Skip to content

Disproof of Pythagorean Theorem

October 10, 2007 pm31 3:13 pm

Go, run, look for yourself:



Richard Mason watches mathematical certainty slip away.

This certainly spins that Greek theory on its head.

11 Comments leave one →
  1. October 10, 2007 pm31 6:48 pm 6:48 pm

    Everybody knows that physicists don’t know mathematics. :-)

    • Anonymous permalink
      April 7, 2010 am30 11:14 am 11:14 am

      u must reconsider it tht physicists dont knw maths!!!

  2. October 10, 2007 pm31 7:21 pm 7:21 pm

    fyi: i can’t see the graphic in your post
    (just an error message indicating that
    SOMETHING.jpg should have been there).

    great find!

  3. October 10, 2007 pm31 7:29 pm 7:29 pm

    That was priceless.

    Maybe the museum knowingly put that exhibit out there to get a conversation started on the topic of “Why empirical experiments don’t constitute mathematical justification.” Is that possible or am I being overly charitable?

    A comment similar to the one that was posted above was made at my house as well. I had to convince my husband that the original blogger was being sarcastic.

  4. October 10, 2007 pm31 8:07 pm 8:07 pm


    it’s a mess here, too. At home it showed up nice. I’ll take a look this evening.

  5. Jackie permalink
    October 11, 2007 am31 4:45 am 4:45 am

    I see the graphic (firefox on a mac). Great find – thanks!

  6. October 11, 2007 am31 5:40 am 5:40 am

    Looks fine to me. I commented on the blog:

    Maybe there is liquid hiding behind the triangle? So in the first picture, there could be more than meets the eye, and in the third, the extra water settles in a thin strip, mostly hidden behind the triangle, but with those two extensions to the left and right.

    Perhaps the Theorem is not broken, but it’s just sprung a leak.

  7. October 12, 2007 am31 4:50 am 4:50 am

    I like this. And it’s cool, though I’m not sure if the densities are on point, just like many of the commenters mentioned. Nonetheless, it’s a fun look at an age-old theorem.

  8. December 2, 2007 pm31 8:58 pm 8:58 pm

    Hi Jonathan, I just belatedly noted your comment on my blog re the botched Pythagoras museum demo.

    The source of the problem was not blatantly obvious from visual inspection of the apparatus. But I doubt that there was a *significant* amount of fluid hiding behind the triangle. That would seem to require *total* cluelessness by the exhibit constructors.

    More likely, the constructors knew basically what they were trying to do, and were reasonably skilled in carpentry, but did not consider the required precision for the uniform depth of the tanks (depth normal to the plane of the triangle). Since the tanks were not very deep (~1 cm), a variation in depth that might seem quite small in absolute distance (~1 mm) could produce a big percentage error in volume and ruin the demo.

    The same one-millimeter construction error in any of the other dimensions of the apparatus would have made much less difference to the volume and thus less fluid overspill, probably not enough to spoil the demo.

    Perhaps this itself is an interesting real-world lesson in mathematics.

  9. March 3, 2016 pm31 10:02 pm 10:02 pm

    Don’t look at the wheel, look at the water wheel. That wheel in the sky keeps on turnin’ like a perpetual motion machine in the sky… Hint hint.


  1. Rewriting the history of math « Let’s play math!

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

%d bloggers like this: