Is the Universe a Black Hole?

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SUMMARY

The discussion centers on the hypothesis that the universe may function similarly to a black hole, specifically regarding light and mass. It references the Schwarzschild radius formula, 2 * G * M / R = c^2, to relate the universe's mass (M) and size (R). By integrating this with the Friedmann equations under the assumption of flat spacetime, it concludes that R = c * t, where t is the universe's age. Additionally, it derives the density of dark energy as rho = (1 / 8 pi G) * 1 / t^2, leading to a present density of dark energy, rho_0, calculated using the Hubble constant H_0.

PREREQUISITES
  • Understanding of Schwarzschild radius in black hole physics
  • Familiarity with Friedmann equations in cosmology
  • Knowledge of dark energy and its implications in the universe
  • Basic grasp of the Hubble constant and its significance
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  • Explore the implications of the Schwarzschild radius on cosmic structures
  • Research advanced concepts in Friedmann equations and their applications
  • Investigate the nature and properties of dark energy in contemporary cosmology
  • Study the Hubble constant and its role in measuring cosmic expansion
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Astronomers, physicists, cosmologists, and anyone interested in theoretical models of the universe and black hole physics.

johne1618
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If the universe is all there is then it can't be radiating light to anywhere else. Thus light must be trapped inside it like light is trapped inside a black hole.

If we carry this analogy further then maybe the size and mass of the universe is given by the expression for the Schwarzschild radius of a black hole:

2 * G * M / R = c^2

where M is the mass of the universe and R is the size of the universe.

If you put this expression into the Friedmann equations for the universe, together with the assumption of a flat spacetime, you find:

R = c * t

where R is the size of the universe and t is the age of the universe.

Also one finds a dark energy term such the the density (rho) of dark energy is given by:

rho = (1 / 8 pi G) * 1 / t^2.

This model gives the present density of dark energy rho_0 as

rho_0 = H_0^2 / 8 pi G

Putting in the present Hubble constant H_0 one finds a value of rho_0 which is a few proton masses per m^3.
 
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