Questions regarding the space in which all matter is thought to exist.

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3answers
675 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 ...
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0answers
43 views

Is our universe expanding? [duplicate]

Is our universe is expanding or contracting. And if it is doing so then what is the basic principle behind it. Is it related to the net energy of the universe or something else.
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9answers
2k views

What's the largest non-spherical astronomical object in the universe?

Some asteroids and comets are non-spherical. But is the nature of big things and gravity so that large things in the universe are always spherical? What is the biggest astronomical object in terms of ...
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1answer
91 views

If the universe keeps expanding, can we travel to the edge of the universe? [duplicate]

If the universe keeps expanding, is it possible to travel to the edge of the universe?
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0answers
28 views

Coincidence with Schwarzschild radius? [duplicate]

I was reading the article for Schwarzschild radius on Wikipedia and I noticed that the article states: The observable universe's mass has a Schwarzschild radius of approximately 13.7 billion light ...
3
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2answers
274 views

Can the theory of multiuniverse explain dark matter?

If there are many universes they must have an gravity effect on each other. Since dark matter is measured through gravity but we dont know the mass behind it, isnt it possible that it comes from ...
9
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1answer
2k views

What is the most dense object in the universe?

Inspired by this answer to the question, Why is the Sun's density less than the inner planets?, what is the most dense object in the universe?
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2answers
101 views

Is there any proof of space being created?

Is there any proof for space being created? Because I guess an explanation for the dark energy (dark = our understanding of it) could be that there is a gigantic amount of matter/dark matter that we ...
0
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0answers
96 views

In a finite universe, what happens when light reaches the boundary?

If a universe is finite and is not expanding at a speed equal to or greater than c, what happens when light or another form of electromagnetic radiation traveling reaches the boundary?
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1answer
83 views

Birthday of the Universe

With every improvement of measurement we are able to determine the age of the Universe more exactly. I just wondered how much and what means it would need to narrow the range of age so that it would ...
2
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1answer
85 views

How could we tell if the Universe is infinite? [duplicate]

I've heard from a number of people that the Universe is infinite, and from my perspective, I can't see how this can actually be known, especially given that the Universe started out a finite size and ...
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1answer
51 views

Locations of farthest matter

Regarding matter that has the highest redshifts, do we see such matter in every general direction we look (relative to Earth: up down left right front back)?
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1answer
42 views

Evidence of CMB redshift

Are there any known spectral lines shifted by ~1100? If not, then how certain is mainstream that the CMB has a redshift of ~1100? All I see is a blackbody radiation curve void of spectral lines.
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3answers
104 views

Are we center of universe? [duplicate]

So I just learned that CMB redshift is 1100 regardless where we look (up down left right). According to Hubble's Law that makes it around 46 billion light years away, making it the farthest matter ...
0
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3answers
102 views

What is the volume of the universe?

Of course it is not exactly known how big the universe is, but I thougt that the universe is about 100 billion lightyears in diameter. But if that is true can you also make an estimation of the volume ...
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1answer
1k views

How many earths fit in the observable universe?

I was pondering our insignificance, when I wondered - how how much smaller is our planet then the (observable) universe? And being as I dont know how to do the math, I'm asking it here. So how many ...
9
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2answers
1k views

Is the earth bombarded equally in all directions by neutrinos?

Perhaps it is hard to known for sure because neutrinos are very difficult to detect, although they do go through the earth in very large numbers. But are they passing through the earth equally from ...
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1answer
34 views

Are there events in universe which we receive first from their neutrino's instead of their photons?

Neutrino's are very small though they have mass. Because of that it is probably that the don't have a speed faster than photons. But is it in all events, like supernova's or else events, where it is ...
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1answer
163 views

What are the 10 most abundant elements in the universe by number of atomic nuclei?

I've seen websites that show the ratios of the 10 most common elements but they compare them by relative mass. I think it's more interesting to know the relative abundances of atomic nuclei because ...
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2answers
97 views

What happens outside of the universe? [duplicate]

Since the universe is always expanding, that means there's an edge right? So what are some theories for outside of that growing edge.
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3answers
175 views

How does the concept of a universe with no center work?

I understand basically that the universe is homogenous (looks the same from every point) and I was told in my astro class that it's supposed to have no center, but how that works boggles my mind. I ...
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2answers
61 views

Regarding the age / size of the Universe [duplicate]

I believe the current estimated age of the Universe is around 14 billion years. I just read in another post on here that the diameter of the Universe is around 90 billion light years. This doesn't ...
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1answer
48 views

Origin of the Universe [closed]

I heard on a you tube video that a new theory came out in 2015 . The theory is that there was no "Big Bang" and that the Universe has no beginning .
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1answer
74 views

Is the flat curvature of the universe in the 5th dimension?

It is hard to imagine that the universe could have a flat curvature while I've read that it is at this moment the most likely. When you look around the universe is expanding in all directions, so it ...
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2answers
69 views

Why can't different regions of the universe be the same as they have the same origin?

The horizon problem states that because of the speed of information can't be faster than light and the distances between far regions are too big there is a problem because they look quite the same. ...
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1answer
8k views

How many sun-like stars are there in the universe?

