All Questions
Tagged with big-bang space-expansion
321
questions
9
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2
answers
1k
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Has the age of the universe changed in 2023?
I teach high school physics and physical science. I was going through the definitions of theory and law when a couple of my students (of different periods) asked about some recent development that ...
- 203
2
votes
1
answer
74
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Are we surrounded by Big Bang? [duplicate]
Maybe the questions is too stupid to be asked or I do not know the technical words, but I could not find any answer to this question.
Here is how I started to think the title:
First I thought of if we ...
- 23
0
votes
1
answer
98
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Does The Big Bang Require An Infinitesimal Point, Or Is Another Shape Possible? [duplicate]
Einstein's Spacetime has four dimensions. If the size of one of these dimensions is zero, then the four-dimensional 'volume' - or whatever the corollary to 3D volume is called in 4D - would be zero.
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0
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2
answers
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Is this the Format of the Observable Universe?
The way I have it is: the Observable Universe looks as follows. In some ball, all the galaxy clusters exist, then in a bigger concentric ball the dark ages exist (no galaxies), then on the surface of ...
- 61
0
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0
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Contradiction b/w Big bang theory and conservation of mass
As per the conservation of mass, matter cannot be created or destroyed.
Doesn't this contradict the big bang theory? Like, it states that it all started from a single point. But seeing the massive ...
1
vote
2
answers
85
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How is Big Bang as a starting point possible?
I have a man-in-the-street question that was probably "predetermined".
If everything around us is co-interacting particles whose source is some infinite small point that started their ...
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12
votes
5
answers
3k
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What experimental evidence shows that the "explosion" model of the Big Bang with an explosion at a single point of space is wrong?
A popular misconception in the layman public is that the Big Bang was some sort "explosion" at a single point of space, where originally all matter was concentrated and then it "...
- 2,837
1
vote
1
answer
89
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Duration of inflationary epoch
Why is it thought that the inflationary epoch of the universe lasted approximately $10^{-30}$ seconds and why did it take the inflaton (assuming its existence) to release the energy contained itself ...
- 495
0
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0
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48
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Time from big bang to here [duplicate]
New to this so apologies for my ignorance, the simpler the answer the better. Here goes.
Light took 13.5 billion years to get to us from the big bang.
On an imaginary neighboring planet that is much ...
5
votes
3
answers
2k
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How can there be a Big Bang without a singularity?
I have read to Sean Carroll that he says that the Big Bang model is correct, but the Big Bang event is incorrect, so what is the difference? And everyone knows that the Big Bang model is linked to ...
- 51
0
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0
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55
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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
3
answers
278
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Can the age of the universe actually be calculated through Hubble's constant?
I was reading a high-school physics textbook, and it stated that the age of the universe is equal to 1 / Hubble's constant. They even give a derivation: $v = H_{0} D$ and $D = vt$, so subbing in gives ...
- 25
0
votes
0
answers
74
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Why is it surprising that the universe was in an extraordinarily low-entropy state right after the big bang? [duplicate]
So I don't understand why it's surprising that the universe in an extraordinarily low-entropy state right after the big bang?
The way I see it the second law of thermodynamics forbids almost anything ...
- 1,389
13
votes
4
answers
2k
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Why can't we run the laws of physics backwards and forwards in time infinitely?
So assuming we know all the laws of physics in differential equation form, and I have an estimate for the current large scale state of the universe (whatever standard assumptions/data cosmologists use ...
- 1,224
0
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1
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LCDM epoch or point where it fails
Nobody denies the currently success of the LCDM of cosmology. Recently, I wondered myself if there is a point or epoch (beyond the space-time singularity) where it breaks down. Does it fail at phase ...
- 6,611