All Questions
2
questions
1
vote
0
answers
19
views
Universe expansion and energy conservation principle [duplicate]
If photons lose energy due to expanding of the universe where the lost energy is stored? Does the energy conversation principle is violated?
- 119
2
votes
1
answer
486
views
What is the mean free path (MFP) of a Cosmic microwave background radiation (CMBR) photon?
If the IGM (inter-galactic medium) had a massive particle (proton) every cubic metre, or a carbon grain every cubic kilometre, what would be the MFP of a CMBR photon? The coherence length of the ...
- 304