Tranform photon to other energy

[kevinsetiono]

hi guys i want to ask you about something . Energy can not be made or destruct , but it can TRANSFORM to other energy . my question is can photon transform to other energy ? :zzz:

 

[russ_watters]

Sure: Whenever it hits something and is absorbed.

 

[kevinsetiono]

russ : how about the light ? if light hits something , will it absorbed ?

 

[Doc Al]

Isn't that the same question? Light is photons, after all.

 

[kevinsetiono]

what will be if photon of light destruct ?

 

[Doc Al]

what will be if photon of light destruct ?

Increased internal energy. Consider what happens when you sit out in the sun: you get hot.

 

[Drakkith]

The following articles explain what light and photons are and how they work. If it's too complicated there are plenty of sites online that are a little more basic. Or you can always ask specific questions here on PF.

http://en.wikipedia.org/wiki/Photon
http://en.wikipedia.org/wiki/Electromagnetic_radiation
http://en.wikipedia.org/wiki/Light

 

[Bob S]

Here is an extreme case of photon energy transformation. Shoot a laser beam of 1-eV photons headlong into a 1-GeV electron beam (γ=1960). The photon Compton scatters off the electron and back along the same direction as the incident electron. The energy of the backscattered photon is 4γ²·1 eV = 15 MeV.

 

[kevinsetiono]

Here is an extreme case of photon energy transformation. Shoot a laser beam of 1-eV photons headlong into a 1-GeV electron beam (γ=1960). The photon Compton scatters off the electron and back along the same direction as the incident electron. The energy of the backscattered photon is 4γ²·1 eV = 15 MeV.

i just think if photon is neutral , it can not be affected by electron , i guess

 

[Drakkith]

i just think if photon is neutral , it can not be affected by electron , i guess

Photons easily interact with charged particles including electrons.

 

[kevinsetiono]

Photons easily interact with charged particles including electrons.

can you explain why this happen , i just think if neutral charged can not be affected by positive charge or negative one

 

[Bob S]

i just think if photon is neutral , it can not be affected by electron , i guess

can you explain why this happen , i just think if neutral charged can not be affected by positive charge or negative one

The photon is comprised of a transverse E field and an orthogonal transverse H field. It is the transverse E field that interacts with charged particles. At very low energies photons interact with the entire atom, like in Rayleigh scattering of sunlight (blue sky). At higher energies, photons interact with individual electrons, and this is called Thomson scattering. See http://en.wikipedia.org/wiki/Thomson_scattering. At relativistic energies, it is called Compton scattering.

The cross ection for Thomson scattering is about 0.665 barns = 0.665 x 10^-24 cm².

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