Absorption of Photon by a Free Electron - Impossible - Conservation Laws?

[Physics Enemy]

Hey,

It seems like this is impossible because momentum conservation is violated. I had a Q where an electron underwent an energy transition and emitted a photon, and then they asked whether it was possible for the photon to be reabsorbed by the electron to undergo the same transition as before (albeit in reverse this time, lower to higher energy level).

Could someone explain why momentum conservation is violated here? Also, the Q suggested that in theory, a centrifuge could 'address' this problem. How exactly?

Thanks!

 

[SammyS]

It's pretty much impossible for any of us to give any help, let alone address "How exactly?", with no details being given.

 

[Physics Enemy]

It's pretty much impossible for any of us to give any help, let alone address "How exactly?", with no details being given.

I gave you the details. It's a conceptual Q about whether an electron can absorb a photon. Apparently it violates conservation laws. The second bit is about a centrifuge 'overcoming' this issue. Nothing else is needed.