All Questions
Tagged with electromagnetic-radiation cosmology
9
questions with no upvoted or accepted answers
7
votes
0
answers
323
views
Trying to reproduce curves with angle of CMB anisotropies as a function of distance and curvature parameter
I am looking for a way to get, by a simple numerical computation, the 3 curves on the following figure:
For this, I don't know what considering as abcissa (comoving distance ?, i.e
$$D_{comoving} = ...
user87745
2
votes
1
answer
486
views
What is the mean free path (MFP) of a Cosmic microwave background radiation (CMBR) photon?
If the IGM (inter-galactic medium) had a massive particle (proton) every cubic metre, or a carbon grain every cubic kilometre, what would be the MFP of a CMBR photon? The coherence length of the ...
- 304
1
vote
0
answers
47
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Radiation from a moving charge particle in expanding universe?
Moving charged particles generally emmit energy in form of radiation.
Assume a charged particle that is situated in a zone that can join the Hubble flow and therefore starts moving away from us.
As it ...
- 2,462
0
votes
0
answers
98
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How can we use CMB to measure the value of the cosmological constant?
Another mystery facing cosmologists is the accelerating expansion of the universe. In 1929, astronomer Edwin Hubble showed that the universe was expanding, but for this expansion to be justified, ...
0
votes
0
answers
36
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Changes to an EM-wave that is propagating in an inflating space
I am trying to get an easier picture of what happens to an em-wave considering space expansion. My question is: If a star in a non-inflating space emits light recorded at a certain distance of the ...
- 1,815
0
votes
0
answers
169
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Infinite universe and the impossibility of monochromatic light and infinite plane waves
I recently asked a question relating to this excerpt from the textbook Optics, fifth edition, by Hecht:
Mathematically, the plane wave extends out to infinity in all its directions, and, of course, ...
- 889
0
votes
0
answers
70
views
Matters Including Resolution of Olbers' Paradox
Is there evidence for galaxies receding from us faster than the speed of light? If so,that might help resolve Olbers' paradox, though other factors must also be taken into consideration. Could such a ...
- 1,710
0
votes
2
answers
395
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Origin of electromagnetic radiation in the universe
I don't know if the total electromagnetic radiation in the universe is finite or not.
But either way: what is the origin of the electromagnetic radiation in the universe? Can we say that all of it ...
- 156
-2
votes
1
answer
213
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Tired light question
How do we arrive at the conclusion that redshifted light from cosmological sources has 'lost' energy during its transit from source to us? If in fact no actual measurement of the energy of the ...
- 49