Reading the chapter titles in a modern college astronomy textbook is much like reading the titles of science fiction stories. Astronomers regularly talk about subjects like black holes, neutron stars, pulsars, quasars, dark matter, novae, supernovae, and even more bizarre topics. Some of the ideas in astronomy push at the limits of what we know, or can know. Many ideas in astronomy are so strange that some astronomers have difficulty accepting them. Understanding these ideas in astronomy requires knowledge of all branches of mathematics, including some less well-known branches like tensor calculus and gauge theories.

Novae and Supernovae

When a star with a mass about the same as our Sun reaches the end of its life, its outer layers slough off, leaving behind a solid carbon core. This core, known as a "white dwarf," is very small, about the size of a small planet. Initially, the core is...