"We've mined all the fissile material on Earth"

[Stravo]

A little back story for this question, in order to build an uber bomb to restart a dying sun humans have been forced to mine and use all the fissile material on the planet.

Ignoring whether such a mining operation can even happen in a single human lifetime, My question is if you remove all fissile material from the planet aren't you dooming humanity anyway? Without those materials wouldn't we bereft of much of our modern technology and power generating ability? Or could we get along in some manner? Bear in mind this is set in the 2050's so Peak Oil is long come and gone.

[Illuminatus Primus]

Uh, you'd render the Earth uninhabitable, because you'd have to pulverize it in its entirety.

[Guardsman Bass]

Are we simply assuming the fissile material in the crust, or literally all of it? A lot of it is sitting far below the crust.

If it's simply the crust, then maybe you could compensate with some really overworked other power sources plus a hell of a lot of solar power, but you'd still probably have some contraction in power supply unless you are living in space.

I don't suppose there are any uranium-rich asteroids floating around in the asteroid belt?

[Androsphinx]

Uh, you'd render the Earth uninhabitable, because you'd have to pulverize it in its entirety.

I assumed that "all fissile material" meant "all reasonably extractable material" - presumably through mining and extraction from seawater, etc.

With regard to the OP, presumably they have ubertuch which mitigates against this. Or have never heard of Peak Oil. Or never really considered it. While it's a nice movie, Suspention of Disbelief was never really one of its priorities (even before it turned into a slasher movie in space).

[Zablorg]

Oh my god, When I read this I thought humanity was screwed some more.

[Wyrm]

A little back story for this question, in order to build an uber bomb to restart a dying sun humans have been forced to mine and use all the fissile material on the planet.

This is the sticking point. No amount of fissile material will restart a dying sun. If anything, it will only hasten its death.

A dying star dies. Period. No restart button.

[Junghalli]

A dying star dies. Period. No restart button.

You could try pumping the heavy elements out of the core. Alternately, if you could disrupt the core enough to redistribute its heavy elements to the outer layers you could buy a little time (which on a human scale might come out to a lot of time). But either one would take some serious uber-tech.

[Stravo]

A little back story for this question, in order to build an uber bomb to restart a dying sun humans have been forced to mine and use all the fissile material on the planet.

This is the sticking point. No amount of fissile material will restart a dying sun. If anything, it will only hasten its death.

A dying star dies. Period. No restart button.

The way it is described is that there is a Q-Ball stuck in the sun that is eating it away from the inside. The bomb is supposed to dislodge the Q-Ball from the sun allowing it to return to normal.

I'm not going to pretend I'm a physicist but it sounds a little bit better than "Rar we are reigniting the sun with uber nukes"

[The_Saint]

Irrelevant in light of the last post but I've always wondered (my knowledge of physics doesn't quite extend this far)...

Could adding enough extra Hydrogen to a star (eg our local one) keep it around longer or would this extra mass just help accelerate core collapse?

conversely:
If removing heavy elements is for a given reason unfeasible and assuming some hypothetical handwavium method of doing so: Would it be possible to increase the lighter/heavier element ratio by adding a given mass of Hydrogen such that the Hydrogen burn stage was prolonged and gave an increased amount of time before heavier element burning or core collapse.


OR is it simply that by increasing the total mass of the star you will only accelerate core collapse.

It doesn't sound feasible to me and I suspect tonight, tomorrow, somewhere it'll dawn upon me why it's not possible but it's something I've always been curious about but never understood quite enough to answer myself.

[Junghalli]

The thing is IIRC red giants are still mostly hydrogen by mass; the issue is with the buildup of heavy elements in the core, where the actual fusion happens.

[Fingolfin_Noldor]

Pumping will not work. Simply no amount of handvium will. The core is where the star is at its densest and hence that's where the fusion takes place. In fact, taking away the core will simply cause the star to not collapse but instead just evaporate out. White Dwarves do not result by the way from huge cataclysmic explosions; the outer surfaces just simply evaporate away.

If you want the star to continue functioning, you'd have to somehow substitute the material at the core with the corresponding amount of hydrogen/helium/what not in the correct composition. How anyone plans to do so really is beyond me since the mass is simply worth a few earths.

[Zixinus]

Restarting a sun is about as possible as restarting a candle that is about to burn out.

