The Big Bang Theory Season 1 Episode 17 : The Tangerine Factor
Penny is furious and breaks up with her boyfriend after he posted details about their sex life on his blog. Meanwhile, Sheldon asks Howard to teach him Mandarin as he's convinced the Chinese restaurant is selling "Tangerine chicken" yet is really using oranges, a cheaper citrus fruit.
As Penny laments her choices in men, Leonard awkwardly asks her out. A few days pass and both Leonard and Penny are worried that this relationship could ruin their friendship. They both seek Sheldon's advice, who uses the "Schrödinger's cat" experiment to explain that at this time, the date has both "good" and "bad" possible outcomes, and the only way to find out is to go on the date and find which outcome it is. When Leonard arrives to pick Penny up, he mentions the "Schrödinger's cat" experiment, passionately ki...