# Gomboc – An Object That Never Falls

###### By Anupum Pant

There’d be hardly anyone among us who hasn’t played with a roly-poly toy during their childhoods. If you know it by some other name, you could think of it as a toy that never falls, no matter how hard you hit it, and sells in variants which look like this. That isn’t exactly what a Gomboc is, but you get an idea about what it does – It does not fall. For more, read on.

### What is a Gomboc?

A Gomboc (Gömböc) is a mathematical 3-D shape which has only one position in which it can stand and is made up of a single material  of uniform density. If you try to make it stand in some other way, or try to knock it down, it moves back to that single stable position, gradually. When placed on its side, it starts rocking magically, gains momentum, straightens itself and gradually comes to rest in that single position. Here is a video of a Gomboc doing its thing.

A Gomboc is an object surrounded by a number of complex curves, it takes an immense amount of accuracy to get the surfaces right. An accuracy of  the orders of around 1/10th of a human hair’s thickness is required for it to work properly. For better, people have started 3D printing these complex shapes.

The world’s largest Gomboc was displayed in China in the year 2010 which measured around 3 meters in all directions.

Terrestrial tortoises, who use a similarly shaped shell to get on their feet when turned upside down, were using it long before humans had found a way to construct it. The first time we made it, was in the year 2006. Evolution got there first!

How is it different than a Roly-Poly toy?
A roly-poly toy usually has an internal counter weight made up of a heavier material. But a Gomboc is made up of a single material.

Uses: Use it as a paper weight or to gift it to your friend who is a math geek. Tortoises use it to save their own lives.