October 13, 2013
I like particle physics (muons aren’t a tribe in the amazon). But it’s all from a distance…meaning, I’m really fascinated with how we discovered these particles and figured out if they are elementary but I’m no physicist. We all know about the two particles in the nucleus of an atom….the proton and neutron. Those aren’t elementary. They are made of quarks; up, down, charmed and others. But let’s just talk about muons and I’ll start by saying that maybe a hundred just went through your body since reading this.
We’ve known about muons for more than 70 years. Is it important to know about them? Maybe, I don’t recall hearing about them until I started reading astronomy texts. When we take classes in high school, someone (some committee) decides what we should learn and I guess they figured we need to know the “basics.” My son is learning the basics I think in 2nd grade. He brought home a bar chart that he completed. I think he could go to work and make at least minimum wage now. They seem to be learning more than we used to a long time ago. I wish they’d teach a kids physics course to him.
A muon is an elementary particle which means we don’t think it’s made of anything else. What’s interesting about muons is that we can use them to our benefit. And people are doing that now. As a matter of fact, 50 years ago someone used them to find out what was inside a pyramid. This is where this gets interesting. It’s all the sun’s fault. Particles like the muon are spraying down on us all the time and we know if they hit something in particular they might scatter slightly. Why not put a detector under the pyramid and see how those muons scatter. It was thought that this one pyramid in Egypt might have a special burial chamber. Instead of disturbing the Great Pyramid of Chefren they put detectors underneath it to find out how those muons behave after going through the pyramid.
Science is way ahead of most of us (it’s not too late to learn I tell myself). But, can you imagine how ingenius you’d be if you thought of applying something so simple as putting a detector underneath a pyramid? That guy, Luis Alvarez (Nobel Laureate), didn’t find a hidden chamber but he was seen as brilliant to come up with that idea (he was brilliant in plenty of other ways). So today we use muons in a similar way to detect what we can’t see. It’s one of the ways we search cargo for nuclear material. Muons behave a certain way when they go through high density materials. We can thank the Department of Homeland Security for applying this method to check for this stuff.
Here’s sort of a list of elementary particles, in case you wondered.
quarks, neutrinos, muons, electrons, photons, gluons, gravitons (hypothetical) and bosons (yeah, the Higgs is one of those guys).
Wow! So the protons and neutrons and electrons are all I learned in school but there are a huge number of other particles…that are known knowns…thanks for the phrase Donald R.
Here’s an interesting study using muon tomography (detection), http://www2.mate.polimi.it/ocs/viewpaper.php?id=70&cf=8