Sunshine : the physics behind. no spoilers so dont worry!

I know few people have seen the movie "Sunshine" yet, but my friend in the IFI has, and he says that to keep the sun alive, they want to attempt to set off a nuclear bomb the size of an american state in the core of the sun to keep it alive ( this much is in the paper anyway so no spoiler!). From my basic basic understanding, setting off a nuclear warhead in the sun wil only help for a very short time. should they not be attempting to place huge quantities of hydrogen and helium into the suns core to replenish its diminishing fuel source?

I don't think it could happen anyway. I mean, nothing in the Universe is able to survive the extreme temperatures and pressures our Sun would have in its 'mantle', let alone the core! Hence why everything is in a nuclear state within.

Every second 6 million tonnes of hydrogen is converted into pure energy at the suns core! (use E=MC2 to estimate the amount of energy), not to speak of how much hydogen is needed in the first place for that to happen given that most of the hydrogen in a nuclear reaction is turned into helium.

Go figure the size of the nuclear bomb that would be !!

Setting off any currently existing nuclear warhead near/at or in the sun is like throwing a smartie at an oncoming train going 100MPH. As for one the size of north america, I still can imagine it would have any effect on something the size of the sun. I doubt all the world nuclear bombs going off together could sustain the sun for more then a nano second.

I doubt all the world nuclear bombs going off together could sustain the sun for more then a nano second.

I doubt we could even come close, even with e.g. 10,000 times as many warheads. The reason being, the Sun (and any star burning at all) uses nuclear FUSSION - we have mostly fission (atomic)-based weapons instead. Weight for weight of raw material, fusion is about a couple hundred times more powerful than fission, and even more when right. Even at that, to yield the same energy as 6 million tonnes of hydrogen-based explosion (in a star) per second? Impossible! The United States alone can only produce about 7.8 million tonnes of hydrogen a year!

The A-bomb uses fission.
The H-bomb("Thermonuclear") uses fusion.

(The H-bomb is so much more powerful it makes the A-bomb look like a firecracker.)

Hmm... typical american response to most situations - blow it up. As Dave L says, all the warheads in the world wouldn't sustain the sun for a nanosecond - just not enough mass. Now if the americans REALLY wanted to make a global contribution to the survival of the planet, they should send in the Marines (into the sun!) Now there's something with enough density to sustain the sun for ages!

Phil
(bang go my chances of a visa... yippee!!!!)