“The Friendship Contraction” — Sheldon’s (Jim Parsons, right) selfish demands force Leonard to reconsider their friendship. Meanwhile, Wolowitz tries to pick his astronaut nickname, on THE BIG BANG THEORY, Thursday, Feb. 2 (8:00-8:31 PM, ET/PT) on the CBS Television Network. Also pictured: Kevin Sussman, left. Photo: Michael Yarish/Warner Bros. Ã?©2012 Warner Bros. Television. All Rights Reserved.