BloodshotPizzaBox t1_iyi8te9 wrote on December 1, 2022 at 4:32 PM

I know this isn't what you meant by the question, but since the vast majority of the universe (not counting dark matter, whatever that is) is made of stars that are mostly hydrogen and helium, basically everything on Earth is very rare compared to the universe in general. So, that's pretty cool.

KnoWanUKnow2 t1_iyioee9 wrote on December 1, 2022 at 6:12 PM

The universe is mostly not matter. It's about 63% dark energy. What little matter there is is mostly dark matter. Only about 20% of all matter is not dark matter.

Of that 20% of matter that's not dark matter, it's mostly Hydrogen. Hydrogen makes up about 80% of all non-dark matter in the universe. The remaining 20% is mostly Helium, which makes up about 19.8% of that 20%.

So that means that everything else, all carbon, all iron, all oxygen, and nitrogen, everything that we are made of and everything that out planet is made of (excepting the hydrogen in things like water) is made of a vanishingly small and rare subset of what's available in the universe.

95% of the universe is dark matter and dark energy. Of the 5% that's left 4% is hydrogen, and Helium takes up most of the remaining 1%. We and our entire planet (excepting the Hydrogen bound up in water and other minerals) are made of less than 0.001% of the universe.

The Calcium in your bones, the Iron in your blood, the Carbon in your food, the Oxygen that you breath, even the ground that you walk upon, all of it is so rare as to be almost impossible.

Acrobatic-Secret374 t1_iyji4zp wrote on December 1, 2022 at 9:23 PM

To expand on this... Virtually everything heavier than iron must be formed by stellar explosions.

Either the star explodes, or two stars collide and explode (like neutron dwarf star collisions (NS-NS) )

Iron uses more energy to fuse than it makes in fusion. So, once a star starts to make iron, it is already dying. Supernova only make a small fraction of stuff heavier than iron (5%) the rest is NS-NS collisions.

Limos42 t1_iylg7ek wrote on December 2, 2022 at 6:59 AM

Fascinating. I've never thought of it this way. Thanks for sharing.