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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In Which Space Did the Big Bang Occur? [duplicate]

If our universe didn't exist before the big bang, the big bang can not have taken place in our universe, but in some external space. How does current physics explain this?
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Primordial black hole mass [closed]

Use dimensional arguments to combine the fundamental constants $\hbar$, $c$ and $G$ to derive the least massive primordial black hole formed shortly after the big bang. I'm not sure how to combine ...
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2answers
114 views

How fast does space/time travel?

It is said that before the big bang there was no before, as space/time was created in the big bang. The big bang creates a rapid expansion of space/time... so how fast is rapid?
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1answer
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Did the initiation of the Higgs Field and the inflationary period occur simultaneously?

My question is: Both of these concepts involve a phase transition and they both started, as far as I know, early in time, so are the above two ideas linked in any way? My first source for this query ...
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1answer
47 views

Why did formation of the first stars (population III) not happen earlier?

Was it the cooling of the universe? Naively, I would expect the lowering density to work against star formation.
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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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could anti-matter black hole is sitting at the center of the universe ? that have all the aniti matter [closed]

i am very curious about the space , matter and anti-matter , i am not a scientist but i have few question , can we calculate the speed of expansion of the universe? , i have made some assumption or ...
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1answer
51 views

Singularity - Origin Point

How can it be said that the real beginning of the real universe involved a "singularity of zero size and infinite density of mass" when no space existed at all to define any density and when ...
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3answers
679 views

What trajectory has the Cosmic Microwave Background radiation taken to get to earth?

I have a few related questions: Where is the CMB coming (emitted/reflected/remitted) from? When CMB hits the earth, is that the first thing those photons hit since they were emitted 400 thousand ...
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Why didn't the Big Bang create heavy elements?

In the case of a supernova explosion it is possible to create heavy elements through fusion. Supernovae have a tremendous amount of energy in a very small volume but not as much energy per volume as ...
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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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0answers
32 views

Why isn't the universe a singularity? [duplicate]

So, i'm just a high-schooler interested in physics, so don't judge me if I misinterpreted anything. But from my understanding of black holes, a singularity is created because any matter inside the ...
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Do the entropy of the universe and third law of thermodynamics conflict? [duplicate]

We know that our universe was in low entropy state at the earlier time after the Big bang. But we also know that the temperature at that times was enormously high. But what the third law of ...
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1answer
121 views

Pre Big Bang knowledge

I have read that no one knows what preceded the Big Bang, but is this true? The Big Bang process (with or without inflation) followed known rules which “existed” prior to time zero. For example, some ...
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2answers
159 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 ...
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0answers
23 views

The universe is said to have begun as a singularity, but how do we know nothing else existed? [duplicate]

When I imagine the big bang, I first imagine a tiny ball surrounded by black void. Then the ball explodes and the universe begins. I assume most physicists have the same basic idea. But how do we ...
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0answers
49 views

Modeling of Big Bang [duplicate]

Well, I’m just an ordinary High School passed student. I had passion towards space-time- relativity and other things related with physics :D I have been watching theories of physics like Big Bang from ...
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1answer
44 views

Equations for Big Bang expansion, distance and energy

On the back page of the CPEP poster “The History and Fate of the Universe” a table gives distance scale (size), temperature, and energy (radiation) for seven expansion times (10-43 sec to now). ...
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3answers
91 views

Is there any situation in which a primordial black hole-sized black hole form AFTER the “Big Bang?”

I have seen that primordial black holes may have formed at the start of the universe due to the density of matter. So, is there any way in which our current Universe could spawn a non-stellar mass ...
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0answers
24 views

What came before the Big Bang? [duplicate]

Is it an inflating bubble in a space time foam? Some concluded that "whereof one cannot speak, thereof one must be silent"
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0answers
27 views

Does the Big Bang Theory explain about the formation and destruction of matter? [duplicate]

I read here here that, The Big Bang theory explains how the universe was created. Even though it was unable to explain that how everything in the universe did came to existence from no matter state ...
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1answer
29 views

particle horizon and big bang

The farthest radiation we can see is from the particle horizon. But the farthest radiation is the CMB. Why does all radiation from the particle horizon stem from that earliest possible source time? In ...
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4answers
301 views

Frame of reference and big bang

I have read Brief History of Time in which he has wonderfully described the formation of universe. What is the frame of reference from which we are viewing the big bang? What is the frame of reference ...
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1answer
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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 ...
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3answers
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Big bang and time

I heard Carl Sagan talking about the Universe 15 Billion years ago, and the Big Bang. He made the statement that it was the biggest explosion of all time (at first I thought this a subtle pun). This ...
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0answers
35 views

Why not “A” big bang [duplicate]

What has led us to believe that there was "1" big bang and not multiple?
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7answers
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Why is there a scarcity of lithium?

