All Questions
10
questions
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233
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How can the recession velocity of the galaxies be constant but the universe expand and a accelerating rate?
This almost seem counter-intuitive to me as if a object is such as a Galaxy is moving away from me at a constant velocity and the space between us is accelerating so should the velocity.
Any help is ...
0
votes
0
answers
57
views
Lower bound on the size of the universe, if closed [duplicate]
As the measurements show the flatness of our universe is approximately 1 but the measurements are with a slight error. If we assume that the flatness is greater than 1 but still within the error of ...
- 385
4
votes
2
answers
466
views
What is the volume of spacetime we can survey?
How large is the fraction of spacetime volume we can observe within a sphere with the radius of the present particle horizon distance?
- 928
1
vote
2
answers
279
views
What is outside the boundaries of our universe (Future horizon) [duplicate]
I m having difficulty understanding what is after the "Future Horizon" as defined per wikipedia
https://en.wikipedia.org/wiki/List_of_cosmological_horizons#Future_horizon
I read the similar "If the ...
- 119
2
votes
3
answers
876
views
How can an infinite universe expand?
Physicists have estimated the universe to be flat and infinite, but I can't seem to understand what this actually means. First of all, what do they mean when they say that the universe is infinite, ...
- 159
-1
votes
2
answers
208
views
Shape of the observable universe or Cosmic Horizon
My question is about the shape of the observable universe or Cosmic Horizon.
In literature it is described as having a radius, constant.
But in an accelerating expanding universe this seems ...
- 63
1
vote
1
answer
87
views
Past size of the present observable universe? [closed]
I always had kind of a difficult time reconciling the idea that the Universe may be infinite beyond what we can ever observe, with the fact that the confines of the observable universe go all the way ...
- 141
1
vote
3
answers
414
views
Why do some physicists think the universe could be infinite?
The deeper we look into space, the more primitive the structures are. Since we can see really primitive galaxies like Quasars, it's reasonable to think that there are even more primitive structures ...
- 1,137
5
votes
5
answers
2k
views
Is the universe bounded?
As I understand it nobody can pinpoint an objective "center" of the universe nor "where" the Big Bang happened. It seems the observable universe is limited by our event horizon at some 14 billion ...
- 1,302
2
votes
1
answer
237
views
Size of the Universe: Curved vs flat? Finite vs infinite?
I have recently heard the theory that the Universe may be smaller than observed but may be curved to the extent that light rays may have looped past us once already and hence appear to have originated ...
- 103