In this post, I'm going to show you what I'm really made of.
Standard Model of particle physics. Everything, absolutely everything, with no exceptions, can be broken down at base into these things. The interactions of these twelve particles and four forces are the cause of absolutely all phenomena. We are very close to understanding these interactions to a very high degree of accuracy, and we are also close to being able to plug the numbers into a computer and have it start calculating, and have it end up predicting everything within certain levels of probability. But obviously, I'm more than just quarks and gluons. I'm a human being, a living thing, and a thing with a mind. As Carl Sagan put it, the beauty of a living thing is not the atoms that go into it, but the way those atoms are put together. So, how did this stuff end up turning into me?
These elementary particles have to come together as composite particles before we can even start to build atoms, which are the smallest pieces of elements. The nucleus of an atom is made of protons and neutrons, and that nucleus is surrounded by a cloud of electrons. Yes, its a cloud even in a hydrogen atom, where there is one electron. Protons and neutrons are made of three quarks each; a proton is two up quarks and a down quark, while a neutron is two downs and an up. The quarks are held together by one of the four forces, the strong nuclear force (which is also gluons). The nucleus of a relatively large atom looks a little bit like this:
star, specifically our Sun. Its emitting a lot of energy, partly in the form of heat and light, because in the middle, gravity is pushing the hydrogen atoms together. Normally, they're held apart by the electromagnetic force, which is much weaker than the strong nuclear force, but holds up better over distance. Gravity is much weaker than the electromagnetic force, but its even better at working at a distance, and the more matter you have, the stronger it gets. When a proto-star gets big enough, the gravity pushes the nuclei close enough that the strong nuclear force beats out electromagnetism, and the atoms snap together in a process called thermonuclear fusion. The energy the particles release when they fuse is greater than the energy needed to push them together, and the star ignites. At its core, our Sun and every other star is fusing hydrogen into helium. Our Sun, amazingly enough, isn't big enough to go on to the next stage when it eventually runs out of hydrogen. Bigger stars start fusing hydrogen into carbon through the triple-alpha process when they near the end of their lives. Really big stars go on to fuse lighter elements into iron. But going any heavier than that stops releasing energy; it takes more energy to fuse the nuclei than they release when it happens. So what made all the elements heavier than iron? There are a lot of them. That process might look a little something like this:
supernova nucleosynthesis. All the heavier elements, everything with an atomic number higher than 56, gets made when the biggest of stars die. Stars that burned billions of years ago and uncounted light years away died, so that you could be here today reading this article. On YouTube, philhellenes said it quite well: Stars must die so that I can live. I stepped out of a supernova.
And so did you.
So, what am I really made of? Energy. Quarks. Atoms. Molecules.
I'm pretty awesome. You are, too.