Scientists just proved the moai could walk, solving a 500-year mystery

After studying nearly 1,000 of the stone figures, Binghamton University anthropologist Carl Lipo and University of Arizona researcher Terry Hunt determined that the island’s inhabitants probably used ropes to rock the statues side to side, allowing them to “walk” forward in a zigzag motion along carefully constructed paths.

Lipo and his colleagues had previously shown through experiments that the towering statues could move upright by rocking back and forth, contradicting older theories that suggested they were hauled lying flat on wooden sleds.

"Once you get it moving, it isn't hard at all - people are pulling with one arm. It conserves energy, and it moves really quickly," said Lipo. "The hard part is getting it rocking in the first place. The question is, if it's really large, what would it take? Are the things that we saw experimentally consistent with what we would expect from a physics perspective?"

To test whether larger statues could move the same way, the researchers built detailed 3D models of the moai. They found specific design features—broad D-shaped bases and a slight forward tilt—that would make the statues easier to rock and maneuver in a walking pattern.

Putting the theory into practice, the team constructed a 4.35-ton replica moai with the characteristic forward-leaning design. Using only 18 people, they successfully moved the statue 100 meters in about 40 minutes, far outperforming earlier vertical transport attempts.

"The physics makes sense," said Lipo. "What we saw experimentally actually works. And as it gets bigger, it still works. All the attributes that we see about moving gigantic ones only get more and more consistent the bigger and bigger they get, because it becomes the only way you could move it."

Further evidence supporting the theory comes from Rapa Nui’s network of ancient roads. Measuring roughly 4.5 meters across and shaped with a gentle inward curve, these routes appear to have been perfectly suited for stabilizing the walking statues as they advanced.

"Every time they're moving a statue, it looks like they're making a road. The road is part of moving the statue," said Lipo. "We actually see them overlapping each other, and many parallel versions of them. What they are probably doing is clearing a path, moving it, clearing another, clearing it further, and moving it right in certain sequences. So they're spending a lot of time on the road part."

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

"Find some evidence that shows it couldn't be walking. Because nothing we've seen anywhere disproves that," said Lipo. "In fact, everything we ever see and ever thought of keeps strengthening the argument."

Lipo said Rapa Nui is notorious for wild theories backed by zero evidence. This research is an example of putting a theory to the test.

"People have spun all kinds of tales about stuff that's plausible or possible in some way, but they never go about evaluating the evidence to show that, in fact, you can learn about the past and explain the record that you see in ways that are fully scientific," said Lipo. "One of the steps is simply saying, "Look, we can build an answer here."

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

"It shows that the Rapa Nui people were incredibly smart. They figured this out," said Lipo. "They're doing it the way that's consistent with the resources they have. So it really gives honor to those people, saying, look at what they were able to achieve, and we have a lot to learn from them in these principles."

The paper, "The Walking Moai Hypothesis: Archaeological Evidence, Experimental Validation, and Response to Critics," was published in the Journal of Archaeological Science.