)

Correction: History Detectives. The webpage for that segment might have some good information for an article about this type of system. DMacks (talk) 07:52, 4 December 2009 (UTC)

For example, National Emergency Alarm Repeater. DMacks (talk) 07:54, 4 December 2009 (UTC)

In some places in the U.S. the emergency sirens can broadcast announcements as well as their really annoying screech. Which would be useful if that tornado ever happens to come at 1 o'clock on the first Saturday of any month (monthly system test time). Rmhermen (talk) 14:44, 4 December 2009 (UTC)

Thanks for the responses - I'll add "radiotchka" to Wikipedia:Requested articles. Tempshill (talk) 07:25, 5 December 2009 (UTC)

[edit] Environmental Impact of ebooks vs paper books

I've seen some e-book distributors advertising ebooks as environmentally friendlier than the 'dead tree' version. On the face of it this seemed reasonable; no trees, no chemicals for paper and ink making, no distribution of heavy books, no bricks and mortar stores (and all the energy to run them), but then I started thinking about the computing required to deliver ebooks. So, which is more environmentally friendly? I'll leave it to you to decide how much of the production / distribution / consumption chain to include, also what constitutes 'environmentally friendly'. Scrotal3838 (talk) 22:02, 3 December 2009 (UTC)

Hmm well this page and this page outline some perceived problems with paper. See also Pulp (paper). On the other hand Electronic waste is often portrayed as being bad fairly serious, and factories that produce Kindles or computers or whatever of course also pollute. On the balance, however, I'd say that electronic distribution is much more environmentally friendly. It could (theoretically) replace a huge amount of printed material, and I just don't think there's any way the pollution generated making a kindle could add up to the pollution generated making a piece of paper for every page a kindle electronically displays. As far as energy to run servers and the devices themselves, I really doubt you could quantify ebooks as being anything but a marginal energy use. I don't see why ebook distribution would take up any more energy than a regular website, which on an energy per unit of information basis is extremely efficient.

However, the argument should be taken with a grain of salt, in my opinion. People were predicting similar improvements with the advent of email replacing memos. But paper use over the period when email became widespread increased, due to it being much easier to produce documents with modern printers and (ironically?) people printing out their work emails to have a paper copy. I forget where I read that last bit, I think it was in the Economist. Regardless, I think ebooks could be portrayed as better for the environment if it can be demonstrated that the user in fact uses less paper, and doesn't just use the same amount of paper and an electronic device that has an environmental impact in its creation, operation and disposal. TastyCakes (talk) 23:26, 3 December 2009 (UTC)

To read an ebook you need to turn your computer on (assuming it was off), and that requires electric power which consumes energy producing CO2, CO, NO, NO2, SO2, etc... Dauto (talk) 01:50, 4 December 2009 (UTC)

Well first, you might live in an area that gets its electricity from hydro or nuclear or some other generator that doesn't produce pollution. And second, turning wood into paper requires significant electricity as well, along with chemicals and the logging of forests. And then you have to fuel the trucks that distribute books and other paper to stores or distribution centres, which also uses energy and produce pollution. I don't think anyone would argue that ebooks have zero environmental consequences. But again, taking everything in account it looks like they have less impact that printed books, which was the question. TastyCakes (talk) 02:43, 4 December 2009 (UTC)

I don't think there is much doubt that this is not a question of energy use. After all, the Kindle runs for a heck of a long time on battery power - and the 60 watt light bulb you are reading it by is consuming at least 100 times more energy than the eBook itself. It's more a question of environmental damage during manufacture and ultimate disposal. That comes down to how long books and eBook readers last. Books seem to be almost immortal. I don't think I know anyone who throws them away...it seems almost sacrilegious to do so - and burning a book is just such a taboo (especially for Ray Bradbury fans!) that I doubt anyone does it routinely. However, if eBook readers are going to be regularly obsoleted like laptops and fancy phones are - with a lifetime of just a few year - then dumped onto landfills - then we can probably say that the eBook is doing more environmental damage. Paper books lock in carbon - and if you dump them into landfill, the compost nicely and their carbon is sequestered - that's a net win if the manufacturing process wasn't too nasty. Most books are read by many people before they eventually go wherever it is they go. Since an eBook player has no moving parts (well, except, perhaps for the switches) - it could last a long time. If they aren't obsoleted, then all likelyhood, the battery will be the thing that finally kills them. Most batteries die because their lives get shorter and shorter over the years - and that's a real problem for an eBook which really needs to be cable-free and to run for MANY hours without a recharge. If things settle down enough technologically - and the battery life is good enough - then perhaps there is a chance of the eBook being a better choice - but I kinda doubt it right now.

(Dear Santa: Steve would like a Kindle for Xmas please - I have carefully sequestered the lump of carbon you sent me last year.)

SteveBaker (talk) 03:49, 4 December 2009 (UTC)

Who uses a 60 watt light bulb to read? A 15W or even 12W or heck even 8W CFL does fine Nil Einne (talk) 08:23, 4 December 2009 (UTC)

OK - even an 8W CFL uses vastly more power than a Kindle. The beautiful thing about ePaper is that the image stays there when you remove the power source. Hence a well-designed ePaper based eBook reader can turn itself completely off and consume literally zero power while you're actually reading. You wake it up by pushing a button to turn the page or something - the on-board computer grabs the next page, formats it, sends it to the ePaper - then turns itself off again about a tenth of a second later. They use truly microscopic amounts of power when you are using them as intended. Of course if you surf the web with them using the wireless link or continually flip back and forth between pages - then it's going to eat more power - but for simply reading a novel or something - their power consumption is almost completely negligable. SteveBaker (talk) 19:18, 4 December 2009 (UTC)

Also, how many of us read ebooks with the Kindle? I had never even heard of it. Most people will use a desktop computer or a laptop and these consume more energy than the Kindle. Most people don't turn the lights off when using a computer either so there realy isn't any savings. Finally, the environmental cost for the production of a paper book happens only once while the power consumption for reading an ebook happens every time you read it. 169.139.217.77 (talk) 14:27, 4 December 2009 (UTC)

See Amazon Kindle and electronic paper. It is true, at this point Kindle and other electronic paper readers have a negligible share of the overall book market. But the real question is whether the average Kindle owner's paper "usage" goes down enough to offset how much environmental damage the Kindle does through its creation, use and disposal. I don't know the numbers (I'm not sure anyone does), so I'll make them up to explain. Say the production of a kindle produces the same "environmental impact" or "environmental footprint" or whatever as 1000 books. I don't know if that's an accurate number or not. But if the owner of the Kindle only reads 100 books on the Kindle over the course of its life, the Kindle has not been better for the environment than the paper equivalent. If, however, they read 5000 books, it is a great improvement. As I state above, I suspect, on average, the Kindle is better for the environment than its paper equivalent over the course of its life, but that is just from a vague feeling of how much damage the paper industry causes compared to the electronic industry. TastyCakes (talk) 17:41, 4 December 2009 (UTC)

I'd like to agree with you - but the niggling problem I have is that paper books are often read by multiple people - when I'm done reading with my books, I either lend them to other people to read - or take them to my local "Half Price Books" store and sell them - or I give them away to some local charity or something. I can't ever recall tossing a book into the trash. Most of the books I read are second hand anyway - so I think it's possible that a typical book is read maybe a dozen times before it finally falls apart or something. That skews things in favor of paper books. If we assume that an average Kindle is used to read 1000 books (that seems like a very high number to me) - then if paper books are each read by 10 different people (or even by the same person 10 times) - then the Kindle has to be more environmentally friendly than 100 paper books - not 1000. I can't help suspecting that the average Kindle will only last at most maybe 10 years...probably more like 5. SteveBaker (talk) 19:18, 4 December 2009 (UTC)

Hmm that's true, multiple readers are left out on my simplistic calculation. And there is the added complication that the Barnes & Noble Nook allows users to lend e-books to others and this capability could become the norm. I guess the easiest (and fairest?) way to measure it would be if electronic readers became more commonplace (say, 10% of the market for new books) and then measure how much paper production per capita decreases in the same market over the same period. Then if you could get a reasonable estimate of how long the average Kindle will last (or how long until its obsolescence) you could estimate how much paper the average Kindle displaces over its lifetime. Of course that's making the big assumption that ebook readers are the only thing affecting paper sales per capita over that period, and it seems likely that a greater percentage of people will read a greater percentage of things on phones, computers and PCs over the same period... TastyCakes (talk) 01:27, 5 December 2009 (UTC)

Why would it so bad to take the carbon from trees and store it in a form (paper) that won't contribute to CO2 percentage for probably hundreds of years? I never understood why transforming trees to stored carbon should be bad, as long as trees are grown again afterwards. ----Ayacop (talk) 18:07, 4 December 2009 (UTC)

Oh that's not bad - it's good. But the environmental impact of printing a paper book is a lot more than just the wood pulp it's made from (which - as you say - is a positive benefit to the environment because it's sequestering carbon). But making paper from wood pulp requires diesel fuel to power the lumber trucks, gasoline for chainsaws, electricity for the pulp-making machine, water (lots of it). Most paper is also bleached - presumably with some nasty toxic chemicals. The ink is laced with antimony and other nasty heavy metals. There is glue in the binding. Many paperback thrillers have the title embossed and coated with a thin metal foil. More gasoline is burned in getting the book from the printer to the bookstore - and for the eventual purchaser to go to the bookstore and back. So paper books certainly do have an environmental footprint. We just don't have the information to compare the size of that footprint to an eBook reader. Gut feel says that a single book is much less destructive than a single eBook reader - but then we don't know how many books are replaced by that reader over it's lifetime - maybe it's a lot - maybe very few because books are so well recycled across many readers. That makes this a tough question to answer. SteveBaker (talk) 19:18, 4 December 2009 (UTC)

[edit] Stars

How are we able to see stars if they are so far away? jc iindyysgvxc (my contributions) 22:02, 3 December 2009 (UTC)

They are bright. --Jayron32 22:09, 3 December 2009 (UTC)

There's not a lot in the way. Light doesn't just fade away over long distances -- it has to go through plenty of interstellar dust before becoming indiscernible. Vranak (talk) 22:12, 3 December 2009 (UTC)

It does spread out, though. The brightness of nearby stars is determined more by the inverse square law than extinction. --Tango (talk) 22:15, 3 December 2009 (UTC)

A more interesting question might be: "How are we able to look at any of the night sky and not see stars?" See Olbers' paradox. Dragons flight (talk) 23:22, 3 December 2009 (UTC)

The previous answers are missing a critical point - and (sadly) it's a somewhat complicated explanation.

