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

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14
votes
3answers
934 views

What's the fastest moving object in the universe?

We know that nothing can have proper velocities larger than the speed of light in vacuum. But are there any objects in space that get close to it? Any comets, or other objects thrown by gravity or ...
10
votes
2answers
212 views

How exactly is our universe mapped?

Watching this youtube video shows that our planet is nothing more than dust in the wind. At the 2:50 mark in the video, you will see a view of the whole Milky Way. At the bottom you will see this ...
10
votes
1answer
153 views

Explaining Dark Matter and Dark Energy to layman

With my little knowledge, I know this: Dark Matter The center of a galaxy controls/attracts its objects (stars, planets, comets etc.) towards itself because of gravity. But the mass of the center of ...
9
votes
7answers
316 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 ...
9
votes
1answer
88 views

On what scale does the universe expand?

According to the theory (or my understanding of it), the universe is not only expanding, but speeding up. If the galaxies are moving apart, are the solar systems within them also moving apart from ...
9
votes
1answer
260 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 ...
9
votes
1answer
121 views

Where is all the antimatter?

The universe supposedly started off with equal parts matter and antimatter and they are said to annihilate each other. Also, nature is famous for it's balance between everything. So all we see is ...
8
votes
1answer
118 views

Why does a planet rotate and revolve?

Why do planets rotate and revolve in the universe?
7
votes
2answers
79 views

How are Galaxy Super Clusters Generated

I have seen pictures of clusters of galaxies, usually used in regards to theories of dark matter and galaxy formations. One of the most famous ones has the perceived shape of a stick-figure. If I am ...
6
votes
2answers
112 views

Why is the observable Universe larger than its age would suggest?

The age of the Universe is estimated at 13.8 billion years, and current theory states nothing can exceed the speed of light, which can lead to the incorrect conclusion that the universe can't have a ...
6
votes
2answers
80 views

Is there any difference between parallel universes and multiverse?

Nowadays we come across with these two terms - parallel universes and multiverse. I wonder if this is the same thing or its two entirely different principles because the names are a bit confusing to ...
5
votes
1answer
175 views

Layout of the universe

I've been working on a space game in my spare time, and lately I've been thinking on how to layout the universe. Though I searched around and found it hard to get a good view of what the universe ...
5
votes
3answers
100 views

Is there a natural process by which hydrogen is generated from heavier elements in the cosmos?

we know that stars fuse hydrogen into helium starting at 3 MK; 13 MK in the Sun's core; carbon fusion starts at above 500 million K, and silicon fusion starts at over 2700 million K for comparison; ...
5
votes
3answers
137 views

Can there be a 2nd possibility deduced from the fact that galaxies are moving away from us?

I just read that according to the BBT the universe is expanding. This is evident from the fact that distant stars (and galaxies) are moving away from us. But it could also happen that the universe is ...
5
votes
2answers
123 views

Do parallel universes exist?

Do other universes like ours exist? If they exist, how do we know that they exist when we have even not seen the ends of our own universe?
4
votes
2answers
121 views

How can we predict a Big Crunch when all galaxies are moving further apart?

I've read that the further away a Galaxy is from us the faster it moves away. By this logic how can scientists predict that there will eventually be a big crunch when every piece of matter is ...
4
votes
1answer
66 views

Are there any alternative explanations for the gravitational force we attribute to dark matter?

It always seemed counter-intuitive to me that we observed an measured a gravitational force and since the universe has not enough mass to account for it, the conclusion was to say there's a different ...
3
votes
2answers
156 views

What is the physical, geometric shape of the universe?

I'm not asking about theoretical ball, vs saddle, vs flat surface which is just a metaphor with 2D space. It's hard to say as we see very little of it, and we see them in the past because light ...
3
votes
2answers
182 views

Is the universe expanding faster than speed of light?

The celestial bodies like stars and galaxies are moving away from each other. How fast are they moving apart? Is that speed more than the speed of light?
3
votes
2answers
77 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 ...
3
votes
1answer
92 views

Does our universe have to be embedded in a higher dimensional space?

I've heard that our universe may be open or closed. If it's closed it might have a toroid shape. If this is the case, would that imply that our 3 spatial dimensions have to be embedded in a higher ...
3
votes
3answers
87 views

What would we find if we could travel 786 trillion light years in any direction

I've sometimes heard of galaxies that are millions or billions of light years away but if we could instantly travel 786 trillion light years in any direction, what are we likely to find? And what if ...
3
votes
0answers
47 views

What is that void that the universe is growing into? [duplicate]

We understand that this is the universe and it is essentially full of space and time, but what is on the outside of the universe, and isn't that nothing, something, and how far does that reach. I.e. ...
2
votes
4answers
91 views

Is it possible to be 'still' in space?

