Gomboc
Tortoise Shell Geometry

The star tortoise shell has a special geometry. The high dome is good for three things.

• It protects the tortoise from the jaws of its predators.
• It helps to keep the tortoise cool.
• It allows the star tortoise to roll back onto its feet using gravity if it gets turned onto its back.

The last part, about rolling upright easily, saves the tortoise's life because a tortoise who can't travel to food and water will die.

That last part interested engineers at the Budapest University of Techology and Economics. Dr. Gabor Domokos and Dr. Peter Varkonyi worked for ten years to find a special shape that would roll back no matter how much it was bumped. They call the shape a Gomboc.

When they discovered the shape, Dr. Domokos thought that it looked a lot like a tortoise shell. (Dr. Domoko told me that turtles are his favorite animal. I think he is a nice man.) He decided to check out his idea about the Gomboc and the tortoise shell. He went to the Budapest Zoo and Botanical Garden and asked for permission to turn tortoises over one time each to see if they would roll back easily.

The head of the zoo gave him permission, but the keeper of the tortoises would not let anybody bother the tortoises. I think that is a good zoo keeper.

Then Dr. Domokos talked to another man who fed the tortoises and told him that if he could turn over each tortoise only one time, the tortoises would not be too upset and the world would start to care more about tortoises. That man agreed to let Dr. Domokos in to turn over the tortoises. Dr. Domokos said, "I realized that I was working on something which is connected to nature. That made us both very happy. When we saw that first turtle roll back, then we saw that we found...a little bit more of an understanding of how nature works."

Two pet shops also let Dr. Domokos turn over tortoises. I think the people in Kis Teki and Leguan helped tortoises, too.

Dr. Domokos has another helper who also likes turtles and tortoises. Her name is Timea Szabo. She lives with a turtle called Beno. You can see how Beno turns over here.

That's the part about tortoises. Read the next page if you want to know more about a Gomboc.

Keep it slow and steady.