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Yes, everything heavier than hydrogen and helium is called metals by astronomers. It's a misleading term for the public, but very widely employed.

(I'm an astronomer)



So it's a three-element periodic table: Hydrogen, Helium, Metals. :)


Yes.

And that's giving far too much weight to the Metals ;-)

(1% of total mass)

The universe really is just Hydrogen + Helium + rounding error...


I heard there might be interesting stuff happening with the metals though. They are self-conscious and stuff?


Wait, the metal talks? And it thinks with its metal?


the metal sings! they can sing by squirting air through their metal!


It's really metal through their metal


They're Made of Meat -> They're Made of Metal: way cooler


The jury’s out on that metaphysically speaking, but even if so that’s a rounding error of the rounding error. This handy chart breaking down the universe by subject area is a useful guide.

https://www.explainxkcd.com/wiki/index.php/2640:_The_Univers...


Yes, they are pretty self-conscious. E.g. gold constantly thinks she's looking too yellow.


Actually, I've heard it called just "Hydrogen and Dirty Hydrogen"


The universe is a zeppelin


Not a led zeppelin though


But a metal zeppelin


Hydrogen is a metal? You must be a very early universe astrophysicist


Reminds me of numbers for database programmers - 0, 1 and many.


Hydrogen, helium, light metal, and heavy metal


Can't we just consider the heavy metal noise?


AC/DC published a study in 1980 asserting that rock and roll ain't noise pollution.


Four actually. There are also heavy metals


More, once we include the combinatoric number of music genres produced by certain grouping of heavy metals on the third cluster from a medium-sized, boring star the metal designates as Sol.


That explains how we got to both dark matter and dark energy.


I would've aced my chemistry class!


Doesn't this have to do with the formation of those elements? As in 'anything heavier than helium is a metal because it was formed in the explosion of a first generation star'? Rather than the chemical definition of what a metal is they probably should have used '2nd generation or later elements' but then again, computer programmers call little boxes with wires attached to them 'mice' and nobody bats an eye (and in fact, that use has now become commonplace).


With the small exception of a tiny bit of lithium made before star formation, yes.


By what process was that Lithium created?



Ok, completely unrelated, but here's a riddle: how many nuclear reactions are there in a thermonuclear bomb?

1. Fission of the plutonium pit

2. Fusion of a small amount of deuterium-tritium at the center of the plutonium pit (designed to be a source of extra neutrons to boost the yield of the plutonium fission)

3. Fission of Lithium-6. Yep, Lithium can undergo fission when bombarded with neutrons. It can't sustain chain reaction, but it's fission nonetheless. The main idea is to generate Tritium, which goes into the next phase, but the energy generated during the fission of Lithium is nothing to sneeze at. Pound for pound, it generates about as much energy as the plutonium.

4. Fusion of the hydrogen (tritium produced from the previous step, and deuterium that's stored in the form of Lithium Deuteride from the beginning)

5. Fission of a rod of plutonium in the middle of the cylinder containing the hydrogen (fission is returning the favor and boosts the fusion reaction)

6. Fission of the uranium temper. The main point of the uranium temper is to be heavy and contain the nuclear reactions for a tiny bit of time, so more generations of reactions can happen, but the secondary outcome is that some of the U-238 nuclei will undergo fission when bombarded by the neutrons from the inside of the bomb.


Wow, I never knew that, thank you so much. So then, what are the chances of there being some primordial heavier than Helium atoms in your body?

We may not be just 'star stuff', but some 'big bang' stuff as well :) (Probably would be anyway if you look at Helium and Hydrogen).





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