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

learn more… | top users | synonyms

18
votes
1answer
182 views

Why is there a matter/anti-matter asymmetry in the universe?

After the big bang occurred what biased the formation of particles over anti-particles? Why are particles more common than anti-particles?
16
votes
4answers
465 views

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 ...
11
votes
7answers
730 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? ...
9
votes
1answer
158 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 ...
6
votes
4answers
122 views

Can it be inferred that our cosmological horizon has increased over time?

If I am right, we can see only those stars that lie within our cosmological horizon, and there may or may not be any stars beyond that. Given last 150 years of using telescopes, and since then our ...
5
votes
1answer
126 views

Might the universe be really small yet seem infinite from spherical reflections? [closed]

if a single source of light quite small, was placed somewhere inside a completely reflective sphere, quite large, what would the reflections look like from the light source's point of view within that ...
4
votes
1answer
72 views

Formation of Cosmic Microwave Background

It is said that the cosmic microwave radiation (CMB) was formed when the universe was 379,000 years old. How is this calculated?
4
votes
1answer
117 views

What is the explanation for rapid inflation just after the big bang?

I often hear about cosmic inflation occurring rapidly after the Big Bang, but have never came across any explanation for it. What supposedly caused this inflationary period in the early universe? ...
3
votes
3answers
119 views

Did big bang happen only one time or it might happen again somewhere million time away from our observable universe?

We know, everything is in existence due to big bang from singularity. Time also started from that big bang point. So, did big bang happen only once or it might happen again somewhere million time ...
3
votes
2answers
277 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 ...
3
votes
2answers
103 views

Why aren't the farthest objects close to each other?

The last years we find some objects like this : MACS0647-JD which are more than 13 billion light-years away from us. This means that the picture we get was created only some million years after the ...
3
votes
1answer
106 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 ...
3
votes
1answer
106 views

Why are explosions always used to represent the Big Bang?

In documentaries the Big Bang is often represented as blackness followed by a big explosion with loud noises. This always feels cheap and falling short of explaining the origin of the Universe. Is ...
2
votes
4answers
249 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 ...
2
votes
3answers
149 views

How is the universe bordered?

This answer says that some models describes the universe as finite. How do those models describe the universe's border? Does the border (theoretically) exist? Is it a solid border? Do they predict ...
2
votes
1answer
84 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? ...
2
votes
1answer
74 views

If the speed at which the universe contracts in reverse time decreases over time, then how did scientists arrive at a date for “The Big Bang”?

If the speed at which the universe expands is constantly increasing (just like a derivative), then the opposite must also be true: the speed at which the universe contracts in reverse time is ...
2
votes
1answer
51 views

World line coordinate finiteness

If you trace two particles' world line backwards in time, according to current theory, both objects should converge at big bang. Would both objects arrive there simultaneously? Another way of asking ...
2
votes
1answer
101 views

In what form was the space at singularity?

It is somewhat imaginable for all the matter or energy to be condensed in sub-atomic size. But what about space? The space is neither 'matter' nor 'Energy'. If there were no space at singularity ...
1
vote
5answers
249 views

How far away is the light that would reveal the Big Bang?

I guess theoretically if we could go faster than light, which we clearly cannot, at some point we'd be able to see the big bang itself. Just curious - how far away is that light?
1
vote
1answer
178 views

How Far Are We From the Edge of the Universe? [duplicate]

Following the Big Bang the Universe continues to expand, presumably and roughly equally in all directions. It is understood that the Big Bang occurred 13.798 ± 0.037 billion years ago. Is there ...
1
vote
3answers
52 views

Could the universe have evolved differently?

Given the initial conditions at the Big Bang, could our universe have evolved any differently? In other words, did the initial conditions predetermine every stage in the evolution of the universe to ...
1
vote
2answers
116 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 ...
1
vote
4answers
305 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 ...
1
vote
1answer
143 views

The reason behind Big Bang

It always amuse us to research about things around us and we always start our research with a question that - what must be the reason for happening of that phenomenon? As we know that the formation ...
1
vote
1answer
97 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 ...
1
vote
1answer
63 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?
1
vote
0answers
18 views

Was the Universe expanding before the beginning of inflation?

My point of view is that first there was the Big Bang singularity, and then the period of inflation which resulted in the observable Universe becoming many times bigger. But was the Universe expanding ...
1
vote
1answer
78 views

How do we know the universe's expansion is speeding up?

Please forgive my ignorance, I am not an astronomer, just an interested layman. The further away a galaxy is from us, the faster it is moving away from us. But the galaxies we see exist in the ...
1
vote
2answers
73 views

Big Bang / Big Crunch cycle?

I've been reading some of Stephen Hawking's work on the theory of the expansion (and ultimate contraction) of the universe and was curious if anyone has every hypothesized that the universe has ...
1
vote
0answers
69 views

How do we know the big bang expanded space and not the other way around?

Whenever we hear an explanation about the big bang, it is always phrased in such a way that it was an explosion which used some kind of pressure to expanded the universe out. I wonder, however, would ...
1
vote
1answer
34 views

Matter and Antimatter Interaction in the early Universe

Well it is said that during the Big Bang, things were created in pairs: one matter and one anti-matter. I think its a part of the Big-Bang Theory. It is also said that matter + anti-matter - Energy ...
0
votes
3answers
256 views

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

Questions I've often wondered about: 1) 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? 2) If the reason #1 ...
0
votes
1answer
30 views

How do we get radio signals of the big bang?

From TV shows I have known that we still get some radio signals of the big bang and they are every where. My question is is the universe expanding so fast that even electromagnetic wave has failed to ...
0
votes
0answers
17 views

How come, in our lifetime, we will see the first stars which ever formed?

Isn't it an unlikely coincidence that we live in such special times, that we will have observatories (JWST) that see all the way back to the first starlight in the universe? Are we dreaming, and is it ...
0
votes
0answers
30 views

How was all the matter curled up inside a singularity during big bang ?

If the singularity had infinite mass, temperature and density, then it should curve space and time but there was no space-time before big bang. So where did the singularity come to existence without ...
-1
votes
1answer
123 views

Distance between Earth and where The Big Bang's happened? [duplicate]

The universe is around 13.8 billion years old. We know how fast the light is. We also know how fast our galaxy moving around inside observable universe. Is it possible to calculating distance ...
-1
votes
1answer
94 views

Thought experiment about the outskirts of the universe [closed]

Suppose I aim at some object that is 13 billion light years away from Earth. Let's assume I have a twin that pilots a ship that travels in infinite speed, meaning that he can reach that object and ...
-2
votes
1answer
110 views

Does science need support from religion or philosophy to explain the creation? [closed]

Science is trying to explain how the universe is made. The beginning of the universe explains the Big Bang theory. But what happened before Big Bang? Science cannot go before that. So, does this mean ...
-3
votes
2answers
112 views

Time dilation at the Big Bang [duplicate]

At the time the Big Bang happened the matter had enormous density. According the GR (I may be wrong here) such density dilates time. If so, could it be that the time periods just after Big Bang which ...
-3
votes
1answer
84 views

Astronomy questions I wondered for hours [closed]

I read a question posted by a community member in my community that shocked me, I think it contains some pretty cool astronomy questions that I cant wait for you scientists to answer. I am asking this ...
-3
votes
1answer
84 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 ...