All Questions
Tagged with electromagnetic-radiation cosmology
55
questions
6
votes
1
answer
348
views
How does the Cosmic Microwave Background give us information about the Big Bang?
I was reading about CMB after this new breakthrough last week and I could not figure this out. The CMB did not exist before the epoch of Last Scattering. They were just photons which were formed at ...
user42733
9
votes
4
answers
2k
views
Do photons make the universe expand?
I have a problem understanding the ideas behind a basic assumption of cosmology. The Friedmann equations follow from Newtonian mechanics and conservation of Energy-momentum $(E_{kin}+E_{pot}=E_{tot})$ ...
- 10.1k
10
votes
2
answers
973
views
Do photons and cosmic rays radiate energy through gravitational waves? If not, why not?
Due to the mass-energy equivalence, both matter and EM radiation bend spacetime, and both are capable of forming singularities (black hole, white hole/kugelblitz). In light of this, why do photons ...
user40753
3
votes
2
answers
436
views
Do electromagnetic fields gravitate?
It's well known that electromagnetic fields contains energy but do they gravitate?
When we talk about the composition of the universe it's now accepted that the 74% is dark energy, the 22% is dark ...
- 905
3
votes
3
answers
620
views
How much of the universes mass is bound up in photons traveling between stars?
I was watching a Scott Manley video on youtube and he mentioned that the Sun was loosing 4 million tons of mass a second as it converts to energy.
With a few trillion trillion stars also converting ...
- 133
2
votes
2
answers
452
views
Why wouldn't Hubble's Law be directly in units of frequency?
Maybe using this as an example:
The energy of a particular color of yellow light is $3.44 \times 10^{-22}$ $kJ$
So if I want to find frequency of that light, I take that number, divide by $h$ and ...
- 821
4
votes
1
answer
3k
views
How is it possible that we see light from shortly after the big bang?
How can astronomers see light from shortly after the big bang? How did we get "here" before the light that emanated from our "creation"?
- 1,241
8
votes
3
answers
2k
views
How much light is there in space and how heavy is it?
Our night sky is filled with stars. On a dark night a significant fraction of the sky is light. This light, we are told, has been in transit for many millions of years. There must therefore be quite a ...
- 219
7
votes
3
answers
2k
views
Where does the light of the Big Bang come from?
I'm wondering whether the residual light of the Big Bang comes from one particular direction and what possibilities do we have to detect its position?
- 422
4
votes
2
answers
1k
views
Big Bang and Cosmic microwave background radiation?
One of the experimental evidence that supports the theory of big bang is cosmic microwave background radiation (CMBR). From what I've read is that CMBR is the left over radiation from an early stage ...
- 1,401