B How can dark energy comprise 74% of the Universe?

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Dark energy is understood to comprise about 74% of the universe's total energy density, which differs from the common perception of mass. The discussion clarifies that cosmologists refer to energy density rather than mass in a conventional sense, with dark matter and dark energy together accounting for approximately 94% of the observable universe. The average energy density is calculated based on the finite observable universe, with the assumption that the non-observable universe behaves similarly, a point debated among participants. The principle of mediocrity is invoked to support the idea that the universe is homogeneous and isotropic on large scales, although some express skepticism about applying this principle universally. Overall, the conversation highlights the complexities and assumptions inherent in understanding dark energy and the universe's structure.
  • #31
Ok I give up. @PeterDonis why say this

PeterDonis said:
The Hubble sphere is not the boundary of "how far we can see" and is not the same as our observable universe.

You now say this

PeterDonis said:
Nobody said you did. You are misunderstanding what we said is the problem.
I explicitly did not equate them at the same time. For the last time I said the expanding Hubble sphere will mean we can see further (than the currently observable Universe) in the future.

Regards. Andrew
 
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  • #32
andrew s 1905 said:
...we can see further (than the currently observable Universe) in the future.
Are you trying to say simply that, in the future, the OU will be larger, allowing us to see farther?
 
  • #33
andrew s 1905 said:
I said the expanding Hubble sphere will mean we can see further (than the currently observable Universe) in the future.

And that is wrong. I explained why in post #30. That is the only statement of yours that I or anyone else is saying is wrong.

If you had just said "we can see further than the currently observable Universe in the future", that would have been fine. But you said more than that.
 
  • #34
DaveC426913 said:
Are you trying to say simply that, in the future, the OU will be larger, allowing us to see farther?
Yes.
But how far we can see is related to...
I agree you can argue they have the same underlying cause.

I have learned my lesson.

Regards Andrew
 
  • #35
PeterDonis said:
And that is wrong. I explained why in post #30. That is the only statement of yours that I or anyone else is saying is wrong.

If you had just said "we can see further than the currently observable Universe in the future", that would have been fine. But you said more than that.
But they are related contrary to your statement. Light has to cross the Hubble sphere to reach us. See section 3.3 https://www.google.com/url?sa=t&sou...FjABegQIBRAF&usg=AOvVaw0gAqrLMM4grSnGgMqhElQs

Regards Andrew
 
  • #36
andrew s 1905 said:
Light has to cross the Hubble sphere to reach us.

That doesn't mean "they are related", or that the reason the observable universe will be larger in the future is that the Hubble sphere will.

In any case, this subthread is off topic, so please do not post further in it.
 

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