The Pythagorean Cup Will Keep You From Drinking Too Much

Stop putting up with greedy friends who try to take more than their fair share of the wine. You know the guy. The one who never brings a decent bottle to the party, but then races to every near-empty bottle so he can top off his glass. You may feel like there’s nothing you can do about it (besides find better friends), but there is one ancient solution to the latter issue: The Pythagorean Cup.

At first glance, the Pythagorean Cup looks like an ornate version of your everyday Greek goblet. Inside, however, is a column sticking up in the middle. Try to fill it up to the brim, and all of the liquid inside quickly drains out from the bottom of the cup. Voila, your once greedy friend gets a lesson in moderation and an immediate need to remove red-wine stains.

The cup is named after Pythagoras of Samos, the Greek mathematician and philosopher who lived around 500 B.C. and is most famous for tormenting adolescent school children with his Pythagorean theorem. Pythagoras and Greeks in general loved more than just math, though; they loved their wine and Dionysus-inspired drinking parties. That went for Pythagoras’s students as well, so Pythagoras invented a solution to keep his students from getting greedy.

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So the story goes at least. Regardless of whether it’s true, the cup carries the man’s name. But before you buy one and start causing a mess all over your greedy friends’ homes, you should probably understand the basics of how it works.

GIF via Periodic Videos / YouTube
GIF via Periodic Videos / YouTube

Basically, the Pythagorean Cup uses the same laws of nature that greedy movie characters use to siphon gas out of a car. The column inside the cup has a small hole at the bottom of the column. Inside the column is a “u”- shaped pathway that loops up and then straight down through the stem of the cup and culminates with a hole at the base of the cup.

When wine is poured into the cup, the “u” shape fills up at an equal level because of Pascal’s Law of Communicating Vessels. Once the wine goes over the column (and therefore the “u”), the wine is siphoned out of the bottom of the cup — and once it starts going it doesn’t stop ‘till it’s gone.

The siphoning works by gravity and hydraulic pressure, just like when the gas in a car is being stolen from a sketchy guy with a water hose. Pressure pushes down on the liquid and through the hose, and the excess pressure pushes liquid from one place to the other.

Same thing with the Pythagorean Cup siphon action. The “u” pathway inside the column becomes a siphon for the rest of the liquid. The pressure at the top of the “u” is reduced by the wine going through the bottom of the glass, which causes the entire contents of the glass to follow suit.

There you have it. A modern-day glass iteration that doesn’t clay chips in your wine. It can be found on Amazon. Siphon away, and enjoy watching your greedy friends get punished.