Black holes are probably my favorite of all astronomical oddities. But for all their deep mysteries they are strikingly simple objects. They are described by three physical parameters: mass, spin, and (in theory, but not in practical cases) electric charge. That’s why I think neutron stars surpass black holes as the Universe’s weirdest objects. Neutron stars are both strange and complicated, to the point where we don’t have a complete physical model for them. They combine strong gravity with the properties of matter under high temperature and density, as well as the most intense magnetic fields we know of. My latest column in The Daily Beast is a scientific ode to the neutron star, and especially the craziest member of that family: the magnetar.
The relatively large mass and tiny size mean that the density of a neutron star is enormous: roughly 400 trillion times the density of water (4 × 1014 grams per cubic centimeter). That’s denser than any material we can make. In fact, it’s about as dense as the nucleus of an atom, but far larger than any atom can be.
The gravity is enough to squeeze atoms until electrons combine with protons to make neutrons. That’s where the name “neutron star” comes from, though they aren’t entirely made of neutrons and they aren’t anything like normal stars. [Read more…]