The sun is a star - a pretty normal, boring kind of star just like many others in the sky. It's so bright that you can't look at it for more than the briefest moment without wrecking your eyesight. Most of the other stars out there are at least that bright - and space is pretty empty - interstellar gasses and dust make very little difference. So the only real effect is that of distance.

As others have pointed out, that's driven by the "inverse square law" - when one thing is twice as far away as another similar thing - it's four times dimmer - four times further away means 16 times dimmer and so on. The sun is only 93 million miles away - that's 8 light-minutes. The nearest star is 4 light-years away. Let's consider Vega (which is one of the brightest stars in the sky) - if you were 93 million miles away from it - it would be about 37 times brighter than our sun and you'd need some pretty good sunglasses and a good dollop of SPF-50! But fortunately, it's 25 light years away. So, Vega is 25x365x24x60/8...about one and a half million times further away. Which means that even though it's 37 times brighter when you're up close, it's 1.5Mx1.5M/37 times dimmer from where we're standing (73 billion times dimmer) because of that inverse-square law thing.

Our eyes are able to see a range of brightnesses from the maximum (which is about where the sun's brightness is) to a minimum of about 10 billion times dimmer than that. On that basis, Vega ought to be about 7 times too dim for us to see - but it's not. It's actually pretty bright. So you can tell right away that that inverse square law that everyone is going on about ISN'T the whole story.

There is obviously something else going on - and that is that the total amount of light from the sun is spread over that large disk you see in the sky - and while Vega is 73 billion times dimmer, all of that light is collected into one tiny dot. It gets hard to calculate the effect that has - but it's actually rather significant because the apparent size of the sun compared to that of Vega is gargantuan. In fact, the apparent area of an object obeys the same inverse-square law as the brightness does - so when you double the distance to something, it looks four times smaller (in area, that is). That concentration of light from a perceptually large object into progressively smaller areas of our retina exactly counteracts the inverse-square law.

Someone's going to complain about that - but think about it...that's why you can see something quite clearly when it's 200 feet away and it's not 40,000 times dimmer than when it's 1 foot away!

That means that until you are so far away that the sun is just a speck that's comparable to the resolution of your retina - it's not really any dimmer to look at than it is up close. The total amount of light is much less - but the light coming hitting each cell in your retina is exactly the same - until the projected image of the sun on the back of your eye starts to get smaller than the size of a single cell. So if you were out at the orbit of (say) Pluto - where the sun casts almost no heat and very little light - staring at the sun's tiny disk would still ruin a very small patch of your eyeball.

But still, 73 billion is a big number - Vega is still a heck of a lot dimmer - as you'd expect. However: remember that the sun is bright enough to literally blind you - and that your eyes are really sensitive - we can see things that are 10 billion times dimmer than the sun - so it's actually quite easy to see Vega even in very light-polluted cities. Much dimmer stars are also visible to the naked eye.

SteveBaker (talk) 23:54, 3 December 2009 (UTC)

I understand that an interesting question is why the night sky is not bright white rather than black, as an infinite number of stars would lead to the former. 89.242.105.246 (talk) 01:13, 4 December 2009 (UTC)

I believe the answer to that question, known as Olbers' paradox (which remarkably was first hinted at by Edgar Allen Poe in his essay Eureka: A Prose Poem), is that the Universe is not infinitely old, so light from the more distant stars has not yet had time to reach us. Attenuation due to red shift may also play a part. 87.81.230.195 (talk) 01:44, 4 December 2009 (UTC)

The Olbers' paradox article is pretty good - it lays out all of the possible reasons for this. SteveBaker (talk) 03:32, 4 December 2009 (UTC)

Aha. I've actually caught the most excellent SteveBaker in a misstatement. In his first response to the OP, refering to brightness of the Sun, he stated, "Most of the other stars out there are at least that bright." In reality, the vast majority of stars are far dimmer than the Sun. They are, in fact, so dim that we don't see them. So what was meant was that of the stars we see, most are at least as bright as the Sun. (Just a tiny correction) B00P (talk) 08:17, 5 December 2009 (UTC)

Indeed - I believe about 90% of the stars in the galaxy are red dwarfs, few (if any) of which can be seen with the naked eye. --Tango (talk) 11:49, 5 December 2009 (UTC)

[edit] The most useless particle

Say you had to choose one type of subatomic particle to be completely rid of: every single particle of that kind would completely disappear and no process would ever produce them ever again. Which would make the least difference to the Universe? Vitriol (talk) 22:37, 3 December 2009 (UTC)

I strongly suspect there is no answer to this - they are all absolutely 100% necessary. Take any one away (if that's even possible - string theory says "No") then the universe would be a dramatically different place - probably life as we know it wouldn't exist. But there is no "marginally less useful" particle. SteveBaker (talk) 23:04, 3 December 2009 (UTC)

String theory in its current form doesn't say anything useful about the Standard Model. The current thinking that there are a huge number of string theory vacua with different effective physical laws in each one. There might be one that looks like the Standard Model with a particle missing. -- BenRG (talk) 02:46, 4 December 2009 (UTC)

Oh, I don't know. A universe without a top quark might not differ much. Top is very hard to create and decays in ~5 × 10⁻²⁵ s. Now there might be secondary effects on the rest of the standard model if one removed the top, and I'm not sure how to predict what modifications to the larger theory might be necessary, but the top by itself seems of little importance. Dragons flight (talk) 23:14, 3 December 2009 (UTC)

There is no particle that could be removed from the Standard Model without either making it inconsistent or making life impossible. However, we could remove a whole group of particles, such as the third generation of the standard model (which comprises the tau, tau neutrino, top quark, and bottom quark) This is the only of the three generations with no practical applications. 74.14.108.210 (talk) 23:13, 3 December 2009 (UTC)

Not to hijack the question but could you elaborate on that a little? Why would it be inconsistent or non-life sustaining if, for example, the top quark didn't exist? Maybe not so many pleasing symmetries would exist but where are the serious effects? 129.234.53.144 (talk) 23:56, 3 December 2009 (UTC)

In physics the math always balances. If the top quark was missing, some physical interaction would not balance which is impossible. So some other particle or effect would, nay MUST, happen instead. Which would then have implications, etc, etc. Make any change, and everything else changes too. Ariel. (talk) 00:01, 4 December 2009 (UTC)

The up-type and down-type quarks couple via the weak interaction, and I think there's a loss of unitarity if you don't have the same number of particles of each type. On the other hand, there are preon theories with nine quarks, four of one type and five of the other, that don't have unitarity problems as far as I know. The story is the same on the lepton side. I don't think there's any known reason why there have to be the same number of quarks as leptons, though, so you can get rid of just two quarks or just a charged lepton and a neutrino without trouble. (This is not quite "getting rid of the top and bottom" or "getting rid of the tauon and tau neutrino" because you would also have to rejigger the CKM matrix or PMNS matrix, which alters the nature of the leftover particles as well.) One problem with dropping a generation is that there can be no CP violation in the weak interaction with two generations, and CP violation of some kind is needed to explain why there's more matter than antimatter. But I don't think the CP violation in the weak force can be used to explain that anyway. My vote for the most useless particles goes to the right-handed neutrinos, unless they turn out to be an important component of dark matter. -- BenRG (talk) 02:46, 4 December 2009 (UTC)

BenRG, the symmetry between the number of leptons and quarks is necessary in order to cancel the gauge anomalies that would otherwise destroy gauge symmetry and spoil renormalization. Dauto (talk) 07:13, 4 December 2009 (UTC)

Oh. Oops. -- BenRG (talk) 17:53, 4 December 2009 (UTC)

More importantly, per Murray Gell-Mann, "that which is not forbidden is mandatory" in particle physics. The existance of the top and bottom quarks is necessitated by the symmetry in the Standard Model. The entire system predictes the existance of said particles, therefore they are ALL equally vital. We have a pschological sense that particles like electrons are more vital because we tend to work with them more often, but the entire system of particles is not seperable; you must take them all, because the laws that created the top quark also created the electron; you could not create a universe with one and not the other. You can think of the Standard Model like a house of cards. If you remove any part of it, the whole system does not stand. See also anthropic principle for more on this. --Jayron32 00:16, 4 December 2009 (UTC)

Here's an interesting article for you Weakless Universe, they imagine a universe where something is missing. But as you see they had to change various other things too to make it work. Ariel. (talk) 00:31, 4 December 2009 (UTC)

Excuse me, but that's totally nonsense answer. If there were no top quark, the standard model would be seriously broken, I agree. But that's still just a human model of physical reality. If the universe had no top quark, then that would imply physicists need to discover a theory of particle physics that is different from the standard model, and one in particular where top quark formation is forbidden. However, because the top quark is almost never involved in interactions at human scales, more likely than not one could invent a new theory (perhaps much less elegant) that still gave the same predictions for human life as we have now. The Standard Model might be a "house of cards", but physical reality need not adhere to your sense of aesthetic beauty in determining its laws. For another example, the Higgs boson has but long sought after and not yet found. Most physicists seem to believe the Higgs will eventually be found, but one can just as well replace the Standard Model with one of several Higgsless models and our physical reality would look the same. Dragons flight (talk) 00:35, 4 December 2009 (UTC)

The Standard Model doesn't predict the number of generations; there's no known reason why there should be three. I don't know of any anthropic reason either. "Everything not forbidden is compulsory" is not about particle content. It's a statement that any interaction or decay that's not forbidden by a conservation law has a nonzero probability of occurring in quantum mechanics (classically forbidden transitions can happen in quantum mechanics because of tunneling). -- BenRG (talk) 02:46, 4 December 2009 (UTC)

If string theory is to be believed - then all of these particles are just modes of vibration on a string - getting rid of one mode of vibration is an entirely unreasonable proposition - so it's very possible that these things are no more removable from the universe than the color yellow or objects weighing exactly 17.2kg. SteveBaker (talk) 03:29, 4 December 2009 (UTC)

Strings have vibrational modes (harmonics), and those vibrational modes are particles, but the modes are quantized in multiples of roughly the Planck mass. All observed particles have masses far smaller than that, so they all belong to the ground state of string vibration. They're supposed to be distinguished by their behavior in the extra dimensions, but there's no reason to believe that the shape of the extra dimensions is unique. You can say a similar thing about quantum field theory. "Particles are just vibrational modes of the vacuum" is an accurate enough statement about QFT. It doesn't make sense to get rid of one vibrational mode, so you're stuck with a certain set of particles—for a given vacuum. But this doesn't answer anything; it just rephrases the question about the particle content as a question about the vacuum.

