Description
What is a Gömböc?

First described by Prof. Domokos and Dr. Várkonyi in 2006, the Gömböc is the first known homogenous convex object with only one stable and one unstable equilibrium point. This means that, when placed on a flat surface, no matter at what point it is placed, the Gömböc will always return to exactly the same resting position - the stable equilibrium point. This effect is similar to that seen in 'Weeble' toys, which no matter how they are placed or pushed, always end up standing upright. However, while Weebles rely on a weight in the bottom of their shape, the Gömböc consists of material that is the same density throughout the object. Thus, the ability of the Gömböc to self-right depends entirely on its unique and curious shape.

The position to which the Gömböc always returns when placed on a flat surface is its stable equilibrium point. In principle, a Gömböc can also be balanced on the point opposite the stable equilibrium point. However, the slightest disturbance will make it fall, similar to a pencil balanced on its tip. This latter point is therefore known as the unstable equilibrium point.

Why is it special?

It can be proven mathematically that no three-dimensional homogenous convex shape exists with less than the two equilibrium points of the Gömböc. The shape is also extremely precise – an error in manufacture of one hundredth of a millimetre (0.0001m) would result in a shape with more than one stable equilibrium point. Gömböc 1209 has been manufactured from aluminium alloy, using a precision machining technique called computer numerical controlled (CNC) milling.

The question of whether Gömböc-type objects existed or not was posed by the great Russian mathematician Vladimir I. Arnold in 1995, and Domokos and Várkonyi’s discovery was inspired by Arnold’s conjecture.

Why is the Gomboc inscribed with the number 1209?

Gömböc 1209 was presented as a gift to the University of Cambridge by Prof. Gábor Domokos and Dr. Péter Várkonyi on April 22nd 2009. The gift was accepted by the vice-chancellor of the University, Prof. Alison Richard, at a ceremony in the Whipple Museum’s Main Gallery. The Gömböc is inscribed with serial number 1209, which celebrates the foundation year of the University of Cambridge.

Both Prof. Gábor Domokos and Dr. Péter Várkonyi work in the Department of Mechanics, Materials and Structures, Budapest University of Technology and Economics. Prof. Domokos is also a member of the Hungarian Academy of Sciences, and in 2009 was a Visiting Fellow Commoner at Trinity College, Cambridge.
08/05/2009
Created by: Joshua Nall on 08/05/2009