The Hofstadter Isotope Season 2, Episode 20 -  Aired April 13, 2009

The Hofstadter Isotope

When Penny accompanies the guys to the comic book store, she is charmed by store owner Stuart and agrees to go on a date with him. Leonard wonders why Penny has fallen for a guy who is just as geeky as he is. In an effort to improve his love life, Leonard ventures out to Ladies' Night with Howard and Raj.

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Guest Stars: Kevin Sussman as Stuart

Writers: Dave Goetsch

Director: Mark Cendrowski

Viewers: 10 million Households Rating: 6/9 Adults 18-49 Rating: 3.9/11

Available on iTunes

Episode Notes

  • The title refers to the perceived similiarities between Leonard Hofstadter and Stuart.
  • This episode marks the first appearance of Kevin Sussman as Stuart Bloom.
  • This episode features the first "Anything Can Happen Thursday", an idea that was recalled in the Season 7 episode "The Anything Can Happen Recurrence".

> Rock Paper Scissors Lizard Spock

Rock Paper Scissors Lizard Spock is briefly mentioned by Howard as he and Sheldon argue over who should get a Batman comic they both need for their collections.

> Weekly Calendar

The guys have the idea of making the third Thursday in every month "Anything Can Happen Thursday", where they break free of their usual (often Sheldon-imposed) schedule.

When Sheldon suggests they go to the comic book store on "Anything Can Happen Thursday", the guys complain they went to the comic book store the night before. Sheldon points out that Wednesday is comic book night, but going on Thursday night would be different as it's Anything Can Happen Thursday.

Episode Quotes

Stuart: Oh, Sheldon, I'm afraid you couldn't be more wrong.
Sheldon: More wrong? Wrong is an absolute state and not subject to gradation.
Stuart: Of course it is. It's a little wrong to say a tomato is a vegetable, it's very wrong to say it's a suspension bridge.

Wolowitz: I'm a horny engineer, Leonard. I never joke about math or sex.

Howard: Are you familiar with the Drake Equation?
Sheldon: The one that estimates the odds of making contact with extraterrestrials by calculating the product of an increasingly restrictive series of fractional values such as those stars with planets, and those planets likely to develop life? N equals R times FP times NE times FL times FI times FC times L?
Howard: Yeah, that one.

Leonard: Oh, hey, Stuart. This is Penny. She's looking for some comic books.
Stuart: Oh, really? Blink twice if you're here against your will.

Penny: Um, you know it's kinda early. Do you wanna maybe come in for some coffee or something?
Stuart: Oh gee, its a little late for coffee isn't it?
Penny: Aw, you think coffee means coffee. That is so sweet.


In a bid to break free from their Sheldon-imposed schedule, the guys have "Anything Can Happen Thursday". They order Thai food instead of pizza, but Sheldon's digestive system struggles to handle the change. Sheldon's idea for the night is to go to the comic book store, which they usually do on Wednesdays. Howard would rather go to a bar and pick up women, but they settle on Sheldon's idea.

As the guys leave for the comic book store, they meet Penny in the hallway, who asks them to pick up a comic book for her nephew. When Sheldon confuses her with an array of options, Penny decides to come along to the store. At the store, Penny meets store owner Stuart, who charms her into giving him her phone number after he draws a sketch of her. Penny agrees to go with Stuart to an art show which is exhibiting some of his work.

After Leonard encounters Penny and Stuart going out for their date, Leonard wonders why Penny is interested in Stuart when he is just like him. Upset about Penny and Stuart, Leonard asks Howard to take him to a bar to meet women. At the bar, Howard and Leonard leave Raj after he orders an embarrassing drink. When Leonard and Howard split off, Leonard finds Howard isn't the ladies' man he claims to be. Howard's desperate attempts to pick up women all fail as Leonard watches on incredulously. At the end of the night, Raj is the only one of the guys to go home with a woman.

Meanwhile, Sheldon finds Penny and Stuart in the hall when they return from their date and interrupts their evening with a debate about Batman. While Sheldon and Stuart debate superheroes, Penny falls asleep on the couch.