You Probably Don't Know Why You Have Mass (Patreon)

Have you ever wondered where all that mass around you comes from? No, it’s not the sugar industry, it comes from the pion condensate. Let me explain.

The Higgs boson is one of the elementary particles of nature. Physicists collect all those particles in what’s somewhat unimaginatively called the standard model. It’s like the collector’s box of particle physics, basically. That the particles in the standard model are elementary means that for all we currently know they’re not made of anything else.

The Higgs boson was the last of these elementary particles to be discovered. That happened in 2012 at the Large Hadron Collider at CERN in Geneva. You might have heard that it’s the Higgs boson that’s responsible for creating masses. But actually that isn’t so.

There are two things wrong with the idea that the Higgs boson gives rise to masses. First, it’s not the Higgs-boson but the condensate of the Higgs-field. Yes, it’s both something with Higgs, but it’s not the same thing. And second, the Higgs field only gives masses to the particles in the standard model, but not to most of the matter around you. Again, that sounds similar, but not the same thing. Let’s look at both issues separately.

The Higgs field fills the entire universe, it’s everywhere and all the time. That’s basically what it means that it’s a field, it being everywhere and all the time. After the initial hot phase of the universe, the Higgs field condenses much like water vapor condenses into dew on a cold morning. This condensate now fills the entire universe. It clings to the other particles and that creates a drag, which gives rise to these particles’ masses. That’s the condensate of the Higgs field. The Higgs *boson on the other hand is a particle that on occasion pops out of this Higgs condensate. To make it pop you need a lot of energy, that’s why they build these large colliders. Yes they do have a reason for that. It’s not just because they look cool.

The Higgs condensate is in some sense similar to the 19th century aether. But only in some sense. The purpose of the aether was to allow electromagnetic waves to travel, and we don’t need the Higgs for that. Also, they thought back then that it was possible to figure out if you’re moving relative to the aether. This is what the famous Michaelson-Morley experiment was looking for. But for the Higgs condensate you don’t expect this to happen. It doesn’t matter how fast you move, the drag from the Higgs field is always the same. And because of this the masses of particles are always the same, too.

This is also why you can’t use a Michaelson-Moley type experiment to find the Higgs condensate, and why finding this Higgs-boson was so important. Because finding the Higgs boson tells us that the field must also be there. So, finding the Higgs-boson did explain how particles get their masses, but they don’t get them directly from the Higgs-boson. Why did they make this so complicated? I don’t know but I swear it wasn’t me.  

Curiously enough, the elementary particles in the standard model all couple with different strengths to the Higgs field, this is why they all have different masses. The neutrinos in particular couple very weakly and so they have very small masses. Some of the quarks on the other hand couple very strongly and so are very heavy. Just why that is so, no one knows.

Be that as it may, while the Higgs field gives masses to the particles in the standard model, that makes only a very small contribution to the mass of most of the matter around us. That’s because most of the mass of matter resides in the atomic nuclei. And these nuclei are made of protons and neutrons which are not particles in the standard model.

The reason neutrons and protons are not in the standard model is that they’re not elementary, they’re composite particles. They are each made of three quarks, held together by gluons, and the quarks and gluons are elementary particles. The gluons are for all we know massless, which means that the only particles with masses inside of atomic nuclei are the quarks. You can then go and just add up the masses of those quarks, but the result you get is nowhere near the actual mass of the neutrons and protons. So where does all the mass come from?

I sometimes hear people say that the rest is energy that comes from the gluons which hold the quarks together, but this isn’t quite right. You see, around those quarks in the atomic nuclei, there aren’t just gluons. There are also virtual particles that pop in and out of existence, quarks and antiquarks, and really any other particles. And if you look at everything that goes on inside an atomic nucleus, it turns out that almost all the action comes from a particle most of you have probably never heard of. It’s called a pion. No, not pile on, but pi-on, though they do pile on.

The pion is denoted with a Pi, and it’s a composite particle of a quark and an anti-quark. Actually there’s three of them, depending on what charge they have, but that isn’t so relevant for today. The pions are also not in the standard model, and again that’s because they’re not elementary, they’re made up of these pairs of quarks and antiquarks. And when when’re talking about what’s going on with other composite particles in atomic nuclei, like those neutrons and protons, then the pions are the thing to talk about because that describes most of what’s happening.

And, here it comes, the pions form a condensate just like the Higgs field, and that pion condensate drags on the neutrons and protons. And that’s where most the mass of atomic nuclei comes from, it comes from the drag of the pion condensate not from the Higgs condensate.

Why have you never heard of this? It’s probably because you didn’t suffer through quite as many years among nuclear physicists as I did, but it’s alright because you have me on YouTube telling you this stuff.

The quiz for this video is here.