#1186 ... Intriguing

The stone floating ball at Te Papa is always intriguing for young and old alike ... there's something about an object which you know is so heavy appearing to float and rotate as though it has no weight.

Some Facts on this Ball inside the entrance

The large ball inside Te Papa’s main entrance is called the Sponsorship Recognition Stone. It acknowledges Te Papa’s founding sponsors.

The stone:
* is 1.4 billion years old – the oldest material in Te Papa
* is made from gabbro (a coarse crystalline basalt often called Swedish Ebony Granite) from Transvaal, South Africa
* sits on a base stone of Indian Hassan Green Granite
* weighs 0.79 tonnes
* measures 82 centimetres in diameter
* was machined by the Kusser Granit company in Germany.

Low-pressure water from a 500-litre tank provides the power to rotate the ball. The layer of water between ball and base is just 0.2 millimetres thick. Solenoid-controlled jets pulse the water to keep the ball moving when no one is pushing it. For hygiene reasons, the water is treated with swimming-pool chemicals and changed weekly.