There was some speculation in the earlier days of string theory that it would turn out to have a unique vacuum which would have the Standard Model as a low-energy approximation, but the current thinking is that there are lots of vacuum states and only some of them match the Standard Model. Whether there are vacuum states corresponding to slight variations of the Standard Model isn't known. It isn't even known that there's a vacuum state corresponding to the Standard Model, though obviously they hope that there is. -- BenRG (talk) 05:13, 4 December 2009 (UTC)

I could definitely do without [fat electrons] being sent down the electricity supply and clogging up my computer:) Dmcq (talk) 06:43, 4 December 2009 (UTC)

[edit] December 4

[edit] Storks

Why do you get storks in places like Germany and Holland but not in Britain? Germany has a more severe winter than Britain, so that cannot be the reason. 89.242.105.246 (talk) 01:08, 4 December 2009 (UTC)

Storks are seen in UK [26], occasionally. However, UK is rather far west and north-west from their habitat (Central and Eastern Europe). They migrate south by one of three routes, AFAIK: western route over France, central route over Italy, or eastern route over Israel. If they were to spend the summer in UK, they would have to fly east to France and then south, which, I guess, they usually don't. --Dr Dima (talk) 01:42, 4 December 2009 (UTC)

[edit] name of physics book

What is the name of the physics book depicted here? In case you are wondering, that is Tiger Woods's car. Thanks. 67.117.130.175 (talk) 01:24, 4 December 2009 (UTC)

See this. hydnjo (talk) 01:42, 4 December 2009 (UTC)

It is “Get a Grip on Physics” by John Gribbin. Edit: the above link does not work for those of us for whom Google automatically redirects to Google.co.uk, so here is a UK version of it: [27] 78.149.192.188 (talk) 11:24, 4 December 2009 (UTC)

Took a minor liberty and Wikilinked the name in your post, 78.149, as I'm a fan of Gribbin. 87.81.230.195 (talk) 12:55, 4 December 2009 (UTC)

[edit] Cat and dog ear fold.

What is the function of the small pleat on the ventral/posterior exterior margin of a cat or dog auricle? Presumably other Carnivora have this feature as well. It looks like this: ----==-===--- where the skin doubles, and the interior fold is divided. The structure is visible in this image: http://en.wikipedia.org/wiki/File:Terrier_mixed-breed_dog.jpg. -Craig Pemberton 01:43, 4 December 2009 (UTC)

I'm going to go out on a limb and say that this fold has no appreciable function. My guess is that it is a vestigial trait left over from some other ancestral characteristic. I also have to admit that I am not at all qualified to make such an assumption so if someone else has evidence to the contrary you can safely ignore my answer. Presumably since some bats have quite gnarly ears, the folds play some role in sensing direction or attenuating certain sound, but a lot of bats also have smooth ears and hear just fine so it seems to suggest that this characteristic doesn't play a major role. Similarly it's hard to imagine the folds in human ears play a significant "functional" part of our hearing, if any part at all. Vespine (talk) 05:26, 4 December 2009 (UTC)

I've always assumed that it has to do with turning the ears. That is, the fold is present when the attached muscle is relaxed, while it's straigtened out and the ear turns when the muscle tenses. StuRat (talk) 05:28, 4 December 2009 (UTC)

[edit] Rechargable Batteries

Just curious: which is faster? Draining a battery OR charging it? or can they be completed in roughly equal periods of time? I'm thinking draining a battery could potentially be faster because (I think?) batteries don't heat up when they lose power, only when they're charged, so the absence of a thermal consideration would allow for a faster rate of flow? Thanks! 218.25.32.210 (talk) 02:00, 4 December 2009 (UTC)

I guess you've never used a smart phone or semi smart phone then. Draining a battery can definitely result in it heating up. This happened even with my Panasonic VS2 which wasn't a particularly fancy phone, when using GPRS or when taking many photos nearly continously. In fact from some quick Googling I see it can happen with continous talking too which makes sense so I wonder if you could probably notice this even with completely non smart mobile phones in some circumstances so you may be able to try this yourself if you have a mobile phone (although it's obviously going to cost money in such circumstances). I'm thinking here of Lithium-ion batteries obviously but I'm pretty sure this would apply to most rechargable batteries. Obviously when it comes down to it, it's depends under what conditions. You could discharge or charge a battery at a very high rate but it may damage the battery or in some cases particularly lithium-ion batteries result in explosions. For example, you can get 15 minute fast chargers for NiMH batteries that are supposed to charge in about ~15 minutes but as the batteries get hot and it isn't particularly good for them to be charged so fast, many have a switch to allow slower charging. (Which would still be faster then most traditional chargers and I suspect even extremely fast charging is probably significantly better for the battery then overcharging that can happen with old unsmart chargers). Similarly most lithium-ion batteries have temperature sensors I believe and these help limit the rate of discharging and charging to prevent the battery getting too hot Nil Einne (talk) 02:39, 4 December 2009 (UTC)

Though I own a smartphone, 99% of my usage is text messages, so I had indeed never experienced what you relate. In terms of my original question, I'm really more interested in laboratory/theoretical conditions and the physics behind the results - though I thank you for your long and detailed response! :-) 218.25.32.210 (talk) 02:55, 4 December 2009 (UTC)

The question is relevant to designing an electric bus to run a fixed urban route. The goal is to have two busses, one always charging and the other always in motion. My assumptions are that the bus design sets no limit on the battery size or weight, the battery type (to be defined) cannot accept charge as fast as it discharges in use, and that any charging arrangement can be made available at the bus terminus. It seems that if the bus is equipped with battery capacity X times as much as needed to complete its route until the busses swap at the terminus, then the battery can be charged at 1/X times the current at which it discharged. That will be achieved by switching the battery cells from parallel for driving, to series for charging. Am I am right? X must be a smallish integer. Cuddlyable3 (talk) 14:33, 4 December 2009 (UTC)

What's the use of a bus if it's always in motion? Also are we talking a dedicated busway here or something? Or just completely empty roads? Nil Einne (talk) 15:59, 4 December 2009 (UTC)

There are services for swapping car batteries, you might want to look at something similar:[28][29]. Fences&Windows 16:06, 5 December 2009 (UTC)

By one bus being "in motion" I mean "in service", meaning it follows a predetermined circular route, stopping when needed to take on or unload passengers. I don't see how a distinction between dedicated busway or empty road affects the calculation. I don't see a future for the battery swapping machine that is an expensive investment, needs a critical interaction of man and machine, and has a lot of ways to go wrong. A bus that is demensioned to carry 40-60 people and serves a route of say 10-40 km can carry its batteries to be changed only when they they wear out after some hundreds of charge cycles.Cuddlyable3 (talk) 23:12, 5 December 2009 (UTC)

[edit] Hair

Why do girls typically have longer hair than boys? jc iindyysgvxc (my contributions) 05:34, 4 December 2009 (UTC)

For the same reasons they wear lipstick when most men don't - cultural norms. Note that men having shorter hair than women on average is not universal to all cultures. In societies in which men traditionally wear turbans, their hair will be very long, perhaps even perpetually uncut such as with Sikhs. In those situations you may very well have most women, even with "long" hair, walking around with less hanging off their skulls than men! 218.25.32.210 (talk) 05:44, 4 December 2009 (UTC)

No, I'm pretty sure that girls are capable of growing longer hair than boys. It's not just a matter of how they cut it. So the OP's question stands. Some google found that estrogen and androgen have an effect on how long hair says in the anagen phase. Google for hormone and hair. Ariel. (talk) 06:32, 4 December 2009 (UTC)

Can you point to any WP:RELIABLE sources for your claim, or just a Googled bunch of blog entries from random Internet people? Tempshill (talk) 07:55, 4 December 2009 (UTC)

I have no real ref. But as evidence I point to the fact that women grow and retain a lot more hair when pregnant (and then it falls out a month or two after they give birth), and men get bald while women don't. It's clear that hair responds to hormones. Ariel. (talk) 23:52, 5 December 2009 (UTC)

I don't see any reason to expect Sikh men to have more hair then Sikh women. Both are expected to observe Kesh (Sikhism) AFAIK. Women may not wear turbans but unless that increases hair growth or reduces it falling out or something then it's fairly irrelevant. Now if you include facial har and body hair and perhaps because men tend to be slightly larger on average you could argue that all that means men would on average have more hair but a more sensible interpretation wouldn't include those factors IMHO so it seems they would have roughly equal amounts of hair. Also since no one has done so yet, I might as well link to Long hair Nil Einne (talk) 08:14, 4 December 2009 (UTC)

(after ec) Rate of hair growth does not differ significantly between men and women, but telogen (easily detached) hair does: PMID 11531795 (they studied both Africans and Caucasians). -- Scray (talk) 08:22, 4 December 2009 (UTC)

As anecdotal evidence contradicting Ariel's contention, consider that I (a British white male) have in two separate periods of my life (ages ca 19-23 and 45-50) grown to and maintained my hair at near waist length with no difficulty: I've also encountered plenty of other adult males with hair as long or longer. There may be weak statistical trends in 'hair-length potential' attributable to sex, but the overwhelming bulk of the generally observed length differences is purely down to fashion. 87.81.230.195 (talk) 12:51, 4 December 2009 (UTC)

I found some data from the 1950s that suggests that women's head hair grows ever so slightly faster than men's - though only by about 0.02mm/day.[30] Fences&Windows 15:25, 4 December 2009 (UTC)

This may be a crazy idea, what if the reason females grew hair faster was because the hormones that signal hair growth in the body were spread out over more places in the male body than the female? Mac Davis (talk) 16:36, 5 December 2009 (UTC)

[edit] Green Laser Pointer

Recently I bought a green laser pointer thinking of high power etc. but when switched it on I saw that it does NEVER foucus single point but in nearly fifty or so points dividing the power all over. I thought that there should be some adjustment that could be removed but no. There is a lens type thing on front that can be slightly rotated ( causing points to dance here and there ) but no way I can foucs it to single point. What I should to it to make it SINGLE point ?

