Bernadette, in the guys' apartment for dinner, shows an interest in physics, particularly in the work that Leonard is conducting. Leonard offers her the chance to watch him conduct an experiment at work. Wolowitz is jealous of this and accuses Leonard of being interested in Bernadette. During a bed scene with Bernadette and Howard, Mrs. Wolowitz interrupts. When she finally leaves, Leonard texts Bernadette thus causing a conflict which provokes her to leave the house angry. The following day, Howard confronts Leonard about "text-blocking" him. Bernadette arrives to watch Leonard's experiment, at which point Howard apologizes, and they kiss and make up.
Meanwhile, Penny seeks out;Sheldon to teach her something about physics so that she might be able to relate to;Leonard and discuss his work. She gets very frustrated with Sheldon's teaching style learning nothing new except where the name for the Fig Newton cookie came from. Later at dinner in the apartment, Penny spouts off a clearly prepared spiel which;Sheldon has coached her in, repeating Sheldon's viewpoint that Leonard's experiment is functionally identical to the one conducted by a Dutch team of scientists thus insulting Leonard.
"Another typical episode. All the pieces are on the board yet the producers refuse to deploy them correctly. The focus of this episode as ever is Sheldon. And he is, but that isn’t the point of this story. Penny feels insecure because she can’t talk to Leonard about his work and Howard is insecure about losing his girlfriend. That should be the focus. It’s not that complicated...But once more the issue of Leonard and Penny’s relationship was ignored. Her insecurity and desire to learn some physics is a nice idea. It points to her affection for him but we don’t see it often enough...In the end she actually learned some physics talk which put down Leonard’s work. She actually insulted him which was completely counterproductive as it made her look either foolish or mean." - The TV Critic's Review
Title Reference: Penny's suggestion that Sheldon should treat teaching her physics as an experiment. Sheldon subsequently names the experiment "The Gorilla Project," after Koko the gorilla who learned sign language.
Mrs. Wolowitz: WHAT'S GREAT ABOUT AN 80 YEAR OLD ARMENIAN MAN WITH HIS HALF OF HIS CHIN SCRAPED OFF?!
Howard: I didn't say anything like that, I said to Leonard to ask my permission! Come on! I don't wanna eat lamb stew with my mother! Dam it! I was this close on your bra!
Sheldon Cooper: Why are you crying?
Penny: Because I'm stupid!
Sheldon Cooper: That's no reason to cry. One cries because one is sad. For example, I cry because others are stupid, and it makes me sad.
Leonard Hofstadter: Relax, it'll be fine. Sit down, you guys.
[Everyone says no as Bernadette goes for Sheldon's spot]
Bernadette: What?
Penny: Oh, yeah. You can't sit there.
Bernadette: Why not?
Leonard Hofstadter: That's where Sheldon sits
Bernadette: He can't sit somewhere else?
Penny: Oh, no, no. You see, in the winter that seat is close enough to the radiator so that he's warm yet not so close that he sweats. In the summer, it's directly in the path of the cross breeze created by opening windows there and there. It faces the television on an angle that isn't direct so that he can still talk to everybody, yet not so wide that the picture looks distorted.
Sheldon Cooper: Perhaps there's hope for you after all.
Bernadette: You must forgive him, but most of what he says is intended to be humorous.
Howard Wolowitz: I thought you liked my jokes.
Bernadette: Well, I laugh anyway because his face light up when I laugh.
Penny: Howard, never let her go.
Sheldon Cooper: This is just the beginning of a 2600 year journey, from the ancient Greeks, to Isaac Newton, to Niels Bohr, to Erwin Schroedinger, to the Dutch researchers Leonard is currently ripping off.
Sheldon Cooper: And all of that tells us that...?
Penny: That Newton was a really smart cookie? Is that why they call them Fig Newtons?
Sheldon Cooper: No, Fig Newtons are named after a small town in Massachusetts - No, don't write that down!
The Technical Consultant David Saltzberg appears in this episode. He was the first person on the left that David Saltzberg, Technical Consultant, sits at the table (in the brown sweater vest)
Howard passed when he entered the dining room introducing Bernadette as his girlfriend to everyone. (Look for the guy in the brown sweater vest at the first table).
There are no cows or penguins in Mario Circuit in Mario Kart, although they may have been in reference to other circuits (namely Sherbet Land and Moo Moo Meadows). This is referenced when referring to Sheldon's lack of skill in Mario Kart (and any other driving for that matter), in which he blames being stuck behind a tree, cow and penguin.