All Questions
Tagged with big-bang space-expansion
32
questions with no upvoted or accepted answers
6
votes
3
answers
166
views
How do you explain cosmological red shifting in terms of gravitons?
We know that the photons from the big bang are continually being red shifted and losing more and more energy. In terms of the graviton view, how would you explain that? Where is the energy going?
Are ...
user84158
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
3
votes
0
answers
173
views
Is the Universe 11 billion years old?
This clip claims scientists found a star 200M years older than the Universe. However, I took another assertion more seriously: scientists estimated a faster expansion rate of the Universe, driving age ...
2
votes
0
answers
88
views
A problem on cosmic inflation
I analyze inflation in this following scenario: Suppose that at some very early epoch, $t_1 ≤ t ≤ t_2$ (where $t_1 ≪ t_2 ≪ t_r$ and $t_r$ is the time at the recombination epoch), the universe resides ...
- 131
2
votes
0
answers
69
views
Could the horizon problem be explained by a finite universe instead of inflation?
Suppose the universe is finite (either closed or open with a non-trivial topology), any point could be within the horizon of another.
- 121
2
votes
1
answer
174
views
Is there any way to tell if the Big Bang happened everywhere or just in some regions of the entire universe?
On large scales, matter seems to spread uniformly in our observable universe so we think the Big Bang happened everywhere in the observable universe.
Is there any way to tell if the Big Bang happened ...
- 455
1
vote
0
answers
68
views
Why is the Hubble law so accurate at scales smaller than galactic voids?
It's possible to derive the Hubble law:
$$v = H_0 d$$
from the FRW metric by differentiation.
Experimentally the Hubble law appears to hold for relatively small distances, say 20 Mpc and smaller. ...
- 841
1
vote
0
answers
60
views
Why is the age of the universe $=D/v$, despite that $v$ is not constant with time?
I am watching a series of lectures by the Noble prize laureate Brian Schmidt and Paul Francis and in this episode (at 4:20) they make the simple assumption that a galaxy receding from us due to the ...
- 157
1
vote
1
answer
117
views
At which point in time in the history of our universe, was the observable universe exactly as big as the entire universe?
At which point in time in the history of our universe was the observable universe exactly as big as the entire universe? Does the Hubble Deep field represent such a time? Does this question make sense ...
1
vote
1
answer
139
views
How was matter in other parts of the universe affected by the Big Bang and inflation in an infinitely sized universe?
I'm trying to understand how the idea of an infinite universe with presumably infinite matter works with the Big Bang and inflation.
I understand that if the universe is infinite, then it's always ...
- 199
1
vote
1
answer
172
views
Early Universe Flatness Problem
My question is about the curvature of spacetime in the early universe (Plank era)
https://en.wikipedia.org/wiki/Flatness_problem
Based on data from Wilkinson Microwave Anisotropy Probe, in order to ...
- 11
1
vote
0
answers
202
views
How was it possible for the big bang to occur?
I think the person who asked this Phys.SE question meant a different thing than any of the people who wrote an answer thought so I'm asking what I'm guessing the author probably really meant. If there ...
- 1,668
1
vote
0
answers
199
views
The steady state theory, can it now be falsified on particle physics grounds, in addition to CMB data?
The steady state theory is no longer taken seriously by most physicists and the Big Bang theory is supported by an enormous amount of evidence, especially the CMB data.
But from a quick scan through ...
user81619
1
vote
0
answers
485
views
What evidence is there of a universe older than 13.8 billion years
I've read an analogy that finding iron-rich galaxies just 900 years after the Big Bang is like finding an old man in a crib in a nursery. We just recently found a supermassive black hole 12 billion ...
user32023
1
vote
1
answer
336
views
Did the Big Bang cause an outward push of gravity?
There is a theory that the big bang’s blast caused an outward push, a kind of reverse gravity if you will, of our universe and everything within it.
My question is how could this have happened? If it ...
- 179