 Jon Ascton  (talk) 07:56, 4 December 2009 (UTC)

You need to hold a suitable (separate) convex lens in front of it. MER-C 11:39, 4 December 2009 (UTC)

See the image in the article Speckle pattern. Cuddlyable3 (talk) 14:07, 4 December 2009 (UTC)

[edit] Restyl tablets

Question removed due to request for medical advice. If you are concerned for your health, please call emergency services.

WIKIPEDIA DOES NOT GIVE MEDICAL ADVICE. Consult the Medical disclaimer

[edit] activation energy and pri/sec/tert advantages

On paper (resonance structures), the benzylic / allylic site looks quite reactive, but from the bond energies table I see that a benzylic and allylic C-H bond is only about 15 kcal/mol weaker than a "normal" C-H bond. Same goes for C-X bonds (halide). Are there other effects at play (besides I guess bond weakness?) In fact choosing iodide as a leaving group over chloride seems to give a much bigger energy advantage than benzylic/allylic!

Btw, is iodide catalysis "true catalysis"? (Where in an alkyl halide SN2 substitution reaction you put some iodide in solution to speed it up.) What I understand is that iodide is a good leaving group but iodide is not that solvated (so you start out with higher energy, allowing it both to react and leave), but chloride is more solvated (so it ends up in lower energy) so in fact you've increased the energy gap between the reactants and the products, altering the equilibrium. John Riemann Soong (talk) 15:17, 4 December 2009 (UTC)

[edit] Organizing chemicals (practical)

I have been tasked with organizing the chemical room of a foodservice D.C. The chemicals are those you'd expect retaurants and other institutions to order - cleansers, chafing fuel, de-greasers, detergents, sanitizers, de-limers, soaps, etc. While they've never had a serious spill, there's no harm in taking some extra precautions, so I'd like to organize the room in such a way to minimize the risks associated with the accidental mixture of chemicals. For the first order of business, I've separated the strong alkalis, acids (of which there's only a few), and flammables (again, only a few) away from each other, keeping more innucuous items like soaps in between. What else ought I keep in mind? Should oxidisers like sodium hypochlorite be given special treatment? Would it be better to have the oxidisers near the alkalis or the acids - or completely separate? Let me emphasize: the actual risk of accidental mixture is very low, the substances are securely packaged and carefully stacked, and we're talking about commercial and light industrial mixtures here, not weapons grade stuff :). Matt Deres (talk) 16:14, 4 December 2009 (UTC)

Follow the normal rules of H&S, i.e. keep heavy items on lower shelves if not on the floor: items which are frequently used closer to hand than items which are infrequently used. Make sure the shelves are properly labelled with the item which is to be kept in that position, so all your plans are not set to nought by people who think they know better! --TammyMoet (talk) 16:24, 4 December 2009 (UTC)

I'm not worried about that stuff (though I appreciate the advice); I organize and design distribution centres as part of my job. I just want to make the room as safe as it can be, keeping potential chemical reactions in mind, as well as the normal stuff. And, to be honest, you don't necessarily want heavy stuff on the floor; something around hip height is best - would you rather pick up a frozen turkey from floor height or from counter height? Matt Deres (talk) 16:43, 4 December 2009 (UTC)

(ec) Even with "low grade" or light commercial chemicals, serious hazards may exist. For example, never mix bleach with ammonia or acid. Be sure to check the MSDS safety sheet for any chemicals - these safety sheets will have storage guidelines that will outline any safety issues associated with storage. Typically, acids and bases are stored in separate cabinets. Oxidizers are never stored near fuels. Pressurized gas falls into its own category, and gas cylinders have entirely separate safety requirements (often mandatory outdoor storage, depending on conditions). Above all, consult the MSDS sheets - these are very informative and will spell out any potential hazards in plain english. Some "benign" chemicals may have storage details that you did not know about. Nimur (talk) 16:44, 4 December 2009 (UTC)

The MSDS's are, of course, the ultimate guide. The problem there is that when you're dealing with hundreds of chemicals, it may be more useful to start with general guidelines and then work your way down, so to speak. It's a shame that the word "bleach" has more than one meaning; hydrogen peroxide is both a bleach and an acid so according to that poster, I should keep it away from itself :-). Matt Deres (talk) 18:12, 4 December 2009 (UTC)

As important as the location is the manner of storage: Flammables in a fire cabinet, liquid acids on a spill tray, gas canisters behind chains, etc. On the other hand, my local supermarket keeps liquid acid drain cleaner right above the liquid base drain cleaner and right near the bread! Rmhermen (talk) 19:20, 4 December 2009 (UTC)

[edit] December 5

[edit] causes of internal ache and chokeness along the throat

Removed request for medical advice. The only advice Wikipedia can give is to call a doctor and have a face-to-face meeting with him/her. Only a medical professional can give responsible medical advice.

WIKIPEDIA DOES NOT GIVE MEDICAL ADVICE. Consult the Medical disclaimer

[edit] Pyruvic Acid vs. Pyruvate as end product of Glycolysis

Most sources I've seen (incl. wiki) say that pyruvate is the end product of glycolysis. Except I was reviewing some biology in the Schaum's Outlines and it said pyruvic acid. According to wikipedia the formual for pyruvic acid is C(3) H(4) O (3) (I don't know how to do subscripts) and pyruvate is C (3) H(3) O(3), which makes sense given that pyruvate is the ionized form. In the glycolysis article it says pyruvate is the end product but if you look at the picture (glycolysis overview) then end product is has 4 hydrogen, which would make it pyruvic acid, not pyruvate. This makes more sense because after glycolysis if fermenation occurs the end product, supposedly pyruvate, is reduced twice by the two NAHDH to make a 6 hydrogen compound, which doesn't make sense because pyruvate reduced twice would only have five hydrogens. So my question is: is the end product of glycolysis pyruvate or pyruvic acid? Thanks, 76.95.117.123 (talk) 02:19, 5 December 2009 (UTC)

They are the same thing. Pyruvic acid is C₃H₄O₃, and pyruvate is the anion C₃H₃O₃^-. If you read the article on pyruvic acid, the second sentence of the lead tells you just that. Pyruvate is the form used by the Citric Acid Cycle. ~ Amory (u • t • c) 02:50, 5 December 2009 (UTC)

They are the same thing, and which form prevails basically depends on the pH in the cell. In this case it's most likely pyruvate - any pyruvic acid generated would have dissociated into pyruvate and proton anyway. Tim Song (talk) 02:59, 5 December 2009 (UTC)

So I could say either as the answer to the question? But if the pyruvic acid disassociated into pyruvate then fermentation wouldn't produce a 6 H compound. The only reason I'm curious is that I do Science Bowl and the question sometimes comes up. Which answer would be more correct? I kinda said that pyruvate is the ionized form of pyruvic acid in my question btw...66.133.196.152 (talk) 03:09, 5 December 2009 (UTC)

Say pyruvate because that is the form it will be in given the conditions. Also, pyruvate and H⁺ are among the reactants in anaerobic respiration. I saw you said that about the ions, apologies if you felt slighted. I just wanted to set up the proper subtext and background. ~ Amory (u • t • c) 03:25, 5 December 2009 (UTC)

If they say it's wrong based on that grounds you can always appeal. Pyruvate may be temporarily protonated in an enzyme at the active site, but usually what happens is that the COOH group has to be deprotonated. This gives the COO- system the electron it needs to expel the weak carbonyl-carbonyl bond and cleave as carbon dioxide. It can't cleave if it's protonated. ;-) The two-carbon molecule remaining (acetaldehyde) is further oxidised is attacked by the sulfur thiol of CoA to become acetyl CoA. John Riemann Soong (talk) 03:28, 5 December 2009 (UTC)

You can think of it like this: The proton of pyruvic acid helps supply protons to the proton pump in the electron transport chain. Note that NADH (reduced form of NAD+) carries 2 electrons but only one proton. The other "lost" proton has to come from deprotonating pyruvic acid. ;-) (As you might know, carboxylate is a weak base so it's not very good at taking back the lost proton.)

Decarboxylation (loss of CO2) donates a pair of energetic electrons (to NAD+) that will be used for the electron transport chain. The thermodynamic stability of CO2 helps drive the donation.

Acetyl-CoA is a useful anabolic building block (if you want to build sugars or fatty acid]]), but if you want to oxidise it all the way (use all its energetic electrons) it's kinda hard to oxidise and pull electrons (via evolving CO2) out of a molecule to nothingness (converting acetaldehyde to formaldehyde and formic acid would be a pretty bad idea), so it goes through the citric acid cycle. John Riemann Soong (talk) 03:57, 5 December 2009 (UTC)

Ok thanks John Riemann Soong! The first explanation you gave helped me alot. And if I challenge I say the wiki ref desk told me :-)

66.133.196.152 (talk) 04:11, 5 December 2009 (UTC)

[edit] heat modelling

this code has come as an outcome of modelling of spot modelling process.i have arrived at eqation (1).If we take initial heat (due to atmospheric conditions) in each point as unity.this in coded in initialisation section. Now dq is sent to ode45 for solving in a prescribed time domain and with initial condition y0=0.

 function dq = heat(t,q) p=5;%number of variables %-------------------------- % generation of const matrix %--------------------------- A = [5 4 3 2 1]';----------------------------------------arbitrarily chosen constant A,B,C,D B = [5 4 3 2 1]';------------------------------------------------ C = [5 4 3 2 1]';------------------------------------------------ D = [5 4 3 2 1 ]';------------------------------------------------ %---------------------------------- dq = zeros(p,1);  %-----------initialisation----------------- for i=1:p    q(i) =1; end %----------------------------------------     dq(1) = A(1)*q(2) + B(1)*q(1) + D(1); for i=2:p-1     dq(i) = A(i)*q(i+1) + B(i)*q(i) + C(i)*q(i-1) + D(i); -----------------(1) end 

here 'i' represents the weld number.code has considered the contribution from a point before ,a point after the point 'i', and contribution of heat added in next point.now my problem is that i want to optimise this process i.e. minimize dq.i.e.i need the welding to be cooled fastly.so what parameter should i consider for optimisation and what method should i adopt. SCI-hunter (talk) —Preceding undated comment added 03:01, 5 December 2009 (UTC).

