Reflection

krd

This might sound like a silly question, but it's something I can't really make sense of.

What is happening when light is reflected from a surface?


I can understand how a tennis ball may be reflected by throwing it against a wall. I can understand how sound waves may be reflected too.

The reflection of light bothers me. I can understand how it can be absorbed, but not how it's reflected.

If photons are being bounced off a surface what are they bouncing off - since at that level it's not like throwing a tennis ball at a wall (or is it). And a photon isn't a solid object like a ball.

Are the photons reflected, new photons?

How do the atoms reflect the photons?

Morbert

krd wrote: »

This might sound like a silly question, but it's something I can't really make sense of.

What is happening when light is reflected from a surface?


I can understand how a tennis ball may be reflected by throwing it against a wall. I can understand how sound waves may be reflected too.

The reflection of light bothers me. I can understand how it can be absorbed, but not how it's reflected.

If photons are being bounced off a surface what are they bouncing off - since at that level it's not like throwing a tennis ball at a wall (or is it). And a photon isn't a solid object like a ball.

Are the photons reflected, new photons?

How do the atoms reflect the photons?

Here is an illustrative application of the interaction of a light-wave with a material interface, demonstrating both reflection and refraction. It becomes especially clear once you reach step 3.

http://www.walter-fendt.de/ph14e/huygenspr.htm

It is demonstrating Huygen's principle. From Wikipedia, regarding the reflection of light:

"In the classical electrodynamics, light is considered as electromagnetic wave, which is governed by the Maxwell Equations. Light waves incident on a material induce small oscillations of polarisation in the individual atoms (or oscillation of electrons, in metals), causing each particle to radiate a small secondary wave (in all directions, like a dipole antenna). All these waves add up to give specular reflection and refraction, according to the Huygens-Fresnel principle."

To understand reflection from a quantum mechanical perspective, you would want to look at quantum electrodynamics. In a nutshell, a photon is scattered by the reflective material, and when you add up all the contributions of the possible paths, you get reflection behaviour.