The universe is dying

[anonymous-user]

The initial message was deleted from this topic on 07 November 2020 at 04:53

[xjay1337]

I love stuff about space.

No wonder really, there's only so much energy!

Although it does beg the question, in a few billion years what actually happens?
I know the world will end, the Sun will die, expand, go supernova and melt us all - But as people, as species, and as one of probably a whole collection of other worlds, what are we going to do?

Or will we all float around in space in ships with home grown food etc.

[IainT]

xjay1337 said:

Although it does beg the question, in a few billion years what actually happens?

Google "universe heat death".

[slybynight]

xjay1337 said:

I love stuff about space.

as people, as species, and as one of probably a whole collection of other worlds, what are we going to do?

Or will we all float around in space in ships with home grown food etc.

Isn't there a first world problems thread somewhere?

[Zod]

Whose fault is it?

[Moonhawk]

Hasn't it always been thus - the amount of thermodynamic free energy in any closed system will always tends to zero over time.

It's a consequence of the 2nd law of thermodynamics.

The universe has been in a constant state of "dying" ever since it came to be (in much the same way as humans).

[ewenm]

xjay1337 said:

I love stuff about space.

No wonder really, there's only so much energy!

Although it does beg the question, in a few billion years what actually happens?
I know the world will end, the Sun will die, expand, go supernova and melt us all - But as people, as species, and as one of probably a whole collection of other worlds, what are we going to do?

Or will we all float around in space in ships with home grown food etc.

Highly likely the human race will be well extinct by then!

[anonymous-user]

Zod said:

Whose fault is it?

And how can it be taxed?

[Moonhawk]

ash73 said:

Is that right? I think the amount of energy is the same, but it's dispersed as EM radiation as entropy increases. I'm just surprised the rate of star formation has reduced so significantly, as the universe is still very young.

Yes the total amount of energy is the same - but the amount of thermodynamic free energy (i.e. the energy available to do work decreases as entropy increases)

https://en.wikipedia.org/wiki/Thermodynamic_free_e...

[V8LM]

Heat death of the Universe is when entropy is maximum - completely random and nothing left to do work. Information is order, so maximum entropy is a minimum in information. Information is currently increasing as we find and research more. Therefore, there will become a time when we can know no more, and as time progresses further we will know less.

Discuss. (10 marks).

Edited by V8LM on Wednesday 12th August 23:35

[V8LM]

I know how you feel; I watched Don't Tell the Bride and didn't understand a frickin' bit of that either.

[IainT]

V8LM said:

Heat death of the Universe is when entropy is maximum - completely random and nothing left to do work. Information is order, so maximum entropy is a minimum in information. Information is currently increasing as we find and research more. Therefore, there will become a time when we can know no more, and as time progresses further we will know less.

Discuss. (10 marks).

What's more random:

. . .
. . .
. . .

or

. ..
.. .
...

The former is 'heat death' even distribution, the latter clumpy 'energy' of our current universe. The former looks ordered, the latter random but the latter is required to store information.

Given the time scales to heat death are not mere billions of years off but even more incomprehensibly far off (the last black hole that will ever form won't decay for 10^100 years after that) we're not on any pressing time frames.

What 'life' would look like at the very end of the universe would be hard to comprehend. Pure energy beings ekeing out an existence on the event horizon of that last black hole?

I'm not convinced that we can conflate the idea of knowledge with the ability to

[Hugo a Gogo]

IainT said:

Given the time scales to heat death are not mere billions of years off but even more incomprehensibly far off (the last black hole that will ever form won't decay for 10^100 years after that) we're not on any pressing time frames.

phew, that's a relief

[IainT]

Hugo a Gogo said:

IainT said:

Given the time scales to heat death are not mere billions of years off but even more incomprehensibly far off (the last black hole that will ever form won't decay for 10^100 years after that) we're not on any pressing time frames.

phew, that's a relief

Yeah, I was considering cashing in the pensions and not booking next year's holiday until I did a little reading

[AshVX220]

ash73 said:

Is that right? I think the amount of energy is the same, but it's dispersed as EM radiation as entropy increases. I'm just surprised the rate of star formation has reduced so significantly, as the universe is still very young.

How do we know the Universe is young? We haven't observed any other universes to make that judgement against surely, we don't know how old a universe can be? For all we know, the universe is actually on the wrong side of middle aged?

[IainT]

AshVX220 said:

ash73 said:

Is that right? I think the amount of energy is the same, but it's dispersed as EM radiation as entropy increases. I'm just surprised the rate of star formation has reduced so significantly, as the universe is still very young.

How do we know the Universe is young? We haven't observed any other universes to make that judgement against surely, we don't know how old a universe can be? For all we know, the universe is actually on the wrong side of middle aged?

Exactly right. Sample size = 1.

[ewenm]

IainT said:

AshVX220 said:

ash73 said:

Is that right? I think the amount of energy is the same, but it's dispersed as EM radiation as entropy increases. I'm just surprised the rate of star formation has reduced so significantly, as the universe is still very young.

How do we know the Universe is young? We haven't observed any other universes to make that judgement against surely, we don't know how old a universe can be? For all we know, the universe is actually on the wrong side of middle aged?

Exactly right. Sample size = 1.

We can make an estimate of the entropy of the universe and make a guess at the time left until heat death. That could give an idea of "old" or "young". It's pretty meaningless in human-scale terms though. How that maps to expecations of star formation etc I guess is linked to the rate of expansion of the universe.

[IainT]

ash73 said:

AshVX220 said:

How do we know the Universe is young?

Star formation will cease in 100 trillion years... and the universe is only 0.0138 trillion years old.

Stelliferous era

Yet we're in an era of decreasing formation so it's not reasonable to cite it as young.

To ascribe young-middle-old equal lengths would be foolish.

[IainT]

ash73 said:

And yet mankind's constant need to be at the centre of everything forces us to use a log plot

Pointless and somewhat foolish comment and apropos of nothing.

Epochs andEras are actually useful young vs old far less so but I'd suggest our universe has settled down into it's long middle-age on the way to an even longer decline through old age.

Edited by IainT on Thursday 13th August 12:17

[qube_TA]

ash73 said:

It's interesting because our Sun is only a second generation G type star.

I don't think the second gen models will ever be regarded as classics, they just didn't have the power of the first gens.