See this duplicate inquiry at WP:RD/Math. Takes your pick but not both. You are in a little maze of twisty passages. hydnjo (talk) 03:49, 5 December 2009 (UTC)

I have formatted the code for readability. Nimur (talk) 04:45, 5 December 2009 (UTC)

The code seems rather nonsensical - the first 'for' loop sets all members of q(1..p) to 1. So surely the second loop sets every element of dq(n) to A(n)+B(n)+C(n)+D(n) ? Why so much complication? You don't say what language this is written in - but what C-like programming language has arrays that start from index 1? This suggests that whatever this code is intended to do...it's not doing it. SteveBaker (talk) 16:16, 5 December 2009 (UTC)

It was subtly implied that it was Matlab code; between the syntax and the reference to ode45; the OP might want to read our guide on asking for help with code. Nimur (talk) 19:11, 5 December 2009 (UTC)

its written in matlab and its approxmately functioning correctly.please help now 220.225.98.251 (talk) —Preceding undated comment added 16:28, 5 December 2009 (UTC).

What do you mean by "minimize dq" ? dq is a function (vector in your code).

More broadly, try following the following steps:

1. Formulate a clear mathematical statement of the physical problem you are trying to solve.
2. Derive (or pick) a mathematical solution/algorithm for the problem (or its discretized/approximate version)
3. Write Matlab code for the algorithm. Test and debug it.

Right now, you seem to be at step 3, and it is not clear (at least to us) if you have followed the previous steps. As such, your code does what it does, but we cannot determine if it actually implements the algorithm derived in step 2, and if the algorithm solves the problem in step 1 (remember GIGO).

PS: You should consult fellow students for tips on better Matlab coding; your current code is pretty poor. For example, the function takes in inputs t and q, and then doesn't use either. Instead it simply defines q. Also your first loop can be replaced by q = ones(p,1). Note that this review is intended to guide, not criticize. Hope it helps. Abecedare (talk) 16:52, 5 December 2009 (UTC)

Abecedare, dq is not a function. That is the syntax for declaring a return value. The function, heat(t,q), returns a vector whose local name is dq. This is standard MATLAB code style. What is unclear is why the code overwrites q, which is an input; and why it does that overwrite in such an inefficient and convoluted way. I suspect the OP used "pseudocode" or dummy assignments instead of writing a comment or actually implementing the correct physics. If the OP reviews Abecedare's and others' suggestions, and our software help guidelines, it will greatly help us answer the problem. I'm also going to posit that the simulated annealing article may be conceptually helpful, as well as the heat equation article. Nimur (talk) 19:40, 5 December 2009 (UTC)

I meant to indicate that dq is not scalar valued, so it doesn't make sense to try and minimize it. My language was ambiguous though; thanks for pointing it out. Abecedare (talk) 19:54, 5 December 2009 (UTC)

I guess if not otherwise specified, minimizing a vector implies minimizing its L2 norm. Nimur (talk) 22:30, 5 December 2009 (UTC)

[edit] Bohr Magneton Number for Copper Sulphate.

Resolved.

I'm currently trying to calculate the dimensionless Bohr Magneton number p_eff for CuSO₄·5H₂O. The formulae I have are:

and

Where all the symbols have usual meanings and values. From this, p_eff should be:

However, the formula I have been given for the dimensionless Bohr magneton number is:

Where the fundamental constant of magnetism of an electron is squared in the denominator, how can this be? Thanks for any help 188.221.55.165 (talk) 13:32, 5 December 2009 (UTC)

When you substituted, you forgot about that square root. Outside the square root use μ_B but if you move it inside the parenthesis you have to square it.. Graeme Bartlett (talk) 21:30, 5 December 2009 (UTC)

Oh, yeah....simple....thanks Alaphent (talk) 08:26, 6 December 2009 (UTC)

And I thought I would have to understand Bohr Magnet(r)on number, but actually only algebra was needed! Graeme Bartlett (talk) 05:58, 7 December 2009 (UTC)

[edit] Does rice water has chemical reaction with mineral water's plastic bottle?

I had collect some rice water after washing rice for watering plants.
Because of keep raining these few days, I kept the rice water in plastic bottles to watering plants later.
But I found that after about two weeks, the plastic bottles had been harden and bloat.
The base of the bottle also bloat until hardly to stand on a flat surface.
I'm wondering is there any chemical reaction between rice water and mineral plastic bottle?
I'm curious and wish to know more about this condition, and also the reason why the bottle becomes like this.
Can anyone helps to find out the reason?

There is some problem statements i wish to know:
1. What is the fators affecting the bottle to bloat and harden?
2. What is the effect (positvely and negetively)
2. Does the chemical reaction brings harm to human?
3. Does it brings harm to plants if i watering plant with the rice water in it?

This is the condition i kept the rice water for about 2 weeks:
1. Date I kept the rice water in plastic bottles: 21/12/2009 to 5/12/2009 (I discovered out the condition on 5/12/2009)
2. Temperature: about 27 degree celsius to 33 degree celsius (sometimes in air-conditioned of 24 degree celsius)
3. Place I kept it: in a cupboard in my room
4. Not exposed to sunlight.

And these are few of the pictures of the bottle's condition:

This picture shows the difference of the base of original plastic bottle and the plastic bottle with rice water inside.

This picture shows that the plastic bottle with rice water inside hardly stand on a flat surface.

This picture shows the upper part of bottle also had bloat.

This picture shows that I kept the bottles with rice water inside in a book shelf with glass windows.

--perfection is not intact.. (talk) 19:26, 5 December 2009 (UTC)

We can't look at the pictures unless you put them somewhere that we all have access to - upload to Commons or somewhere equally accessible. Mikenorton (talk) 17:14, 5 December 2009 (UTC)

Your links are inaccessible as well. bibliomaniac15 18:00, 5 December 2009 (UTC)

Thanks, that's much better. Mikenorton (talk) 18:51, 5 December 2009 (UTC)

I'm sorry about previous condition. I'm still a newbie in wikipedia, that's why I'm keep finding the instructions and ways to fix those problems. And thank you for your help to guide me. Just now, I'm still finding the ways to reply.--perfection is not intact.. (talk) 19:26, 5 December 2009 (UTC)

Perhaps you are inadvertantly making rice wine? 75.41.110.200 (talk) 18:06, 5 December 2009 (UTC)

I have to agree that fermentation of rice starch in the water, creating carbon dioxide, is a likely cause of this. Mikenorton (talk) 18:58, 5 December 2009 (UTC)

But I just kept the rice water after I wash the rice. At first my motive is just to watering the plants later because the past few days were raining. Until yesterday only i found out that the shape of bottle had change and had harden. Err..does it means that I'm accidentally make of rice wine which produce carbon dioxide, and the carbon dioxide had harden the bottle?--perfection is not intact.. (talk) 19:26, 5 December 2009 (UTC)

Two weeks at that sort of temperature is certainly enough to ferment the starch. The bottle should have a bit of pressure inside, when you open the top it will outgas. There should be some nasty smell associated, your result is probably not drinkable. But plants may be able to tolerate it. Graeme Bartlett (talk) 21:25, 5 December 2009 (UTC)

Yes!!I just try to open the cap and it releases gases..so is it carbon dioxide release?I don't have lime water at home,so unable to test it.And there is nasty smell too!But after I open the cap and the gas had releases, the bottle had back to it's softness. So, can I conclude that rice water under the condition of high pressure and the temperature will results in fermentation? Does it apart of anaerobic respiration reaction?But there is no yeast inside.Besides that, does bacteria inside the bottles can replaced the yeast? --perfection is not intact.. 06:28, 6 December 2009 (UTC)

I doubt that the bottle itself has changed its hardness. It's just that the contents are under such high pressure that they're pushing out against the walls of the bottle really hard.

Incidentally, it's only a matter of time before those bottles burst and spray that rice water all over the place. It might not be a good idea to store them so close to a bunch of books. APL (talk) 21:52, 5 December 2009 (UTC)

Thanks for reminding me. =) I had placed the bottle in a bucket.I had an crazy idea..I wonder that if i still keeping the rice water in that bottle, how long does it takes to burst or does it will burst. It may test the "toughness" of the bottle too..haha xD --perfection is not intact.. 06:28, 6 December 2009 (UTC)

The yeast naturally arrives from the air. 75.41.110.200 (talk) 18:15, 6 December 2009 (UTC)

Indeed it does: in Belgium, Lambic beers are fermented by allowing wild yeasts (and some bacteria) to drift in and 'infect' the wort, rather than by adding cultivated yeasts as in more conventional brewing. On a similar note, I find that if I partly consume a carton of pure orange juice, but then leave it in my refrigerator for a couple of weeks, it begins to ferment, adding a not-unpleasant tang to the taste. 87.81.230.195 (talk) 00:50, 7 December 2009 (UTC)

[edit] Eye water

What is the substance composed of that wets and lubricates the human eye? Mac Davis (talk) 16:26, 5 December 2009 (UTC)

See tears. The standard "wetness" is referred to as "basal tears" and according to the article it contains contains water, mucin, lipids, lysozyme, lactoferrin, lipocalin, lacritin, immunoglobulins, glucose, urea, sodium, and potassium. Matt Deres (talk) 16:38, 5 December 2009 (UTC)

[edit] classical music and emotions

I find it very strange which songs trigger strong emotions in myself — e.g., I get flushing waves of "tingles" whenever I hear Pachelbel's Canon, even though I can't recall having any strong memories associated with the song. Bits of Wagner hit me similar. I would probably generalize that it is probably only classical music that affects me in this particular way (the waves of "tingles," whatever that is), but I'm not a particularly big fan of classical at all (and haven't spent long amounts of time listening or playing it or anything along those lines), and generally do not think of myself as a terribly sentimental person (nor someone who is unusually appreciative of or interested in music). What causes this? Is it just some sort of long-lost association to music playing in stores around Christmastime when I was a child? Some property of this type of music itself—mathematical "problems" being proposed and solved? Just a sign of how complicated and weird the human brain is? I know there has been a lot written and researched on music and the brain, but I'd love a summary, if someone out there has thought about it much. --Mr.98 (talk) 16:45, 5 December 2009 (UTC)

Anything in the music psychology article give you any clues? Between cultural conditioning and a biological predisposition to perceive rhythm, tonal scales, and harmonics, music can inspire a strong psychological response. It's pretty much impossible to pinpoint what exactly triggers this response for you, but a lot of research has been done on music and psychology. Nimur (talk) 19:15, 5 December 2009 (UTC)

I have heard the term aural orgasm used to describe this, although I can't find any particularly reliable sources that define it. Mitch Ames (talk) 02:57, 6 December 2009 (UTC)

Isn't this sensation the basic meaning of the word "thrill"? --Anonymous, 04:55 UTC, December 6, 2009.

