All Questions
8
questions
-4
votes
2
answers
102
views
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 ...
4
votes
3
answers
759
views
Constant speed of light violates accelerating expansion of universe?
My question regards the following:
One of the most fundamental principles of Einstein's GR is that all free bodies move through spacetime with constant velocity $c=1$.
However, in 1998 Hubble showed ...
- 201
1
vote
3
answers
136
views
Measuring the Hubble Constant
Attempts to measure the expansion of the universe have come in various forms. The recent Cosmology Crisis (https://www.space.com/why-is-there-a-cosmology-crisis) has me pondering the expansion rate ...
- 11
2
votes
1
answer
59
views
What is observed by Astronauts traveling from M at just under $c$, but proper distance increases at greater than $c$ due to spacetime expansion?
A rocket is traveling at a reasonable speed directly away from planet M at a large distance D. M is shaped like a coin and to the astronaut looking through a telescope directly out the back of the ...
- 143
1
vote
0
answers
52
views
What implications does special relativity have on the accelerating expansion of the universe? [duplicate]
Under special relativity we have the Lorentz factor:
$$
\gamma = \sqrt{\frac{1}{1-\frac{v^2}{c^2}}}
$$
Which essentially mathematically describes how the relative speeds between objects can never ...
- 261
3
votes
1
answer
95
views
Is it possible that the universe is not expanding faster than the speed of light? [closed]
What if the speed of light increases proportionately to the expansion of space? Is it possible that light traveling in the medium of space gets to travel faster if the medium is expanding? An analogy ...
- 31
3
votes
3
answers
2k
views
Expansion of the Universe regarding Time and lightspeed
According to our current understanding, the universe is expanding... it is often said that every galaxy is moving away from us (I'm assuming that isn't true for galaxies in our local group), and it's ...
- 409
4
votes
5
answers
2k
views
Does the expansion of the universe soon after the Big Bang affect the amount of time that light takes to reach us?
If faster than light travel is impossible, how is it that light emitted from matter so close together in the time soon after the Big Bang is only now just reaching us? I would assume that there would ...
- 41