In reply to David Roberson's message of Thu, 18 Apr 2013 13:18:08 -0400 (EDT): Hi, [snip] >Does anyone know how a free electron in space can absorb a photon of moderate >energy? I was thinking of the interaction between a light photon and a free >electron when it occurred to me that it might be impossible for the photon to >deliver all of its energy and momentum to a single particle. I chose the >frame of reference as being where the electron is stationary for this thought >experiment although it might be better to choose a different one. > I agree, see my other post. However you have to go very far indeed to find a "free" electron. That is to say, an electron not under the influence of magnetic or electric fields. Any electron in such a field is not really free, and is capable of absorbing/emitting photons. (Otherwise radio wouldn't work).
Regards, Robin van Spaandonk http://rvanspaa.freehostia.com/project.html
