Radial expansion of the universe and the speed of light

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SUMMARY

The discussion centers on the relationship between the expansion of the universe and the speed of light, proposing that the universe's radius may represent time. It asserts that if the universe's expansion ceases, time would also stop, leading to the conclusion that light and photons would no longer move. Participants suggest that the speed of light could influence the perceived rate of the universe's expansion, indicating a complex interplay between these fundamental concepts. Key points include the assertion that the speed of light and the universe's expansion rate are intrinsically linked.

PREREQUISITES
  • Understanding of cosmology and the shape of the universe.
  • Familiarity with the concept of spacetime and its implications.
  • Knowledge of the speed of light as a fundamental constant in physics.
  • Basic grasp of the implications of time dilation and its relationship to cosmic expansion.
NEXT STEPS
  • Research the implications of the Friedmann equations in cosmology.
  • Explore the concept of spacetime curvature and its effects on light propagation.
  • Study the relationship between cosmic expansion and the speed of light in the context of general relativity.
  • Investigate time dilation effects in relation to the expansion of the universe.
USEFUL FOR

Astronomers, physicists, cosmologists, and anyone interested in the fundamental principles governing the universe's expansion and the nature of light.

AugustusM
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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 ?
 
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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.
 

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