Cup of Justice

Background

Around 570 BC, the Greeks were able to spend time on math and scientific understanding. Pythagoras lived during this time. You may know him from the Pythagorean Theorem. He had other discoveries and innovations, too. According to one legend, Pythagoras created the cup to punish his peers who greedily over-filled their cups of wine. For this reason, the cup is often also referred to as a "Greedy Cup". Other theories suggest that Pythagoras created the cup to remind people to drink in moderation (Kerrigan).

This design was not just accepted in Greece, but in other countries. Below is an example of a Chinese Pythagorean Cup.

What is it?

A Pythagorean cup also known as a Pythagoras cup, Greedy Cup, Cup of Justice or Tantalus cup is a practical joke device in a form of a drinking cup, credited to Pythagoras of Samos. When it is filled beyond a certain point, a siphoning effect causes the cup to drain its entire contents through the base. The Pythagorean cup, or “greedy” cup is a specially designed cup which will empty its contents once filled to a certain point (DHWTY).

Here is a diagram of how it works

Uses for today...

Did you know there is a Pythagorean cup in your house! Your washing machine has one in its soap tray to keep it from overfilling (Sharp).

Directions

Making a Pythagorean cup is very simple.

All you need is a Styrofoam cup and a straw.

First, you want to bend the straw and put it through the middle of the Styrofoam cup.

The last thing you need to do is position the straw to where when the water gets to a certain point it will pour out (Richeson). See this video to make your own...

If you are interested to learn more, we welcome you to visit www.thepythagoreancup.com

Sources

Dhwty. “More than a SIP and You Feel a Drip: A Morbid Motif for the Crafty Pythagoras Cup.” Ancient Origins, Ancient Origins, 21 Sept. 2019, https://www.ancient-origins.net/artifacts-ancient-technology/sipl-drip-morbid-motif-crafty-pythagoras-cup-0010112.

Kerrigan, Saoirse. “The Pythagorean Cup - the Cup That Spills Your Drink When You Get Too Greedy.” Interesting Engineering, Interesting Engineering, 22 June 2018, https://interestingengineering.com/culture/the-pythagorean-cup-the-cup-that-spills-your-drink-when-you-get-too-greedy.

Richeson, Posted by Dave. “Make Your Own Pythagorean Cup.” David Richeson: Division by Zero, 4 Jan. 2019, https://divisbyzero.com/2018/12/31/make-your-own-pythagorean-cup/.

Sharp, Nicole. “The Greedy Cup in Your Washing Machine.” FYFD, 2 Dec. 2020, https://fyfluiddynamics.com/2020/12/the-greedy-cup-in-your-washing-machine/.