So I was reading this answer about how galaxies are the fastest moving objects in the universe because space is expanding faster than the speed of light. This got me wondering, would it be possible to ...
2
votes
2answers
79 views

Has life been discovered outside of Earth?

I've just watched a movie that made me curious as to whether life has really been discovered on another world such as Europa??
2
votes
4answers
129 views

What is the speed of light relative to (in space)?

From what I understand the universe is expanding faster than the speed of light and accelerating so that it's possible that a given galaxy: $A$ will no longer be visible to another given galaxy: $B$. ...
2
votes
1answer
67 views

why are galaxies different in color?

whether its in movies,television,real-life or some planetarium different galaxies are shown in different color. For ex:- Milky way is always seen in Blue where as Andromeda gives out a bit reddish ...
2
votes
1answer
49 views

“How the Universe Works”: is it scientifically accurate? [closed]

The documentary/mini-series How the Universe Works is based on scientific evidence and according to what is known nowadays, or sheer bunk? Throughout the series, are there any particular topics which ...
2
votes
0answers
23 views

Can we only see the past of the universe? [duplicate]

So I was reading some interesting stuff about universe and Big Bang and wanted to make sure one thing. As far as I understand everything we can see about universe is the past, right? I mean all the ...
1
vote
2answers
122 views

Age of the universe

A Galactic year is estimated to be around 250 million "terrestrial" years. That means there will be about 4 rotations per billion years. And age of the universe is estimated to be near 13.8 billion ...
1
vote
2answers
75 views

Relation between black hole mass and radius, and our universe's

Is there a graph of known black holes, with their estimated mass in the X axis and their estimated radius in the Y axis? If so, where can we find it? I would like to know if a black whole with the ...
1
vote
2answers
138 views

Observable Universe: why distant galaxies not visible?

Assuming that the Universe is and has been expanding ever since its creation (BBT), the galaxies that are now at the 'edge' (not visible theoretically) must have been (at some point in time) at place ...
1
vote
1answer
108 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
2answers
354 views

Is it possible to create an artificial Black Hole?

I am quite curious about black holes. Once I just thought whether it is possible to create an artificial Black Hole, i.e. an human made black hole. Also explain there formation if it is possible.
1
vote
1answer
64 views

If we lived in a multiverse, what would our universe most likely then be named? [closed]

For instance, we live in the Milky Way Galaxy. We don't just call it "The Galaxy", because we know there are multiple different galaxies. So if we lived in a multiverse, it wouldn't make much sense to ...
1
vote
2answers
88 views

Can we know whether any distant galaxy is moving away in same direction or in opposite direction w.r.t. our galaxy?

The Hubble law states that the recessional velocity of a galaxy is proportional to its distance from us. It takes redshift and angular sizes (for distance) of the galaxy to determine velocity, and ...
1
vote
2answers
66 views

Are we moving away or towards each other?

There are numerous theories about the shape of the Universe. I've read somewhere most probably in 'A Brief History of Time' that there is a possibility that the Universe is spherical. So is it ...
1
vote
1answer
28 views

Our universe the surface of a 4-dimensional sphere?

The cosmic microwave background that we observe uniformly around us is usually explained by assuming that our universe is the surface of a four dimensional sphere. That way the uniformity makes sense ...
1
vote
0answers
52 views

Integral calculus for the Olympiad? [closed]

This year I am going to participate at the Astronomy Olympiad, in the beta group (seniors) - 15 years old or above. I have already participated at this Olympiad in the alpha group (juniors)... now, a ...
0
votes
1answer
98 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 ...
0
votes
1answer
72 views

Contradict the expansion of the universe?

Lets say that we observe in a distant galaxy cluster, which in all the galaxies move far away from us. and here we see in the same cluster a galaxy that move away from us in a much lower velocity ...
0
votes
1answer
78 views

Does the holographic principle contradict eternal inflation?

As it is for example explained here, Andrei Linde's chaotic inflation is among the potential winners or survivors of the spring cleaning induced by the potential detection of primoridal gravitational ...
0
votes
1answer
44 views

What do shape of universe mean? [closed]

What shape does a three dimensional universe have ? and how did scientists determined that it is flat and not curved.
0
votes
1answer
95 views

How big is the universe. How does it works?

I watch this movie: How big is the universe https://www.youtube.com/watch?v=b34gwCKIM50#t=50m00s I can't understand where is there triangle with 180 degrees. What exactly is this red spot on the ...