A rigorous introduction to the study of the universe, based on physical principles. We begin with thermodynamics and light, and then move outward on the distance ladder to discover stars, galaxies, and the history of our universe. Along the way, we will use gravity to investigate binary and planetary orbits, black holes, and dark matter. Weekly laboratory exercises will test hypotheses against observational data. Intended for students with a science/engineering background. Not open to students who have earned credit for PHYS 108.