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Re:Ask HN: What’s the most important modern simple invention? by frutiger on Monday February 10, 2020 @09:14PM (#22295391)
Surely the three most common elements (by any measure) are hydrogen, helium and lithium?
Re:Ask HN: What’s the most important modern simple invention? by rriepe on Monday February 10, 2020 @10:40PM (#22295851)
It's complicated. Helium does make the list, but lithium doesn't. Carbon and oxygen are higher than you'd expect if you're just going by atomic weight.
Re:Ask HN: What’s the most important modern simple invention? by frutiger on Tuesday February 11, 2020 @12:08AM (#22296235)
I remember from my astrophysics course that Lithium was formed in the aftermath of the Big Bang. I would imagine that interstellar space is full of Hydrogen, Helium and Lithium.

I can imagine that stable nuclei such as carbon or iron would form as a result of stellar fusion but I would be hard pressed to imagine that these outmass the more primordial elements. I would be interested to see references if you have any.

Re:Ask HN: What’s the most important modern simple invention? by rriepe on Tuesday February 11, 2020 @01:58AM (#22296641)
Wikipedia has a good writeup: https://en.wikipedia.org/wiki/Abundance_of_the_chemical_elem...

TL;DR: Stars burn it up.

Re:Ask HN: What’s the most important modern simple invention? by frutiger on Tuesday February 11, 2020 @09:44AM (#22298833)
That table is for the milky way though, not the universe.
Re:Ask HN: What’s the most important modern simple invention? by rriepe on Tuesday February 11, 2020 @03:59PM (#22302782)
Yeah but all the elemental matter in the universe is like three dust specks floating in a lecture hall. You can ask about the dust specks or the lecture hall interchangeably.
Re:Ask HN: What’s the most important modern simple invention? by frutiger on Tuesday February 11, 2020 @04:39PM (#22303174)
This is a common misconception. Intergalactic space is filled with about half of the matter in the universe. See: https://en.m.wikipedia.org/wiki/Warm–hot_intergalactic_mediu...

As to your original point though, there doesn’t appear to be too many elements here apart from ionized hydrogen and hydrogen.

Re:Ask HN: What’s the most important modern simple invention? by rriepe on Wednesday February 12, 2020 @09:21PM (#22314798)
Great point. I almost missed this. It really seems like there should be another separation in the article I linked, between "Universe" and "Milky Way."