Incas May Have Used Sun to Cut Stone

An Earth sciences professor who has visited and done research at several sites in Peru where the Inca Indians lived 1,000 years ago believes he has the answer to a mystery that has puzzled archeologists for years.

The Incas used solar power, not manpower, to cut the huge stones they used to build their massive cities, according to Dr. Ivan Watkins of St. Cloud State University.

Watkins says his theory supersedes all previous theories because those do not account for all of the evidence. He believes there is enough circumstantial evidence of the preserved Inca traditions to support his idea.

The sun was important to the Incas and was venerated in an annual festival, he noted. Some cultural records indicate that the Indians renewed an external flame by lighting a torch with sun rays reflected from a priest’s bracelet.

“There’s no doubt in my mind that they knew how to do it,” Watkins said.

Watkins believes the Incas used gold, dish-shaped, or parabolic, reflectors to concentrate the sun’s energy to carve the rocks with a beam of light.

“They had that technology 1,000 years ago,” he said.

Every Inca temple contained a golden dish, he said. Watkins believes the dishes probably were cut up and destroyed when the Spanish conquistadors conquered the Incas in the 15th Century.

Additional evidence to support the theory can be found in the Gold Museum at Bogota, Colombia, he said. Four small, gold dishes appear to have the shape needed to focus the sun’s rays.

A parabolic dish looks like a TV satellite dish. When sunlight is reflected on a parabola, the focused energy can be directed by moving the dish, Watkins said.

The dishes used by the Incas were “two men across,” he said. “That’s a pretty big dish and it could burn a lot.” It would be large enough to cut rock easily, he said.

The huge dishes allowed the Incas to cut the rocks in a precise fashion, Watkins said. The stone blocks are so closely matched that a knife blade cannot be inserted between them, he noted.

Previously, scientists have theorized that the massive stones of Incan cities were hammered with other stones, broken with wooden or metal wedges, etched with organic acids or sanded with grains of sand and water.

But Watkins says some of the rocks are carved with sharp inside corners, and there are clean edges of cut rock near stress fractures in the rocks. Crude stone hammers could not have achieved those results, he said.

Watkins said his theory evolved after he had noticed a glaze on the wall of a cave that had Inca stonework in it.

“In order to get a glaze, what you have to do is heat the rock, fire it up,” he said. “What happened in this cave is they had heated the material quite severely.”

The Inca villages were rediscovered in 1911. The capital of the Inca empire was located near the Peruvian town of Cuzco, but the most famous of the sites is Machu Picchu in the mountains of south-central Peru.

Watkins conducted experiments on his theory at the federal Bureau of Mines in the Twin Cities and found that rock could be cut with a 100-watt laser.