Sun Expansion: What Would Humans Do?

[curious_cat]

Hello! I'm new here, and I don't honestly know anything about astrophysics, so I'm sorry in advance for the upcoming questions and would like to ask you to be as elaborate and as simple as possible.
So, if the sun expands, when do you think this will happen? If Earth is still alive, what do you think humans would do? Would we potentially have the technology to save our world, simply change locations?
Please share your theories:)

 

[Matterwave]

The Sun is not expected to expand (significantly) for another 4-5 billion years, when it will turn into a Red giant.

The Red giant may very well engulf the Earth, since it may expand to sizes larger than the Earth's orbit. The Earth may escape this fate, if the loss in mass of the sun is enough to let the Earth orbit farther out. This is uncertain.

Long before that, though, the Sun would have dried out the Earth, since it's getting hotter and hotter. The Oceans will boil in ~ 1 billion years. Human's have about that much time to find something to do.

 

[wofsy]

Hello! I'm new here, and I don't honestly know anything about astrophysics, so I'm sorry in advance for the upcoming questions and would like to ask you to be as elaborate and as simple as possible.
So, if the sun expands, when do you think this will happen? If Earth is still alive, what do you think humans would do? Would we potentially have the technology to save our world, simply change locations?
Please share your theories:)

I think as long as we pursue the exploration of space we will have left Earth long before the Sun dies. We may even discover ways to produce our own energy and not have need of a star.

 

[Waveform]

As all ready mentioned here.

Long before the Sun goes to the Red Giant stage we should have learned how to control vast amounts of energy and have developed technology that today hasn’t even been thought of.

That is of course, provide we haven’t succumb to some sort of catastrophic event or worse yet rendered ourselves extinct.

I think when that time comes there will be at least a few options and they will probably have the technology to deal with it or perhaps even have dealt with it long before it occurs.

Sort of ironic as the sun expands some of the outer planets will warm and actually for a certain time become conducive to life. However, it will be a short lived period.

 

[qraal]

Hello! I'm new here, and I don't honestly know anything about astrophysics, so I'm sorry in advance for the upcoming questions and would like to ask you to be as elaborate and as simple as possible.

You said that last time.

So, if the sun expands, when do you think this will happen?

Hard to tell. The Sun's Main Sequence lifespan depends on its core metallicity and the Main Sequence might end when it's somewhere between 9 and 11 billion years old.

However that's assuming it's not accreting significant amounts of dark matter. If dark matter built up and increased the Sun's mass significantly then it would burn faster and leave the Main Sequence earlier.

If Earth is still alive, what do you think humans would do?

Re-engineering the Sun might eventually be possible. Only its core is being depleted in hydrogen presently - if we can cause the Sun's mass to convect, then we might be able to cause its lifespan to increase significantly. Otherwise we might need to lift mass off it and control the core indirectly that way.

Would we potentially have the technology to save our world, simply change locations?

Maybe, but why bother? A shell around the planet with variable albedo would reduce the influx of heat sufficiently to keep it habitable. However if the Sun is sucking up dark matter at a great rate, then we'll probably have to do something about moving the planet eventually. If the Sun retains it sufficiently well, then the Sun might eventually exceed the Chandrasekhar Mass and go supernova - though that's less urgent than an accelerated Main Sequence.

Please share your theories:)

What cut do I get from your novel or whatever it is you're working on?

 

[Chronos]

It does not appear dark matter will be a factor in the evolution of the sun. The amount currently present in the solar system is estimated at around 10% the mass of the asteroid Ceres - re:
Dark Matter in the Solar System
http://arxiv.org/abs/0806.3767

 

[qraal]

It does not appear dark matter will be a factor in the evolution of the sun. The amount currently present in the solar system is estimated at around 10% the mass of the asteroid Ceres - re:
Dark Matter in the Solar System
http://arxiv.org/abs/0806.3767

Maybe, maybe not. Lorenzo Iorio disagrees with your extrapolation in this (more recent) paper...

http://arxiv.org/abs/1001.1697"

...and since nuclear fusion rates are rather sensitive to pressure in the Core I would suggest the mass accreted will have significance in the giga years ahead.

