Let's imagine I have a vacuum chamber bisected by a wall of glass (2 coaxial chambers), and I conduct a "light speed" experiment in which light is introduced into the end of one chamber and shined through the opposite end of the other chamber. c in the first chamber is 299,792,458 m/s and c in the second chamber is 299,792,458 m/s; however, c through the glass is (arbitrarily) 214,137,470 m/s (5/7 c in a vacuum).
The photons impart a very small amount of energy to the glass as they are slowed; however, they accelerate to their original speed upon exiting the glass. How is this possible? Whence cometh the energy to accelerate those photons?
I realize the accelerated mass is going to be infinitesimal, and that the rate of acceleration is going to be near infinity, but the energy still has to have come from somewhere.
2006-07-03 11:21:47 · 5 answers · asked by wireflight 4 in Science & Mathematics ➔ Physics
Piz_Tell_Me: Am I correct in assuming then that the intensity or luminosity of the light may diminish, but the energy of the escaping photons is unaltered?
This seems consistent with the notion of quanta.
2006-07-03 12:53:29 · update #1
The photons exiting the glass do move at the speed of light but there are less of them!!!
Remember E = hv ?
Well the glass stops some of the quanta of energy (the photons) and that turns into heat. What is the result?
The light is simply DIMMER or a different color coming out than it was going in.
QED!
2006-07-03 16:12:03 · answer #1 · answered by cat_lover 4 · 1⤊ 0⤋
you question is confusing you. it is based on partial facts.
when light passes through glass, it's wavelengh changes
not frequency. repeating: its frequency remains the same, but
both the velocity and wavelengh change.
the energy of a photon is
E= h * nu
where nu is the frequency.
When light is passed through a medium, zillions of photons
pass.
energy is lost (from the beam) when some of these photons are
(1) elastically scattered
(2) reflected
(3) absorbed
(4) loose energy to electrons ( excitation, ionsisation, scattering) etc.
thus as per se, in classical terms, light does not loose energy !!!
2006-07-03 11:27:50 · answer #2 · answered by Plz_Tell_Me 3 · 0⤊ 0⤋
In the body energy comes from stored fats and carbohydrates in the case of your question why would you would one want to bisect (I think you mean Dissect) a vacuum anyway?
2006-07-03 12:10:07 · answer #3 · answered by Sister Sandy (RN) 3 · 0⤊ 1⤋
Hay Foccult how much water does it take to stop a photon---
2006-07-03 11:27:30 · answer #4 · answered by Balthor 5 · 0⤊ 0⤋
Change
2006-07-03 11:51:27 · answer #5 · answered by 22 2 · 0⤊ 1⤋