Protons, Neutrons and Electrons

The universe is an incredibly large place with hundreds of billions of galaxies. Each galaxy has hundreds of billions of stars in it. So there are more than 10,000,000,000,000,000,000,000 stars out there, and most of them are bigger than our sun. There is probably much more as well. That's just all we can see.

All of that stuff out there is made of matter, all of which is made up of protons, neutrons, and electrons. There are other particles that pop in and out of existence and apply the forces, but they aren't matter like protons, neutrons, and electrons.

Protons and neutrons are indeed composed of smaller particles called quarks, that stick together like magnets. An enormous amount of energy is required to get quarks to fly apart because the energy of motion has to be greater than the energy of attraction. Other than in the lab, quarks haven't been by themselves for billions of years.

For about the first hundred thousand years following the Big Band, the Universe was much smaller than it is now, but it still had the same amount of mass and energy, so the amount of energy in a single particle was so big that particles like quarks just could not stick together. The soup of particles that constituted the universe was so hot that no protons or neutrons existed yet.

After this period of time things started cooling down. Of course cooling here means hotter than the sun, but that is cold enough for quarks to start sticking together. The next phase was the combination protons, neutrons, and electrons into atoms like helium and hydrogen.

These atoms began to clump together into gigantic clouds of dust, many hundreds of thousands of light years across. They swirled around until dense spots formed into stars. In their life cycle, stars produce atoms like iron, copper, and carbon. When it finally died and exploded, the star spread these elements were across the galaxy to eventually form planets. But of course all of these still consisted of the same three particles; protons, neutrons, and electrons.

Still today, everything that we can see, touch, taste, smell, and for that matter even hear, is made of three basic particles. We can't see them directly, but they are there, interacting at an incredibly small scale to create the atoms, molecules, and eventually complex systems that allow us to survive, and even thrive.