Wikipedia: History of Photon

Difference (from prior major revision) (author diff)

Changed: 3,5c3,4

In a vacuum, photons move at the speed of light, around 3x10⁸ meters per second. Light of frequency f consists of photons of energy
:E = h f
where h is Planck's constant. As photons move through media, they will slow down at rates dependant on their frequency, refracting the light, and causing light of different frequencies and colours to separate into a spectrum.

In a vacuum, photons move at the speed of light c, around 3x10⁸ meters per second. Light of frequency f consists of photons of energy E = h f and momentum p = h f / c,
where h is Planck's constant (see wave-particle duality). As photons move through media, they will slow down at rates dependant on their frequency, refracting the light, and causing light of different frequencies and colours to separate into a spectrum.

	Revision 21 . . October 29, 2001 12:24 am by AxelBoldt [+link to wave-particle duality, +formula for momentum]
	Revision 20 . . October 28, 2001 7:30 am by AxelBoldt [+Planck's formula]
	Revision 19 . . (edit) October 27, 2001 2:09 pm by Josh Grosse