Questions tagged [big-bang-theory]

Questions regarding the currently prevalent cosmological model for the origin of the universe.

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51 votes
7 answers
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What is in the center of the universe?

If the universe has formed & originated by a Big Bang Explosion, then there must be empty space left in the center of the explosion site, as all the matter is travelling at tremendous speeds away ...
Engineer Ishrat Hussain's user avatar
18 votes
5 answers
12k views

How can the universe be infinite?

I've heard from renowned astrophysicists that we don't yet know whether or not the Universe is infinite. How is that possible regarding the big bang theory is accepted (as they all do)? Are they ...
harogaston's user avatar
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22 votes
7 answers
8k views

Do we know the exact spot where big bang took place?

If you rewind the universe back 14,7 billion years, all matter were in one spot, and then started expanding. Do we know where this is in reference to our own solar system? And is there anything there? ...
bogen's user avatar
  • 2,356
19 votes
3 answers
4k views

How can the 13.8 billion years old universe have a radius of 46 billion light years? [duplicate]

The universe is about 13.8 billion years old. Assume at the big-bang it starts from a small region and the maximum possible speed according Einstein is the speed of light how can the universe got a ...
Wernfried Domscheit's user avatar
37 votes
5 answers
16k views

Why did the big bang not just produce a big black hole?

Questions I've often wondered about: If all the matter and energy were concentrated at a single point at the big bang, why wasn't that a black hole, or why didn't it form one? If the reason #1 above ...
yadda's user avatar
  • 567
5 votes
2 answers
340 views

Is there another explanation, apart from the doppler effect, for the redshift observed in distant galaxies?

On episode 10 of the original Cosmos TV series, Carl Sagan mentions that some scientist don't agree that the redshift observed in distant galaxies is evidence of the big bang, stating that probably ...
Eduardo Serra's user avatar
4 votes
3 answers
1k views

How can the universe be expanding faster than speed of light? [duplicate]

So the story goes like this: A long time ago, 13.799±0.021 billion years to be exact, something happened. It was a big bang, loud explosion and universe came to existence. It grew and grew, and now ...
Farhan's user avatar
  • 701
2 votes
1 answer
879 views

What was "space" like before big bang?

I have a simple question which I think about often but have no answer. If The Big Bang is true, than if the whole space was just a point 14 billion years ago, then what was around that point, some ...
Bhaskar Vashishth's user avatar
6 votes
2 answers
630 views

Outside of a Universe and its origin

Per the Big Bang Theory, the universe was formed from a dense singular point which existed 13 billion years ago and has been expanding ever since. This suggests that the point should have existed ...
toddlermenot's user avatar
16 votes
1 answer
3k views

Can we see the Big Bang happen if we look far enough?

The observable universe is constantly expanding as more light from the Big Bang reaches us. This light has been travelling for billions of years, so we are looking at the universe as it was a few ...
Nirvik Baruah's user avatar
5 votes
1 answer
406 views

Why is the Cosmic Microwave Background evidence of a hotter, denser early Universe?

In his book Gravitation and cosmology, Steven Weinberg says that CMB makes it "difficult to doubt that the universe has evolved from a hotter, denser early stage". In my understanding, the ...
Ritesh Singh's user avatar
4 votes
1 answer
210 views

Is it possible to get a glimpse of the Big Bang through gravitation waves?

I read in an article announcing the detection of gravitational waves by LIGO that it will be possible to detect them from the Big Bang. Is this true?
signsgeek's user avatar
  • 357
4 votes
2 answers
533 views

How could universe inflate itself out of the very dense and curved early spacetime? Could it happen in a black hole too?

Wasn't spacetime as much curved as a black hole directly after Big Bang, because mass was so densly packed? Wasn't everything like an event horizon and how could things expand across it? Could ...
LocalFluff's user avatar
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4 votes
1 answer
2k views

Why can't we determine the center of the universe [duplicate]

I find this baffling. If we can observe objects moving away from us and each other, than it stands to reason that we can track their paths (relative to each other and ourselves) backward to find a ...
MegaMark's user avatar
  • 341
2 votes
1 answer
440 views

Does a White hole lies behind a Black hole?

