Naked Science Forum

Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: theThinker on 20/07/2019 17:42:43

Title: photon violates energy conservation?
Post by: theThinker on 20/07/2019 17:42:43
Let's assume an atom A emits a photon of energy E₁ = hγ₁. The photon is absorbed by another atom B moving with a velocity relative to A. Because of the Doppler effect, the frequency of the absorbed photon is γ₂ where γ₁ != γ₂. This means the absorbed energy is E₂ = hγ₂ and E₁ != E₂. This implies a violation of energy conservation.

Where is the error?   
Title: Re: photon violates energy conservation?
Post by: alancalverd on 20/07/2019 21:00:30
You have done work by moving the second atom. It doesn't have to be a photon. Imagine a bullet fired from a stationary gun, hitting a moving target. The impact energy depends on the relative velocity of the bullet and target.
Title: Re: photon violates energy conservation?
Post by: yor_on on 20/07/2019 22:28:19

Sweet thinking Alan