One of the major impediments to the widespread adoption of electric cars is a shortage of lithium for the batteries. I read an article a while back that says that there is simply not enough lithium ...
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0answers
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Backtracking position [duplicate]

Using a hypothetical photo from a hypothetical telescope, we were able to determine that the farthest galaxy present in the photo is 1 billion light years away. Because we are awesome we were able to ...
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1answer
114 views

Faster than speed of light [duplicate]

I was watching a Physics TV show, When someone called Alex Filippenko said that when there was the Big Bang, the Space extended at a speed faster than speed of light. He said that it wasn't against ...
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31 views

How to explain the homogeneity of the universe through a physic model [duplicate]

If in general, two objects homogenize themself by combining it's parts, why the horizon effect, based on a big bang model, excludes such an important physical interaction process? I wonder if this ...
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1answer
57 views

About Time and the Big Bang [duplicate]

In a TV ducumentary, I heard that time started with Big Bang, and it is meaningless to talk of "before". This was given without any further explanation, in the peculiar, irritating style of ...
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1answer
166 views

If big bang theory is real.. then why do scientists do not accept “matter CAN disappear to Void”? [closed]

I believe in the big bang theory.. perhaps it was a big lightning not an explosion.. but even that is pretty much same as "big bang theory".. so matter came from "nothing" (zero). and existence is ...
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0answers
75 views

Does second law of thermodynamics imply the big bang?

Given that the second law of thermodynamics states that entropy always increases and the universe is currently not in a state of maximal entropy does that not imply that it must have started at a ...
2
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1answer
47 views

C&CP-Symmetry Violation in Baryogenesis

In cosmology, during the big bang; how does C-Symmetry violation allow for a greater number of baryons to be produced than anti-baryons in Baryogenesis, similarly how does CP-Symmetry tie into this?
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understanding time: Is time simply the rate change?

Is time simply the rate of change? If this is the case and time was created during the big bang would it be the case that the closer you get to the start of the big bang the "slower" things change ...
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186 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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5answers
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Does entropy increase or decrease as our Universe is expanding?

Scientists say that entropy of our universe is increasing as it is expanding and our universe is cooling down gradually from the time of its birth. If something is getting cooler and cooler, then how ...
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1answer
47 views

Superstrings in the 10th Dimension [closed]

Physicists say that the superstrings vibrating in the 10th dimension are what create the subatomic particles that make up our universe and all other possible universes as well. If that is true, ...
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2answers
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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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2answers
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When did the first carbon nucleus in the Universe come into existence?

I am a chemist with a passion for astrophysics and particle physics, and one of the most marvellous things I have learned in my life is the process of stellar nucleosynthesis. It saddens me how my ...
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2answers
302 views

Probability of spontaneous Boltzmann brain formation

I was reading through Scott Aaronson's notes (pdf), but I can't make sense of his discussion about Boltzmann brains on p61. Specifically the fact that it says: But the problem is worse. Since in ...
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2answers
93 views

If temperature is dependent on mass, how did the early universe have a temperature?

I am near the end of the book The First Three Minutes by Steven Weinberg. I am reading it in order to get a better picture of the early universe in the Big Bang model. But one thing I am having ...
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1answer
329 views

Stephen Hawking's theory of multiple universes [closed]

Is it correct to think that there are multiple universes? Does my thinking of having more than one big bang?
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1answer
215 views

Can space be created or destroyed [duplicate]

Wikipedia says It appears that space was created in the Big Bang, 13.8 billion years ago This seems a little off to me: can we say something has been created if there was no before it had ...
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3answers
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Why can we see the cosmic microwave background (CMB)?

I understand that we can never see much farther than the farthest galaxies we have observed. This is because, before the first galaxies formed, the universe was opaque--it was a soup of subatomic ...
5
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1answer
603 views

Additional merits to Wetterich's “Universe without expansion” compared to standard cosmological redshift interpretation?

A recent news item in Nature promotes Wetterich's preprint "A Universe without expansion". All sounds very exciting but hard to judge for non-experts. As I understand from the Nature's article, the ...
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2answers
228 views

Origin of Universe [duplicate]

The universe is believed to have originated from absolutely nothing, and we know it is still expanding. Physics says "something can arise from nothing". I understand how mass and energy are related ...
5
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1answer
599 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 requires separating spacetime into a 3D coordinate system and a time track. I fail to understand why it is appropriate to take ...
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1answer
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 ...
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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?)?