These events happened in the 2000s:
Events
The Big Bang Theory
- Sometime this decade: Stuart came to Pasadena and opened up the Comic Book Store.
- 2000: Amy begins training in the field of neurobiology.
- August 22, 2003: Sheldon and Leonard met for the first time; the duo also met Howard and Rajesh Koothrappali.
- November 12, 2003: Leonard met for the first time Howard and Raj in the university in an experiment.
- Leonard conducted a scientific experiment that ended up breaking the elevator. The Elevator to the Apartment Building is destroyed.
- Leonard and Joyce Kim hooked up.
- 2004: Leonard earned his doctorate and officially became a doctor.
- April 12, 2005: The guys met Raj's sister Priya for the very first time at a Big Boy's restaurant before they started going to The Cheesecake Factory.
- 2006: Sheldon had an ear infection, causing the guys to create a protocol "Code Milky Green" (The Pancake Batter Anomaly).
- 2003-2007: Penny moved to Pasadena, started dating Kurt, and got a job at The Cheesecake Factory.
- September 22, 2007: Leonard and Raj created an idea involving the conversion of footsteps into electromagnetic energy to make it possible for one to recharge their cell phone while walking.
- Before September 24, 2007: Penny broke up with Kurt.
- 2009: Leonard's mother Beverly Hofstadter is introduced and Leonard saw her again for the first time in several years after leaving New Jersey.
- Penny, Sheldon, Howard and Raj met Beverly for the first time.
- Leonard and Penny has started dating.
- December 20, 2009: Penny introduced Howard and her work friend Bernadette to each other for the first time.