In this week's "Ask a Physicist" we get a little salty and explore the ins and outs of quantum spin. Also, why your intuition will betray you at the slightest provocation and why it's awesome to be made of fermions.
This week's question was put to me by Peder Norrby (who has sent a lot of questions to the column, so his turn had definitely come due). He wants to know:
What the hell is spin?
He's right to be all worked up. Spin is one of those weird things in quantum mechanics that sounds so much like something from your ordinary experience that you might be tempted to think your intuition will help you out, but it won't. In fact, your intuition is much more likely to knee you in the groin and steal your girl. Don't trust it for a moment.
So first off, all particles have a fundamental spin. Just like electric charge or mass, spin helps to define which type of particle is which. Alasdair did a really nice write-up of the standard model not too long ago, and a follow-up about particles that we might soon detect.