What is going to happen when the sun dies?

  • #1
ThaCYCLIST
Oh hey guys. So basically the sun has a 10 Billion years lifetime and it's almost halfway through its lifetime. What is gonna happen when the sun dies? Another sun up for the job or we're screwed?
 

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  • #3
stefan r
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Within around 1.1 billion years the Sun will be hot enough that complex life on Earth as we now know it will not be possible.
The Cambrian explosion happened around 540 million years ago. No ancestor of today's animals had either a backbone or a shell. None of the Ediacaran biota that we know of exists. Several hundred million years is not a time scale to worry about. Most branches of the genus homo went extinct in under 1 million years. We should expect our species to "be screwed" several thousand times over before the Sun's expansion becomes a major factor.

There are possibilities. In the event that ancestors exist in a billion years they will have speciated multiple times.
 
  • #4
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Indeed, Humans will not exist in several milion years let alone a billion due to evolution. Whether we stay on the Earth or manage to live in space, evolution will go down different paths but we will still not be human as such.
 
  • #5
phinds
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Indeed, Humans will not exist in several milion years let alone a billion due to evolution. Whether we stay on the Earth or manage to live in space, evolution will go down different paths but we will still not be human as such.
You state that as a fact and while I agree that you are probably right, I still don't think it's something that can be stated as a fact. As Yogi Berra likely would have said, predicting the future is problematic, especially when it's about something that hasn't happened yet.
 
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  • #6
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Look at the post above mine, there were no creatures with backbones or shells just 500 million years ago. We developed from very small mammals to what we are today in the 65 million years since the dinosours were extinct. There were no humanoids several million years ago.

Is it that hard to believe we will be entirely different in a million years? Do you not believe in evolution? It never stops :)

On a lighter note, we will probably have dedicated fingers just to control our smartphones by then :)
 
  • #7
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Why do you think that our successors would not call themselves humans?
 
  • #8
phyzguy
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Why do you think that our successors would not call themselves humans?
For the same reason we don't call ourselves tree shrews.
 
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  • #9
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For the same reason we don't call ourselves tree shrews.
Well, if the tree shrews had mental capacity to name themselves, and were able to transfer this naming generation after generation, it could easily happen that we call ourselves "tree shrews".
 
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  • #10
phinds
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For the same reason we don't call ourselves tree shrews.
Yeah, but neither did tree shrews
 
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  • #11
Ken G
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By the way, the initial link about the helium flash near the end of our Sun's life repeats the usual error that is worth replacing, because the way gases actually work is much more interesting. It says:
"However, unlike when the Sun was young and its core contained normal matter, adding more heat to the electron-degenerate helium does not cause it to expand and cool. As I noted when I was discussing quantum mechanics, electron-degenerate matter behaves more like a liquid than a gas when you heat it: its temperature swiftly rises, but it doesn't expand. In other words, the self-regulating mechanism that keeps main-sequence stars so stable (hydrostatic equilibrium) is turned off in electron-degenerate matter. If you add heat to a white dwarf, it just gets hotter."

Degenerate electrons are a gas, and all gases obey a very simple rule: when you add heat to them, their internal energy goes up, and their pressure is proportional to their internal energy. So their pressure goes up, period. Then another important dynamical principle is that things whose pressure goes up expand. Thus, the real truth is that any nonrelativistic gas (that doesn't include internal binding forces, and degenerate electrons don't) that has heat added to it will expand in just exactly the same way, and degeneracy doesn't alter that one iota.

So what actually happens? Degeneracy alters the partition of the internal energy between the electrons and the ions, that's the kind of thermodynamic effect that degeneracy has. It means that the electrons have the lion's share of the internal energy, even as the ions become hot enough to fuse helium. That also means that when the perfectly normal expansion occurs (unlike the source says), the necessary work is done by the electrons, not the ions, so the ions don't lose energy due to the expansion. That's what the thermodynamics of degeneracy does, it shields the ideal-gas ions from losing energy when the gas expands, so the fusion runs away. To see the difference, note that if for some reason the ions and electrons were equally degenerate, the usual explanation would make you think the fusion would still run away, but it wouldn't-- that case would be stabilized in exactly the same way the Sun is now. And isn't that more interesting than the claim that expansion doesn't occur, or that a gas is somehow a liquid?
 
  • #12
MathematicalPhysicist
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Look at the post above mine, there were no creatures with backbones or shells just 500 million years ago. We developed from very small mammals to what we are today in the 65 million years since the dinosours were extinct. There were no humanoids several million years ago.

Is it that hard to believe we will be entirely different in a million years? Do you not believe in evolution? It never stops :)

On a lighter note, we will probably have dedicated fingers just to control our smartphones by then :)
There wouldn't be any smartphones by then though.

Everything will be communicated by telepathy by then... :cool:
 
  • #13
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Agree that smartphone will not exist, 20 years ago people were saying we would all develop big thumbs for pressing buttons on remote control's.

The point is we will likely evolve to better interface with whatever technology is around us at that time.
 
  • #14
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The point is we will likely evolve to better interface with whatever technology is around us at that time.
Well, nobody can really foresee the distant future, but I tend to disagree with this point.
Timescales of the evolution (by natural selection) are incomparable longer than timescales of the technology advancement we can see in recent past. It is more likely that the technologies will be more and more adjusted (or perhaps integrated) to our bodies. What would be the advantage, when your body "evolve" to be more compatible with some technology, but few years/decades later the technology will be obsolete and replaced by another one?
 
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  • #15
jim mcnamara
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Okay - too many tree shrews, aliens, too much anthropomorphism, too much speculation. We go to General discussion. FWIW - the fate of virtually all species has been extinction. Humans are no exception.
This states that 99.9% of species have gone extinct. It also mentions the possibility of a current 6th mass extinction:
https://www.pbs.org/wgbh/evolution/extinction/massext/statement_03.html
 
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  • #16
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Okay - too many tree shrews, aliens, too much anthropomorphism, too much speculation. We go to General discussion.
It was only a question of time when this happens :smile:

t. It also mentions the possibility of a current 6th mass extinction
Unfortunately yes, the human activities have pretty devastating impact on the global ecosystem, and forecasts are not any good. Sadly, it wouldn't be any surprise if our activities already triggered the next mass extinction :cry:

In the above posts, I believe most of us silently assumed the hypothetical case, when humankind will somehow manage to survive the immediate threats.
 
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  • #17
Evo
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I'm afraid this thread has been answered...repeatedly, and useful discussion on topic is over.
 
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