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Dead galaxy questions


Bmpbmp1975

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21 minutes ago, Bmpbmp1975 said:

What I meant was you keep saying dark energy but isn’t that the cosmos constant also, which is at minus 1

They are different things. The clue is in the fact that they have different names: "cosmological constant" vs "equation of state".

The cosmological constant is the energy density of space. It has a small positive value and is what causes the rate of expansion of the universe to increase. 

The equation of state of dark energy is the pressure of the energy (which is negative) divided by its density (the cosmological constant). It seems that the pressure and the density have nearly equal values (but opposite signs) so that the ratio (the equation of state, w) is close to -1 (or maybe exactly 1).

As noted above, if the value is exactly -1 then the energy density of dark energy is constant.

 

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48 minutes ago, Strange said:

They are different things. The clue is in the fact that they have different names: "cosmological constant" vs "equation of state".

The cosmological constant is the energy density of space. It has a small positive value and is what causes the rate of expansion of the universe to increase. 

The equation of state of dark energy is the pressure of the energy (which is negative) divided by its density (the cosmological constant). It seems that the pressure and the density have nearly equal values (but opposite signs) so that the ratio (the equation of state, w) is close to -1 (or maybe exactly 1).

As noted above, if the value is exactly -1 then the energy density of dark energy is constant.

 

So what fell below 0 then?

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2 hours ago, taeto said:

The source for a change in Λ might be something like Barrow and Shaw "The Value of the Cosmological Constant", arxiv.org/abs/1105.3105.

Not sure what this means 

2 hours ago, taeto said:

I see Ghideon already made the same comment.

But luckily for us, the probability that it happens during our own lifetime is exactly zero. Indeed it could only happen at its very end ☠️.

Also this part what shows this

Edited by Bmpbmp1975
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6 minutes ago, Bmpbmp1975 said:

Not sure what this means 

Also this part what shows this

!

Moderator Note

Listen, this is a science discussion forum. The platform is very good at filling in gaps in knowledge, and for clarification on various topics, but it's NOT a teaching platform. I don't know why you didn't learn science formally in school, but that's where you need to be right now. I think it's really harmful that you're trying to learn science from popular articles. It's quite obvious that your approach is confusing the hell out of you, and you have no formal curriculum, so you bounce from misunderstanding to misunderstanding. No offense, but you're like a 5-year-old who's trying to learn politics by reading the newspaper. Why aren't you taking some science classes instead of trying to understand it so haphazardly?

Sorry, but you need to learn some other way. This is a stupid approach to learning anything. The membership keeps giving you answers to your questions, and your next question shows you didn't understand the answer, and then you complain that nobody is answering your questions. This thread is DONE, and we don't want any more like it. Take some formal science classes, please. Discussion helps fill gaps in our knowledge, but you need to bring the basic knowledge with you.

 
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