From The Big Bang Theory Wiki
Events of 2010
(second half of the third season, first half of the fourth season)
- January: Leonard and Howard go on a double-date with Penny and Bernadette, while Raj and Sheldon meet Abby and Martha at a university mixer (0312).
- Leonard's and Sheldon's apartment gets robbed and Sheldon considers moving to Bozeman, Montana (0313).
- 14 February: Leonard and Raj visit Geneva to see CERN's Large Hadron Collider, leaving Penny and Sheldon home sick (0315).
- Thursday, 4 March: Stan Lee does a comic signing at Comic Center. Sheldon has a summons for a court appearance (0316)
- late March: Sheldon is given the Chancellor's Award for Science from Cal Tech. His acceptance speech is, uh, interesting (0318).
- mid-April: During a bowling match against a team including Wil Wheaton, Penny breaks up with Leonard (0319).
- mid-May: Dr. Elizabeth Plimpton stays a few nights with Sheldon and Leonard. Especially with Leonard. And Raj. (0321).
- late May: Sheldon meets Amy Fowler and begins a friendship which grows over the summer. By late September, they are in a full relationship (although completely non-physical) (0401)
- summer: Howard takes scuba diving lessons, only to discover that he's afraid of the ocean (0404)
- early October: Sheldon and Amy "break up", until Sheldon's mother cleverly convinces them to get back together (0403)
- mid-October: Howard and Bernadette resume their relationship
- October 26: Priya comes back in town and spends the night with Leonard. Raj finds out about their on-and-off relationship (0406)
- early November: Howard is refused security clearance because of comments that Sheldon made to an FBI agent (0407)
- mid-November: Penny's dad spends a few days in California and meets Leonard (0408)
- December 31: the guys go to a New Year's Eve party at the Comic Center and invite Penny and Zack to come along (0411)