All Questions
15
questions
0
votes
0
answers
37
views
Is there a formula for gravitational time dilation at the cosmological scale?
There is a standard formula for gravitational time dilation used in eg the operation of the global positioning system. It is based on the integration of g(h) where g is a function relating ...
- 371
1
vote
2
answers
95
views
Time dilation between now vs right after the Big Bang should imply the universe is much older than 13.8 bn years? [duplicate]
The universe is said to be 13.8 bn years old. But if we go back in time towards the Big Bang singularity time will slow down more and more and eventually stop because of the density of the singularity....
- 11
0
votes
3
answers
499
views
Where in the universe does time pass fastest relative to time on earth?
It is my understanding that time essentially moves slower in higher gravitational fields relative to time on earth. Conversely, in lower gravitational fields, time passes faster relative to earth. Is ...
2
votes
1
answer
84
views
Will a clock that is isolated and stationary with respect to the CMB report the highest possible value for the age of the universe?
We have a very special clock that has existed since the dawn of time. Its purpose is to measure the age of the universe. It is always very far from any massive body or gravitational field and it is ...
- 2,403
4
votes
3
answers
1k
views
Does GR explain cosmological time dilation?
There is plenty of evidence for a cosmological time dilation effect. For instance a supernova that takes 20 days to decay will appear to take 40 days to decay when observed at redshift $z=1$ (see Ned ...
- 5,925
0
votes
0
answers
32
views
If matter was compressed at big bang was time more and more compressed too in the past for us now (opposite expansion for time going in the past)? [duplicate]
If everything was smaller or compress in the past, did this compress time?
In the foundation of Big bang theory, all is expanding now, galaxies expand space between. Then they must had been closer or ...
1
vote
1
answer
123
views
Equation for effects of the density on time dilation
The higher the density of an object is the more it will cause distortion on space and time.
I want to know the equation that links density to time dilation.
I found the Lorentz equations that link ...
- 23
2
votes
6
answers
983
views
Can there be a theoretical synchronised ‘now’ moment at all points across the universe?
Einstein’s relativity rejects the notion of a universal ‘now’ moment. It underlines how the concept of ‘now’ is compromised due to time passing at differing rates in differing frames of reference, ...
- 719
1
vote
2
answers
294
views
If time is relative, then how is the age of the universe calculated? [duplicate]
I am very new to the world of relativity, so the answer may be trivial, but to me measuring the age of the universe seems an impossibility due to there being no fixed frame of reference from which to ...
- 321
0
votes
0
answers
59
views
Formulaic representation of time differential
It is a known fact that time passes at a different rate on earth than it does elsewhere in the universe. Where a second on earth passes uniformly, at an altitude of 11000 or also passes uniformly but ...
- 131
-3
votes
1
answer
149
views
Expansion of what? [duplicate]
When people say "the expansion of the Universe" they seem to mean the expansion of the space between mass-dense regions. However, my understanding is that space and time are intrinsically linked, so ① ...
- 323
2
votes
1
answer
378
views
Is it possible to be at rest relative to the cosmic background radiation? [closed]
Could there be a body in the universe which is at rest relative to the cosmic background radiation? And how much slower would time elapse at this point relative to Earth?
The Milky Way is moving ...
- 333
3
votes
5
answers
4k
views
Time dilation of distant cosmic events. What is it?
I was reading the Wikipedia's page about "tired light", where we read that any alternative explanation to the observed redshift (described by Hubble's law) should be able to overcome several ...
- 155
0
votes
1
answer
181
views
Clocks at rest in Kruskal coordinates
The proper time in Kruskal coordinates is given by $$d\tau^2=\frac{4}{e^rr}(dT^2-dX^2)$$ (where r is measured in units of Schwarzschild radii). Since at $T=+/-\infty$, $dT^2-dX^2$ goes to zero for an ...
- 2,467
2
votes
2
answers
3k
views
Gravitational time dilation caused by a galaxy, and by
In a word, if you are sitting on the Earth, if I'm not mistaken you are experiencing Time Dilation compared to being in deep solar system space. Due to the mass of the Earth.
However. We're all ...
- 994