It's Saturday! This week, in an eminently practical analysis of the Boltzmann brain conjecture, physicists put constraints on the idea that memories could arise from random fluctuations in entropy rather than reflecting the actual past of the universe—news you can use! Researchers managed to put t housands of sodium atoms in a "Schrödinger's cat" state. And an ancient mass grave revealed the impact of the earliest-known pandemic. ...read more read less