The experimenting (or torturing) physician in Clockwork Orange was surprised at the strong reaction the young thug Alex had to classical music. Stanley Kubrick seemed to be making the same point: Alex epitomised unsentimentality and was not particularly well educated, but he responded to Beethoven, not pop, with bliss. BrainyBabe (talk) 19:37, 6 December 2009 (UTC)

[edit] Showering with contact lenses

Why do most manufacturers of soft contact lenses warn against showering with them in or using tap water to rinse out the lens case? What negative effects could showering with them in have on the lenses? Thanks! --98.108.36.186 (talk) 20:27, 5 December 2009 (UTC)

It's to do with contaminating the lenses. Normal tap water carries bacteria that, in the normal way of things, isn't a problem for most people. However, if it gets on your lenses the bacteria will be in contact with your eyes for hours at a time, and your tears can't wash it away properly. If these are lenses you wear for more than one day, the bacteria will continue to breed and grow, feeding on bits you haven't properly washed off the lens. And they'll still be there, more plentiful than ever, when you next put them on. It can potentially blind the lens wearer. Here [31]. 86.166.148.95 (talk) 21:51, 5 December 2009 (UTC)

Thank you! —Preceding unsigned comment added by 98.108.32.19 (talk) 01:45, 7 December 2009 (UTC)

[edit] Raccoon

I was just walking back across campus and I saw a small animal on the path ahead. I assumed it was a cat, but the nose was the wrong shape, so I assumed it was an opossum. No biggie; opossums are vicious, but they aren't likely to have rabies. Then when I was close enough to clearly make out the raccoon's markings (it's at night), I noticed that it was so content on drinking the contents of the puddle that it didn't notice me. I must have passed within five feet of it. It is a college campus, so perhaps it's just abnormally tame, but isn't an early sign of rabies an intense thirst? I did look at the article, but I can't tell whether the thirst comes before or after the animal is unable to drink. Just as a note, I did report it to campus police. Falconus^{p t c} 23:31, 5 December 2009 (UTC)

You seem to have been checking it out quite intently -- perhaps you're into raccoon drinking-voyeurism? :) I'm just saying that it's very easy to jump from "it was drinking and didn't see me" to "it must have a rabid thirst for it to not have seen me." DRosenbach ^{(Talk | Contribs)} 00:50, 6 December 2009 (UTC)

Well, I thought it odd, as most wild animals will at least look at you when you walk within a few feet. Falconus^{p t c} 00:56, 6 December 2009 (UTC)

Have you ever spent some time around racoons, even wild ones? Most that live close to people generally behave exactly as you describe, in my experience. When I was growing up, it was not uncommon to have racoons in my yard picking through the trash. They frequently didn't even pay me any attention, even if i yelled, threw rocks, whatever. I had to get close enough to grab them, and they would move far enough away for me to pick up all the trash. Then they went back to picking through it as soon as I walked away. They simply don't seem to pay humans much mind, and they certainly weren't much afraid of me. --Jayron32 01:08, 6 December 2009 (UTC)

My experience with urban raccoons is that they don't care very much about humans and regularly ignore them. (Dogs are another matter.) They are tough animals that nobody hunts near cities. --Mr.98 (talk) 01:34, 6 December 2009 (UTC)

Well, I guess I made a big deal out of nothing. I have just never seen an animal do that. Falconus^{p t c} 01:52, 6 December 2009 (UTC)

A little known fact about raccoons is that they wear raccoon coats not for fashion reasons. Bus stop (talk) 02:02, 6 December 2009 (UTC)

I often see raccoons around the house, and they are pretty intelligent creatures. They aren't likely to regard you with anything more than peripheral vision unless you do something problematic. Vranak (talk) 04:15, 6 December 2009 (UTC)

I don't know, I frequently see raccoons peering in through the bottom panel of my glass door at night. They're pretty curious. Looie496 (talk) 17:45, 6 December 2009 (UTC)

That's because you've got stuff they'd like to eat and rummage through, not because they care about you. --Mr.98 (talk) 20:10, 6 December 2009 (UTC)

[edit] December 6

[edit] Vacuoles, vacuolation, vacuolisation and vacuolization

Is vacuolation the same as vacuolization? As it stands, the former currently redirects to a section in the article for vacuoles in which it states that this is a process in which vacuoles form pathologically, while the latter is its own article that might seem to indicate pathosis but doesn't necessarily spell it out nicely. Vacuolisation, which appears to me to be nothing more than a (perhaps British) spelling variant of vacuolization, redirects to the main article on vacuoles. This is what I think -- correct me if I'm wrong:

1. Vacuolisation and vacuolization are spelling variants of the same thing
2. Vacuolation and the aforementiones spelling variants are variant words of the same thing -- sort of like dilation and dilitation.
3. The mini-section on this concept within the article on vacuoles should make a statement or two about it and include a link to the article that will delve into it deeper.

Let me know if there's any disagreement on the definitions, etc. before I go ahead and do it. Thanx! DRosenbach ^{(Talk | Contribs)} 00:47, 6 December 2009 (UTC)

It may be best if this discussion happened on the talk page of the articles in question (pick one to have the discussion, and leave notices on the other talk pages). Since this involves a question which stands to have a material impact on the content of the article space, the discussion should probably happen on those talk pages, since editors who edit and patrol those articles would likely be interested in it. --Jayron32 01:04, 6 December 2009 (UTC)

I didn't imagine that the talk pages of any of these articles were nearly as high-volume as this page. Additionally, the editors of the aforementioned articles obviously have left this crucial point unmanaged for some time. DRosenbach ^{(Talk | Contribs)} 02:12, 6 December 2009 (UTC)

OK -- I placed notes on both the article talks to see here. Now we can discuss it here. DRosenbach ^{(Talk | Contribs)} 02:15, 6 December 2009 (UTC)

Wouldn't WikiProject Biology be the place to discuss such article issues? Fences&Windows 16:13, 6 December 2009 (UTC)

I agree with Fences - discussion of article content belongs in article Talk space, where it will be archived along with the article, or in a linked wikiproject created for such a purpose. -- Scray (talk) 18:08, 6 December 2009 (UTC)

[edit] Why does increasing CO2 concentration matter?

Doesn't 350 ppm CO2 absorb the same amount of infrared from the miles of Earth's atmosphere as 400 ppm? I can see how the difference between 350 and 400 ppm CO2 in air would change how much infrared could be absorbed by a test tube's width, but for the vast depth of Earth's atmosphere, I just can't understand how it could change the total absorption. Are there any articles or sources that discuss this? I've looked at greenhouse gas, global warming, radiative forcing, and their talk pages, but maybe I overlooked something? 99.56.139.149 (talk) 01:13, 6 December 2009 (UTC)

350 to 400 ppm represents an increase of 14.2%, so all other things being equal, this will increase the "greenhouse effect" contributed by the CO2 by 14.2%, which is a significant and measurable amount. Regardless of the size of the sample, a 14.2% increase is a 14.2% increase. --Jayron32 01:25, 6 December 2009 (UTC)

Unfortunately not, Jayron - changing the concentration at the bottom of the atmosphere by 14% does not increase the total absorption by 14%. See optical depth for the physical mechanism of increased gas concentration on total atmospheric absorption. For gas of uniform density, optical depth is exponentially related to concentration. Compound this by the fact that the atmospheric profile is also roughly exponentially decaying with altitude. Nimur (talk) 02:23, 6 December 2009 (UTC)

Also keep in mind that greenhouse effect is only one effect. Atmospheric chemistry and climate are extremely complicated subjects. It is probably a great misrepresentation to say that CO₂ is harmful primarily because of its contribution to a greenhouse effect. As you correctly point out, the albedo change and the difference in optical depth between 350 ppm and 400 ppm are very small. I would go so far as to call them negligible, and I can find a lot of planetary science references to back me up on that. However, and this is critical - the greenhouse effect is only one of many ways that a changing atmospheric composition affects climate. You may want to read climate change, which discusses some of the mechanics, and atmospheric chemistry, which will broaden the view of how carbon and other atmospheric constituents affect conditions on Earth. Nimur (talk) 01:57, 6 December 2009 (UTC)

You can use a web-based radiative transfer model to help you see that the amount of radiation absorbed at 350ppm is not the same as at 400ppm. It's actually easier to see the difference if you use the pre-industrial value for the concentration of CO2 of ~280ppm and a value we're likely headed towards ~450ppm. -Atmoz (talk) 01:59, 6 December 2009 (UTC)

Spaceborne measurements of atmospheric CO2 by high resolution NIR spectrometry of reflected sunlight, published in GRL in 1997, is a good quantitative overview of the Carbon Dioxide near-infrared spectrum in an experimental, in-situ, atmospheric context. Nimur (talk) 02:01, 6 December 2009 (UTC)

