What Is the Rh = ct Cosmology?

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SUMMARY

The Rh = ct cosmology describes a theoretical model of the universe where the Hubble radius (R_h) increases over time in a perfectly empty universe. In this model, h represents the Hubble constant, c denotes the speed of light, and t signifies time. The equation suggests that objects within such a universe would move at a constant velocity. While this model aligns with some observational data, it fails to accurately represent the universe's behavior during its early stages.

PREREQUISITES
  • Understanding of the Hubble constant (H_0)
  • Familiarity with the speed of light (c)
  • Basic knowledge of cosmological models
  • Concept of the Hubble radius (R_h)
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  • Research the implications of the Hubble constant in cosmology
  • Explore the concept of coasting cosmology
  • Investigate the limitations of Rh = ct in early universe models
  • Learn about observational data that supports or contradicts Rh = ct cosmology
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Astronomers, cosmologists, and physics students interested in theoretical models of the universe and their implications for cosmological observations.

Buzz Bloom
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I have been looking at several articles recently about the Rh = ct cosmology, but none of them have explained the meaning of the equation. They just assume than anyone looking at such an article will already know what it means. I guess that (1) h is the Hubble "constant", and (2) c is the speed of light, and (3) t is some kind of time. But R is a mystery. R must be a units like m s, but i can't think of what such a variable might be.

Will someone please explain this?
 
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Coasting cosmology. This would be an accurate picture of our universe if the universe was perfectly empty. All objects within such a universe would move at constant velocity.

The "R_h = ct" description is because in such a universe, the Hubble radius (given by R_h = c / H_0) increases with time as ct.

People talk about this universe because it rather coincidentally comes somewhat close to matching observations (it completely fails to describe our universe at very early times, however).
 
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Hi Chalnoth:

Thank you very much for your post completely answering my question. I also apperciate your not mentioning the dumb mistake I made regarding Rh having units m s.

Regards,
Buzz
 

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