While reading about a White holes, I stumbled upon a question "Where does the matter emitted by a White hole come from?" There seems to be 2 possible candidates: It was the matter engulfed by a ...
pooja somani's user avatar
2 votes
1 answer
270 views

if the big bang only expanded the universe when and how did it originate? [duplicate]

If the big bang expanded the universe from a singularity point, that means that there was matter before, so where and how did matter form for the first time if it's even possible to know such a thing?
A.K's user avatar
  • 97
30 votes
3 answers
5k views

Could liquid water have existed in open space 15 million years after the Big Bang?

Around 15 million years after the Big Bang, the ambient temperatures was about $24^\circ {\rm C}$, which is in a range where water could be liquid. Could liquid blobs of water be existent then? PS: I ...
Cerelic's user avatar
  • 403
24 votes
3 answers
7k views

Is the Big Bang a theory or a model?

I ask this because someone mentioned ‘it isn't a theory, it's a model’ in the comments in an old question of mine: Is the expansion of the universe proof of the big bang? I guess defining terms is ...
Kilise's user avatar
  • 435
6 votes
4 answers
3k views

Why can we still see 10 billion year old galaxies?

I've never fully understood why we can still see galaxies that are 10 billion light years away. The age of the universe is calculated to be 13.9 billion years old and we live on a planet that it is ...
MattCowen's user avatar
5 votes
2 answers
289 views

Is mass+energy conserved when a new universe forms inside a black hole?

My understanding is that there are credible theories out there in which the formation of a singularity in a black hole also represents the beginning of a new universe via a big bang. We can't see the ...
kuzzooroo's user avatar
  • 369
5 votes
4 answers
1k views

Is the expansion of the universe proof of the big bang?

Is the expansion of the universe proof of the Big Bang theory? Or are there other proofs?
Kilise's user avatar
  • 435
4 votes
2 answers
1k views

Why are distant galaxies not visible in the observable Universe?

Assuming that the Universe is and has been expanding ever since its creation (Big Bang theory), the galaxies that are now at the 'edge' (not visible theoretically) must have been (at some point in ...
Vivek's user avatar
  • 155
4 votes
2 answers
332 views

Was the Big Bang an event within a preexisting Universe, or did it mark the beginning of the entire Universe, beyond just the observable Universe?

Could it be that the Universe is truly infinite, and the Big Bang was merely a singular, specific event that resulted in the birth of a 'bubble,' i.e. what we perceive as 'the observable universe'? ...
impact's user avatar
  • 51
3 votes
2 answers
174 views

Center of the universe

Big bang is not an explosion, but an expansion of space and time. Universe had almost infinite density... wait a moment. If it had ALMOST infinite density, it had a certain volume, and thus, space ...
Felix L.'s user avatar
  • 193
2 votes
2 answers
534 views

How thick is the cosmic microwave background, including the part we cannot see within the observable universe?

What I want to know is how thick the observable universe is from the point of the cosmic microwave background and beyond. It appears the thickness of the cosmic microwave background itself (the part ...
Jonathan's user avatar
  • 4,375
2 votes
1 answer
502 views

Future redshifting and effect on the 'pitch' of CMB radiation

After discovering this question exploring the sound of a blackbody, I started wondering about the sound of the Cosmic Microwave Background radiation from the Big Bang, specifically what the current ...
Alec's user avatar
  • 123
1 vote
1 answer
95 views

Location of Big Bang [duplicate]

Can I point to somewhere in the sky where the Big Bang happened? A pathway so to speak on where we (and our progenitor elements) came from?
iMerchant's user avatar
  • 1,052
1 vote
2 answers
850 views

Calculating the age of the universe

Is the calculated age of the universe that of the visible universe or the entire universe? I dont know how the age is calculated but if it is believed that all we see visibly IS the entire universe ...
Anoop Alex's user avatar
0 votes
1 answer
276 views

What does it mean for space to expand?

In this YT video Michelle Thaller says The Big Bang wasn’t an explosion but an expansion and as such there's no empty center where the explosion would've been. To explain expansion she uses the ...
Randy Zeitman's user avatar
0 votes
0 answers
136 views

Does the other side of the Big Bang factor into JWST observations?

Our (roughly) 13.6 billion light year view to the point of origin (big bang) is just along a radial axis. Assuming most matter ejected in a (roughly) spherical pattern, the diameter of the universe is ...
TonyG's user avatar
  • 109
-2 votes
1 answer
280 views

Big Bang Thoery, what triggered it and why [closed]

Given the vast infinite nature of universe, billions of worlds, distances and masses that we cannot comprehend, do you feel Big Bang theory is inadequate and in some ways tells you that it was all ...
Jabran's user avatar
  • 15