All Questions
Tagged with faster-than-light space-expansion
104
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530
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Please help me with this paradox [closed]
Physicists believe that some galaxies are moving away from us at faster than the speed of light. A galaxy that is moving away from us at faster than the speed of light would be moving backwards in ...
- 53
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3
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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
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2
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Can we use the fabric of spacetime to go faster than the speed of light?
If the fabric of spacetime isn't bound by the limit of the speed of light (the universe is expanding faster than the speed of light), could humans somehow wrap a spaceship in a bubble of the fabric of ...
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2
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How does the "York time" measure the expansion of space; why is it equal to the divergence of the comoving observer's four velocity for warp drive?
The mysterious York time, θ is important in warp drive topic. It is plotted on the famous diagrams and is considered the measure of the mechanism that "drives" the warp drive bubble at ...
-4
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1
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76
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What would happen if two super-massive black holes collide faster than the speed of light? [closed]
I know objects can't move through space faster than light. But there's no law against the expansion of the universe increasing the distance between two objects faster than the speed of light. But this ...
- 101
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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
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Is the kind of physics proposed for "warp drive" related to the way that space really is expanding?
As I understand, some parts of Universe really are moving faster than light -- is this expansion something we think we can create artificially?
And if we can do this artificially, could it be done a ...
- 2,238
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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
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2
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If galaxies beyond the cosmological event horizon move faster than light is then that motion a combination of their KE and space expansion?
If galaxies beyond the cosmological event horizon move faster than light is then that motion a combination of their KE and space expansion? Their KE alone isn't enough for them to move faster than ...
- 2,255
13
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Why does an Alcubierre drive, travelling FTL, violate causality, if the universe expanding FTL doesn't?
An Alcubierre drive seems to be plausible as a means to travel faster than light, because
it doesn't move the object itself, but the space around it.
it's said that matter and information can't move ...
- 151
3
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334
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Can we observe the universe expanding faster than light?
I am looking at the sky, and I see two objects moving away from each other with speed greater than the speed of light.
Light from one object is not fast enough to reach the other. So I decided to help ...
- 2,127
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Is there empirical evidence supporting a universe expanding faster than light?
We receive no light from galaxies beyond the cosmological horizon, but if they were moving away only at light speed, it seems to me their light wouldn't reach us. Is there any observations or ...
- 93
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Why is FTL travel impossible if the universe expands FTL?
If the universe is expanding spacetime faster than light (FTL), is FTL travel no longer completely impossible?
Do not care about energy requirements or needing new tech, just if it is NOT physically ...
- 141
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130
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Faster-than-light gravitational waves and faster-than-light expansion in the inflation
I have no introduction to the inflationary epoch. I know, however, that during this time space-time expanded with a speed faster than the speed of light. If gravitational waves are perturbations of ...
- 585
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Questions on observations of faster than light recession of galaxies [duplicate]
I've been reading several threads here and online articles trying to absorb the current understanding of observations of far galaxies receding faster than the speed of light, it is said because the ...
- 1