In the Big Bang Theory, Season 5, Episode 16, The Vacation Solution:

Amy: Okay, smart guy. I'm about to remove the locus coeruleus, which is incredibly delicate work. Have at it.

Sheldon: All right. I'm no stranger to a little gray matter. Locus coeruleus. Locus coeruleus.

Amy: You're getting warmer, it is, indeed, in the brain. Hope your hands are steady. It's the width of a single hair. But this is just biology, so I'm sure it's no problem for a genius like you.

Sheldon: It's not. I'll have you know, in the field of physics, we work with particles so small, they make fat jokes about the locus coeruleus, i.e., when your locus coeruleus sits around the house, it sits around the house.

The above is a joke in the Big Bang Theory, I can't understand the bold sentence: when your locus coeruleus sits around the house, it sits around the house. Could you explain to me what's the meaning?

  • 7
    Perhaps a form of exaggeration. It encompasses the house? When it sits around the house (acts lazy) it sits around (encompasses) the house. Aug 28, 2023 at 0:09
  • 9
    Laurel’s answer provides the two meanings used in the joke, but this is a stock joke probably going back to vaudeville tradition. “My wife is so fat” (Stock audience response: “How fat is she?”) “Well, when she sits around the house, she really sits around the house”. Needless to say it’s considered poor taste today, but that’s part of the joke that the writers were making with Sheldon.
    – Ben Murphy
    Aug 28, 2023 at 5:06
  • 1
    @BenMurphy and that was revitalized in the 90s with the "yo mama's so x" jokes, which I am hoping is dead and forgotten now. Aug 28, 2023 at 8:20
  • 3
    You must have it wrong -- Sheldon would never confuse i.e.with e.g.!
    – TonyK
    Aug 28, 2023 at 10:57

1 Answer 1


The first time, he's using "sit around" to mean

to sit somewhere and do nothing or do nothing in particular:

He just sits around the house watching TV.


The second time, he's playing on a different meaning of "sit around": to encircle. (I believe he also emphasizes the word "around" to indicate where the wordplay is.) This is a fat joke, so that's saying that the locus coeruleus is so big it could fit around a house. Here's the relevant definition from McGraw-Hill via TFD:

to be seated at the edge or perimeter of something.

They sat around the camp fire for hours. We used to sit around the big kitchen table and talk.

This joke predates the Big Bang Theory. The earliest example I found was in the 1963 TV Guide:

For instance, if somebody hollered "fat," Morey [Amsterdam] might crack, "My uncle is so fat that when he sits around the house he sits around the house."

  • 5
    Right, it's an old joke, they made it "geeky" by using a technical term for part of the brain.
    – Barmar
    Aug 28, 2023 at 14:44

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .