Leonard and Sheldon are invited to a party at the home of actor Wil Wheaton, who is Sheldon's arch-nemesis. Leonard wants to attend, but Sheldon makes it clear that doing so would be the end of their friendship, though he regrets this decision a bit when he learns that Brent Spiner will also be in attendance. He finally decides to go as well, resulting in a reconciliation with Wheaton and the declaration of a new enemy: Brent Spiner himself.
Meanwhile, Howard has been chosen to travel into space to install his telescope design into the International Space Station. Bernadette objects and enlists his mother's help in keeping him firmly planted on terra firma.
This Episode's Science
Schroedinger's Friendship - Sheldon expresses that his friendship with Leonard is in "two mutually contractory states," referencing the classic Schroedinger's Cat thought experiment. This thought experiment involves a situation created to demonstrate the counterintuitive nature of quantum physics. In it, a hypothetical cat ends up in a superposition of both living and dead states. No actual cats were harmed in the making of the thought experiment.
Heisenberg's Uncertainty Principle - In this fundamental property of quantum physics, there are certain physical traits which can only be measured to a certain level of precision, based upon the precision of measurements of other properties. Specifically, this principle means that you cannot know the exact position and exact momentum of a particle at the same time.
Sheldon: [to Leonard] At this moment, our relationship exists in two mutually contradictory states. Until you either do not go or go to Wil Wheaton's party, you are simultaneously my friend and not my friend. I'm characterizing this phenomenon as Schroedinger's friendship.
Leonard: Got it. Can I have my water?
Sheldon: Of course. [Sits it on the table, then knocks it across the room.] Get it yourself, you traitor.
Penny: Wait. What is going on?
Sheldon: In case you have forgotten, Schroedinger's Cat is a thought experiment ...
Penny: No, no. I didn't forget. There's this cat in a box and until you open it, it's either dead or alive or both. Although back in Nebraska, our cat got stuck in my brother's camp trunk and we did not need to open it to know there was all kinds of dead cat in there.
Leonard: Pretty cool about Howard, huh?
Sheldon: Don't talk to me as if nothing's happened between us! And, yes, it sure is, buddy.
Leonard: For god's sake, will you stop with the Schroedinger stuff?
Sheldon: Would you prefer a simpler application of Heisenberg's Uncertainty Principle, where I could either know where you are or whether I like you, but not both?