When light bounces off a mirror does it transfer momentum?

Question

Does the mirror receive 2xmomentum of the photon (conservation of momentum? If yes is the energy (colour) of the light the same after the collision.
I was thinking about 2 mirrors facing each other in space with light bouncing between them - do they get further apart and the light get gradually lower in energy?
If not why doesnt light transfer momentum?

Answer 1

I believe that when light bounces off there is a minute change in energy (because of the small contact time) and this change in energy can be observed as heat

Answer 2

Yes. And the energy (or color or wavelength) of the photon is nearly the same afterwards. If the mirror was initially at rest, and not fixed in place, then it will be moving away from the photon after the collision, and the photon will have lost a small amount of energy. If instead you treat the mirror as rigidly fixed to an infinite mass, then the photon will not lose energy.

You're correct about the mirrors in space. After many many bounces, the lower photon energy would be noticeable, and the mirrors would get farther apart. BUT how would you monitor where the mirrors are during the experiment? If you shine a light on them to see them, that would overwhelm the effects of being hit by a single photon.

Answer 3

Yes, there is momentum transfer from the momentum to the mirror. If you are assuming a perfect mirror, the light will have a slightly higher wavelength to account for the kinetic energy of the mirror after the bounce. With each bounce, there will be both momentum transfer and energy transfer, so the light will gradually increase in wavelength.

For a real situation, there will also be absorbtion of the light by the mirror. Most of this energy goes into heating up the mirror.

Answer 4

Well I'm no physics head or claim to be anywhere near the likes of Einstein or Hawking but I would surmise that the photon doesn't actually exist in the mirror. As the photon approaches the mirror isn't it just a reflection and nothing more. Obviously the mirror's surface will absorb the light energy that hits it. In the case of two mirrors facing each other I would agree that the energy of any photons is diminished because this is what we 'actually' see in the perception that there are an infinite number of mirrors stretching on for infinity, as can plainly be seen if you've ever done that trick, and they become distorted and dull as a result of the depreciation of energy.

Answer 5

Yes...
Each time light hits something some energy is transferred (absorbed, etc) - the colour of the light will change if more/less of a frequency/frequencies in the light are absorbed.
The mass of light is very small, and would not have much of an effect on the mirrors.

2 Mirrors facing: energy is lost each time light hits a surface, and because the light travels further, each reflection is darker & smaller in size - eventually the energy would so mintue that the reflections would be too small & too dark to see.

Answer 6

It transpondenenately exiges at a tangential rate of decay until it euphobrically exudes into the minimal state of currency.
Basically, it just defragulates right down until it reaches the insurance threshold and cranulises.
Of course there have been other explanations, specifically by Tronhauser in his theory of cantabularity, but to be honest since Fingleheimer-Tutt in the late 60`s (I think it was 68..not sure, try Wikipedia) put forward the notion of expressed cranulation the Law of Spon appears to have been upheld. So yes, it would appear to be doing that while actually it was doing something else.

Science is fun isn`t it ?

Answer 7

Yes, it does. Each photon has momentum being
(Planck's constant)/(wavelength).
The transfer is maximal 2 x this value when the reflection is perpendicular at the mirror, else it it less.
Th

Answer 8

Yes

Answer 9

very well, now you couldnt extremely go right into a room coated with mirrors and shine a laser and anticipate the completed room to refill, for most causes (youre contained in the way of a minimum of one million diverse guidelines the mild ought to might want to commute). yet when there have been a splendidly round room coated with a splendidly reflective reflect, interior which there turned right into a suitable vacuum and also you someway were given a beam of sunshine to "commence" in there with no source to intervene with the reflections, theoretically it ought to bounce round continuously, yet that brings up the cat contained in the container idea of quantum mechanics, technically, that is going to likely be bouncing round and under no circumstances bouncing round at the same time till you extremely word it so that you ought to under no circumstances particularly comprehend

Answer 10

Light doesn't weigh much.

Mirrors aren't perfect, either.

Light can be used to push objects, this has been well demonstrated.

Do a search on "solar sail" for example.