According to the current cosmological theories, it's the model that explains the early life of the universe, starting from a rapid expansion of hot and dense matter.

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1answer
471 views

Doesn't dating the universe violate the concept of spacetime's inseparability?

It would seem that measuring an age of the universe from the big bang arbitrarily separates spacetime into a singularity and a time track.
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1answer
148 views

Obtaining a copy of Hawking's Ph.D thesis - Properties of Expanding Universes

Due to its popularity, I am interested to know the 4 chapter titles and topics covered in S.W. Hawking Ph.D, Properties of Expanding Universes. I also ask this because that thesis is hardly available. ...
22
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1answer
2k 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 ...
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0answers
29 views

Best evidence for Big Bang? [duplicate]

Why is the existence of cosmic microwave background regarded as the best evidence of Big Bang (or Big Bang model?)?
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2answers
89 views

Quantum entanglement and the big bang

Prior to the Big Bang all matter was compressed into a point of high density. Why isn't all matter already entangled?
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2answers
128 views

The Big Bang theory hypothesis

Is there a simple way to state the hypotheses of the Big Bang theory? I have the impression that the Big Bang singularity is merely a consequence of Freedman equations. Could somebody clarify what ...
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2answers
178 views

I understand the Big Bang Theory (BBT), but how was the matter in the BBT created?

I understand the Big Bang Theory to consist of all of the matter being pulled into one great gravitational pull. such a great force that it expelled the matter out causing the idea of Red-Shift and ...
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4answers
2k views

Why is the singularity of the Big Bang not considered to be the center of the Universe? [duplicate]

If the universe is expanding, then at some time in the past, it must have started from a single point but why this point is not the center of the Universe. Just like the singularity of black holes is ...
0
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1answer
42 views

General questions related to inflation of the universe

(i) We know that the universe is expanding. As it expands, something has to "fill in", even if it is vacuum. Isn't energy required for this? For creating new "dark matter"? But we can't get energy ...
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4answers
104 views

Has cosmic microwave background kept a constant frequency?

Has the frequency of CMBR changed at all since the beginning of the universe? Has it always had a microwave frequency or has the frequency increased/decreased over time or is the change due to factors ...
4
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3answers
237 views

What was the density of the universe when it was only the size of our solar system?

What was the density of the universe when it was only the size of our solar system? Did it approach neutron star density? Is it physically correct to even ask such a question?
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0answers
54 views

Is the Big Bang notion compatible with the flat space? (A problem with the **moment** of Big Bang, not with the place of it) [duplicate]

A passage from a paper: "If one imagines running the clock backward in time, any given region of the universe shrinks and all galaxies in it get closer and closer until they smash together in ...
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2answers
70 views

If energy can't be created and can't destroyed [duplicate]

Then wouldn't be logical that all the energy in the big-bang-created-universe will equal to the energy that was released by the Big Bang? The sum is zero? Edit The cited dup is asking "Did the law ...
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2answers
44 views

Hubble Constant at understandable distances

If I had two tennis balls, one meter apart, at what velocity are they moving away from each other due to Hubble flow? (Assume they are in a zero G environment, and nothing impedes their movement.)
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1answer
55 views

Where is the universe expanding from? [duplicate]

It seems to be quite a common question to ask "what is the universe expanding into?" However I want to ask "where is the universe expanding from?" Is there a "centre of expansion" of our universe ...
2
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2answers
573 views

Can the Universe create itself?--Is Gott's Use of CTC in Planck time or less valid?

My question is the title of a 1991 paper by Richard Gott and Li-Xin Li: http://arxiv.org/abs/astro-ph/9712344 and is also a subject of his popular book, "Time Travel in Einstein's Universe" Ultimately ...
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1answer
120 views

Big Bang…or…Everywhere Stretch?

Recently I watched a minute-physics video that suggested that a better name for the beginning of time would be "Everywhere stretch" because there wasn't a space-time singularity that formed where the ...
4
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1answer
213 views

Probability of spontaneous Boltzmann brain formation

I was reading through: http://www.scottaaronson.com/papers/giqtm3.pdf But I can't make sense of page 61 discussing Boltzmann brains. Specifically the fact that it says: But the problem is worse. ...
3
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1answer
93 views

Could the singularity that gave rise to our universe be past-eternal?

Are there any compelling models that include a past eternal singularity that ultimately gave rise to our universe? Does the "no-boundary" hypothesis that utilizes imaginary time have past eternal ...
3
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2answers
107 views

Is entropy absolute (as in absolute temperature)?

Following this question on the Entropy at the Big Bang where I asked: Since Entropy always increases (in general); its expected that the entropy at the beginning of the universe should be the ...
-1
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1answer
63 views

What proof do we have that space is expanding? [duplicate]

how can we really say that space is expanding when we cannot see the distant galaxies forming nor are the planets nearby newly formed, nor is anything expanding in size nor are we going far away? ...
0
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1answer
36 views

Is there a real and relevant relationship between Big Bang and dark matter?

Since the postulate of dark matter is based on the unexpected rotational velocity around the centre of a spiral galaxy, then it can be presumed that the Big Bang Theory is not relevant to the search ...
4
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2answers
348 views

Age of the universe and the singularity at the Big Bang

Using the standard model of cosmology we calculate the Hubble time to obtain an estimate of the age of the universe. This model assumes a beginning of time in the past. But that point is a true ...
3
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3answers
388 views

Has anyone ever tried to formulate physics based on computer science or information processing?

