All Questions
59
questions
0
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0
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100
views
Movement of galaxies vs expansion of space
I can readily accept the theory that the universe is expanding as a mathematical model to explain the fact that all galaxies are moving away from each other, but I have difficulty understanding ...
- 1
1
vote
0
answers
35
views
Does Dark Energy contribute to increase the isothermal temperature of plasma in galaxy clusters?
I have a question about this work called "Dark energy and key physical parameters of clusters of galaxies"
There, towards the end, the authors talk about the isothermal velocities and ...
- 2,462
0
votes
2
answers
115
views
Not an "intelligent design" question: How do galaxies collide given the Big Bang? [duplicate]
If all matter began from one infinitesimally small point, and flew outward from there. How can we have galaxies colliding? Did they make left hand turns or something? Or it is possible multiple ...
2
votes
5
answers
1k
views
Why is it that the further a galaxy is, the greater is its recessional velocity?
The exam question is:
Explain how red-shift provides evidence for the Big Bang theory.
One of the points in the answer is:
the further away the galaxy is, the greater is their recessional speed
...
- 21
7
votes
2
answers
2k
views
Why are there no enormous galaxies near us?
Recently the James Webb space telescope detected six massive ancient galaxies. They are very old and very far away. But these galaxies must still exist today and be even heavier now. Why can't we see ...
- 89
-1
votes
1
answer
40
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The centre of what we can now see in the universe
If the JWST has just discovered the furthest away galaxies in one place we can now triangulate to where the centre of what we can see
This is observable and appears not symmetric with everything ...
0
votes
2
answers
44
views
Age of the universe due to expansion
"If gravity working on matter is the only force at work on large scales, then the attactive force of gravity will act to slow the expansion. In this case, the universe was expanding more rapidly ...
0
votes
1
answer
52
views
How do we know if a distant galaxy's light we see today was also reaching our location before approximately 4.5 billion years (Earth formation)?
This has actually to do with the estimation of of how distant an observed galaxy is?
How we can be sure if we do not know if we could see the light comming from the galaxy even before the Earth was ...
- 4,170
1
vote
4
answers
152
views
How cosmologists know if the observed redshift of galaxies is due to expansion and not intrinsic to the galaxy?
Is there a way to experimentally test if the cosmological red shift observed is due to the expansion or intrinsic to the galaxy? If anyone knows how to do this or how to extract from the data please ...
- 4,170
0
votes
2
answers
66
views
Why galaxies with a redshift > 2 have a lower velocity now, compared to when the light was emmited?
I was playing around with astropy cosmology data, and I made the following graph:
On the x axis I plotted Redshift, and on the y axis the speed of light as 1c, 2c etc.
Until a redshift of ~ 2, my ...
- 43
1
vote
0
answers
52
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Will we see more or fewer galaxies because of accelerating space expansion?
I have read this question:
The short answer to this is: We see less stars with time, due to the fact that cosmic expansion is accelerating. Although what we really see at the relevant distances are ...
- 29k
3
votes
0
answers
77
views
Confused about size of the universe in the past
From Wikipedia, I got that the photons of the cosmic microwave background radiation originated when the spherical volume of space which will become the observable universe was 42 million light-years ...
user338734
-1
votes
1
answer
113
views
Is HD1 Galaxy a potential Big Bang theory killer?
I have heard some first explanations of why the farthest ever galaxy discovered about 13.27 Bly away the HD1 appears so UV active and about the population III stars inside this galaxy made only from ...
- 4,170
2
votes
1
answer
71
views
Can empty space 'press' galaxies?
If gravity slows the effects of time, then empty space will see greater expansion than space inhabited by massive objects. So the space within a galaxy will be expanding more slowly than the space ...
0
votes
3
answers
104
views
Do the stars in galaxies expand wrt each other because of dark energy?
Expansion of space is observed between galaxies. In the galaxies themselves, the effect is very small obviously. But is space, no matter how little, actually expanding or is it countered by local ...
