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Life and Death of a Planetary System

exoplanets.nasa.gov

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Re: Life and Death of a Planetary System

#21

Post by posterboy »

hannasanarion wrote: post #15
ImprovedSilence wrote: post #14

Earlier quoted context omitted.

As much fun as it is to hate on religious beliefs, the Hindu version actually sounds close to scientific theories, no?

No, not really. Entropy only goes in one direction. The universe began in a state of complexity and diversity, and it's history since then has been the story of flattening, cooling, mixing, evening out into boring eternal sameness.

That only counts for closed systems. Does that pertain to our universe? We don't know; We can not see a limit, to say the least, and we have absolutely no agreeable model for any kind of edge. The idea that U closes in on itself, like the surface of a baloon, without any borders, is indeed reminiscent of hindu's Darma idea. It is rather descriptive of our mode of thought: cyclic and self centered; focused on origin and phobic of ...

end of story

Re: Life and Death of a Planetary System

#22

Post by dylan604 »

winchling wrote: post #2

Q. Will Earth always be able to support life? A. Probably not [...] Over the next couple of billion years, the increasing amounts of energy Earth will receive from the aging, expanding Sun will warm its atmosphere. Two billion years' work is a hefty amount in terms of scientific and technological development, assuming people survive. So, as David Deutsch would point out, what actually happens will depend on what sola…

Maybe we can come up with a way to adjust the Earth-Moon system's orbit. As the sun starts to expand, the orbit gets wider with it. Sure, it'll be in the same orbit as Jupiter or something, but it's all just a stop gap until the sun goes BOOM. Don't think it'll be anything but a dead rock at that point.

Re: Life and Death of a Planetary System

#23

Post by vkou »

dylan604 wrote: post #22
winchling wrote: post #2

Q. Will Earth always be able to support life? A. Probably not [...] Over the next couple of billion years, the increasing amounts of energy Earth will receive from the aging, expanding Sun will warm its atmosphere. Two billion years' work is a hefty amount in terms of scientific and technological development, assuming people survive. So, as David Deutsch would point out, what actually happens will depend on what sola…

Maybe we can come up with a way to adjust the Earth-Moon system's orbit. As the sun starts to expand, the orbit gets wider with it. Sure, it'll be in the same orbit as Jupiter or something, but it's all just a stop gap until the sun goes BOOM. Don't think it'll be anything but a dead rock at that point.

The sun will not go BOOM, barring collision with another, much larger star.

Stars have to be above a particular weight to go supernova - the sun will grow into a red giant, and then, once it burns most of it's hydrogen, collapse into a brown dwarf.

Re: Life and Death of a Planetary System

#24

Post by saagarjha »

dylan604 wrote: post #22
winchling wrote: post #2

Q. Will Earth always be able to support life? A. Probably not [...] Over the next couple of billion years, the increasing amounts of energy Earth will receive from the aging, expanding Sun will warm its atmosphere. Two billion years' work is a hefty amount in terms of scientific and technological development, assuming people survive. So, as David Deutsch would point out, what actually happens will depend on what sola…

Maybe we can come up with a way to adjust the Earth-Moon system's orbit. As the sun starts to expand, the orbit gets wider with it. Sure, it'll be in the same orbit as Jupiter or something, but it's all just a stop gap until the sun goes BOOM. Don't think it'll be anything but a dead rock at that point.

You'll need to pump a huge amount of energy to do this.

Re: Life and Death of a Planetary System

#25

Post by saagarjha »

gonvaled wrote: post #3
winchling wrote: post #2

Q. Will Earth always be able to support life? A. Probably not [...] Over the next couple of billion years, the increasing amounts of energy Earth will receive from the aging, expanding Sun will warm its atmosphere. Two billion years' work is a hefty amount in terms of scientific and technological development, assuming people survive. So, as David Deutsch would point out, what actually happens will depend on what sola…

At some point it will become more economical to terraform other planets than to prevent the Earth from unterraforming. Assuming the technology is there, we will have lots of choices available. Maybe we can even do both.

> Assuming the technology is there

This is a rather large assumption to make, considering we can’t even control the environment of our own planet currently.

