The Big Bang Theory Season 11 Episode 13
Overview
When Sheldon kicks Amy out to work solo, she and Leonard bond during a series of science experiments. Also, Bert the geologist replaces Wolowitz in the band Footprints on the Moon, and Sheldon finds Penny a surprising source of scientific inspiration.
Director: Mark Cendrowski
Guest Star: Brian Posehn, Jeffrey Cade Ross Brown, Laurie Metcalf, Pamela Adlon