How are neutron stars magnetic?
If spinning-and-moving charges make magnetic fields, why does a giant neutral thing have one?
Image credit: NASA, Chandra X-ray Observatory, SAO, DSS, via http://apod.nasa.gov/apod/ap140725.html.
“By allowing the positive ions to pass through an electric field and thus giving them a certain velocity, it is possible to distinguish them from the neutral, stationary atoms.” -Johannes Stark
A little bit of physics goes a long way, and that’s especially true in astrophysics, where the tiniest of forces and the smallest of effects become the only things that matter. It is, of course, due to the extreme concentrations and amounts of material that we’re dealing with! Take something as innocuous as our little, insignificant planet.
The fact that we have a molten, rotating and changing core with an active magnetic dynamo inside of it does much more than make compass needles point towards the pole. The magnetic field generated at the Earth’s core extends well out into space, protecting us from cosmic dangers and diverting fast-moving charged particles away from us.