Some physicists and university researchers say it's possible to test the theory that our entire universe exists inside a computer simulation, like in the 1999 film "The Matrix." In 2003, University ...
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0answers
67 views

Is there evidence that the universe truly is the entirety of “everything”? [closed]

This is a question that has popped in my head recently. Do we have any verifiable proof that the "known" universe truly is everything that is out there? I'm not talking about the multiverse theory ...
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1answer
123 views

Age of the universe [closed]

Does the fact that the edge of our observable Universe contains information from the beginning of the Universe give us an ability to determine its age? The edge of our observable universe surely has ...
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2answers
102 views

Where did energy come from?

So it is my understanding that before the big bang there was a very small point that held all of the matter in the universe. My question is what form did energy of the universe take on when it was in ...
4
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1answer
87 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 ...
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3answers
343 views

Where is all the Dark Matter? Theoretical Question

In my Physics Class we had to look into possible areas where Dark Matter could be "hiding." Such as Black Holes and so on. Dark matter really can be "seen" through its gravitational effects, and we ...
0
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1answer
45 views

Discrepancy problem in lithium?

Why is there a discrepancy between the amount of lithium-7 predicted to be produced in Big Bang nucleosynthesis and the amount observed in very old stars?
0
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1answer
57 views

Doesn't the Big Bang negate the law of conservation of matter? [duplicate]

I was watching Hawking (2004 film) and in the movie, Hawking has a sudden insight that all the matter and energy observed in the known universe may, in fact, have sprung out from nothing (singularity) ...
2
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4answers
169 views

Does big bang have really any justification while we are living within a huge chaos?

All the physicists already know that the n-body problem reveals chaos, so that the planets around the sun should undergo deterministic chaos with a Lyapunov exponent of the order of, say, ...
6
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4answers
811 views

Does (it make sense to say that ) the universe has a center?

I was reading this page: http://www.guardian.co.uk/science/2011/oct/23/brian-cox-jeff-forshaw-answers and I found this sentence by Brian Cox: That seems to imply that everything is flying away ...
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2answers
33 views

Is there a friction or retarding force in creating spacetime?

As matter and energy expand with the big bang, they create spacetime (or so I've been told). Is there any evidence that this creation of spacetime has a retarding force on the expansion? If not, ...
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1answer
45 views

What does inflationary theory explain which quantum entanglement cannot?

Introduction This is an honest question... I don't study inflationary theory extensively (This is an understatement) but I am lost as to why it was developed in the first place. Here is why: ...
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0answers
25 views

Do physicists theorize an origin to the big bang?

Do we have any theory that covers a possibility of the big bang's origin? This seems like the most difficult question of all. Logic tells us that every effect has a cause. But every cause must be the ...
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0answers
18 views

Is a big bang capable of producing infinite outcomes?

I hear commonly about the (perhaps silly)idea of there being an infinite number of universes, a new one for each possible difference. For example there would be a universe where I'm a millionaire. ...
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0answers
56 views

What happens if the big bang occurs once again?

according to string theory every universe is a large brane and big bang is a event which takes place when two branes collide with each other. if our universe brane collides with another brane there ...
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5answers
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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 ...
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1answer
62 views

Is the center of the universe in another dimension?

If we live in a four dimensional world and when we try to find the center of the universe (where the big bang occured) we found that there is no apparent center, could that means that the big bang ...
23
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11answers
2k views

How can it be that the beginning universe had a high temperature and a low entropy at the same time?

The Big Bang theory assumes that our universe started from a very/infinitely dense and extremely/infinitely hot state. But on the other side, it is often claimed that our universe must have been ...
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0answers
58 views

Why did the universe have a low entropy at the big bang?

Sean Carroll, in his book "From Eternity to Here", asks the following question. Why did the universe have a low entropy at the big bang? in John Cramer version of the Wheeler - Feynman absorber ...
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0answers
38 views

Can quantum fluctuation happen outside space-time? [duplicate]

So far I know, quantum fluctuations happen inside the vacuum which resides in the space-time. So, can it happen outside space-time? Because, one proposition suggest, big-bang was result of some kind ...
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3answers
1k views

Is there a center of the Universe if the Universe is finite?

Ok, let me make myself clear. I saw all the other questions related to the question, but none of them actually asks the question the way I would put it and therefore no one answers it the way I want ...
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0answers
44 views

Does Big Bang Cosmology imply/require infinite space?

The reason I am asking this question is because if all points in space observe recession of galaxies the same as we do from Earth, the universe would have to be infinite (or a closed sphere in 4D or ...
4
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3answers
283 views

Is there an exact formal definition of the Universe?

I've read several articles about observable Universe, Universe and Hubble volume, including Wikipedia article and references on it, and I wondered: Is there a formal, rigorous definition in physics of ...
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0answers
131 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 ...
3
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1answer
91 views

Could Hyper-Massive Black Holes be due to Dark Matter in the Early Universe?

An interesting discussion started here: Is there a limit as to how fast a black hole can grow? I am curious if Thompson Scattering and Eddington Luminosity have the same effect on Dark Matter (or ...
0
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0answers
38 views

Infinite universe, big bang = no singularity? [duplicate]

If we traced an infinite universe back in time towards t=0(ish) would a singularity still be formed? Would the singularity be infinite in size? (To me it seems it would have to be) This reminds me ...
0
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1answer
47 views

Is the size of the universe directly related to its temperature? [duplicate]

The universe was at its hottest when it was at its smallest. As the universe expands, it gets cooler. Is the expansion of the universe the direct cause the cooling? I suppose it would be more clear ...