but heavier - 206.77 times heavier, to be precise.

Muons are super fascinating for a number of famous reasons, including (and this is definitely

an incomplete list) as an experimental test of time dilation, as a catalyst making fusion

possible at room temperature, and that they can be used to make muonic versions of atoms,

like muonic hydrogen (with a proton and a muon, instead of a proton and electron).

But muons decay into an electron and some neutrinos after just a few microseconds on

average, so they're hard to store.

So to do experiments on muons, you need to have a source of muons on hand.

A small number of muons are produced naturally by cosmic rays striking our atmosphere, but

one of the best ways of consistently and reliably making a lot of muons is with a particle accelerator.

First, you take hydrogen and you strip off the electrons, leaving you with protons (protons,

as a reminder, are not fundamental particles - they consist of two up quarks and a down

quark, stuck together by mutual attraction due to the strong nuclear force).

Then you accelerate the protons really fast in an electric field (or a bunch of electric

fields) and crash them into some other atomic nuclei, like lithium or carbon or whatever.

The energy of the collision creates a whole mess of particles that goes flying out, but

most importantly for our purposes, it creates a particle called a pion - either a pion with

positive electric charge made from an up quark and an anti-down quark, or pion with negative

electric charge made of a down and anti-up quark.

If the pions keep traveling in a vacuum so that they don't bump into anything else,

they'll spontaneously decay after about 26 nanoseconds, most frequently turning into

a muon and a neutrino.

Which you can use for fusion, or testing special relativity, or making cool cloud chamber designs.

And that's how you make muons - accelerate protons with enough energy that when they

crash into other nuclei, the energy of the collision creates pions, which then decay

into muons.

Which, of course, after 2.2 microseconds on average, themselves spontaneously decay.

If you want to prevent your mind from spontaneously decaying, you may want to check out the new,

daily math & science problems from this video's sponsor, Brilliant.org.

To turn keeping your brain sharp into a regular habit, they're now offering fun daily problems,

like what happens when you cut a möbius strip in half?

Can you use a solar sail to crash into to the sun?

If you bake a loaf of bread that's twice as big, how should you change the temperature

and length of time it's in the oven?

You can solve these problems (& sign up for a new quick question to your inbox every day)

by going to Brilliant.org/minutephysics, which will also give the first 200 people 20% off

a premium subscription to Brilliant with access to all of their courses & puzzles & past daily

problems.

Again, that's Brilliant.org/minutephysics to stop your brain from spontaneously decaying.