The Prestidigitation Approximation Season 4, Episode 18 -  Aired March 10, 2011

The Prestidigitation Approximation

Priya feels threatened by Leonard spending time with Penny and demands he cut her out of his life. Leonard struggles to choose between his girlfriend and Penny. Meanwhile, Howard plays mind games with Sheldon by performing a magic trick the great scientist can not figure out.

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Guest Stars: Aarti Mann as Priya

Writers: Bill Prady (Story), Steve Holland (Story), Eddie Gorodetsky (Story), Chuck Lorre (Teleplay), Steven Molaro (Teleplay), Eric Kaplan (Teleplay)

Director: Mark Cendrowski

Viewers: 12.06 million Households Rating: 7.3/12 Adults 18-49 Rating: 3.8/11

Available on iTunes

Episode Notes

  • The title refers to the magic trick which Howard performed on Sheldon.

> Sheldon's Knock

Sheldon uses his knock when he goes to Leonard's bedroom, while Leonard is with Priya, to perform a card trick. Leonard refuses to answer the door so Sheldon shows the cards underneath the door.

Episode Quotes

Penny: Oh, big deal. Not knowing is part of the fun.
Sheldon: "Not knowing is part of the fun." Was that the motto of your community college?

Rajesh: Why so glum, chum?
Sheldon: Apparently you can't hack into a government supercomputer and then try to buy uranium without the Department of Homeland Security tattling to your mother.

Sheldon: So, you're saying this is a regulation deck?
Howard: I'm saying believe in magic, you muggle.

Leonard: Okay, uh, how do I put this? Um, are you familiar with Darwin's observation of the finches in the Galapagos Islands?
Penny: Did they make a movie about it?
Leonard: No.
Penny: Then no.

Sheldon: If you plan on having children I suggest you switch from briefs to boxers. Your testicles look a tad warm.

News Stories

Title Date Posted
Episode 4.18 Ratings March 11, 2011

The ratings for the March 10th episode of The Big Bang Theory are out.  Full story

CBS Announces Episode 4.18 February 17, 2011

CBS has announced the details for the March 10th episode (4.18) of The Big Bang Theory.  Full story


Leonard and Priya are in bed when she suggests he should get contact lenses as she thinks he has beautiful eyes. Later, in the university cafeteria, Howard offers to perform a magic trick for Raj. Sheldon interrupts to tell them how magic is a trivial waste of time. Howard performs the card trick for Raj anyway, mystifying Sheldon who needs to know how it was done. Leonard causes a scene when he arrives wearing his new contact lenses, crashing into the tables and several people.

Back in the apartment, Penny is impressed when Howard performs his magic trick for her, as Sheldon watches carefully trying to understand the workings behind the trick. Leonard arrives back from shopping with Priya and has a new wardrobe of "more grown-up" clothes. When Leonard and Priya head to his bedroom, Priya talks to Leonard about how she's uncomfortable with the amount of time Leonard spends with Penny. Meanwhile, Sheldon is still struggling to understand Howard's trick and is even more perturbed when even Penny understands Howard's magical secret.

When Leonard and Penny run into each other doing laundry, Leonard backs out of fulyl explaining to Penny that he can't spend time with her any more. Back in the bedroom with Priya, Leonard assures her he talked to Penny. Meanwhile, Sheldon's obsession with Howard's trick has grown, leading him to hack a supercomputer to analyze shuffling patterns. Sheldon wonders if Howard used a radioactive tracker and thus attempts to secure uranium off Craigslist.

Leonard and Priya are eating dinner at an Indian restaurant when she reveals her company offered her a job in Los Angeles. Leonard is thrilled at the news but the couple's moment together is interrupted when Penny walks by the restaurant. After tapping at the window to get their attention, Penny comes into the restaurant and starts chatting with Leonard and Priya, while sampling Leonard's food. Elsewhere, Sheldon claims to have figured out Howard's magic trick and offers to perform it for him. When Sheldon hands Howard a card he, not so subtly, swipes it with a barcode scanner.

After their encounter at the restaurant, Leonard finally talks to Penny about how they can't be so close any more. Penny promises Leonard she will keep her distance now. At the university cafeteria, Sheldon arrives in a sullen mood, after the Department of Homeland Security tattled to his mother about his attempts to buy uranium. Feeling bad for him, Howard offers to tell him how the trick works, but Sheldon wants to work it out himself. Howard offers to perform the trick again, but Sheldon insists he perform it on him so he knows there's no monkey business. When Sheldon picks a card, Raj looks at the card and signals it to Howard. Sheldon is deflated at yet again not knowing the trick works.