Adam Riess

An artist's impression of how ULAS J1120+0641, a very distant quasar powered by a black hole with a mass two billion times that of the Sun, may have looked. Credit: ESO/M. Kornmesser, CC BY 4.0

Is the Universe Different In Different Directions?

Hubble constant, Cepheid variables, Type Ia supernovae, Edwin Hubble, Georges Lemaître, Henrietta Swain Leavitt, Adam Riess, Hubble parameter, Wendy Freedman, Vesto Slipher,

Why Scientists Are Confused About How Fast the Universe Is Expanding

Why Two Conflicting Measurements of the Universe’s Expansion Have Scientists Excited