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Related to this discussion, astronomers’ usage of ‘metal’ is a fun example.
by DiggyJohnson 2y ago
Related to this discussion, astronomers’ usage of ‘metal’ is a fun example.
- hamilyon2 2y agoAnd musicians!
- dylan604 2y agoSalts in chemistry too
- dmoy 2y ago"it can't be that bad, can it?" > astronomers use the word metals as convenient shorthand for all elements except hydrogen and helium what, ok
- kadoban 2y agoYeah, fun, right? I've looked up why before, tldr it's just because historically astronomers have never had to care in any detail about chemical reactions (this is not strictly true of course, but somewhat close for at least a large subset). So they just need a term for "crap that came from stars".
- adastra22 2y agoEh, that grosses over the defining difference that hydrogen, helium, and a little bit of lithium are everywhere everywhen all at once because of The Bog Bang, whereas everything else is concentrated due to being produced in supernovas and neutron stars.
- wavemode 2y agoReminds me of: https://xkcd.com/2205/ https://xkcd.com/2205/
- dataflow 2y agoIsn't there predicted to be liquid metallic hydrogen in Jupiter's core?
- danparsonson 2y agoMetallic as an adjective, behaving like a metal - due to the insane pressures. Different usage of the word "metal".
- TeMPOraL 2y agoSo for astronomers, metallic means "behaving like everything else other than hydrogen and helium". In fact, I'm guessing "metal" (noun) came from use of "metallic" (adjective). The mention of helium betrays it - helium is what hydrogen behaves like normally "due to the insane pressures" (and heat), so what it basically says is just "not hydrogen".
- Sharlin 2y ago"Metal" to astronomers simply means "non-primordial". As in, not created by the primordial nucleosynthesis.
- layer8 2y agoTo keep on topic, that makes Earth's and Mars' atmospheres consist of metals.
- cjfd 2y agoHydrogen can be a metal too. https://en.wikipedia.org/wiki/Metallic_hydrogen https://en.wikipedia.org/wiki/Metallic_hydrogen
- Sharlin 2y agoPoint is, not in the astrophycisists’ use of the word (and not really in any other use either – metallic hydrogen is not a metal, just behaves in some aspects like metal). To astrophysicists, hydrogen is not a metal by definition, which is literally "everything except hydrogen and helium". No matter how exotic a phase. Nb. The subset of astronomers who call everything after helium "metals" is mostly disjoint from the subset that’s interested in gas giant interiors.