Yesterday, and this morning, I thief started on the essay part of the course assignment. It’s all about the Stern-Gerlach experiment – which showed that particles do indeed have spin.
It’s a really fascinating topic, and I guess most people that have touched anything to do with quantum have heard of it. But, I also guess, like me, you just assumed electrons are spinning around themselves as well as spinning around nuclei. And you’d never looked Inyo why this question popped up in the first place, i.e. why did we find they have spin – for that we can blame Pauli.
Well, turns out physicists lie to us as much as chemists/science teachers. Electrons are not spinning around their own access. They only intrinsically do so. That is, the Stern-Gerlach experiment showed that they act as if they have spin, but physics tells us if they did, then they would be spinning around 10x the speed of light (something that more than quantum tunnels into the realm of impossibility).
This article is a good intro to spin:
and this to the experiment:
Good job they do have this intrinsic property though – it allowed us to develop lasers, electron scanning microscopes etc. It also leads us to understanding fundamental particles – 1/2 spin particles are fermions (such as electrons and protons); and 1 for bosons, such as photons.
I’m looking forwards into researching this more and turning into a 1000 word essay…
Let’s get entangled…