All Questions
4
questions
-3
votes
1
answer
90
views
Why is the cosmic background 4K? Where are the other photons? [closed]
The cosmic background is 4K. Where are the other photons? A 4K photon produced at the big bang is detected by our detector. Time stops for the photon and hence we are seeing the big bang. Shouldn't we ...
- 43
0
votes
0
answers
42
views
Where does $H = \frac{M_0}{T^2}$ come from?
In this case: $M_0 = \frac{M_{Pl}}{1.66 g_*^{\frac{1}{2}}}$ and $H$ is the Hubble constant (which is not always constant depending on he constitution of the Universe).
where $M_{Pl}$ is Planck's mass ...
- 84
2
votes
1
answer
1k
views
Why does the temperature of the early Universe decrease as it expands? [duplicate]
According to the Big Bang theory, the universe cooled down as it expanded. I would like to know why does the temperature decrease? And by "why" I mean how. What causes the temperature to decrease, ...
- 151
1
vote
3
answers
790
views
What happened to high temperatures in the universe?
We know that after the big bang the temperature was about 10^32 K.
But now the average temperature of the universe is about 4 K. What happened to the temperature at that time? Where did it go?
- 435