After yesterday's announcement of the Kepler telescope finding a huge amount of newly observed exoplanets, i saw a headline claiming that as much as 22% of sun like stars in the universe have planets ...
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1answer
66 views

Why is there a difference between the cosmic event horizon and the age of the universe?

According to wiki the cosmic event horizon is 5 Gpc but the age of the universe is about 13,7 billion years. Usually light from far galaxys needed at most 13,7 billion years to reach the earth so the ...
5
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2answers
163 views

Why when we look through a telescope in space, do the billions of stars not block our view from seeing further?

I know that we are able to "see back into time" by looking very far away through telescopes such as the Hubble telescope, but my question is, wouldn't you run into at least a couple of stars that were ...
2
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3answers
247 views

Meaningful theories of the shape of the universe

Normally, when people say "the universe is infinite" they generally mean something like "the observable universe is locally flat, it is easy to assume that it is flat way beyond the observable ...
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0answers
27 views

Are there other universes? [duplicate]

Our universe is a very unlikely place. Alter some of its settings even slightly and life as we know it becomes impossible. In an attempt to unravel this "fine-tuning" problem, physicists are ...
4
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1answer
105 views

What is driving the expansion of the Universe?

Is it just the momentum from the Big Bang? If yes, how can it account for the acceleration of the expansion? Why isn't the collective gravitational force slowing it down? What part does dark energy ...
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2answers
61 views

Is parallel universe possible [duplicate]

Does parallel universe really exists or just science fiction which ain't possible? Can we ever know ?
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2answers
66 views

Large hadron collider [closed]

Whether the collision of particle will lead to a massive WORMHOLE or if BLACKHOLE is also possible? How much I know is that it's created for einstien's E=mc^2 ,conservation of energy from mass and ...
-6
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1answer
115 views

Is this Universe scenario correct? [closed]

I will try to give you my reasoning behind my scenario. Ok I've researched and found That 95 percent of the galaxy has been formed already, And the other 5 percent is still to come.http://www....
3
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1answer
104 views

How do we know the current state of the universe by observing it from Earth?

Since light travels at the constant speed and takes more than a billion years to travel from the distant parts of the Universe, how do we know the state of the distant regions? Do those still exist or ...
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2answers
110 views

Does every object in the Universe have gravity? Space has no gravity, why?

My science teacher told me that every object in Universe has gravity but space is a part of Universe too, so, why does the space have no gravity?
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1answer
65 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 ...
6
votes
3answers
329 views

How does light affect the universe?

When light is emitted by for example a star, that star loses energy - which causes it to reduce its gravity. Then that energy begins a journey for potentially billions of years, until it reaches some ...
7
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4answers
236 views

Why does it make sense to say the universe has no centre?

If we suppose we and everything in the universe is perfectly flat. That is, we have width and depth, but no height. And we are situated on the surface of a balloon blowing up with air and expanding "...
0
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1answer
65 views

Second Big Bang [duplicate]

Just say you are immortal and will live forever. Since the universe is claimed to be unstable, what would happen after it ends? Would all of the universe's mass just fly back into another compressed ...
2
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4answers
101 views

If I were to point into the sky, how many galaxies would be in this line?

If I point in the sky and draw a line from the tip of my finger to the end of the universe, how many galaxies would this line cross? I had a discussion with my dad and he said due to the universe ...
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1answer
88 views

How do we know that the Universe is still expanding now?

Yes, I know that most galaxies have a red shift and that means they are moving away from us. The problem is that the farthest galaxies are 13.8 billion light years away. That means that the info is ...
5
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3answers
176 views

Are black holes expanding?

We know that it is a commonly heard claim that in every black hole there is a universe. It is also believed that the universe is expanding. If we use both of these, can we conclude that every black ...
2
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1answer
92 views

Does gravity bend light, and how much time does it take for light to cross gravity of a Black Hole?

This is very confusing to me, so the question might be same. Please go through it, if required i will add more text. According to Einstein's theory of general relativity, photons are not technically ...
3
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1answer
57 views

Formation of our Universe

So I got this information from a magazine , Scientific American issue Physics at the Limits. The theory is that our Universe came about, when in the "Bulk Universe", which is four dimensional, a four ...
2
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1answer
42 views

What does an Einstein-De Sitter universe look like?

I know an Einstein-De Sitter universe is a "flat" universe, i.e. with a K ("bendiness", sorry, don't really know what to call it in English) factor of 0, but does that entail anything as to its ...
12
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2answers
484 views

Why does a planet rotate and revolve?

Why do planets rotate and revolve in the universe?
2
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2answers
92 views

Is time itself speeding up universally?

Time moves more slowly near a mass than in relatively empty space. For example, I get that an observer would see someone falling into a black hole to appear to move more slowly and get "stuck" on the ...
2
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3answers
94 views

infinite Universe [duplicate]

I was watching a documentary and they said that Cosmologists have determined that the Universe is infinite. I find this to contradict the expansion theory. If the Universe had a starting point then ...
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1answer
167 views

If the Universe is infinite, would heat death be impossible?

If the Universe is infinite, one would imagine that if we kept moving through space, we'd constantly find newer and newer galaxies and objects forever. This would imply that there is an infinite ...