Is the Accelerating Expansion of the Universe Wasting Energy?

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SUMMARY

The discussion centers on the concept of the universe's accelerating expansion and its implications for energy consumption. Participants clarify that the expansion of space is quantified by the Hubble constant and does not equate to a waste of energy, as no energy is expended for the universe to expand. The distinction between the energy of the vacuum and the creation of space is emphasized, with the consensus that current physics does not provide a definitive answer regarding energy expenditure in this context.

PREREQUISITES
  • Understanding of the Hubble constant and its role in cosmology
  • Familiarity with concepts of energy in physics, particularly vacuum energy
  • Knowledge of the scale parameter and its derivatives in cosmological models
  • Basic grasp of the differences between velocity and acceleration in the context of cosmic expansion
NEXT STEPS
  • Research the Hubble constant and its implications for cosmic expansion
  • Explore the concept of vacuum energy and its relevance in modern physics
  • Study the scale parameter and its derivatives in cosmological equations
  • Investigate the relationship between velocity, acceleration, and the expansion of the universe
USEFUL FOR

Astronomers, physicists, and students of cosmology interested in understanding the dynamics of the universe's expansion and its energy implications.

mister i
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This is my first (non-professional) post: It seems accepted that space is "created" (otherwise the expansion of the universe would exceed the speed of light). We are talking about "creation" (!!). The question would be: does current physics tell us if this represents a waste of energy for the universe? (which would be different from the energy of the vacuum, which is the energy that exists within space, but not its creation, for me they are different things)
 
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mister i said:
It seems accepted that space is "created"
I don't think that's accurate.
mister i said:
otherwise the expansion of the universe would exceed the speed of light
The expansion of space, to the extent that's really a thing, does not have a single speed. It is quantified by the Hubble constant, and comparing this to the speed of light is like asking if a kilogram is more than a meter. It doesn't make sense.
mister i said:
does current physics tell us if this represents a waste of energy for the universe?
I don't think there's a meaningful question to answer here - you can't define the total energy of the universe in a way anyone can agree on, so whether or not it is changing isn't answerable.
 
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mister i said:
We are talking about "creation" (!!).
No, we're not.

mister i said:
The question would be: does current physics tell us if this represents a waste of energy for the universe?
No energy is expended for the universe to expand. The matter in the expanding universe is in free fall.
 
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Ibix said:
The expansion of space, to the extent that's really a thing, does not have a single speed. It is quantified by the Hubble constant, and comparing this to the speed of light is like asking if a kilogram is more than a meter. It doesn't make sense.
here talks about acceleration and velocity: https://en.wikipedia.org/wiki/Accelerating_expansion_of_the_universe
 
mister i said:
here talks about acceleration and velocity: https://en.wikipedia.org/wiki/Accelerating_expansion_of_the_universe
And, as it says, the key quantities are the scale parameter ##a## and its derivatives and the Hubble constant. Individual galaxies have a velocity (although there are caveats), but this is not limited to be below ##c## and does not characterise the expansion.
 
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