Is the Accelerating Expansion of the Universe Wasting Energy?

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Discussion Overview

The discussion revolves around the concept of the accelerating expansion of the universe and whether this expansion represents a waste of energy. Participants explore the implications of space being "created" during this expansion and the relationship between the expansion rate and energy considerations within the framework of current physics.

Discussion Character

  • Debate/contested
  • Conceptual clarification
  • Technical explanation

Main Points Raised

  • Some participants propose that space is "created" as the universe expands, raising questions about the energy implications of this process.
  • Others argue against the notion of space being created, stating that the expansion of space does not have a single speed and is quantified by the Hubble constant, which cannot be directly compared to the speed of light.
  • One participant suggests that there is no meaningful way to define the total energy of the universe, making it difficult to assess whether the expansion represents a waste of energy.
  • Another claim is made that no energy is expended for the universe to expand, as matter within the universe is in free fall.
  • Participants discuss the importance of the scale parameter and its derivatives in understanding the expansion, noting that individual galaxies can have velocities that do not necessarily characterize the overall expansion.

Areas of Agreement / Disagreement

Participants express disagreement on the interpretation of space creation and its implications for energy. There is no consensus on whether the expansion of the universe can be considered a waste of energy, and multiple competing views remain regarding the nature of the expansion and its energy dynamics.

Contextual Notes

Participants highlight limitations in defining the total energy of the universe and the complexities involved in comparing different physical quantities related to expansion.

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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