Quantum Physics: Quarks (Part 1)

I know that people usually post blogs/articles about their lives and what they are doing, but I’m a huge science nerd, so I would love to rant about quantum physics for a little bit!

Let’s start with the basics: we all know the structure of an atom—it has a nucleus in the middle, the heaviest part, with protons (positively charged particles) and neutrons (obviously neutrally charged particles) in it. Then, outside the nucleus, somewhere in the electron cloud, we have electrons (we can’t really know their precise location at a given moment, but rather the probability of them being located in a certain place; more about that in another post).

Today, I really want to delve into quarks. Protons and neutrons are made up of quarks. As of today, quarks are considered fundamental (meaning they are not made up of anything else—they are fundamental particles). Quarks are also considered fermions, meaning that they are building blocks of matter (as opposed to bosons, which carry forces…but don’t worry about bosons right now).

The most abundant types of quarks are “up” and “down” quarks because they are the most stable. (I will dive deeper into other types of quarks in future posts.) These quarks have a really interesting charge. We are used to charges being whole numbers, like -1 or +1, yet these quarks have something special going on: an up quark has a charge of +⅔, while a down quark has a charge of -⅓. A proton is made up of two up quarks and one down quark, giving it a total charge of +1. A neutron is made up of one up quark and two down quarks, giving it a charge of 0 (neutral).

You’ve probably heard of the four fundamental forces: the strong nuclear force, weak nuclear force, gravitational force, and electromagnetic force. Well, as can be inferred from its name, the strong nuclear force is the one that acts between quarks. Interestingly enough, when you try to pull quarks away from each other (and hence isolate them), the strong nuclear force gets stronger, making it impossible to isolate a quark. I’ve heard a good analogy for this situation: it’s like pulling on a rubber band with your hands—it gets more tense as you pull it farther and farther.

I don’t want to overwhelm this post with too much information, as I want to break it down into simpler ideas and explore more concepts in later blogs :)