Sign up for the Starts With a Bang newsletter Travel the universe with Dr. Ethan Siegel as he answers the biggest questions of all. The story of the expanding Universe has been a back-and-forth one over the past 110 years: ever since general relativity was first introduced. Initially, Einstein introduced the notion of a cosmological constant — a form of …
Read More »Ask Ethan: Is dark energy no longer a cosmological constant?
