A

• [+] Aether theories (19 P)
• [+] Alchemy (7 C, 52 P, 2 F)

B

• [+] Obsolete medical theories (1 C, 14 P)
• [+] Obsolete biological theories (11 P)

C

• [+] Classical elements (35 P)
• [+] Early scientific cosmologies (3 C, 24 P)

F

• [+] Flat Earth theory (1 C, 11 P)

H

• [+] Hollow Earth theory (1 C, 18 P)

P

• [+] Phrenology (1 C, 19 P, 1 F)

S

• [+] Scientific racism (2 C, 37 P)

• Superseded scientific theories

A

• Adamic language
• Aether (classical element)
• Aether drag hypothesis
• Age crisis
• Air (classical element)
• Alchemy in history
• Antiperistasis
• Austrium

B

• Barlow's law
• Berzelium
• Birth cries of atoms

C

• Caloric theory
• Carolinium
• Central Fire
• Contact electrification
• Coronium
• Corpuscular theory of light
• Cubical atom
• Cyclol

D

• Dark star
• Davyum
• Decipium
• Dianium
• Dirac large numbers hypothesis
• List of discredited substances

E

• Earth (classical element)
• Emission theory
• Emission theory (vision)
• Enochian
• Etheric force
• Expanding Earth

F

• Firmament
• Flat Earth
• Fluid theory of electricity

G

• Galactocentrism
• Geocentric model
• Geophysical global cooling
• Paul Gerber
• Gnomium

H

• Heliocentrism
• Helvetium
• History of astrology
• Hollow Earth
• Hollow Moon
• Horror vacui (physics)

I

• Ilmenium
• Imponderable fluid
• Island of California

J

• Japhetic theory

L

• Laser star model of quasars
• Le Sage's theory of gravitation
• Limbic system
• Lorentz ether theory
• Lucium
• Luminiferous aether

M

• Magnetic photon
• Martian canal
• Mechanical explanations of gravitation
• Milne model

N

• N ray
• Neptunism
• Non-standard cosmology
• Nordström's theory of gravitation

O

• Open Polar Sea

P

• Panchromium
• Passing star hypothesis
• Pelopium
• Phantom of the Poles
• Phlogiston theory
• Phrenology
• Pleomorphism
• Plum pudding model

R

• Rain follows the plow
• Reactivity–selectivity principle
• Rutherford model

S

• Sequanium
• State theory (time)
• Static universe
• Steady State theory
• Sublunary sphere

T

• Tetrahedral hypothesis
• Theory of impetus
• Tired light
• Toroidal ring model
• Trepidation (astronomy)
• Tychonic system

V

• Vis viva
• Vitalism
• Vortex theory of gravity
• Vulcan (hypothetical planet)

W

• Wasium
• Water (classical element)
• Welteislehre
• Whitehead's theory of gravitation