Radial expansion of the universe and the speed of light

AugustusM
Messages
3
Reaction score
0
Just wondering if the two are fundamentally linked ?

If the universe is in the shape of a 3 sphere and if it's radius represents time, then does the expansion rate of the radius determine what the speed of light is ?

I've also read elsewhere that the passing of time is linked to the expansion of the universe along it's radius. If the expansion of the universe stopped, would time stop. With timed stopped would light and photons then stop moving ?
 
Physics news on Phys.org
AugustusM said:
Just wondering if the two are fundamentally linked ?

If the universe is in the shape of a 3 sphere and if it's radius represents time, then does the expansion rate of the radius determine what the speed of light is ?

I've also read elsewhere that the passing of time is linked to the expansion of the universe along it's radius. If the expansion of the universe stopped, would time stop. With timed stopped would light and photons then stop moving ?
Maybe it's the other way around. The speed of light might be determining how fast the universe appears (to us) to be expanding. After all, the speed of pretty much any process here on Earth (down to the speed of chemical and even atomic processes, which still depend on photons and other particles being transferred back and forth at a small scale) can probably be linked to the speed of light. If the speed of light changes, our clocks (no matter what they are made of) and our subjective perception of time will change too. If our clocks slow down (because the speed of light slows down), but the universe keeps merrily expanding at its normal rate, it will appear to be accellerating. Just a random thought...
 
Just a simple logical conclusion

1. Just say that the speed at which the radius of the universe is increase is the same as the speed of light.

2. If the universe stops expanding, then time stops.

3. If time stops, then all movement stops.

4. Even light cannot move in this scenario.

5. If the speed of light is now zero (as the universe's radial increase velocity is now zero also) then this means that light cannot move anyways.
 

Thread 'I don't see how a black hole's event horizon can be crossed'

OK, so this has bugged me for a while about the equivalence principle and the black hole information paradox. If black holes "evaporate" via Hawking radiation, then they cannot exist forever. So, from my external perspective, watching the person fall in, they slow down, freeze, and redshift to "nothing," but never cross the event horizon. Does the equivalence principle say my perspective is valid? If it does, is it possible that that person really never crossed the event horizon? The...
View full post »

Thread 'Synchronizing clocks in an inertial frame if light is anisotropic'

ASSUMPTIONS 1. Two identical clocks A and B in the same inertial frame are stationary relative to each other a fixed distance L apart. Time passes at the same rate for both. 2. Both clocks are able to send/receive light signals and to write/read the send/receive times into signals. 3. The speed of light is anisotropic. METHOD 1. At time t[A1] and time t[B1], clock A sends a light signal to clock B. The clock B time is unknown to A. 2. Clock B receives the signal from A at time t[B2] and...
View full post »

Thread 'Is the variation of the metric ##\delta g_{\mu\nu}## a tensor?'

From $$0 = \delta(g^{\alpha\mu}g_{\mu\nu}) = g^{\alpha\mu} \delta g_{\mu\nu} + g_{\mu\nu} \delta g^{\alpha\mu}$$ we have $$g^{\alpha\mu} \delta g_{\mu\nu} = -g_{\mu\nu} \delta g^{\alpha\mu} \,\, . $$ Multiply both sides by ##g_{\alpha\beta}## to get $$\delta g_{\beta\nu} = -g_{\alpha\beta} g_{\mu\nu} \delta g^{\alpha\mu} \qquad(*)$$ (This is Dirac's eq. (26.9) in "GTR".) On the other hand, the variation ##\delta g^{\alpha\mu} = \bar{g}^{\alpha\mu} - g^{\alpha\mu}## should be a tensor...
View full post »

Similar threads

B Is the Accelerating Expansion of the Universe Wasting Energy?
Replies
4
Views
1K
B The expansion of the Universe and time travel (By a non-scientist)
Replies
2
Views
2K
B Experience Travel on a Photon: Hitch-Hiker's Guide to the Universe
Replies
7
Views
2K
I A question about the speed of light and electromagnetism
2
Replies
51
Views
4K
I Has anyone measured the speed of light in one direction?
Replies
45
Views
6K
B Could Universe Expansion Be Causing a Decay in the Speed of Light?
Replies
22
Views
2K
B Energy loss of a photon
Replies
1
Views
992
I I want a good reference to a discussion of the meaning of "the speed of light is constant"
2
Replies
60
Views
4K
A 1-Way Speed of Light
Replies
42
Views
746
I Hubble's Law and Star Velocity
Replies
40
Views
4K

Hot Threads

Recent Insights

Back
Top