5 ms·
My fun little factoid about criticality is: sometimes it just happens naturally, on earth. https://en.wikipedia.org/wiki/Natural_nuclear_fission_reactor https:
by mock-possum 3y ago
My fun little factoid about criticality is: sometimes it just happens naturally, on earth.
https://en.wikipedia.org/wiki/Natural_nuclear_fission_reactor https://en.wikipedia.org/wiki/Natural_nuclear_fission_reacto...
> The natural nuclear reactor formed when a uranium-rich mineral deposit became inundated with groundwater, which could act as a moderator for the neutrons produced by nuclear fission. A chain reaction took place, producing heat that caused the groundwater to boil away; without a moderator that could slow the neutrons, however, the reaction slowed or stopped. The reactor thus had a negative void coefficient of reactivity, something employed as a safety mechanism in human-made light water reactors.
> After cooling of the mineral deposit, the water returned, and the reaction restarted, completing a full cycle every 3 hours. The fission reaction cycles continued for hundreds of thousands of years and ended when the ever-decreasing fissile materials, coupled with the build-up of neutron poisons, no longer could sustain a chain reaction.
What a wild story!
- defrost 3y agoIt was a different time then approximately 1.7 billion years ago, during the Statherian period of the Paleoproterozoic, and continued for a few hundred thousand years, probably averaging less than 100 kW of thermal power during that time.
- danparsonson 3y agoAt least we now know how early life kept their devices charged.
- Terr_ 3y agoInterestingly, the -oid suffix usually refers to things that only resemble the thing, so an andr-oid is not really a man, a meteor-oid is not really a meteor, and fact-oid... might not really be a fact. However the really amusing bit is that that everybody can agree--for different reasons--that: > Here is a factoid: A factoid is a small fact.
- danielbln 3y agoThe correct word would be a factlet, but factoid has been defacto taken its place. The fluidity of language, I suppose.
- Terr_ 3y agoI wonder if anyone's done studies to measure and quantify the "distance" of slang (in years or generations) before an older person feels instinctive linguistic revulsion...
- marcosdumay 3y agoIt's a continuous value, that is visibly different from zero almost immediately; children will experience it in a few contexts.
- anyoneamous 3y agoBut is the collective noun for fully-grown factlets "facti" or "factodes"?
- selimthegrim 3y agoThe octolets will get back to you.
- bmacho 3y agoI think I prefer factlet over factoid.
- adrian_b 3y agoYes, the -oid suffix is cognate with words like video and vision, referring to sight, so X-oid means something that looks like X.
- selimthegrim 3y agoSchizoid?