Richard Feynman is really interred in Altadena, CA. He is buried at Mountain View Cemetery and Mausoleum, Founders Lawn, Lot 4390, Grave 11, Curb No. 1617.
The day after this episode aired, Barry Barish and Kip Thorne (2 CalTech physicists) were awarded the Nobel Prize in Physics.
Previously, Regina King character, Janine Davis, was in the Human Resource department. This time, she's in the Dean's office.
When Amy tells Bernadette how Sheldon reacted to the copious funding she receives at her work, Bernadette replies: "He said that to your face? What a dick!" This is the only time in the entire series where this word is used.
Sheldon identifies the three largest problems in physics as dark matter, quantum gravity, and supersymmetry. All of these indeed try to reconcile the 'incompleteness' in either of the standard models of cosmology or Standard model of particle physics.