"This presents us with an interesting set of science and engineering problems," Witchey says in a press release.
The crack could be the result of one of a number of situations or factors. Natural, unrelieved stress in the block when the original stone was quarried could be the culprit. Or when the globe was manufactured, it could have been subjected to extreme heat. The simplest reason could be the thermal difference between the upper part of the model exposed daily to the sun and its cooler, submerged bottom.
Creators of the kugel, Kusser Granitwerke of Aicha vorm Wald, Germany, and the Science Museum will perform tests on the kugel to learn the depth of the crack and the effect of possible thermal stress. In the meantime it will remain still.
Witchey poses possible remedies. A large bolt could be put through the center of the kugel, designed to squeeze the granite with 15 tons of pressure. It could be shielded from sunlight. Water could be sprayed from the top to keep its temperature more consistent with its bottom. A lighter-colored kugel could be created that would absorb less sun. Or a brand new exact replica of the Grand Kugel could be constructed.
"It is up to Kusser to repair or replace the kugel," Witchey says, because the sculpture is under warranty.
It took two years to raise from private donors the $1.25 million it cost to purchase the kugel. When completed, it was shipped from Germany to Norfolk and driven by truck to Richmond. The Science Museum installed the kugel Jan. 6, 2003.
Since then it has prompted untold "oohs and ahs," says museum spokeswoman Nancy Tait. "It's a landmark," she says. "People love it." Brandon Walters
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