I know, a blog post that has the exact same name as my blog. How creative! For me, titles are the hardest things to create, so I hope you’ll make do with the uninventive name and stay to learn something new. There’s a lot to explain about elementary particles, so I’m going to split the topic up into three posts. The next two posts will go into detail about the different types of particles, but in this post I’ll just describe what elementary particles are and explain the reason behind my blog name.
Imagine, if you will, the smallest known things in existence. They’re known as elementary particles, and they exist on an inconceivably small scale. Think of the size of a cell. While that cell might already seem small, it is made up of trillions of atoms. This atom contains protons, neutrons, and electrons. The proton and the neutron are subatomic particles, which are made up of elementary particles, but an electron is actually an elementary particle. It isn’t composed of any other particles, and therefore is very, very, small. (I contemplated adding more “verys,” but it didn’t seem like a good idea.) Elementary particles have some unique characteristics that make them fascinating to learn about.
Spin – But Not the Kind of Spin You’re Thinking of
There’s a quality that all elementary particles share called spin. Before I go too far into this, I’ve got to add that I don’t understand spin very well yet. I think even physicists don’t really understand spin either. Its complexities practically warrant a blog post all of its own, so I’ll just include a brief summary of what I comprehend spin to be. Right now as I talk about spin, you’re probably imagining a little particle spinning on its own axis. When talking about particles, however, that image is entirely false. Spin is the quantum version of angular momentum, also known as “normal” spin.
Spin could be described as the characteristic that causes particles to act as magnets, although you encounter issues when you measure the strength of the magnetic field they give off. We know that the faster these particles are spinning (I’m actually talking about angular momentum now), the greater of a magnetic field is produced. Taking into account the properties of the particles, they would have to be rotating faster than the speed of light. For those of you unfamiliar with the laws of physics, that’s a big no-no. So, we just accept spin as the quality that allows particles to rotate that quickly. Spin has many other parts we could go into, such as the fact that it has a direction and the different spin of different particles, but those can be explained at a later date. I feel like I’ve been confusing enough for one day.
Antiparticles – The Quantum Version of “Opposites Attract”
Let’s move on to somewhat simpler topics like antiparticles. They’re something I need to talk about because every elementary particle I’m going to discuss has an antiparticle with the same mass but an opposite charge. The electron has a positron, the quark an antiquark, and so on. These particles have opposite charges, so in close proximity they are attracted to each other, bringing a new meaning to the phrase “opposites attract.” These two particles, if they collide, will proceed to annihilate each other. This annihilation results in new particles being produced from the collision. We can thank the physicist Richard Feynman for the diagram on the right, where you can see that an electron and a positron (e+ and e-) have annihilated each other, creating two photons (y and y).
My Blog Name
As you’ve begun to grasp the tininess of these particles, I hope you’ve
started to understand the reasoning behind my blog’s name. The fundamental particles and the interactions between them make up everything in this world. Just as these particles are the simplest, smallest parts of all that we know, my blog aims to detail complex thoughts in physics in a simple way. I hope to break these concepts down into understandable ideas for anyone. I decided it was fitting to write my first blog post about the elementary particles, and I hope you’ve enjoyed learning about them. Soon I’ll have more posts written about the specific types of particles. Please comment below or email me about any questions you have. Until next time!
I always want to include some links with more useful information that has to do with what I’ve written about.
Want to read the next blog post in this series about one of the categories of elementary particles, fermions? Click here: Elementary Particles – Fermions
If you want to learn more about antiparticles, theoretical physicist Matt Strassler has some fascinating posts at his blog, Of Particular Significance:
- Of Particular Significance – What are anti-particles?
- Of Particular Significance – Particle/Anti-Particle Annihilation
Are you still confused about spin? Because I am! Scientific American and Ask a Mathematician have some really good articles that can probably explain spin better than I can.
- What exactly is the ‘spin’ of subatomic particles such as electrons and protons? Does it have any physical significance, analogous to the spin of a planet?
- What is “spin” in particle physics? Why is it different from just ordinary rotation?
The channel Looking Glass Universe also made a great YouTube video talking about what spin is. I found it very helpful.