Researchers Lift Obelisk With Kite to Test Theory on Ancient Pyramids
|July 6, 2001|
PALMDALE, CaliforniaWhen people think about the building of the Egyptian pyramids, they probably have a mental image of thousands of slaves laboriously rolling massive stone blocks into place with logs and levers. But one Caltech aeronautics professor has set out to demonstrate that the task could have been accomplished by several people using a kite to move the heavy stones.
On June 23, Mory Gharib and his team raised a 6,900-pound (3132.6 kg), 15-foot (3.0 m) obelisk into vertical position in the desert near Palmdale by using only a kite, a pulley system, and a support frame. Although the blustery winds were gusting up to 22 miles (35.4 km) per hour, the team set the obelisk upright on their second attempt.
"It actually lifted up the kite flyer, Eric May, so we had to kill the kite quickly," said Gharib. "But we finished it off the second time."
Emilio Castano Graff, a Caltech undergraduate who tackled the problem under the sponsorship of the Summer Undergraduate Research Fellowship program, was also pleased with the results. "The wind wasn't that great, but basically we're happy with it," he said.
Despite the lack of a steady breeze, the team raised the obelisk in about 25 secondsso quickly that the concrete-and-rebar object was lifted off the ground and swung free for a few seconds. Once the motion had stabilized, the team lowered the obelisk into an upright position.
The next step is to build a bigger obelisk to demonstrate that even the mammoth 300-ton monuments of ancient Egyptnot to mention the far less massive building blocks of Egypt's 90-odd pyramidscould have been raised with a fraction of the effort that modern researchers have assumed.
Gharib has been working on the project since local business consultant Maureen Clemmons contacted him and his Caltech aeronautics colleagues two years ago. Clemmons had seen a picture in Smithsonian magazine in 1997 of an obelisk being raised, and came up with the idea that the ancient Egyptian builders could have used kites to accomplish the task more easily. All she needed was an aeronautics expert with the proper credentials to field-test her theory.
Project Born of a Passion
Clemmons' kite theory was a major departure from conventional thinking, which holds that thousands of slaves used little more than brute force and log-rolling to put the stone blocks and obelisks in place. No one has ever come up with a substantially better system for accomplishing the task, and even today the moving of heavy stones would be quite labor-intensive without power equipment.
As an indication of how little progress was made in the centuries after the age of the pyramids had passed, Gharib points out, the Vatican in 1586 moved a 330-ton Egyptian obelisk to St. Peter's Square. It is known that lifting the stone into vertical position required 74 horses and 900 men using ropes and pulleys.
Although Clemmons has no scientific or archaeological training, she has managed to marshal the efforts of family, friends, and other enthusiasts to work on a theory that could alter thinking about ancient engineering practicesand the interpretation of ancient symbols.
Researching the tools available to the Egyptian pyramid builders, she discovered, for example, that a brass ankhlong assumed to be merely a religious symbolmakes a very good carabiner for controlling a kite line. And a type of insect commonly found in Egypt could have supplied a kind of shellac that helped linen sails hold wind.
The test team views the use of a pulley as an intermediate step only, and has planned to shift to a reliance on windlasses like those that apparently were used to hoist sails on Egyptian ships.
"The whole approach has been to downgrade the technology," Gharib said. "We first wanted to show that a kite could raise a huge weight at all. Now that we're raising larger and larger stones, we're also preparing to replace the steel scaffolding with wooden poles and the steel pulleys with wooden pulleys like the ones they may have used on Egyptian ships."
For Gharib, the idea of accomplishing heavy tasks with limited manpower is appealing from an engineer's standpoint because it makes more logistical sense.
"You can imagine how hard it is to coordinate the activities of hundreds if not thousands of laborers to accomplish an intricate task," said Gharib. "It's one thing to send thousands of soldiers to attack another army on a battlefield. But an engineering project requires everything to be put precisely into place.
"I prefer to think of the technology as simple, with relatively few people involved," he explained.
Gharib and Graff came up with a way of building a simple structure around the obelisk, with a pulley system mounted in front of the stone. That way, the base of the obelisk would drag on the ground for a few feet as the kite lifted the stone, and the stone would be quite stable once it was pulled upright into a vertical position. If the obelisk were raised with the base as a pivot, the stone would tend to swing past the vertical position and fall the other way.
The top of the obelisk is tied with ropes threaded through the pulleys and attached to the kite. The operation is guided by a couple of workers using ropes attached to the pulleys.
No one has found any evidence that the ancient Egyptians moved stones or any other objects with kites and pulleys. But Clemmons has found some tantalizing hints that the project is on the right track. On a building frieze in a Cairo museum, there is a wing pattern in bas-relief that does not resemble any living bird. Directly below are several men standing near vertical objects that could be ropes.
Gharib's interest in the project is mainly to demonstrate that the technique may be viable.
"We're not Egyptologists," he said. "We're mainly interested in determining whether there is a possibility that the Egyptians were aware of wind power, and whether they used it to make their lives better."
Now that Gharib and his team have successfully raised the four-ton concrete obelisk, they plan to further test the approach using a ten-ton stone, and perhaps an even heavier one after that. Eventually they hope to obtain permission to try using their technique to raise one of the obelisks that still lie in an Egyptian quarry.
"In fact, we may not even need a kite. It could be we can get along with just a drag chute," Gharib said.
An important question is: Was there enough wind in Egypt for a kite or a drag chute to fly? Probably so, as steady winds of up to 30 miles per hour are not unusual in the areas where pyramids and obelisks were found.
(c) 2001 Caltech
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