Monday, March 16, 2009

Math on the Simpsons Last Night

Last night on The Simpsons they had a math problem. Homer solved it! Since Jeff Westbrook (PhD from Tarjan) is one of the writers, and I've heard they have other writers with a math bend, I'm not too surprised that they had a math problem. I am surprised that Homer solved it. Its a problem you've probably heard in other forms:
Homer has with him Baby Maggie, his dog, and a jar of poisons that look like delicious candy. (Homer: Oh, why did I take my baby and my dog with me when I went to buy poison! And why do the poison has to look so delicious!?) He needs to get all three across the river. He can only take one of them at a time in his rowboat. He can't leave Maggie with the poison. He can't leave the dog with the poison. (He CAN leave Maggie and the dog.) How does he do this?

The Simpsons has had lots of math on it. There is a webpage of all math on The Simpsons here, though it doesn't have last night's episode yet (quite reasonable--- if you expect that then you expect to much from the digital age).

How does The Simpsons compares to Numb3rs in terms of the accuracy of the math presented? I suspect The Simpsons is more accurate; but, to be fair, they don't have to find some goofy math way to solve a crime every week. The math on Numb3rs, goofy as it sometimes is, does connect to some math of interest, see this web page.


  1. Actually, he can't leave the dog with Maggie because the dog will chew up Maggie's stuffed animal.

  2. In his solution he DOES leave the dog with Maggie
    at one point. Oh well.

  3. This old puzzle turns out to be still a subject of research — Woeginger had a talk on it at ESA 2008.

  4. In what sense is this a math problem? Isn't it just common sense thinking?

  5. Homer takes the poison first then comes back and gets Maggie. Take Poison back and pick up Dog and take him across. Finally go back and get poison. Easy peasy.

  6. Actually when I watched it he never proposed to leave the dog with Maggie.

    His idea was to take Maggie across then go back to get the poison after which he would take Maggie back. He then takes the dog over and finally returns to get Maggie. At no point was Maggie left alone with the dog.

    I like also how it pokes fun of how idealized Maths solutions are. And how quickly they can fall apart in real life.

  7. Kudos to Anon 6!- I rewatched that segment to check and YES the
    problem was NOT as I stated it.
    The problem was indeed that
    CANT leave Maggie with Poison
    CANT leave Maggie with Dog
    but CAN leave Dog with Poison.

    Is it math or common sense thinking?
    Its reasoning which is some math,
    though not alot. If you have more items and more constraints then use graph theory and its more math.
    But GOOD QUESTION- at what point does common sense reasoning become math.

  8. soz im a little late but yeah i would label the problem as 60% common sense 40% mathematical reasoning

  9. I think it's math and common sense but as far as I'm concerned how is leaving a dog with poison in any "common sense" equation a good thing, dogs gonna chew on the poison too. Just sayin