Re: Life and Death of a Planetary System

#26

Post by nerdponx »

amelius wrote: post #18
winchling wrote: post #2

Q. Will Earth always be able to support life? A. Probably not [...] Over the next couple of billion years, the increasing amounts of energy Earth will receive from the aging, expanding Sun will warm its atmosphere. Two billion years' work is a hefty amount in terms of scientific and technological development, assuming people survive. So, as David Deutsch would point out, what actually happens will depend on what sola…

They will probably be hired by a company that makes people click ads.

Sounds like a side plot from The Hitchiker's Guide to the Galaxy.

Re: Life and Death of a Planetary System

#27

Post by JewsDidIt »

dang wrote: post #20
aaaaaaaaaab wrote: post #9

Earlier quoted context omitted.

According to the Lord of The Rings, the world was sung into existence by Eru Ilúvatar and his Valaar. Elves, orcs, trolls, goblins and other creatures also came into existence.

Please do not take HN threads further into religious flamewar.

>dang >kills the fun

Yep, name checks out!

Re: Life and Death of a Planetary System

#28

Post by hannasanarion »

posterboy wrote: post #21
hannasanarion wrote: post #15

Earlier quoted context omitted.

No, not really. Entropy only goes in one direction. The universe began in a state of complexity and diversity, and it's history since then has been the story of flattening, cooling, mixing, evening out into boring eternal sameness.

That only counts for closed systems. Does that pertain to our universe? We don't know; We can not see a limit, to say the least, and we have absolutely no agreeable model for any kind of edge . The idea that U closes in on itself, like the surface of a baloon, without any borders, is indeed reminiscent of hindu's Darma idea. It is rather descriptive of our mode of thought: cyclic and self centered; focused on origin…

The universe is by definition a closed system. The universe is all that exists, if there is something that could have an effect on it, it would be part of the universe.

The universe is expanding, distances are getting bigger, and there is no reason to think that it'll suddenly decide to stop and get small again.

Balloon theory was blown up by the discovery of an increasing cosmological constant (aka dark energy).

Once a fire has burned to ash, you can't turn it back into wood again. Cyclical time is wishful thinking, contradicted by all evidence.

Re: Life and Death of a Planetary System

#29

Post by gonvaled »

saagarjha wrote: post #25
gonvaled wrote: post #3

Earlier quoted context omitted.

At some point it will become more economical to terraform other planets than to prevent the Earth from unterraforming. Assuming the technology is there, we will have lots of choices available. Maybe we can even do both.

> Assuming the technology is there This is a rather large assumption to make, considering we can’t even control the environment of our own planet currently.

We are talking about two billion years! It's a possibility, in no way the only one.

It can happen that any crisis wipes us, or even life in the planet, out.

Re: Life and Death of a Planetary System

#30

Post by posterboy »

hannasanarion wrote: post #28
posterboy wrote: post #21

Earlier quoted context omitted.

That only counts for closed systems. Does that pertain to our universe? We don't know; We can not see a limit, to say the least, and we have absolutely no agreeable model for any kind of edge . The idea that U closes in on itself, like the surface of a baloon, without any borders, is indeed reminiscent of hindu's Darma idea. It is rather descriptive of our mode of thought: cyclic and self centered; focused on origin…

The universe is by definition a closed system. The universe is all that exists, if there is something that could have an effect on it, it would be part of the universe. The universe is expanding, distances are getting bigger, and there is no reason to think that it'll suddenly decide to stop and get small again. Balloon theory was blown up by the discovery of an increasing cosmological constant (aka dark energy). Onc…

You are making the mistaking of supposing you conclusion as hypothesis, don't you. Because:

> The universe is by definition a closed system.

There is no de-finit-ion, that's my hole point (excuse the pun, it fits better than any other time)

> The universe is all that exists, if there is something that could have an effect on it, it would be part of the universe.

Yes sure, but what if it's endless? That's not closed in the sense of thermodynamics I don't think.

To conclude from your statement, that the universe is a closed system, kind of requires to presume universal entropy increase, in case of infinity. I can't do the maths though, so I might be wrong. It's just a hunch.

> The universe is expanding, distances are getting bigger,

The visible ...

background radiation may invite inference, but really you get interference.

> and there is no reason to think that it'll suddenly decide to stop and get small again.

In a e.g. 10^50 years would not exactly be suddenly

> Once a fire has burned to ash, you can't turn it back into wood again. Cyclical time is wishful thinking, contradicted by all evidence.

I don't disagree.

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