Flying Stones

Thousands of years after the Egyptians piled up millions of huge stones to build their pyramids, scientists still ask: “How'd they do that?” A group of researchers, including a team from the California Institute of Technology, has a surprising answer—by using kites and the desert wind to help lift the stones! To test their theory, the researchers designed a simple rope-and-pulley system and mounted it on a support frame. They attached one end to a large kite and the other to the tip of a 3.4-ton obelisk shaped like the Washington Monument. Critics called them pyramidiots, but it took the researchers only 25 seconds to raise the huge stone in a 15–20 mph wind, such as is common in the Egyptian desert. Archaeologists point out that there is no evidence that the Egyptians used kites in building. But this summer the pyramidiots plan to lift a 10-ton obelisk using only materials that were available to the ancient Egyptians. Will they unlock the mystery of the pyramids? Stay tuned!


A shaft with four sides that tapers to a point.

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  1. What simple machine is used to lift the obelisk?
    [anno: A rope-and-pulley system is used to lift the obelisk.]
  2. What energy source is used to pull up the obelisk?
    [anno: Wind energy is used to pull up the obelisk.]
  3. Design a machine that uses a ramp or a lever to help move a heavy object. Draw a picture of your machine. Write a few sentences about your machine. Tell what powers your machine and how your machine moves the heavy object.
    [anno: Answers will vary.]