Astrophysics is the physics of stars, and more broadly, the physics of the universe. It allows us to understand the structure and evolution of planetary systems, stars, galaxies, interstellar gas, and the world as a whole.

In this concise introduction, leading astrophysicist James Binney describes the rapid expansion of the field of astrophysics over the past century, thanks to the vast amounts of data collected from telescopes exploring all regions of the electromagnetic spectrum and the rapid increase in computational power, factors that have enabled the development of increasingly effective mathematical models.

The author explains how the application of the fundamental principles of physics – regarding energy, mass, and momentum – along with the two pillars of relativity and quantum mechanics, have led to a substantive understanding of phenomena ranging from rapidly spinning pulsars to the collision of giant spiral galaxies.

This is an accessible and scientifically accurate introduction to astrophysics at a basic mathematical level, for readers who wish to engage meaningfully with its fundamental concepts.