Understanding the Compton Effect: How Light Reflects on a Mirror Explained

  • Thread starter wolverine
  • Start date
  • Tags
    Stupid
In summary, the mirror reflects light because it has a mirror symmetry that helps to solve many problems in electrodynamics.
  • #1
wolverine
11
0
Could you explain me how does Light reflect on a mirror?

I assume that Compton effect on electrons is the only way for light to come back to my eyes but in that case, there would be a change of frequency of the photon (and a change of color).

Does it mean that it is not me in the mirror ?

Am I wrong ?

HELP ME, PLEASE ...
 
Physics news on Phys.org
  • #2
While I can't answer exactly how it happens, I can tell you that it IS IN FACT YOU in the mirror. Doesn't everyone else look the same in the mirror to you as they look normally aside from the inversion?
 
  • #3
Is it really wolverine in the mirror? How does he get back out? Go back to your basic physics book and review waves, and optics.
Bring your image with you too. -Mike
 
  • #4
I'm agree with you because of the daily experience, but even if optics can explain how ligth reflect on a mirror, I wonder how can modern physics (QED ...) descibe the reflection ...
 
  • #5
And at the point of reflection, does light have zero velocity?
 
  • #6
My physics instructor at Yale, Prof. Beringer, once explained to me that a mirror was to light as a radar was to radio waves. (Or an oven cavity is to microwaves, I guess.)

Electromagnetic radiation impinging upon a mirror - a conductor in the visible range; EMR cancels at a conductor - thus maintains a potential opposite to that of the incident ray, which manifests in turn with the emission of the image's reflected photonic signal.

Using mirror symmetries likewise helps solve many problems in electrodynamics.
 
  • #7
wolverine

If you think of light as a a wave packet of photons, when it stirkes a surface it has four possible outcomes. First, it might travel right through it, like pure glass. Second, it may not travel through it at all but be totally absorbed by it. Thirdly, it may be reflected totally. And lastly, it may be some combination of all of the above. What happens to the light when it strikes the surface depends on the wavelength of the light and the composition of the material it strikes.

For a 100% reflective mirror, the wavelengths cannot penetrate and they reflect. The easiest way to vinsualize this is using the light ray model. But, using QED, as Richard Feynman so aptly describes in his book, QED, we find that the reflection is all about the probability that a photon travels along this path or that depending on the least time it takes.

Hope this is some additional help to you.

Regards
 
  • #8
It does , thanks.

I just thought that there were a "classical" explanation, like photons hiting electrons and going back to my eyes or photons passing trough matter without doing any interacion.
Assuming that, I was thinking that R was equal to

Ninteractions
_____________

Ntotal

But it seems that we need to use QED to explain that.
 
  • #9
Originally posted by wolverine
It does , thanks.

I just thought that there were a "classical" explanation,
Sure there's a classical explanation. Light is an electromagnetic wave. The electric field oscillates at the light frequency. But a metal surface "shorts out" the electric field, effectively pinning it to zero at the surface. The wave therefore has no choice but to reflect. It is analogous to waves on a string. Fix one end of the string in place, and the wave you send down the string reflects perfectly. In more detail: the medium outside the mirror permits waves in any direction. But the only wave that when added to the incoming wave always gives zero electric field at the surface of the mirror, is in identical wave coming backward as a reflection.
 

1. What is the purpose of asking a "stupid question"?

The purpose of asking a "stupid question" is often to provoke thought and encourage critical thinking. It can also help break down barriers and create a more open and inclusive atmosphere for discussion.

2. Is there really such a thing as a "stupid question"?

In the context of scientific inquiry, there is no such thing as a truly "stupid question". Any question that encourages learning and understanding is valuable, regardless of how it may be perceived by others.

3. How can asking a "stupid question" be beneficial in a scientific setting?

Asking a "stupid question" can help identify gaps in knowledge and challenge existing assumptions. It can also lead to new insights and ideas, and ultimately contribute to the advancement of scientific understanding.

4. Are there any situations where asking a "stupid question" is not appropriate?

In a professional or academic setting, it is important to consider the context and tone of your question. If it is clear that the question is meant to be disrespectful or disruptive, it may not be appropriate to ask. Additionally, asking a question without first trying to find the answer through research or discussion may not be seen as productive.

5. How can we encourage others to ask "stupid questions"?

One way to encourage others to ask "stupid questions" is to create a safe and non-judgmental environment for open discussion. This can involve actively listening and valuing all questions, regardless of how they may be perceived. Additionally, leading by example and asking "stupid questions" yourself can help normalize the practice.

Similar threads

  • Special and General Relativity
Replies
26
Views
351
  • Other Physics Topics
Replies
2
Views
1K
Replies
16
Views
2K
  • Special and General Relativity
Replies
2
Views
602
Replies
57
Views
3K
Replies
5
Views
799
Replies
1
Views
619
Replies
172
Views
14K
Replies
14
Views
2K
Replies
1
Views
729
Back
Top