The Tangerine Factor

Summary
After another messy break up Penny asks Leonard why she can’t go out with a nice honest guy. So he asks her out. She says yes but they both feel nervous about it and go to Sheldon for advice. He has his own problems though as he is learning Mandarin in order to properly accuse his local Chinese Restaurant of serving his orange chicken instead of tangerine chicken.

Trivia

 * The 'little crush' that Menelaus had on Helen of Troy was enough to launch the Trojan War when Paris of Troy stole her away.
 * Sheldon is quite correct that 'light years' are a measure of distance, not time, and 'foot pounds' is a measure of work, not weight.
 * If you're not sick of hearing about them (or are still confused about what they are), there is plenty of online information about Erwin Schrödinger, and the theory about his cat.

Critics
"I believe that this final episode is the seasons best. It is not the funniest but it does engage the emotions of the viewer more than any previous effort." - The TV Critic's Review