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Ancient WorldsAncient Worlds

Meet the Extreme Geoengineers of Ancient Times

ByAllison EckNOVA NextNOVA Next
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This is no simulation.

Editor’s Note: This article was originally published in an edition of NOVA’s email newsletter, NOVA Lens, and has now been repurposed for NOVA Next. Sign up for NOVA Lens here (select “NOVA Newsletters”).

This might look like an otherworldly video game, but it’s not. What you’re looking at is the outline of an ancient Mayan megalopolis.

“We found five new cities,” said Francisco Estrada-Belli, a research assistant professor at Tulane University.

Estrada-Belli and 29 other scientists discovered 60,000 previously unknown Mayan buildings, homes, ceremonial structures, agricultural adaptations, and pyramids using LIDAR—a technology that uses pulsed laser light to reveal the shape of objects, including those obscured by dense forest canopies. “This is the largest archaeological survey done by LIDAR in the whole world,” he said.

Thick Central American jungles conceal many remnants of ancient Mayan cities from view. People—including looters—have stumbled across these sites over the years, though more recently LIDAR has allowed professionals to rapidly analyze the landscape without harming it. What’s different about this survey, in particular, is its enormous scale. “There’s more of everything than we would have predicted,” said Marcello Canuto, a professor of anthropology at Tulane University, who was also part of the research team.

Researchers have always assumed that Mayan cities were not dense. But the new LIDAR data suggests that they developed huge populations in urban settings similar to the early metropolises of China and Rome. A complex, humming urban landscape is “no longer seen as impossible for the Maya,” Estrada-Belli said.

The team mapped a total of 810 square miles (not all of which was contiguous). It paints an entirely different picture of the way Mayans used their land. One could say that Mayans were extreme geoengineers—they drained wetlands and built terraces on hillsides and dug irrigation channels almost everywhere.

“They were not only good mathematicians and astronomers, but they were also very good engineers of their environment,” