The Big Bang Theory Season 1 Episode 9
The Cooper-Hofstadter Polarization
After cleaning up after an internet experiment, Leonard discovers a letter in the trash can inviting the roommates to present some research they've done to a physics conference. However, Sheldon refuses to let them do it and Leonard chooses to go on his own. The two end up having a fight that Penny tries to solve but ends up making worse. Sheldon goes to the conference to try and stop Leonard by "blowing up" his head a la Scanners. When that doesn't work they get into a physical fight that Wolowitz records and puts on Youtube.