Could life on earth continue to exist without the Sun?

[Number Six]

I assume it couldn't continue to exist with our current technology. But suppose we had way more advanced technology. We'd need energy. But a small amount of matter contains a large amount energy and maybe with our extremely advanced technology we could convert matter into energy routinely and continue to exist.

But if we could do that, would we run out of matter and thus energy eventually? Or could we re-capture the heat from the energy indefinitely and keep using it?

Maybe the first thing we'd have to do is build a big dome around the earth so that heat doesn't escape into the very cold of outer space.

If we needed more matter to convert to energy maybe he'd have to send some ships out to catch passing asteroids and comets or maybe get some matter from nearby planets.

Yes, I know this is all silly and unrealistic, but I'm just wondering what a civilization with extremely advanced technology is capable of.

[CynicalSkeptic]

Quote:

I'm just wondering what a civilization with extremely advanced technology is capable of

Magic.


--Arthur C. Clarke.

[Ziggurat]

Originally Posted by Number Six

I assume it couldn't continue to exist with our current technology. But suppose we had way more advanced technology. We'd need energy. But a small amount of matter contains a large amount energy and maybe with our extremely advanced technology we could convert matter into energy routinely and continue to exist.

The only matter to energy conversion is matter-antimatter annihilation. And mass to energy conversion is limited by various conservation laws, which means even with advanced technology, you're limited to fission and fusion.

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But if we could do that, would we run out of matter and thus energy eventually?

We would definitely run out of fuel (not matter) eventually.

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Or could we re-capture the heat from the energy indefinitely and keep using it?

No, that would violate the 2nd law of thermodynamics.

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Maybe the first thing we'd have to do is build a big dome around the earth so that heat doesn't escape into the very cold of outer space.

That would only buy time, it wouldn't solve the problem.

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Yes, I know this is all silly and unrealistic, but I'm just wondering what a civilization with extremely advanced technology is capable of.

Pipe-dream stuff? Use a gas giant as fuel for fusion. That's enough power to do a hell of a lot, for a very long time indeed.

Or if you really want to go all-out, a Dyson sphere.

[Soapy Sam]

Originally Posted by Number Six

Maybe the first thing we'd have to do is build a big dome around the earth so that heat doesn't escape into the very cold of outer space.

.

Neat idea.
But someone beat you to it.
http://en.wikipedia.org/wiki/Dyson_sphere

[RenaissanceBiker]

If there's someplace else in the galaxy you would rather be, why not invent the technology to take our sun with us? It seems a simpler, more elegant solution.

[NobbyNobbs]

Originally Posted by Ziggurat

The only matter to energy conversion is matter-antimatter annihilation.

This can't be right. Every time someone eats an apple, lights a fie, starts a car, grows a plant, etc., matter is converted to energy without the need for antimatter.

[383LQ4SS]

Originally Posted by NobbyNobbs

This can't be right. Every time someone eats an apple, lights a fie, starts a car, grows a plant, etc., matter is converted to energy without the need for antimatter.

food, wood, fossil fuels, plants.....none of those things will last long without the sun. You would need to convert things like ...rocks.

[Ziggurat]

Originally Posted by NobbyNobbs

This can't be right. Every time someone eats an apple, lights a fie, starts a car, grows a plant, etc., matter is converted to energy without the need for antimatter.

Nope. Matter changes form, and it loses mass. But every single proton, neutron, and electron is conserved in every process you mentioned. They're rearranged, but that's not a conversion of matter to energy.

[roger]

Originally Posted by NobbyNobbs

This can't be right. Every time someone eats an apple, lights a fie, starts a car, grows a plant, etc., matter is converted to energy without the need for antimatter.

I think the point is that in all these reactions, matter is not being converted into energy. When you burn a stick, for example, the matter is being changed into other matter - ash, smoke, water vapor, etc. The total amount of matter does not change.

[RecoveringYuppy]

Originally Posted by Ziggurat

Nope. Matter changes form, and it loses mass. But every single proton, neutron, and electron is conserved in every process you mentioned. They're rearranged, but that's not a conversion of matter to energy.

So what is the definition of matter you are using? Apparently it's not "anything with mass".

[Number Six]

Originally Posted by 383LQ4SS

food, wood, fossil fuels, plants.....none of those things will last long without the sun. You would need to convert things like ...rocks.

