#Astrophysics

Astrophysics is the branch of physics that takes its laboratories from the stars. Instead of running experiments on Earth, astrophysicists use telescopes to read the chemistry, motion, and history of objects so distant the light reaching us today left them billions of years ago. The posts collected under this tag cover stars and stellar lifecycles, black holes, the cosmic microwave background, the search for exoplanets, and the slow accumulation of evidence that the universe began with the Big Bang and is still expanding.