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Showing posts from 2019

Atoms in The Universe

Computer scientists like to talk about the number of atoms in the universe when talking about computational complexity. If you have 10**100 nodes to evaluate, and there are only 10**86 atoms in the universe, then there is no way to compute your node tree.

10**86 atoms? Where does that number come from? Who made this up. In [1] the claim is that there are 10**86 hydrogen atoms out there. That seems like alot, right? Remember Avogadro? He came up with a number too [2]. His number is 6.022 x 10**23 atoms per mole. That's alot of atoms too, right?


If you had one cubic mole of something, how many atoms are in there? Well, that's (10**23)**3, or about 10**69. That's not 10**86, but it's close. How many cubic moles are 10**86 atoms then? Well, about 86/69, or about 1.25 cubic moles.

So the total sum of all atoms in the universe is just 1.25 cubic moles? Or rather, let's topsy turvy this. There are more atoms in 1.3 cubic moles of water than the universe.

Ah snap. I b…