
Pythagorean Cup: Practical Joke Chalice Overflows with Ancient Greek Humor - misnamed
http://99percentinvisible.org/article/pythagorean-cup-practical-joke-chalice-overflows-ancient-greek-humor/
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amenghra
Cliff Stoll has a page about this. He calls it a Cup of Tantalus and it's part
of his Klein Bottle collection. Makes for a fun gift for geeks.

[http://www.kleinbottle.com/Tantalus.html](http://www.kleinbottle.com/Tantalus.html)

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fsloth
In respect of the greeks, this is one cheap souvenir that can actually provide
timeless merriment. I have a few made of burnt clay that are souvenirs from
decades ago and still there are new people who can delightfully be educated on
the principles of these wonderfull devices.

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StavrosK
Wouldn't it actually be very annoying to have to mop and/or clean things every
time?

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fsloth
Some houses are equipped with sinks, bathubs, etc :)

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StavrosK
Ah yes, the old "Here's your completely ordinary cup of wine. Please drink it
over the sink for no particular reason" gag. Gets them every time! :)

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hashkb
With respect to "drinking normally" when the cup is filled below the siphoning
point: if you drink by tipping the cup towards the drain pipe, wouldn't that
engage the siphon?

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DiThi
The drain pipe is as close to the center as possible. When you tilt a cylinder
half full of water, the point at the center remains at the same height.
Considering the cups are slightly wider at the top than the bottom, it can
hold more liquid when tilted, so the height at the center would be a bit
lower.

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bhaumik
Here's a neat 4 min video demonstrating how the cup works & how to "beat" it
with mercury:
[https://www.youtube.com/watch?v=ISfIT3B4y6E](https://www.youtube.com/watch?v=ISfIT3B4y6E)

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danaliv
Neat. It's like a tiny toilet.

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analog31
Self flushing urinals used to work this way. The tank above the urinal was
filled at a constant rate, and would discharge when the level ran over the top
of the siphon.

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rebootthesystem
I remember this cup. I also remember thinking Those both greedy and smart
could have simply plugged the hole with their finger and all is good.

Pythagoras should have given his students smaller normal cups because, if we
go Machiavellian for a moment, people are unscrupulous and will plug the hole,
therefore a smaller cup will be more effective. And limited servings.

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robryk
You can make this harder by providing multiple small holes all over the bottom
of the cup.

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custos
This is how toilets work.

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mrfusion
Anywhere to buy one cheaply?

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IgorPartola
3D print one?

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robryk
3D printing stuff that's foodsafe is nontrivial. You not only need a material
that is not directly harmful (in temperatures it will be used in), but also
most 3d printed surfaces will not be smooth. This makes them very hard to
properly clean (especially the parts of such a cup that wouldn't be
reachable), which causes biological problems (bacteria and mold growing
there).

Whatever material such a cup was made out of, I'd've wanted to be able to
dismantle it for cleaning, which lessens the advantage of 3d printing over
more traditional fabrication techniques.

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chrisbrandow
Also like Soxhlet extractors. That is the coolest chemistry glassware.

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kahrkunne
I'd encourage anyone to read up on Pythagoras. He was a really weird guy who
held some inane beliefs and superstitions. Also a cult leader.

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empath75
I don't think we can know what he really believed or if he existed at all.
He's a semi-mythical figure and there are no contemporary accounts of him.