 

[Frame Dragger]

Spoiler Alert!


Humanity will not be there to see it. :rofl:

 

[Algr]

If humanity survives long enough to see the Earth being threatened by the sun, we'd have long since spread across the universe. Saving the Earth would be like saving the great pyramids - historically important, but hardly a threat to our survival.

Planets can be moved by sending lots of asteroids on close encounters. Their gravity would (slowly!) pull the Earth in whatever direction required.

I wonder if you could cover large sections of the Earth with mirrors and create something like a solar sail? That would cool the Earth, and push it away from the sun.

 

[Frame Dragger]

If humanity survives long enough to see the Earth being threatened by the sun, we'd have long since spread across the universe. Saving the Earth would be like saving the great pyramids - historically important, but hardly a threat to our survival.

Planets can be moved by sending lots of asteroids on close encounters. Their gravity would (slowly!) pull the Earth in whatever direction required.

I wonder if you could cover large sections of the Earth with mirrors and create something like a solar sail? That would cool the Earth, and push it away from the sun.

Given the amount of time we're talking about, it's hard to imagine any form of life persisting for such a long period; there is nowhere near the that kind of precedent. If you consider our history, there is only one safe bet, and it isn't on us.

All the more reason to enjoy these intellectual exercises... life is one after all is said and done. We'll all be ashes in an expanding gas cloud, dimly lit by the heat trapped in the degenerate electron matter that was The Sun, fading as the universe expands and the cosmological horizon changes so radically that humans then wouldn't have a reason for attatchment to any particular stellar grouping. The 'long run' is never really happy after all.

 

[qraal]

Given the amount of time we're talking about, it's hard to imagine any form of life persisting for such a long period; there is nowhere near the that kind of precedent. If you consider our history, there is only one safe bet, and it isn't on us.

All the more reason to enjoy these intellectual exercises... life is one after all is said and done. We'll all be ashes in an expanding gas cloud, dimly lit by the heat trapped in the degenerate electron matter that was The Sun, fading as the universe expands and the cosmological horizon changes so radically that humans then wouldn't have a reason for attatchment to any particular stellar grouping. The 'long run' is never really happy after all.

Personally I suspect that whatever lives then will - however distantly - be related to us, and might welcome some long-term thinking by their ancestors. But the struggle for survival might prove tougher if Dark Matter influences stellar evolution as dramatically as Iorio's computations imply.

 

[Algr]

Given the amount of time we're talking about, it's hard to imagine any form of life persisting for such a long period; there is nowhere near the that kind of precedent. If you consider our history, there is only one safe bet, and it isn't on us.

GIANT ROBOTS! They will be our decedents. But since they were originally created to serve us, they will keep us as pets and take us to breeding shows. The winner will have a capitlistic society in a box and the young robots will gather around and say "Look at the little humans they are so cuuuute!"

 

[Frame Dragger]

Personally I suspect that whatever lives then will - however distantly - be related to us, and might welcome some long-term thinking by their ancestors. But the struggle for survival might prove tougher if Dark Matter influences stellar evolution as dramatically as Iorio's computations imply.

Do you look to our ancestors of millions of years past for their thinking on ANY subject, for any but academic curiosity? Given our burgeoning ability to modify ourselves, I doubt that any descendant of humanity would resemble it in any way. Forget evolution... we'll change ourselves to suit conditions before we change the world to suit us in more than the crude ways we already do.

If FTL isn't to be achieved, then descendants will be cut off from their pasts by the very act of setting out on an intersellar journey; more so if they travel near c. I think the key to life is in the setting we can comprehend as humans, limited, but one to which we are adapted. To pretend that we can imagine the world of a million or a billion years from now is fanciful, but understandable.

 

[Algr]

"Can I pet the little humans pleeease?"

