Pythagorean Cup Was A Practical Joke To Punish Greedy Drinkers And It Still Fools People

Conny Waters - AncientPages.com - Some ancient scientists had great humor, and one of the world's best practical jokes comes from Pythagoras, who invented a cup to punish greedy drinkers.

It's a funny and clever ancient invention that has become so popular it can be bought today in many stores. The cup looks like just an ordinary cup, and it can fool anyone, even those who tried using it in modern times. Rest assured, it can undoubtedly be an excellent prank to play on someone.

Pythagorean Cup Was A Practical Joke To Punish Greedy Drinkers And It Still Fools People

Credit: Public Domain

Pythagoras of Samos (c. 570 – c. 495 BC) was an ancient Greek philosopher who transformed the ancient world and still inspired science, mathematics, philosophy, and the arts.

His famous mathematical model, the Pythagorean Theorem, which states that the square of the hypotenuse of a right triangle is equal to the sum of the squares on the other two sides, is still used today by different works in many real-life applications.

Pythagoras was knowledgeable, but he didn't like those who drank too much wine.

It is often said Pythagoras created the Cup of Justice, but there is no conclusive evidence that links this vessel to the ancient Greek philosopher. Based on what is known, the cup appeared in the mid-6th Century B.C., so it's assumed it was an invention of Pythagoras, but we don't know this for certain.

Pythagorean Cup Was A Practical Joke To Punish Greedy Drinkers And It Still Fools People

Source: Nevit Dilmen/Wikimedia Commons

The cup's innocent look doesn't raise any suspicions, but the engineering behind it is a work of a mastermind. Once the unsuspecting drinker fills the cup past a specified level, the liquid mysteriously drains out. So how does it work?

The Cup of Justice has a small column in the middle fixed right over the cup's stem. "The cup's stem is hollow, leading to a small hole in the base of the cup.

Within the column is an open chamber. The column also features a small hole that allows the passage of liquid between the cup and the central column. When you fill the cup to just below the tip of the column, you're able to drink without any issues. But, if you fill the cup beyond the column, then you're going to run into some problems.


It's all thanks to Pascal's principle of communicating vessels. When the cup is filled beyond the column, the liquid moves through the small hole, up into the column, and drains out through the stem and the hole in the base. In doing this, a siphon is created, which causes the entire cup to be drained. Therefore, if you try to overfill your glass, you end up losing everything you've just poured." 1

This is also how most flush toilets work.

The Greedy Cup was invented to remind people to drink sensibly, and it remains a popular practical joke. It happens often people drink too much alcohol while being at a party. Why not surprise those who consume too much with the Pythagorean cup?

Pythagoras was a very remarkable man. Did you know he and his followers didn't eat beans?

Written by Conny Waters – AncientPages.com Staff Writer

Updated on January 13, 2023

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Expand for references
  1. Saoirse Kerrigan - The Pythagorean Cup - The Cup That Spills Your Drink When You Get Too Greedy, Interesting Engineering

Skulls in the Stars - Physics demonstrations: the Pythagoras cup