[Stark]

Except the star isn't 'dying', it's been interfered with by something which the magical bomb of mini-big bang is going to dislodge. That everyone complains about the ridiculous setup for Sunshine is very amusing.

[Sarevok]

Thing is if you are so powerful and advanced that you can resurrect a dying a star you would not need a star in the first place.

[Stark]

If you can travel faster than the speed of light causality doesn't work?

The setup for Sunshine is almost totally irrelevant. I mean, you're not out of radio contact with Earth before you reach Mercury either (I mean, in the 60s there was no problem lol), which is a much more glaring bit of silliness. It's retarded, but the first 80% is a cool movie anyway. All the whinging about 'zomg teh sunz lol' certainly didn't ruin my enjoyment of the movie, because it's not about giant bombs at all, it's about people.

Plus it features no voting.

'So let's vote.'
'No. We're scientists and astronauts, and we're going to make the most informed decision we can using the available data.'
'Which means you?'
'Which means the only person who has the technical knowledge to determine if the utility of a second payload is worth the risk of the detour.'

CAPA, PAYLOAD SPECIALIST '... fuck.'

[Admiral Valdemar]

It is interesting to note, though, that Boyle explicitly went to CERN to get some reason for Sol dying and then produce a pseudo-MacGuffin to deal with that. It made a lot more sense than a similar movie in the '90s called Solar Crisis.

The whole anti-voting thing rocked too. I expect a fair few laypersons were like "ZOMG!!1! FUCKING SCIENTISTS AND THEIR ELITE CRAP11!! DEOMOCARCY R00LZ!".

[kc8tbe]

If we removed all the radioactive material from the Earth, wouldn't we end up looking like Mars? My impression is that radioactive decay is what heats the Earth's core, which is what produces the magnetic field that prevents our atmosphere from being stripped away by the solar wind.

[Sea Skimmer]

Ignoring whether such a mining operation can even happen in a single human lifetime, My question is if you remove all fissile material from the planet aren't you dooming humanity anyway?

If we have the technology to mine billions upon billions of tons of fissile material out of the ground, and billions upon billion of tons more out of the ocean, and then assemble this all into a bomb, which we can then somehow lift into orbit and then hurtle into the sun then we ALREADY have the capability to start large scale colonization of other planets, on which I’m sure we can find more uranium.

Not to mention we could also use that same uber space lift technology to assemble all sort of huge arrays to capture solar energy, and frankly the energy costs involved in putting that bomb into orbit are going to make the whole issue irrelevant anyway. Clearly we’ve already got some absurdly powerful energy source going on to make all that rocket fuel,

[Wyrm]

The way it is described is that there is a Q-Ball stuck in the sun that is eating it away from the inside. The bomb is supposed to dislodge the Q-Ball from the sun allowing it to return to normal.

I'm not going to pretend I'm a physicist but it sounds a little bit better than "Rar we are reigniting the sun with uber nukes"

That makes more sense. Thanks.

As to the question in the OP, using up all the nuclear fuel to build a bomb would send civilization to the pre-industrial age at the very least. You say this is after Peak Oil, which means that we have moved beyond oil to the more sustainable nuclear power (necessary if you're going to sustain an industrial society past Peak Oil capable of building a rocket that can perform this stunt). Your civilization can't sustain itself without fissile materials -- burning other fossil fuels in its stead will just disrupt the climate and bring it to an end in short order.

Depending on the physics of Q-Balls, it might simply be preferable to just let the sun die and move to another system. After all, the sun has about a million years of energy stored in its radiative zone which will keep it puttering along at the same luminosity, even if all fusion stops, and there's still Kelvin-Helmholtz contraction, which will keep the sun shining at its present luminosity for tens of millions of years.

PS, you're basing this on Sunshine, aren't you?

[Winston Blake]

A little back story for this question, in order to build an uber bomb to restart a dying sun humans have been forced to mine and use all the fissile material on the planet.

Ignoring whether such a mining operation can even happen in a single human lifetime, My question is if you remove all fissile material from the planet aren't you dooming humanity anyway? Without those materials wouldn't we bereft of much of our modern technology and power generating ability? Or could we get along in some manner? Bear in mind this is set in the 2050's so Peak Oil is long come and gone.

If you've removed all the fissile material, then why not get going on the fissionable material? U-235 and thorium are very rare compared to U-238. Breeder reactors and plutonium for all!