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How would you place a 13 ton stone hat on top of 30-foot-tall moai statue?

UO Physics professor Ben McMorran helps in collaboration with former UO student Sean Hixon’s honors thesis on Easter Island moai.

“We were talking about inclined planes and rolling motion, and Sean mentioned his honors thesis work on the question of how the inhabitants of Rapa Nui managed to place large, cylindrical stone hats on top of 30-foot-tall moai statues,” said McMorran. “What was a rather rote mechanics problem for introductory physics became a nice collaboration in which we may have solved the mystery.”

Polynesians likely set up ramps using a parbuckling technique. That’s a simple way to roll objects and has been used to right capsized ships.

The center of a long rope is fixed to the top of a ramp, and two trailing ends are wrapped around a cylinder to be moved. Rope ends are then brought to the top where workers pull on the ropes to move the cylinder safely up the ramp. At the top, the hat would have been tipped and rotated into place.

You can read the full Around-the-O article here.