RECAP of "The Big Bang Theory" Season 7 Episode 7, "Proton Displacement": Sheldon, Leonard and Amy visit a drug store and Sheldon spots Professor Proton, there.

Sheldon goes over to have a talk with him, which Leonard think will be equal to bothering him. Sheldon tells Professor Proton he may not remember him because of his advanced age, but the latter does remember him, and expresses the same with a grim face. Sheldon introduces Professor Proton to his girl friend.

Professor Proton is amused to see that Sheldon has a girl friend. Amy gets excited that Professor Proton and she are wearing the same kind of shoes. This makes Professor Proton believe that Amy is Sheldon's girlfriend for sure. Professor Proton asks Leonard about Penny and tell him that he remember his girl friend very well.

At the cafeteria, Leonard tells Sheldon that he received a message from Professor Proton. He needs Leonard's advice on nano vacuum tubes. Sheldon checks his messages and is all smiles that he received two messages from Professor Proton. But, he is dejected after reading the messages. Professor Proton's first message to Sheldon was sent to know Leonard's email id and second to tell him not to bother as he found it.

Sheldon is bugged that Professor Proton did not seek his help. He calls him "Hollywood Phoney." Also, Sheldon tells Amy that Professor Proton is a pervert as he lures children to love him by using sweet candy of science. He thinks the professor must be on some cuckoo pills. Amy tells Sheldon that Professor Proton may not have sought his help because he is a "bit much." Sheldon tells her that when it comes to social skills, he has mastered the big three: "Coy smile, friendly chuckle and vocalisation of sympathy." He is still working on the last.

Sheldon feels that Amy wants to use the word "annoying" for him. He chases her out of the house by asking her again and again to say the word "annoying." Later, he visits Professor Proton's house, early in the morning. Professor Proton is not too pleased to see him. Sheldon tells him that his girlfriend thinks that he is "annoying." Professor Proton quips: "She sounds like a keeper." Sheldon tells him that he won't mind if he uses the word annoying for him. Unlike Amy, Professor Proton does tell Sheldon that he is "annoying."

Leonard is helping Professor Proton with his nano vaccum tubes, and Sheldon comes there to introduce them to his new friend, Bill Nye. He calls him the "science guy" and tells Professor Proton that "I replaced you with a newer model." Bill Nye is happy to see Professor Proton and tells him that his show would have not happened with his show. Professor Proton tells him that that is why he sent him a court order. Bill Nye thinks he is there to teach a class, while Sheldon had asked him to come over to teach someone a lesson.

Bill Nye gets interested in the vacuum tubes. Professor Proton screams: "Haven't you stolen enough from me. Back Off, Bow-Tie!" Later, Leonard gets a picture message from Sheldon on his phone, which shows him having a smoothie with Bill Nye. Professor Proton wants to know why Leonard put-up with Sheldon. Leonard tells him that Sheldon and he are friends. Professor Proton wants to know "why."

Leonard describes Sheldon as loyal, trustworthy and that they have fun. Professor Proton tells him that he is describing a dog. Leonards says that Sheldon did bite him once, and adds that Sheldon is the smartest person he has ever met. "He is broken and he needs me, and guess I need him, too."

Bill Nye ditches Sheldon and puts a restraining order against him. However, Professor Proton visits Sheldon and seeks his opinion on his research paper. Sheldon tells him that he already hacked his email ID to read his paper and that the paper was inspired. Professor Proton refuses his offer to come inside the apartment, but when Penny says hello to him, he steps inside.

Professor Proton asks Penny if he she has single grandmothers. She informs him that both are married. Professor Proton wants to know if they are married "happily."

Raj joins the girls for the jewellery night, making bracelets and necklaces. Howards makes fun of him. However, he soon joins them and suggests a less-messy way, minus the glue, to make jewellery. He calls himself the Jew in the jewellery night. Raj isn't happy about Howard's presence. He tells him that he likes the jewellery night with the girls because he can share with them. They listen to him, without making fun of him like Howard does. Howard feels guilty hearing that and tries to bond with Raj, cheering him up. Seeing the bonding, Amy comments that they (Raj and Howard) are gonna have sex before Sheldon and she does.

Later, Raj presents Howard a light belt buckle. Howard is happy to get that but is not amused when Raj shows his own buckle of the same kind.