Howard Wolowitz (Simon Helberg) may have taken a giant leap for nerds everywhere on "The Big Bang Theory," but episodes like "The Extract Obliteration" are a huge step backwards for the show. It also represents serious backsliding in the Leonard/Penny relationship.
Penny (Kaley Cuoco) tells her girlfriends that she is taking a history class at Pasadena Community College. She was hesitant to tell Leonard (Johnny Galecki), though, because she was afraid he might become overly encouraging and supportive. Penny turns out to be right as Leonard rewrites her paper on the origins of slavery without permission.
While trouble brews in her apartment, Sheldon (Jim Parsons) is proud and excited that Professor Stephen Hawking accepted his online invitation to play "Words with Friends." Sheldon uses the word "extract" to gain an edge over Hawking, but Howard warns him that the famous scientist doesn't like to lose.
Sheldon obsesses over the fact that Hawking hasn't played a word for several days. He constantly stares at his iPad over lunch at Caltech and while sitting in his favorite spot on the sofa. Sheldon even tries a Jedi mind trick on Hawking, but his mental powers appear to work only on Leonard.
After an agonizing wait, Sheldon finally takes Howard's advice and allows Hawking to win. The famous scientist calls him afterward for some computerized trash talk: "What do Dr. Sheldon Cooper and a black hole have in common?" "They both suck."
Penny has some success of her own by earning a "B-"on her history paper. As it turns out, Bernadette (Melissa Rauch) and Amy (Mayim Bialik) helped her rewrite her original essay.
"The Extract Obliteration" dredges up old problems in Leonard and Penny's long-standing relationship. When they began to date in Season 3, Leonard encouraged his new love to go back to school, but to Penny, it appeared that she wasn't smart enough for him. After enduring various romantic obstacles, this couple is facing that familiar issue once again.
The only relationship that's back on track is the one between Howard and Raj (Kunal Nayyar). The friends open the episode playing a computerized dancing game. Later on, Raj adopts an American accent while Howard does his stereotypical Indian voice. There's no mention of Stuart (Kevin Sussman) in this episode or Raj's relationship with him.
"The Extract Obliteration" eradicates a lot of progress made this season on "The Big Bang Theory." Here's hoping that future episodes regain that lost ground.