What is the Universe’s third most common element?
Hydrogen is #1, Helium is #2. Who’s number 3? Hint: it’s not #3 in the periodic table!
“It is the function of science to discover the existence of a general reign of order in nature and to find the causes governing this order. And this refers in equal measure to the relations of man — social and political — and to the entire universe as a whole.” -Dmitri Mendeleev
In the earliest stages of the Universe, it was too hot to form neutral atoms or even atomic nuclei, as they’d immediately be blasted apart by a collision. By time the Universe had expanded and cooled enough that we could form stable nuclei, things were sparse enough that we wound up with 75% hydrogen, 25% helium and just 0.0000001% lithium, with nothing stable beyond that. For tens of millions of years, that’s all the Universe would know, but once we started forming stars, all of that would change.
Today, the Universe is still overwhelmingly hydrogen and helium, but there’s a new #3 in town, and lithium is nowhere close to it. The…
