To a photon, the universe is the same size it was when it first began.

And that explains a lot about a lot of other things.

Here is Matt Strassler’s far more technical explanation of how the Higgs Field imparts mass.

There is math, but it’s not that hard to understand the gist of it. It is 100% technically accurate. But it is by no means easy overall.

Unlike some theories or areas of inquiry, you can’t really understand any of the Standard Model or quantum theory unless you understand all of it. That makes it a very tough nut to crack.

It took me a decade of studying all of it nearly every day to get to where I could make sense of it in some cohesive way.

How the Higgs Field (Actually) Gives Mass to Elementary Particles.

This is just too simplified to be worth anything. It doesn’t work like that. These metaphors are frickin’ useless. They make you dumber than you were before.

I know Strassler is a physicist so he definitely understands how the Higgs Field and how the Higgs Mechanism works (I’ve read other things of his more complex than this), so it’s not lack of knowledge. In trying to make what’s happening intelligible to the non-trained, though, he just makes it too basic to be worth anything.

To offer a better explanation, the Higgs Field is the only field that has a non-zero equilibrium constant value, or to put it another way it has a non-zero vacuum expectation value — unlike all other known fields. This means that in (notionally) empty space, it can still “operate” on other types of particles (field excitations) in that space. Thus, having a non-zero vacuum expectation value means the Higgs interacts with other fields and gives previously-massless particle mass by two different methods (not important to know about here). So why doesn’t the photon gain mass by interacting with the Higgs field? Heh, well, it’s because the model would be inaccurate, basically. Also, the Higgs field has no color charge (related to the strong force) and is not electrically charged, so photons can’t “see” it. Thus, they remain massless¹

There is a much deeper, but much, much better explanation that involves symmetry breaking and the linear combinations of the four SM gauge fields, but you must have a lot of grounding in a lot of different areas and a very big brain to understand that. But that’s just to give you breadcrumbs to follow, if you are of a mind to do so.

Back to the topic at hand, though. The very short explanation of why the Higgs field gives mass to most elementary particles (the gauge bosons, quarks and leptons) is because its vacuum — or resting — state is one of excitation. Again, quite the opposite of other fields where their resting state is zero energy. For our purposes here, I’m going to be a a bit circularly-referential as the real deeper explanation is just too much for almost anyone reading this, but the Higgs field gives mass to excitations (particles) of those fields that can “see” it. It does this by donating a little energy to them, and in this universe energy equals mass². And it’s as simple as that.

That said, most mass in the universe does not come from the Higgs field/mechanism. The Higgs just explains why particles that should be massless in the Standard Model have intrinsic mass. Most mass in the universe arises from the strong interaction in the nucleus, which is not related to Higgs directly.

Isn’t that fun?

1. More technically, only particles with matching left and right hand terms in their quantum formulae have intrinsic mass. The photon exhibits chirality and is a one-handed particle, so to speak, so has no mass.
2. For particles possessing rest frames. Photons and gluons do not.