"No dear, if they find out they aren't in charge they get sick."

 

[Frame Dragger]

"Can I pet the little humans pleeease?"

"No dear, if they find out they aren't in charge they get sick."

:rofl: I think that's more near-term than long-term lol.

 

[Algr]

Do you look to our ancestors of millions of years past for their thinking on ANY subject, for any but academic curiosity? Given our burgeoning ability to modify ourselves, I doubt that any descendant of humanity would resemble it in any way.

I'm going to go eat some cooked meat while wearing clothing that compensates for my lack of fur. :)

 

[Frame Dragger]

I'm going to go eat some cooked meat while wearing clothing that compensates for my lack of fur. :)

Yes, well... point taken. Damn. Still, do you really think that given the pace of progress we'll have so much in common with our descendants separated by a similar span of time? I don't think so, but you've made some very good points.

Given the advent of computer-human interfaces, and genetic modification (yes, a matter of time, but if we're to survive it probably will emerge), micro/nano technology... I don't know. I don't know enough about what it means to be human, or conscious to imagine how our descendants might shape themselves according to answers to those great questions.

If consciousness can be transferred digitally (or by some other means), that would have implications for the necessity of a physical existence outside of a 'blue box'. If physical modifications are the main trend because unique personal traits are linked to your brain, and can't be transferred... who knows.

It's not fair that so many questions exist in so many fields, and that we'll only ever know a miniscule fraction of the answers. Most of the time we're all just trying to find the right questions to ask in the first place, or just how to ask it. Our lifespans and society continually disrupt steady progress. Very upsetting.

 

[Chronos]

Nanobots encoded with our DNA is a viable option for preserving the human race. It is an unromantic and desperate measure, but, within the grasp of believable physics and technology.

 

[qraal]

Nanobots encoded with our DNA is a viable option for preserving the human race. It is an unromantic and desperate measure, but, within the grasp of believable physics and technology.

Nanobots encoded with our DNA are called "ova" and usually require a womb to produce a human being from them. Otherwise the DNA is just a random bit string. It needs a context to be understood.

 

[Frame Dragger]

Nanobots encoded with our DNA is a viable option for preserving the human race. It is an unromantic and desperate measure, but, within the grasp of believable physics and technology.

Within the grasp of current psychology I would question whether humanity at any stage would take such a long view. In a way, that view is deeply inhuman. When we're gone... we'll be gone.

 

[Chronos]

This is merely a technology within our grasp, not a solution most people would find attractive. The universe would probably view this as an infection, but, I am a big fan of humanity. Our theoretical ancestors would probably be grateful. Perhaps we are the consequence of a similar past event.

 

[qraal]

This is merely a technology within our grasp, not a solution most people would find attractive. The universe would probably view this as an infection, but, I am a big fan of humanity. Our theoretical ancestors would probably be grateful. Perhaps we are the consequence of a similar past event.

Makes one wonder. I think it's a curious fact that many eukaryotic genes are probably to be found in the archea & eubacteria & viruses - the usual suspects for panspermia. Does that mean we're merely elaborations of prokaryotic/viral genetic architecture and biochemistry? I'd suggest we are - after all the common organelle in all eukaryotes are the mitochondria, which are suspected of once being bacteria, and our cells regularly have hundreds of mitochondria. Only a few mitochondrial genes remain present in them, the rest moved into the 'nucleus' long ago, and now the nucleus itself is suspected of once being a giant virus like the Mimivirus!

 

[Frame Dragger]

To Chronos: Agreed.

To graal: I tend to agree with that point of view. Our DNA is lousy with viral fragments. We're a product of our environment after all. I wonder if such unique interactions are required to form complex life? If so, how would a similar process evolve on a silicate-earth, or a carbon-earth?

Hmmmm...

I wonder if crystalline structures (much like some viruses we know!) would play that role. Fascinating! Yet another question: "When is life, alive? When is it dead? What is Wigner's friend doing to that poor cat?" :rofl: