All Questions
15
questions
4
votes
3
answers
2k
views
If the observable universe had only one galaxy, how would people know the expansion of the universe?
Hubble measured high redshifted galaxies to discover the cosmic expansion. In a hypothetical universe where only one galaxy exists, would there still be observational evidence for the Big Bang theory? ...
- 195
0
votes
0
answers
55
views
Big Bang and where do we stand relative to it? [duplicate]
Maybe dumb question, not sure, but I would need some help here to understand.
https://theglobestalk.com/james-webb-telescope-see-back-in-time/
So according to physics we can look back in time ...
1
vote
0
answers
33
views
Can we infer the size of the whole universe from its expansion rate? [closed]
If the universe inflated to 100 billion km in its first second, that suggests only 1/160,000 of it was observable from any point at that moment. The expansion rate slowed after that, of course, but ...
- 384
-4
votes
1
answer
120
views
Cosmos at minimum 250x bigger than our observable Universe, so why then the need for a Big Bang?
Please correct me If I'm wrong but does not the BB only refers to our light speed limited observable Universe (OU) from our home position?
Also it is estimated that the Cosmos is minimum 250 times the ...
- 4,170
4
votes
1
answer
663
views
Why don't we see the big bang?
excuse my understanding, my brain is melting.
So I understand that pictures of far away objects is like viewing the past.
and I think I pretty much get that the big bang was in every direction since ...
- 973
1
vote
2
answers
153
views
Can the age of the universe be much bigger than 13.8 billion
If observable universe is only a small fraction of the existing universe, does it imply that the age of the universe is much more than 13.8 billion years or the expansion of the universe is much ...
- 57
1
vote
0
answers
54
views
How is the expansion of the universe measured if redshift depends on the expansion itself? [duplicate]
To me this seems like a bit of a chicken egg problem.
Based on the redshift of light (plus the assumption that physics worked the same way back then and there as it does now and here), we can ...
0
votes
1
answer
261
views
Does the Big Bang imply a finite quantity of matter in the universe, and that the universe is spatially finite (if boundaryless)?
If all matter was created in the Big Bang (not counting spontaneous generation of particle-antiparticle pairs), wouldn't that imply that a finite (if very large) amount of matter exists in the ...
- 540
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
0
answers
40
views
What is our understanding of what our (i.e. observable) universe has expanded into? [duplicate]
In his latest Fermilab video, Dr. Don Lincoln explained:
(...) even though we shrunk the visible universe down to tiny size, the number line is still infinite. That means that, even when the ...
- 196
2
votes
2
answers
672
views
How is observable universe so big if the universe is so young? [duplicate]
The diameter of observable universe is 93 billion light years but the age of universe is only estimated to be 14 billion years. So how does light have 46.5 billion years to travel from the boundary of ...
3
votes
0
answers
124
views
Do we really need a new physics? [closed]
I have heard many times in news that a new discovery has taken place, and we need a new physics.
It has recently been announced in scientific news that the world is apparently expanding faster.
And ...
- 187
5
votes
2
answers
738
views
Hubble time and age of the universe
I'm having trouble with the following derivation of the 'age of the universe': https://i.sstatic.net/CvbwK.jpg
The parts I'm struggling to conceptualize is what a 'universe expanding' means, and also ...
- 151
4
votes
1
answer
900
views
When they say the universe was the size of a baseball about a billion billion billion billionth of a second
after the big bang. Does that means the observable universe was the size of a baseball, or does it mean the entire universe? I'm guessing it means the observable universe - as we really don't ...
- 5,678
9
votes
2
answers
2k
views
Can the coordinate of the big bang point be calculated via observed universe or it is impossible? [duplicate]
We know all galaxies spread out after Big Bang theory.The key idea is that the universe is expanding after that theory. Can we play back the scenes via observable universe (galaxies) and can we ...
- 521