Well does it?
2007-04-24 08:28:22 · 8 answers · asked by Anonymous in Science & Mathematics ➔ Physics
Einstein said the velocity of light is constant IN A VACUUM. But the velocity of light changes any time it passes through a different medium. The property of the medium which affects the speed of light is known as the "Index of refraction."
v = c/n
v is the speed of light in the medium
c is the speed of light n a vacuum......3 X 10^8 m/s
n is the index of refraction.
2007-04-24 08:43:27 · update #1
If the front surface of the mirror is reflecting, the light doesn't slow down at all. If the mirror is made of glass and the back side is mirrored (as is normal practice), yes, light passes through 2t where t is the thickness of glass and is slowed down by a tiny fraction of a second. Since t is quite small in practice, the slowing down can be neglected in all but the most critical cases.
2007-04-24 08:54:28 · answer #1 · answered by Swamy 7 · 1⤊ 0⤋
the speed of light changes depending on what substance it travels through. the beam of light would slow down as it enters the glass. and regain speed when reentering the air.
contrary to the many comments above... THE SPEED OF LIGHT IS NOT CONSTANT. Lene Hau managed to slow light to 37 miles per hour and in 2001 she stopped it momentarily. Einsteins theory of general relativity only imposes a top speed for light, not a minimum.
and if proppperly measured the light in your hypothetical case would be 'slowed' by 2*C since its reversed.
2007-04-24 15:41:15 · answer #2 · answered by mrzwink 7 · 1⤊ 0⤋
No. It may slow down when it enters the thin layer of glass before the reflective coating, but when it re-enters the air medium, its speed is equal and opposite in direction to when it started.
2007-04-24 15:34:33 · answer #3 · answered by kennyk 4 · 1⤊ 0⤋
Einstein said that the speed of light is a constant. That means that it is always the same.
2007-04-24 15:35:39 · answer #4 · answered by Renaissance Man 5 · 0⤊ 1⤋
No, not even if the mirror is moving away at near light speed.
2007-04-24 15:47:42 · answer #5 · answered by Anonymous · 0⤊ 0⤋
No way! The velocity of light is a constant which is 3 lakh kilometres per second..
2007-04-24 15:36:45 · answer #6 · answered by AP 2 · 0⤊ 1⤋
No it doesn't, Light can loose speed only when its CHANGING MEDIUMS; that from one substance to another. but it WILL LOSE Energy when its reflected through glass because of impurities (No surface if 100% pure) losing energy means that light can fade when transmitted over long distances (this is what happens in optic fiber cables after the light is reflected of the glass in the cable) but speed isn't affected. hope this helps
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2007-04-24 15:49:05 · answer #7 · answered by ralphtips aj 1 · 1⤊ 0⤋
I don't think so. But I might be wrong.
2007-04-24 15:33:23 · answer #8 · answered by ? 5 · 0⤊ 0⤋