Caltech researchers successfully raise obeliskwith kite to test theory about ancient pyramids
When people think about the building of the Egyptian pyramids, they probably have a mental image of thousands of slaves laboriously rolling massive stone blocks with logs and levers. But as one Caltech aeronautics professor is demonstrating, the task may have been accomplished by just four or five guys who flew the stones into place with a kite.
On Saturday, June 23, Mory Gharib and his team raised a 6,900-pound, 15-foot obelisk into vertical position in the desert near Palmdale by using nothing more than a kite, a pulley system, and a support frame. Though the blustery winds were gusting upwards of 22 miles per hour, the team set the obelisk upright on second try.
"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 (SURF) 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 seconds—so quickly, in fact, 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 an even bigger obelisk to demonstrate that even the mammoth 300-ton monuments of ancient Egypt—not to mention the far less massive building blocks of Egypt's 90-odd pyramids—could 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.
Clemmons' kite theory was a drastic 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.
To demonstrate how little progress was made in the centuries after the age of the pyramids had passed, Gharib points out that, in 1586, the Vatican 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.
It is a credit to Clemmons' determination that the idea is so far along in the testing stage. With 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 well revolutionize the knowledge of ancient engineering practices—and perhaps lead to a reinterpretation of certain ancient symbols as well.
In the course of researching the tools available to the Egyptian pyramid builders, she has discovered, for example, that a brass ankh—long assumed to be merely a religious symbol—makes 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 to make linen sails hold wind. As for objections to the use of pulleys, the team's intention was always to progress later—actually, "regress" might be a more appropriate word— to the windlasses apparently used to hoist sails on Egyptian ships.
"The whole approach has been to downgrade the technology," Gharib says. "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," says 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."
The concept Gharib has developed with Graff is to build a simple structure around the obelisk with a pulley system mounted somewhat forward of the stone. That way, the base of the obelisk will drag the ground for a few feet as the kite lifts the stone, and the stone will then be quite stable once it has been pulled up to 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. A couple of workers guide the operation with ropes attached to the pulleys.
Of course, no one has any idea if the ancient Egyptians actually moved stones or anything else with kites and pulleys, but Clemmons has found some tantalizing hints that the project is on the right track. On a building frieze now displayed 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 is not necessarily to make archeological contributions, but to demonstrate that the technique is viable.
"We're not Egyptologists," he says. "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 with everyone watching, they will proceed to a 10-ton stone, then perhaps to 20 tons. Eventually they hope to receive permission to raise one of the obelisks that still lies 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."
Finally, one might ask whether there was and is sufficient wind in Egypt for a kite or a drag chute to fly. The answer is that steady winds of up to 30 miles-per-hour are not unusual in the areas where the pyramids and obelisks are found.
Contact: Robert Tindol (626) 395-3631