4 ms·
Many are keen to point out that we live in proximity of a giant fusion reactor and ought to be smart enough to harness its output. But it took me a long time t
by nonrandomstring 4y ago
Many are keen to point out that we live in proximity of a giant fusion
reactor and ought to be smart enough to harness its output.
But it took me a long time to appreciate something odder; We're living
on a giant fission reactor [1]. The Earth's core isn't hot because it
just hasn't cooled down in the icy void of space. It's actively
producing heat. Our gravity acts upon the heavy elements, which sink
through the molten iron and silicon, to the core, where they become
fissile.
[1] https://blogs.scientificamerican.com/observations/nuclear-fission-confirmed-as-source-of-more-than-half-of-earths-heat/ https://blogs.scientificamerican.com/observations/nuclear-fi...
- foobarbecue 4y agoNot a fission reactor. Just a radiothermal generator. It's not critical. This article doesn't say anything surprising; the news is that these guys calculated how much heat is produced.
- foobarbecue 4y agoOk I just read a bit more and apparently there are some fringe geophysicists who think it really is more like a reactor. I didn't know that.
- defrost 4y agoThere were actual "natural" fission reactors in the crust in central Africa some time ago[1] .. the broader region provided the bulk of the ore for the Cold War production of weapons grade ore. [1] https://en.wikipedia.org/wiki/Oklo_Mine https://en.wikipedia.org/wiki/Oklo_Mine
- pencilguin 4y agoNature used up the best ore billions of years ago. We did get radiation-resistant microbes in exchange.
- defrost 4y agoThe news here, specifically, is that: > Enter Quaise, which “is developing technology to blast rock with microwaves to potentially drill the deepest holes on Earth. ie. there's a new, untried at extremes, bore drilling technique. The calculation of heat production from earths core isn't new here, and nor, sadly, is any demonstration of a bore hole at a 10 mile depth. They do acknowledge the deepest convential borehole so far was 7.6 mile (at some considerable effort at no small expense).
- julian_sark 4y agoMostly. https://en.m.wikipedia.org/wiki/Natural_nuclear_fission_reactor https://en.m.wikipedia.org/wiki/Natural_nuclear_fission_reac...
- sidewndr46 4y agoWhen I asked a physicist about this, he said it's mostly conjecture. You can't really prove it because we can't actually visit the Earth's core. Yes, I'm aware how the neutrino velocity measurement supposedly confirms it. But I don't think the scientific community has accepted it at large.
- foobarbecue 4y agoRadiothermal heating of planetary cores is established scientific fact. It's not a fission reactor because there's no chain reaction, just a lot of unstable elements in one place. Some details are controversial, but not the basics. (I have a geochemistry PhD)
- foobarbecue 4y agoOk I just read a bit more and apparently there are some fringe geophysicists who think it really is more like a reactor. I didn't know that.
- sidewndr46 4y agoYes, I think that is the where the debate is over the exact nature of things. Fission happens spontaneously, even the bismuth in Pepto Bismol has a bit of a fission going on, slowly decaying into thallium.
- amluto 4y ago²⁰⁹Bi decay to ²⁰⁵Tl is alpha decay — the bismuth nucleus splits into an alpha particle (helium) and a thallium nucleus. I think you’d be hard pressed to find a nuclear physicist or engineer who calls that “fission”. Here’s the Wikipedia article on fission. It’s a rather different process: https://en.m.wikipedia.org/wiki/Nuclear_fission https://en.m.wikipedia.org/wiki/Nuclear_fission
- saboot 4y agoCan you link to what you are reading? I am a nuclear engineer, I suspect they are using a very loose definition of critical, one that would imply the entire universe itself is critical.