· Astrophysics
What Is Dark Matter? The Evidence for the Invisible Mass
Dark matter makes up about 27% of the universe and outweighs ordinary matter roughly five to six times, but it gives off no light. So how do we know it is there? This post walks through the evidence, from fast-spinning galaxies to the Bullet Cluster and the Planck satellite, works through the orbit formula, and is clear about what is still unknown.