The Ultimate Field Guide to Subatomic Particles

[pokerfan]

Can't explain it any more clearly than this...

Muons, neutrinos, supersymmetric partners, the infamous Higgs boson - with so many different subatomic particles flying about, it's no wonder theoretical physics can be so confusing. That's why we made this (reasonably) simple guide to all the different elementary particles.

This is, as you might imagine, a pretty big topic, so we're splitting it into (at least) two posts. Today we're going to deal with just the particles that physicists are certain (or, at least, reasonably certain) exist, and then tomorrow we'll get into the even stranger world of particles that have been hypothesized but may or may not actually exist. I've also made a handy cheat sheet listing all the elementary particles and their vital statistics, which you can find here. But to understand what all of that means, you'll really want to read on.

http://io9.com/5639192/the-ultimate-field-guide-to-subatomic-particles

[leveymg]

1. Thanks for this - nothing beats simplicity and clarity!

Not that I really understand what all this little critters are, but this helps. Please explain the meaning of the three sets of numerical values. The top value looks like the amount of energy needed to liberate the particle. Just a guess - is that correct?

[Geoff R. Casavant]

2. If I recall my physics --

The top number is the particle's mass, the second number is charge, and the third number is spin.

[leveymg]

5. Please explain charge and spin in this context.

Is charge the normal electro-magnetic positive-negative, or something else? What's the significance of charge for the behavior of subatomic particles.

Also, please a short, similar explanation of spin. Thanks!

[pokerfan]

6. charge is indeed electric charge

For quarks, it's either -1/3 or +2/3. Three quarks make up a proton or neutron which have a composite charge of +1 or 0 respectively.

Spin is another property and can either be +1/2 or -1/2. It can be thought of as the rotation of the particle but this is probably not entirely accurate as quarks are generally treated as point sources. It's just another fundamental property of elementary particles.

http://en.wikipedia.org/wiki/Quark#Properties

[leveymg]

7. Thanks, again.

[pokerfan]

3. eV

You are correct to recognize that as a unit of energy but since mass and energy are equivalent (E=mc²), physicists use eV to represent the particle's mass. Physicists also use a different set of units where the speed of light has a value of 1 instead of say, 186,000 mph. That allows them to use eV directly to represent mass.

[leveymg]

4. Makes sense. Thnx

[Orsino]

8. The Legos of God.

Thanks for posting.