Features: Physicist to the stars: real-life physicist/UCLA professor David Saltzberg's consulting relationship to the show; Testing the infinite hilarity hypothesis in relation to the Big bang theory: season two's unique characters and characteristics; gag reel.

Various personal production credits ; Created by Chuck Lorre & Bill Prady.

Johnny Galecki, Kaley Cuoco, Jim Parsons, Simon Helberg, Kunal Nayyar, Sara Gilbert.

Originally broadcast on television during the 2008-2009 season.

Physicists Leonard and Sheldon understand everything from the inescapable gravitational pull of a black hole to the intricate structure of the atom. But take those atoms and assemble them into a woman, and their comprehension comes to a grinding halt. This season, Leonard gets a girl. So does Sheldon. (Sheldon?!), Howard drives the Mars Rover into a ditch, Raj woos a terminator, gorgeous girl-next-door Penny falls under the spell of Age of Conan, and super-smart, uberconfident Leslie Winkler reduces mere men to spineless jellyfish. Includes all 23 episodes, plus never-before-seen featurettes.

TV Rating: Not rated.

DVD, NTSC, region 1, widescreen (matted, enhanced); Dolby Digital surround stereo.

Closed-captioned; English or Portuguese dialogue with optional French, Spanish, Chinese, Portuguese or Thai subtitles and English subtitles for the deaf and hard-of-hearing.