All Questions
Tagged with observable-universe redshift
9
questions
3
votes
3
answers
1k
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Could the redshift of all incoming photons be explained by a massive ring of distant masses pulling the sources of the photons away?
ChatGPT and wikipedia have informed me that the primary evidence for the theory that the universe is expanding is the fact that photons that arrive to our planet from all directions are being ...
- 231
3
votes
0
answers
69
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How do we know universe is expanding and not light slowing down? [duplicate]
We tend to take some things for granted, for example the light of speed is constant, but what if it isn't? How can we know that light is not slowing down at great distances for example, or that light ...
- 31
9
votes
1
answer
279
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How distant were the furthest currently-observable cosmic events when their currently-observed radiation was emitted?
(Edited for clarity. Thanks to James K and Connor Garcia.)
This question about the most distant, observable cosmic objects made me wonder if we know the distance that was between us and them at the ...
- 175
6
votes
2
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How does the hypothesis of the "inconstant Hubble constant" solve the current crisis in cosmology?
It was published in a paper more or less like two months ago. I'd like to know also if more accurate measurements are necessary to close the gap between the model of the universe and the data reported....
0
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0
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How long does it take for a galaxy (or other object) to disappear behind the cosmic sight horizon?
After looking at this question, I am wondering, how long does it take for a galaxy or other space object, to disappear from our view from the Milky Way due to the expansion of the universe? Assume GN-...
- 6,684
1
vote
1
answer
221
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Intuitive explanation for why the Doppler effect (and red-shift) happens?
I was looking for an intuitive explanation as to why the Doppler effect happens. I haven't found any, but this is what I thought:
-Waves emitted travel at a constant speed
-The source emits a wave
-If ...
- 201
1
vote
1
answer
327
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How fast would we have to go for the red(/blue)shifts of galaxies ahead of us to differ from those behind us with statistical significance?
Here, we are looking for a statistically significant difference between the mean redshifts of galaxies ahead and those behind, with reference to a prior-specified direction. For example, suppose that ...
- 111
17
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5
answers
7k
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Why are all quasars so far away?
Why are all quasars so far away?
If the universe is homogeneous, we should expect to have a homogeneous distribution of quasars, but all of then seem to be far away from Earth. Why is that?
- 503
4
votes
1
answer
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Red shifting galaxies
I am an amateur astronomer please correct if any of my understandings are wrong. We all know that from the Hubble's ultra deep field image the most distant galaxies which were created shortly after ...
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