Yeah but in our hypothetical case with our ridiculously advanced technology, converting matter (or mass or whatever the hell) to an amount of energy equal to that expressed in e=m * c * c would be easy. That'd be a whole lot of energy from, say , a 10 pound rock.

This makes me wonder about something else that maybe I'll figure out sometime but if I post it on here someone else may beat me to it. Humans consume energy to live, say 2,000 calories a day. (The amount of energy in the food consumed via e = m * c * c must be hugely grater.) If you could convert, say, 1 pound of matter into energy, how many people would that amount of energy be able to food at, say, 2,000 calories a day? Or, maybe another way of asking it would be, with 7 billion people on the planet now, how long could one pound of matter feed everybody if converted into energy. (Okay, the amount of mass that, in a gravitational field as strong as the earth at sea level, weighs one point. Or whatever. You all know what I mean, don't go gettin' pedantic.)

[phunk]

Originally Posted by Ziggurat

That would only buy time, it wouldn't solve the problem.

Buying time is all you can do, the only question is how much time would it buy.

[RecoveringYuppy]

Originally Posted by Number Six

If you could convert, say, 1 pound of matter into energy, how many people would that amount of energy be able to food at, say, 2,000 calories a day

That would be almost enough to feed the entire world for a day.

[Ziggurat]

Originally Posted by phunk

Buying time is all you can do, the only question is how much time would it buy.

Not much unless you had far more advanced technology than we currently have.

[Ziggurat]

Originally Posted by RecoveringYuppy

So what is the definition of matter you are using? Apparently it's not "anything with mass".

My definition of matter is particles with mass. But mass is not the same thing as matter. Mass depends on the configuration of matter. Changing the configuration but keeping the same particles can change the mass, but it's still the same matter. For example, a proton and an electron separated by one meter have a different mass than a proton and an electron bound together to form a hydrogen atom. But it's still the same matter in both cases.

[Pulvinar]

Originally Posted by Ziggurat

Changing the configuration but keeping the same particles can change the mass, but it's still the same matter.

Wouldn't we eventually end up with rather sickly looking protons and neutrons? Looks matter to me.

[Number Six]

Originally Posted by phunk

Buying time is all you can do, the only question is how much time would it buy.

Yeah but even with the Sun all we're doing is buying time too if you look at things in the real long term.

[elipse]

Aren't there little sea-vent critters who already exist without the direct benefit of the sun?

So, yeah, it could, unless the existence of the sun indirectly affects these critters.

I have no idea if it does, of course. I'm just noticing that the OP didn't say anything about human life, and I figure sea vent organisms probably have the best chance.

[geni]

Originally Posted by Number Six

I assume it couldn't continue to exist with our current technology.

Wrong. Thermal vent based ecosystems should survive.

Quote:

But suppose we had way more advanced technology. We'd need energy. But a small amount of matter contains a large amount energy and maybe with our extremely advanced technology we could convert matter into energy routinely and continue to exist.

But if we could do that, would we run out of matter and thus energy eventually?

Given the ammount of matter availible in the solar system we would probably hit issues with the big rip first.

Quote:

If we needed more matter to convert to energy maybe he'd have to send some ships out to catch passing asteroids and comets or maybe get some matter from nearby planets.

Yes, I know this is all silly and unrealistic, but I'm just wondering what a civilization with extremely advanced technology is capable of.

http://en.wikipedia.org/wiki/The_Culture

[Floyt]

Stop Jupiter's rotation. Stick a fusion candle into it and nudge it a bit closer to Earth (say, moon orbit). Ignite fusion on Earth-facing side, controlled (and probably more importantly, pressurized) by liberal amounts of handwavium shunting coils. Resume pool party.

[Floyt]

Originally Posted by geni

Wrong. Thermal vent based ecosystems should survive.

Not if the oceans freeze solid.

[geni]

Originally Posted by Floyt

Not if the oceans freeze solid.

When you consider the pressure at depth and the tidal forces of the moon as well as the heating effects of the vents themselves it seems unlikely.

[MontagK505]

Originally Posted by Number Six

I assume it couldn't continue to exist with our current technology. But suppose we had way more advanced technology. We'd need energy. But a small amount of matter contains a large amount energy and maybe with our extremely advanced technology we could convert matter into energy routinely and continue to exist.

But if we could do that, would we run out of matter and thus energy eventually? Or could we re-capture the heat from the energy indefinitely and keep using it?

