Human, a very interesting argument. However, I believe that light is a constant speed, 299,792 kilometers per second, it just takes longer to travel through, say, air, than through a vacuum. My reasoning is thus: in a vacuum, there is nothing, or almost nothing, for photons to interact with. Light is able to follow a straignt course (this is all aside from gravity and other similar things, of course). However, in glass, as Schnee said, light doesn't go through it as fast. This is because there are many more particles in glass than in a vacuum (by definition!) and photons of light can bounce off these particles, thus effects like that associated with a prism. Because remember about wave/particle duality: particles and waves exhibit qualities of both, and thus are susceptible to the same laws.

• Re: Well I think... - Human I. Scientist - July 2, 1998 - 13:12 UTC