All Questions
27
questions
1
vote
3
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86
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Does the fact that we are able to see CMBR implies that universe expanded faster than light?
Supposedly, the universe underwent rapid expansion immediately after the big bang, surpassing the speed of light. If we can detect remnants from that era, does this suggest they moved faster than ...
- 21
1
vote
2
answers
470
views
Isn't the universe older than 13.8 billion years? [duplicate]
To preface this, I'm not an expert, I'm just an avid astronomer with little mathematical knowledge.
I was watching a video that was explaining the cosmic scale and how the observable universe is only ...
- 299
9
votes
2
answers
4k
views
Why do we need inflation?
wiki (https://en.wikipedia.org/wiki/Inflation_(cosmology)) says that immediately after BB there was expansion at speed greater than $c$, what makes this necessary, what would happen if expansion took ...
user337596
-1
votes
1
answer
53
views
Big Bang and relativity [duplicate]
Wasn't the big bang's explosion itself faster than speed of light? how does this not violate relativity, I had read an explanation earlier but it wasn't sufficient, can someone explain to me how the ...
2
votes
1
answer
82
views
Can we observe an event that occurs more than 13.7 billion light years away? [duplicate]
In Kurzgesagt's latest video about the largest black holes, the narrator says that two black holes have been observed orbiting each other at a distance of 17 billion light years from Earth. So light ...
- 437
0
votes
0
answers
34
views
Can the expansion of the Universe be faster than the speed of light? [duplicate]
I am reading the textbook "The Cosmic Perspective 8th ed.", in the chapter describing the earliest moments of the Big Bang, one of the sentences is
[...] a sudden and dramatic expansion of the ...
- 111
0
votes
2
answers
73
views
Speed of at expansion at the start of the big bang [duplicate]
If I understand the basics of the big bang correctly it starts with a very small dense point. At the moment of the big bang, less then microseconds after, the universe is already the size of our solar ...
- 1
0
votes
0
answers
32
views
How big is the universe 1 second after the Big Bang? [duplicate]
In his book Astrophysics for People in a Hurry, Neil de Grass Tyson starts of with the Big Bang and narrates on what (probably) happened within the first moments of our universe. He further states (p. ...
- 143
0
votes
0
answers
33
views
How can the universe expand faster than the speed of light? [duplicate]
In Neil deGrasse Tyson's Astrophysics for People in a Hurry, he writes:
By now, one second of time has passed.
*
The universe has grown to a few light-years across...
If nothing can move faster than ...
- 168
0
votes
1
answer
71
views
Seeing the Big Bang [duplicate]
The Big Bang happened almost 14 Billion years ago.
Theoretically speaking , if we could teleport (Instant teleportation) to somewhere that’s 20 Billion light years away from the Earth , if we looked ...
user199067
2
votes
0
answers
34
views
Rate of expansion of universe during big bang [duplicate]
We say big bang was the explosion not in the space but of the space itself that took place in a fraction of seconds. Speaking practically, we say the universe has no edge and is infinite. If the ...
user63923
0
votes
1
answer
210
views
Faster than speed of light [duplicate]
I was watching a Physics TV show, When someone called Alex Filippenko said that when there was the Big Bang, the Space extended at a speed faster than speed of light.
He said that it wasn't against ...
- 137
0
votes
2
answers
204
views
Did the Earth (amongst other things) travel faster than light?
It's often said that when you look far across space with a telescope you are looking back in time, as the light has only just reached our position in space.
However, given that the Earth and many ...
- 103
3
votes
2
answers
609
views
How do we know that space expanded with speed faster that a speed of light during big-bang inflation?
How do we know that space expanded faster than a speed of light in inflation?
I have read this Phys.SE question, and it says that limit for faster than a speed of light is for matter and waves only.
I ...
- 1,125
4
votes
6
answers
336
views
Is the universe expanding at a speed of almost $2c$?
I've been told nothing can travel faster than the speed of light. Therefore, from my vantage point the diameter of the universe is increasing at a rate of $2c$. Are there any flaws in my thinking?
- 161