Maybe the first thing we'd have to do is build a big dome around the earth so that heat doesn't escape into the very cold of outer space.

If we needed more matter to convert to energy maybe he'd have to send some ships out to catch passing asteroids and comets or maybe get some matter from nearby planets.

Yes, I know this is all silly and unrealistic, but I'm just wondering what a civilization with extremely advanced technology is capable of.

"A Pail Full of Air" - short story by Friz Lieber (ca 1961)

As I recall, the air freezes out and the only people to survive where those who had time to build shelters around intstuitions that had access to nuclear power plants. (Irony) Eventually mining colonies would have to be setup around uranium mines. In modren terms, you could harvest hydrogen and oxygen from frozen air for fuel cells and the like. You could grow food in greenhouses with lights powered by nuclear power plants. (Irony) Most of humanity and the earths life would freeze to death in short order.

[phunk]

Originally Posted by Number Six

Yeah but even with the Sun all we're doing is buying time too if you look at things in the real long term.

That's my point. There's no way to "solve" the problem, whatever you come up with will run out eventually also. You have to consider how long the "solution" will last, not whether or not it's permanent, because nothing is.

[phunk]

Originally Posted by Ziggurat

Not much unless you had far more advanced technology than we currently have.

I think that's going to be a requirement of surviving the end of the Sun.

[alfaniner]

Quote:

Could life on earth continue to exist without the Sun?

I would think, "Yes", for about 8 minutes, at least.

[catsmate1]

Originally Posted by geni

Wrong. Thermal vent based ecosystems should survive.

Originally Posted by geni

When you consider the pressure at depth and the tidal forces of the moon as well as the heating effects of the vents themselves it seems unlikely.

Total geothermal power production of the Earth is ~45 terawatts, tidal is ~3 terawatts; solar input is ~173,000 terawatts
My guess is that the oceans would stay liquid for a few hundreds/thousands of years, especially after the upper layer freezes and helps insulates them.
Though average surface temperate would reach uninhabitable levels within a year or two.

Originally Posted by geni

Given the ammount of matter availible in the solar system we would probably hit issues with the big rip first.



http://en.wikipedia.org/wiki/The_Culture

The sun converts 4.3x10⁹kg of mass into energy per second so converting the mass of the Earth at 100% efficiency would last us ~44 million years. Though personally I'd use Venus/Jupiter et cetera instead of our home. And surely we'd not need to replace all that power, the Earth only gets about one-half bilionth of the sun's output.
With sufficiently advanced technology I'd suggest a network of satellites orbiting the Earth, inside a Dyson shell.

[RussDill]

Originally Posted by Floyt

Stop Jupiter's rotation. Stick a fusion candle into it and nudge it a bit closer to Earth (say, moon orbit). Ignite fusion on Earth-facing side, controlled (and probably more importantly, pressurized) by liberal amounts of handwavium shunting coils. Resume pool party.

Geez, what a horrible plan. My far superior plan involves moving the Earth into Jupiter orbit.

[BenBurch]

Bacteria can live in deep aquifers and those would remain warm for a billion years or so even if the sun went out tomorrow. In fact we found one place where radioactive decay was FEEDING the bacteria.

So, you and I would freeze to death in a matter of a few days, but the deep bacteria will not be effected by it in any way.

[jj]

Well the bacteria around the black smokers would probably not even be aware of the disaster for many, many years to come.

[MrQhuest]

With radioactive decay, and tidal friction, there would be enough heat for *some* kind of life. Maybe if we dug real deep, humans could find a way to live of geothermal energy, (the City of Zion in The Matrix for example)
As long as we're looking at science fiction (ok, I am anyway) Larry Niven's Pierson's Puppeteers, had a severe problem with global warming, that they decided to move their planet s away from their sun. http://en.wikipedia.org/wiki/Fleet_of_Worlds
Bottom line: Life needs energy. Doesn't matter if its light, or heat.

MrQ

[-Fran-]

I don't quite get it. As our sun's death is described it seems it will take the whole earth with it in its death throes, turning into a red giant and maybe swallowing earth up, and in either case scorch it beyond any human ability to survive... Or...? I mean, it won't just slowly die down, leaving us in the cold, so to speak :-D So after it finally did die down so completely that we would need another energy source... there'd be no us to need it??