The other paper I like to point out in discussions of "global warming" and atmospheric chemistry is this 2003 Eos publication: Are Noctilucent Clouds Truly a “Miner’s Canary” for Global Change. This paper points out some very interesting atmospheric effects - notably, it provides the novice atmospheric scientist with a reminder about conservation of energy. Unless the net power from the sun is changing (which is experimentally not the case), then for any "global warming," there must be some "global cooling" somewhere else - in this case, the mesosphere [32]. Observations of mesospheric weather therefore would be a good indicator of climate change - probably a better indicator than (say) average temperature measurements or atmospheric chemical content. "Of the infrared radiatively most important gases (CO2,O3,O, and perhaps H2O), none can currently be measured with sufficient accuracy at mesopause altitudes to establish its abundance there within anything like percent accuracy, not to speak of any significant long-term change." Therefore, these numbers about Atmospheric Carbon Content are sort of useless - remember, all the quoted numbers are for the troposphere, and almost all the data comes from surface measurements. The actual total carbon content of the atmosphere, per the opinions of the scientists of these papers, is actually very poorly known. On top of this, our only method to probe it is via NIR optical density measurements - and the first paper I linked will give you some idea of the quantitative measurement accuracy for that. Unfortunately, these statements and this line of reasoning sparked huge controversy back in 2003, because it does not tow the simplistic "more carbon ppm = evil" rote argument. But in reality, it's simply establishing an actual scientific context for evaluating the meaning of one particular surface measurement - atmospheric carbon concentration at the surface level. Changing the tropospheric carbon content will certainly result in a different chemistry mechanism in the upper atmosphere, and again, we have extremely complex, non-greenhouse-effect climate-change consequences. Nimur (talk) 02:07, 6 December 2009 (UTC)

I'm not following the conservation of energy argument. In order for global warming to demand global cooling, the earth would have to be treated as a "closed" system (with a constant and equal input and output). The net input from the sun is assumed constant, but isn't the fundamental argument of the greenhouse effect that the amount of energy radiated from the Earth is decreasing? If energy in is constant and energy out is decreasing, net energy in the system is increasing. Compartmentalizing the system might change the amount of energy locally (at surface or at mesosphere) but the system as a whole can still experience a net increase. Open systems need not obey conservation of energy, and the earth is not a closed system. SDY (talk) 02:31, 6 December 2009 (UTC)

If the planet temperature increases, its blackbody spectrum will change and it will radiate power faster according to the Stefan-Boltzmann law. Surface temperature may change as a result of greenhouse effect, but planet effective temperature cannot. Nimur (talk) 02:34, 6 December 2009 (UTC)

According to our articles, Stefan's Law relies on emissivity, and the effective temperature is also a function of albedo. Again, emissivity is arguably what is changing, and changes in albedo (ice has very high albedo, melted ice has less) are also a concern. Why must effective temperature be constant? SDY (talk) 03:25, 6 December 2009 (UTC)

Nimur, you are complicating things much more than necessary. It is true that the effective temperature does not change. But that does not require cooling of the mesosphere (though some cooling is possible). None of that is required to understand the basic idea behind global warming which is what the question is about. Dauto (talk) 03:17, 6 December 2009 (UTC)

Ok. What I said above is not entirely accurate. The effective temperature CAN change if earth's albedo change. But it will not change as a (direct) consequence of the increase on atmospheric CO2. Dauto (talk) 04:31, 6 December 2009 (UTC)

The original questioner noted that a change of 350ppm to 400 ppm does not significantly change the transparency of the entire atmosphere (integrated over the full height) to infrared wavelengths. This is a scientific fact, set forth in the articles I linked. The complexity comes in because climate change can still occur even though the additional CO₂ is not adding to the cumulative greenhouse effect. So, the logical question is - "if climate change is not strictly the result of greenhouse effect, then what is it an effect of?" And, again, the answer is "very complex atmospheric chemistry changes which may result in a different energy distribution in the troposphere." Sorry that this is not a simple answer - but "more carbon = more greenhouse effect" is an overly simplistic and scientifically incomplete picture. Let me succinctly rephrase: adding CO2 may still cause climate changing effects, even if the total change in atmospheric IR absorption is negligible, because other effects come into play. Nimur (talk) 05:27, 6 December 2009 (UTC)

That's a bunch of nonsense. The additional CO₂ IS adding to the greenhouse effect, and that's why the earth's mean temperature is increasing. Dauto (talk) 14:06, 6 December 2009 (UTC)

I'm sure that is what you read about in high school science textbooks and the newspaper, but I would suggest moving to a geophysics or planetary science journal to get a more accurate scientific picture. Here is a nice, albeit old, piece from Science: Cloud-Radiative Forcing and Climate: Results from the Earth Radiation Budget Experiment, (1989). Again, experimental and quantitative results suggest that carbon dioxide induced "greenhouse effect" is not the most relevant effect. It may play a role, and anthropogenic carbon may be a root cause of some other changes, but the climate change is not due only to greenhouse effect: "Quantitative estimates of the global distributions of cloud-radiative forcing have been obtained from the spaceborne Earth Radiation Budget Experiment (ERBE) launched in 1984.... "The size of the observed net cloud forcing is about four times as large as the expected value of radiative forcing from a doubling of CO2. The shortwave and longwave components of cloud forcing are about ten times as large as those for a CO2 doubling. Hence, small changes in the cloud-radiative forcing fields can play a significant role as a climate feedback mechanism." Do you really intend to stick to your simplistic model of greenhouse insulation, when experimental observation has repeatedly shown it to be 10 times smaller than other atmospheric physics effects?[33][[34] Even these are small compared to massive climate-scale energy redistributions, e.g. Does the Trigger for Abrupt Climate Change Reside in the Ocean or in the Atmosphere? (2003). To reiterate: the carbon dioxide in the atmosphere is present; it is probably anthropogenic; and its biggest impact on climate is probably not actually related to greenhouse warming, but to other effects that CO2 can induce. Nimur (talk) 15:11, 6 December 2009 (UTC)

Nimur, I do not deny that there are many complex positive and negative feedback effects that must be taken into account in order to reach a precise quantitative description of climate change. But none of that is necessary to give the OP an answer that makes sense. You said "the additional CO₂ is not adding to the cumulative greenhouse effect". And that's just not true. Dauto (talk) 15:45, 6 December 2009 (UTC)

┌─────────────────────────────────────┘

It seems that my efforts to link to scientific papers are not getting my point across. Let me make an analogy, which is actually very analogous to the situation (except that CO2 is blocking "upgoing" photons which are re-radiated from the earth... I'm only concerned with the opacity of the atmospheric window, though, so direction doesn't matter). Imagine that you are building a roof, and for some reason you are trying to block light from the sun, and you use thick steel plates to block the sunlight. Each steel plate is 1 inch thick, and blocks most of the photons. For your purposes, you want to really block the sunlight, so you build a giant structure and you put 350 steel plates between you and the sunlight. Now, along comes an upstart engineer, who says he has 50 more steel plates in the scrap-yard, and he's going to add them to your structure, whether you want them or not. Two questions: (1)how much more sunlight are those extra 50 steel plates going to block? Probably none. (2) Are there other problems that those extra steel plates will produce? Absolutely. Your structure wasn't designed for 400 steel plates on its roof.

How does this correspond to the atmospheric carbon situation? Well, the carbon dioxide atoms are narrow-band absorbers of photons. They really only affect a small part of the total solar energy spectrum. And by the time we have 350 ppm, they are pretty much blocking all the sunlight in that particular part of the infrared spectrum. Dauto, you are absolutely correct, in that adding more carbon will increase the absorption - in the same way that adding more steel plates to a roof will block more photons. Because of the way that exponential functions work, this change is negligible. So, if we really have a problem with adding excess carbon, it isn't because of the greenhouse effect or because those carbon molecules will be blocking any extra solar energy. Other effects are the real potential problem - and we need to understand those effects to make sure our roof doesn't collapse under the weight of 50 extra steel plates. Nimur (talk) 16:08, 6 December 2009 (UTC)

No, Nimur, that is not a good analogy. There is a very good article by Spencer Weart on RealClimate here. Yes, the direct opacity of the atmosphere is not significantly changing when adding more CO2. But what does happen is that the "final" emission layer moves further up the atmosphere, providing more chances for re-emission towards the ground. This is a physical effect, not a chemical process. And while this also is an exponential decay, it still is quite significant - that's why doubling CO2 without feedbacks gives us a ≈1℃ increase in temperature. --Stephan Schulz (talk) 16:30, 6 December 2009 (UTC)

That is a good read, Stephan. And, as you say, the absorption profile is very relevant as well. Changing the concentration will change the relevant scale height for the near infrared spectral effects. I still disagree with your unsourced assertion that doubling carbon would yield a 1 degree celsius increase in surface temperature. I stand by the references I linked earlier - most importantly, the quantitative analyses of total radiative effects and energy balance experiments - but at this point I think it's moot to argue. Nimur (talk) 16:40, 6 December 2009 (UTC)

Thanks Schulz. That's finally putting us into the path towards giving the OP a sensible answer to the question asked. The point of the greenhouse effect is not how much of the earth's radiation gets absorbed by the atmosphere. How much of that energy finds its way back to the surface IS the relevant question. Dauto (talk) 16:39, 6 December 2009 (UTC)

I think you somewhat misrepresented that Eos review: it is about Noctilucent clouds and whether they are signals of climate change, and does not mention anything about conservation of energy. Indeed, the article states that "The temperature will be affected by any anthropogenic changes of the CO₂ and/or O₃ abundances". Your comment that "Unless the net power from the sun is changing (which is experimentally not the case), then for any "global warming," there must be some "global cooling" somewhere else" is wrong as Earth is not a closed system; the cooling occurs in space. Of course atmospheric content affects surface temperature, which is why Mars is freezing, Earth is warm and Venus is toasty. Why are you quoting from 10-20 year old papers about how CO₂ affects climate when there are newer articles on the topic? e.g. [35][36][37] Fences&Windows 16:54, 6 December 2009 (UTC)

I usually quote papers I've read - sometimes I read them 10 years ago. There's no shortage of new material. But, given that everybody is trying to establish a long-term-change, don't you think it may be worth checking primary source data from previous decades before making bold claims about massive changes in recent years? In any case, ERBE was a great experiment on a great spacecraft, and a hallmark of empirical data collection for global climate studies. It should be cited more often. Nimur (talk) 16:56, 6 December 2009 (UTC)

That picture above should help make clear why adding more CO2 to the atmosphere increases the surface temperature even after saturation is achieved. The amount of energy cycling between the earth's surface and the atmosphere can be (and is) much larger than the amount of energy coming from the sun. More CO2 increases the energy being fed back to the surface warming it up. Dauto (talk) 22:12, 6 December 2009 (UTC)

is the difference in heat absorption between the green (300 ppm) and blue (600 ppm) from 20 km of atmosphere anywhere near 14%?

