The Easter Island Statues Really “Walked,” and Physics Confirms It

For years, researchers have wondered how the ancient inhabitants of Rapa Nui did the impossible and moved their iconic moai statues. By combining physics, 3D modeling and field experiments, a team including professors from Binghamton University and the State University of New York confirmed that the statues actually walked, with a small rope and remarkably few people.

Studying nearly 1,000 moai statues, Carl Lipo, an anthropology professor at Binghamton University, and Terry Hunt of the University of Arizona found that the people of Rapa Nui likely used a rope and “walked” over the giant statues in a zigzag pattern along carefully designed routes. The article is published in the Journal of Archaeological Sciences.

Lipo and his colleagues had previously demonstrated, through experimental evidence, that large statues “walked” from their quarries to ceremonial platforms using a vertical swinging motion, calling into question the theory that the statues were moved lying on wooden devices.

“Once you get it moving, it’s not difficult at all: People pull with one arm. It saves energy and moves very quickly,” Lipo said. “The hardest part is getting it to vibrate in the first place. The question is: If it’s really big, what would it take? Are the things we’ve seen experimentally consistent with what we expect from a physical perspective?”

To explore how a larger statue might move, Lipo’s team created high-resolution 3D models of the moai and identified distinctive design features (wide D-shaped bases and a forward tilt) that would make them more likely to be moved in a rocking, zigzag motion.

Putting their theory to the test, the team built a 4.35-ton replica moai with a distinct “forward-leaning” design. With just 18 people, the team was able to transport the moai 100 meters in just 40 minutes, a marked improvement over previous vertical transport attempts.

“The physics makes sense,” Lipo said. “What we’ve seen experimentally actually works. And as it grows, it still works. All the attributes we see about moving gigantic objects just become more and more consistent as they grow, because that becomes the only way to move them.”

The roads of Rapa Nui reinforce this theory. Measuring 4.5 meters wide and with a concave section, the roads were ideal for stabilizing the statues as they moved forward.

“Every time they move a statue, it looks like they’re making a road. The road is part of moving the statue,” Lipo said. “We actually see them overlapping, and a lot of parallel versions. What they’re probably doing is clearing one path, moving it, clearing another path, clearing it more, and moving it to the right in some sequences. So they spend a lot of time on the road.”

Lipo said nothing else currently explains how the moai were moved. The challenge for anyone is to prove him wrong.

“Find evidence that shows he couldn’t walk. Because nothing we’ve seen anywhere refutes that,” Lipo said. “In fact, everything we see and think keeps reinforcing the argument.”

Lipo said Rapa Nui is known for its wild theories backed by no evidence. This research is an example of testing a theory.

“People have told all kinds of stories about things that are plausible or possible in some way, but they’ve never evaluated the evidence to show that in fact you can learn about the past and explain the records that you see in a fully scientific way,” Lipo said. “One of the steps is just to say, ‘Look, we can construct an answer here.'”

Lipo said the research also honors the people of Rapa Nui, who achieved a monumental feat of engineering with limited resources.

“It shows that the Rapa Nui were incredibly intelligent. They figured it out,” Lipo said. “They’re doing it in a way that’s consistent with the resources that they have. So it’s really a credit to these people, saying, look what they’ve been able to achieve, and we have a lot to learn from them in these principles.”