I guess we'd be better off finding a way to escape earth before that happens, but then I guess we'd try to find an earth-like planet with a sun of its own on a suitable distance. But is that so far into the future that there might be no humans anymore anyway, we would have died out, or evolved into something else?

[ThunderChunky]

There was some interesting discussion in this thread on how a civilization might survive if it's planet got ejected from it's orbit or galaxy:

http://forums.randi.org/showthread.php?t=202164

Basically same idea's that came up here, insulate planet (or part of planet) with biodome and use nuclear power to survive as long as possible. There wont be much space debris to use as fuel if you aren't near a large gravity sink like a star inside a galaxy.

[Andrew Wiggin]

Originally Posted by Floyt

Stop Jupiter's rotation. Stick a fusion candle into it and nudge it a bit closer to Earth (say, moon orbit). Ignite fusion on Earth-facing side, controlled (and probably more importantly, pressurized) by liberal amounts of handwavium shunting coils. Resume pool party.

You'd better have that up and running by the time I finish flying my bussard ramjet around the galaxy and back. I'd like a planet with a bunch of women on it too. (assuming you're referencing the story I think you are)

[Trent Wray]

What's the matter with our Sun ?

[BowlOfRed]

Originally Posted by Number Six

Humans consume energy to live, say 2,000 calories a day. (The amount of energy in the food consumed via e = m * c * c must be hugely grater.) If you could convert, say, 1 pound of matter into energy, how many people would that amount of energy be able to food at, say, 2,000 calories a day? Or, maybe another way of asking it would be, with 7 billion people on the planet now, how long could one pound of matter feed everybody if converted into energy. (Okay, the amount of mass that, in a gravitational field as strong as the earth at sea level, weighs one point. Or whatever. You all know what I mean, don't go gettin' pedantic.)

Asimov did the calculation in another way. I don't think I have the book any longer, but from memory he calculated that you could take (the energy equivalent of) about 130 average cells in your body per day for your power requirements.

[Roboramma]

I think that given enough warning and the will to do it we could build a city of a million people with modern technology that could survive for a long time in this scenario.

Most of our modern energy sources: coal, oil, natural gas, uranium, would still be viable. Hydro power, solar (particularly for growing food and heating), and wind would no longer be available. So, you build your city in an easily insulted place: ideally underground caverns. You build nuclear power plants, but might as well store as much oil/coal/natural gas as is economically feasible as well. Make the whole thing insulated from the outside, but also insulate living areas separately.
Farms with grow lights (probably best done hydroponically given the cost of keeping the whole space warm) supply the food. Bring in as many resources as possible, but things that are needed can also be sourced from outside on expeditions.

[Number Six]

This thread makes me realize what a massive security blanket the Sun is for us. If the Sun wasn't there then we're saying "We could continue to exist if we did this or that." But IOW, if we could make the right machine and maintain then perhaps we could keep going. But it would always depend on keeping that machine or technology going.

OTOH, with the Sun we don't have to worry about that. It's always there. We have to worry about not screwing up the earth so much we can't continue to live here so I'm not saying we have it completely made, but the Sun is a pretty big part in maintaining life on earth and it's always there for us. How nice and convenient.

Considering there size of the universe and assuming life exists here and there in the universe, there may be life on some planet circling a star somewhere where the supply of energy from the star to the planet for whatever reason is unstable or the stars life is running out or something. Some situation where the life on that planet can't count on their star to supply a steady indefinite supply of energy.

Imagine how much that would suck. I mean, if something goes wrong on earth we can maybe fix it depending on what it is, but if our Sun started failing we would be screwed big time.

[CapelDodger]

Originally Posted by jj

Well the bacteria around the black smokers would probably not even be aware of the disaster for many, many years to come.

I rather doubt that bacteria are aware of anything. I've met people that are barely aware of much.

[CapelDodger]

Originally Posted by Floyt

Stop Jupiter's rotation. Stick a fusion candle into it and nudge it a bit closer to Earth (say, moon orbit). Ignite fusion on Earth-facing side, controlled (and probably more importantly, pressurized) by liberal amounts of handwavium shunting coils. Resume pool party.

If the Sun suddenly disappeared, orbits would be a thing of the past straight away. And if the Earth were flung out of its orbit by, say, a black-hole zooming past, it wouldn't be the only planet with a new future, heading out or (more briefly) heading in.

Best not worry about it and just party on.