There are 411,000,000 cosmic microwave photons per cubic meter of the universe. The average energy of a cosmic microwave photon is very small: only E=1.02 x 10^-22 joules. What is the energy density of the Cosmic Microwave Background, in joules per cubic meter?
Using Einstein's relation, E= mc^2, what is the equivalent mass density, in kilograms per cubic meter? What fraction of the critcal density, P sub crit= 10^-26 kg/m^3, does this density represent?
Thanks so so much!
Using Einstein's relation, E= mc^2, what is the equivalent mass density, in kilograms per cubic meter? What fraction of the critcal density, P sub crit= 10^-26 kg/m^3, does this density represent?
Thanks so so much!