All Questions
Tagged with big-bang space-expansion
321
questions
68
votes
5
answers
16k
views
Can space expand with unlimited speed?
According to this article on the European Space Agency web site just after the Big Bang and before inflation the currently observable universe was the size of a coin. One millionth of a second later ...
- 783
33
votes
9
answers
9k
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Is space really expanding?
In a book called "Einstein, Relativity and Absolute Simultaneity" there was this sentence by Smith:
There is no observational evidence for a space expansion hypothesis. What is observed are ...
user311398
31
votes
1
answer
3k
views
Why haven't we seen the big bang?
The Andromeda galaxy is 2,538,000 light years away, so if we view Andromeda from a telescope, we see Andromeda how it was 2,538,000 years ago. Now the diameter of the visible universe is 92 billion ...
- 1,925
30
votes
5
answers
6k
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If the universe is expanding, what is it expanding into? [closed]
If the universe is expanding, what is it expanding into?
When the big bang happened where did it occur?
When the big bang happened how did it occur?
Where did the energy come from? Energy can not be ...
- 441
29
votes
2
answers
4k
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Why is the Cosmic Microwave Background evidence of a hotter, denser early universe?
In his book Gravitation and Cosmology, Steven Weinberg says that the Cosmic Microwave Background (CMB) makes it "difficult to doubt that the universe has evolved from a hotter, denser early stage&...
- 1,421
26
votes
9
answers
7k
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How can the universe expand if there is gravitation?
We live in an expanding universe - so I'm told. But how can that be possible? Everything imaginable is attracted by a bigger thing. So, why can't gravitation stop the expansion of the universe? I know ...
- 487
26
votes
7
answers
4k
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Why did the universe not collapse to a black hole shortly after the big bang?
Wasn't the density of the universe at the moment after the Big Bang so great as to create a black hole? If the answer is that the universe/space-time can expand anyway what does it imply about what ...
- 517
24
votes
7
answers
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Given that matter cannot escape a black hole, how did the big bang produce the universe we see today?
Extrapolation of the expansion of the Universe backwards in time using general relativity yields an infinite density and temperature at a finite time in the past.
If the matter contained within our ...
Daniel X Moore
22
votes
4
answers
4k
views
Why does CMB radiation propagate towards us?
There is something with CMB radiation that does not sit well with me... It seems very counterintuitive that we are able to see it. If CMB radiation formed at the early phases of the universe, would it ...
- 563
18
votes
2
answers
4k
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How long ago was the Universe small enough for interstellar travel?
Currently, even the nearest stars are lightyears away, and impossible to reach in our lifetimes. If space is always expanding, and was once infinitely smaller, then at what point in the past was space ...
- 719
16
votes
2
answers
3k
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What evidence do we have that CMB is the result of the Big bang?
I got the main picture repeated over and over again about why if there's a Big bang we indeed should see the CMB with this feature. In this question I'm asking something different: what independent ...
- 944
16
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2
answers
5k
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How can a quasar be 29 billion light-years away from Earth if Big Bang happened only 13.8 billion years ago? [duplicate]
I was reading through the Wikipedia article on Quasars and came across the fact that the most distant Quasar is 29 Billion Light years. This is what the article exactly says
The highest redshift ...
- 161
15
votes
4
answers
2k
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Are scientists missing the point with distant cosmic objects, or is it just me?
I was reading this article this morning:
http://www.bbc.co.uk/news/science-environment-13539914
Scientists have discovered a gamma-ray burst whose light has taken 13.14 billion years to reach Earth. ...
- 259
14
votes
3
answers
5k
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What has been proved about the big bang, and what has not?
Ok so the universe is in constant expansion, that has been proven, right? And that means that it was smaller in the past.. But what's the smallest size we can be sure the universe has ever had?
I ...
- 1,387
14
votes
3
answers
5k
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What does it mean that the universe is "infinite"?
This question is about cosmology and general relativity.
I understand the difference between the universe and the observable universe. What I am not really clear about is what is meant when I read ...
- 13.5k