Original questioner here. I understand what's been said, but nobody has addressed my actual question: why does the concentration change so slight in bands where the atmosphere is almost completely opaque make any substantial difference in the total amount of absorption? Or to put it another way, the diagram on the right shows the transmission spectra of 300 ppm and 600 ppm. The total amount of energy difference represented by the difference between the blue and green lines isn't anywhere near 14%, is it? What is the actual amount of energy forcing between the actual Earth's atmosphere at 350 ppm and 400 ppm?

Update: I take it back! Stephan Schulz addressed my question correctly at 16:30 above. Thanks Stephan! 99.62.185.148 (talk) 00:53, 7 December 2009 (UTC)

[edit] Size of average Caucasian female head

What is the average size of a Caucasian female head? --I dream of horses (T) @ 02:25, 6 December 2009 (UTC)

14.4 centimeters. Nimur (talk) 02:29, 6 December 2009 (UTC)

Slightly in theme, the circumference of the head of a cat is equal to the length of his tail. So, when a cat goes to a hat shop, he only has to let the clerk measure his tail. --pma (talk) 09:40, 6 December 2009 (UTC)

That sounds problematic for a tailless cat. moink (talk) 11:58, 6 December 2009 (UTC)

Seems problematic for a headless cat as well. Dauto (talk) 14:01, 6 December 2009 (UTC)

The problem is moot for a headless cat. --Tango (talk) 15:03, 6 December 2009 (UTC)

Note however that neither tailless nor headless cats wear hats. --pma (talk) 16:21, 6 December 2009 (UTC)

Are you sure? I don't think that is entirely true. SpinningSpark 16:44, 6 December 2009 (UTC)

You mis-read the part about headless and tailless. Nimur (talk) 16:52, 6 December 2009 (UTC)

If I decapitate a hat-wearing cat, the hat might stay on the head, but you (Tango and pma) are saying that "the cat is not wearing his hat" (...because he is not wearing his head). If we assume the essence of being of a cat is based on his brain, we have just proven that a cat's brain is below his neck rather than being in its head. Wanna co-author the paper? DMacks (talk) 18:01, 6 December 2009 (UTC)

From an answer to a question a few months ago, I have to sadly report that this paper already exists. Essence or no, decerebrate cats are quite alive and do have most of their normal respiratory and gastric functionality intact, because these functions are controlled by the spinal cord and brain stem. Nimur (talk) 18:06, 6 December 2009 (UTC)

I haven't looked at the paper, but there is a difference between decerebrated and decapitated. The cerebrum is just one part of the brain. --Tango (talk) 23:07, 6 December 2009 (UTC)

I would define a cat as the combination of a cat's head and a cat's body. If you cut the head of a cat, you no longer have a cat. (The definition is chosen primarily so that you will be wrong, but it is a justifiable definition!). --Tango (talk) 23:07, 6 December 2009 (UTC)

We're really drifting off topic from the OP's question. Sorry for my contribution to that effect. Per the guidelines, let's stay on topic for the OP. Nimur (talk) 18:11, 6 December 2009 (UTC)

[edit] Human nervous system latency

Resolved.

I am looking for the human nervous system latency time. I couldn't find it in the artical nervous system. Basically, I am looking for the number of milliseconds or microseconds between 2 events.

Situation: the human is driving a car and a child crosses the road 20 meters ahead. The driver has to turn the wheel to avoid the child.

Event 1: the light reflected by the child (visual signal) enters the eye of the driver.

Event 2: the hand of the driver starts moving to turn the wheel.

Assume that the human is normal, awake, has not been drinking and attempts to react as fast as possible. I am basically looking for the total latency necessary for these operations: visual signal to reach the brain, brain processing of the signal and recognising danger, brain making decision to turn the wheel, brains instructing hand to turn the wheel, then message to transit from brain to hand and arm muscles, and finally, muscles to begin contractions. I don't need the split between the operations, just the total number of milliseconds between event 1 and event 2. Could you please help? This is not homework question :-) --Lgriot (talk) 03:27, 6 December 2009 (UTC)

Reaction time is probably the best we have; it cites 180-200 milliseconds to detect a simple boolean visual stimulus; your instance is a much more involved problem and so you can, I think, expect the reaction time to be greater. --Tagishsimon (talk) 03:37, 6 December 2009 (UTC)

Thanks, that is exactly what I was after. --Lgriot (talk) 04:48, 6 December 2009 (UTC)

In the Highway Code in the UK there are a set of stopping distances for a variety of speeds. In that publication, stopping distance is given as the sum of thinking distance and braking distance. Thinking distance is invariably given as the distance in feet being equal to the speed in mph. So the estimated time to see something happen and shift a foot to the brake pedal (similar to seeing something and steering) is estimated by the UK driving authorities as about 0.7 seconds. --Phil Holmes (talk) 11:25, 6 December 2009 (UTC)

That's not exactly the same, though, even though I doubt it would matter much in practice. You hopefully always drive with your hands on the steering wheel, but I'm guessing the same can't be said for having a foot on the brake all the time. -- Aeluwas (talk) 14:18, 6 December 2009 (UTC)

[edit] Interferomics possible editorial problems

I recently came across this article and after doing some corrections noted that the term was coined by researcher Gaurav Rana, when I reviewed the history the article was created by User:Gauravsjbrana, a subsequent google search revealed this article [jmd.amjpathol.org/cgi/reprint/9/4/431.pdf] which mentioned the emerging field of Interferomics in 2005 however makes no attribution to Gaurev Rana. I see a number of issues here firstly it is a specialized field so inaccurate editing maybe remain undetected, second it appears to be self promotion, thirdly it could be false representation. I am hoping someone with more experience in these matters can take a look. Matt (talk) 03:57, 6 December 2009 (UTC)

• edit - oops it appears I may have asked this question in the wrong place
• please ignore this article I have posted a welcome to this user and a short note regarding the possible issue with the article Matt (talk) 04:21, 6 December 2009 (UTC)

[edit] my son ( 10 yearls old )

Removed request for medical advice. Wikipedia cannot give medical advice. Only a medical professional can give responsible medical advice.

WIKIPEDIA DOES NOT GIVE MEDICAL ADVICE. Consult the Medical disclaimer

[edit] William Thompson

What substantial contribution did William Thompson make in the field of physics? Kittybrewster ☎ 12:34, 6 December 2009 (UTC)

I suspect you're thinking of Lord Kelvin. - Nunh-huh 12:45, 6 December 2009 (UTC)

Indeed. Thank you. Kittybrewster ☎ 13:13, 6 December 2009 (UTC)

Pub quiz question? Fences&Windows 13:30, 6 December 2009 (UTC)

Science test paper. "Homework for Grown-ups". Kittybrewster ☎ 13:59, 6 December 2009 (UTC)

Maybe we should but the disambig link to the Thomson page a bit higher on that page? It seems like a pretty easy mistake to make. --Mr.98 (talk) 14:36, 6 December 2009 (UTC)

Thought the same thing... --Stephan Schulz (talk) 15:34, 6 December 2009 (UTC)

I couldn't see him anywhere on that page! I'll go and add him. Dmcq (talk) 16:20, 6 December 2009 (UTC)

Well, the issue is that he doesn't have a p in his name, so ol' Lord Kelvin himself doesn't belong on that page... I've done something like what I think might be useful (putting the non-P see-also at the top, rather than at the bottom). --Mr.98 (talk) 16:43, 6 December 2009 (UTC)

If we want to increase the usefulness of disambiguation pages, we shouldn't insist on exact spelling. Similar spelling or similar pronunciations should be enough; the pages are so that articles that could be confused with each other can be found and distinguished. There should be one Thomson/Thompson disambiguation page for each Thomson/Thompson, with appropriate redirects pointing to it. - Nunh-huh 23:10, 6 December 2009 (UTC)

Not to mention Tomson or even Tompson (although there are only two of those). Mikenorton (talk) 23:21, 6 December 2009 (UTC)

[edit] How long are viruses active?

When you are suffering from the Common cold you are spewing cold viruses all around your home or workplace when you cough and sneeze. How long can these viruses stay active and possibly infect someone else? And what eventually happens to them -- do their molecules eventually disintegrate, or do they just spread out so much that they can no longer cause an infection? —Preceding unsigned comment added by Fletcher (talk • contribs) 10:37, 6 December 2009

A quick search of the reference desk archive (box at the top of this page) for 'virus "outside the body"' yields a link to a relevant discussion. Also, our Common cold article has some relevant info, though I would agree that those resources don't answer your question directly (I did not search the RefDesk exhaustively, so others may find a really good answer to what seems like it would be a frequently asked question). Virus survival in the environment varies widely based on environmental conditions. How those conditions affect viral infectivity depends on viral characteristics. For example, the most common cause of a cold is one of the many serotypes of Rhinovirus. Rhinoviruses are picornaviruses, which have a RNA genome, making them more susceptible (than DNA viruses) to genetic damage (which would render them noninfectious); making them much more resilient, though, is their lack of lipid coat such that they survive complete drying. Additional issues include the amount of virus shed, since a heavily-shed virus (relative to its infectious dose) will remain infectious longer. It seems clear that cold viruses can remain infectious for days (PMID 6261689, full text here), at least under some conditions (keep in mind that virus from your nose would never be in "buffered water", and drying in the presence of albumin, as they did in some experiments that showed more prolonged infectivity, is closer to the normal situation). This article references earlier studies on environmental persistence of infectious rhinoviruses, and the efficacy of various disinfection measures. There's also an interesting study of flu virus viability relative to environmental conditions. -- Scray (talk) 17:11, 6 December 2009 (UTC)

Thanks, very helpful! Fletcher (talk) 17:58, 6 December 2009 (UTC)

[edit] Burns and clothing vs. bare skin

Are burns more or less severe when the burn area of the victim is covered by clothing? That is, does clothing, as opposed to bare skin, alleviate or exacerbate