Basically the title. The wavelength of light from the CMBR has expanded as the universe expanded and so it has lost energy since it is inversely proportional to the wavelength. Where did this energy go? It may have been asked before but I couldnt find it...
$\begingroup$
$\endgroup$
3
-
$\begingroup$ @badjohn There is the same number of photons as before, but not the same amount of energy -- the photons started out as a blackbody radiation with temperature of ~3000 K, and now it's closer to ~3 K. $\endgroup$– ThrivethCommented Dec 8, 2018 at 18:56
-
$\begingroup$ @Thriveth Of course. So, there is an interesting question here. $\endgroup$– badjohnCommented Dec 8, 2018 at 19:17
-
$\begingroup$ There's this paper that talks a bit about it. I find it rather good. people.smp.uq.edu.au/TamaraDavis/papers/SciAm_Energy.pdf $\endgroup$– ThrivethCommented Dec 8, 2018 at 23:10
Add a comment
|