Never seen this addressed anywhere, and maybe it doesn't matter;(adsbygoogle = window.adsbygoogle || []).push({});

but, regarding the cosmic background radiation, in any given instant, how many 2.73K (on average) photons are in a given volume ?

See, we would measure the same background temperature with our instruments over a range of 'densities', but the actual energy content could vary.

(or does the temperature finding of 2.73K take that into account ?)

And then a follow up, what would the total energy content in the entire observable universe be for the CMB? And then what is the mass equivalent of that ? (solve for M instead of E in E=MC\

2)

I know this hasn't been overlooked in the field of cosmology, it just hasn't filtered down to my level.

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# 'Density' of 2.73K Cosmic Microwave Background

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