The Big Bang Theory (2007– )
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The Bath Item Gift Hypothesis 

Leonard is disappointed when Penny develops an interest in an attractive physicist at the university. Meanwhile, Sheldon struggles to find an appropriate Christmas gift for Penny.



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Sheldon is angry at Penny because she bought him a Christmas gift. Sheldon now feels he has to reciprocate and go through the trouble of buying something for someone he doesn't really understand, all at the same price of the gift he is about to receive. Meanwhile, David Underhill, last year's MacArthur grant award winner based on his work which has basically rendered Leonard's recent work meaningless, is a new addition to the Physics department at Cal Tech. Regardless, Leonard is enthralled to be working with Dave, who is not only good looking, but Leonard learns is a Renaissance man. Upon their meeting, Dave is attracted to Penny, and vice versa, and they decide to date. Penny even pretends to be a science geek to impress him. Leonard is angry at Penny's hypocrisy, since she was scared that Leonard was too smart for her to date. Penny, however, has some more important news about her relationship with Dave. Written by Huggo

Plot Summary | Plot Synopsis


Comedy | Romance


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Release Date:

15 December 2008 (USA)  »

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Did You Know?


The napkin really is signed by Leonard Nimoy. A photograph exists of Jim Parsons holding it up. See more »


In the beginning of the episode, Dave Underhill entered the cafeteria scene and sat with a group of people. During the scene, he changes seat 3 times within a 15 second span. See more »


[first lines]
Sheldon Cooper: Your argument is lacking in all scientific merit. Now, it is well established Superman cleans his by flying into Earth's yellow sun, which incinerates any contaminant matter and leaves the invulnerable kryptonian fabric unharmed and daisy-fresh.
Howard Wolowitz: What if he gets something kryptonian on it?
Sheldon Cooper: Like what?
Howard Wolowitz: I don't know. Kryptonian mustard.
Sheldon Cooper: I think we can safely assume all Kryptonian condiments were destroyed when the planet Krypton exploded.
Raj Koothrappali: Or it turned into mustard kryptonite, the only ...
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Crazy Credits

CHUCK LORRE PRODUCTIONS, #233 Recently the magazine Entertainment Weekly had an article entitled the "The 25 Smartest People in Television." Yours truly was ranked at number twenty. If the article is to be taken seriously, and God knows, why wouldn't any sensible person take it seriously, that means there are currently nineteen people in the TV biz who are smarter than me. Now I'm just thinking out loud here, but if something were to happen to those nineteen people... if say, they were to, one by one, have horrible accidents, or mysteriously disappear, then that would make me, ipso facto, the number one smartest person in television. Then I'd just have to keep an eye on number twenty-one. Christina Wayne, Senior VP of original programming at AMC, looks like the kind of woman who would stop at nothing to move up a spot. See more »


References Star Trek: Amok Time (1967) See more »


History of Everything
Written by Barenaked Ladies
Performed by Barenaked Ladies
[Series theme song played during the opening titles]
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User Reviews

The Bath Item Gift Hypothesis is a most hilarious holiday episode of "The Big Bang Theory"
22 December 2008 | by (Baton Rouge, LA) – See all my reviews

As the geeks discuss Superman and his Krypton sweat, scientist David Underhill arrives and asks Leonard to be his lab partner. Leonard is more than enthused. Penny arrives to give Leonard and Sheldon gifts so Sheldon feels he has to reciprocate. Penny also takes a shine to David and vice versa. It doesn't turn out well for her...Hilarious from beginning to end, "The Big Bang Theory" is on fire this season both in terms of quality and audience ratings. And there's a very funny yet touching bit involving Sheldon, Penny, and a napkin of Leonard Nimoy, Mr. Spock himself, at the end (though, regretfully, he doesn't appear). Having missed much of this season's episodes because of Hurricane Gustav and the renovations that entailed, I felt I had to watch this one to find out how things were going. I'm very glad I did. So all I want to say at this point is Merry Christmas to the cast and crew of "The Big Bang Theory" and hope the new year brings even more fans to this wonderful sitcom courtesy of the 20th smartest person in television according to the magazine "Entertainment Weekly": Chuck Lorre.

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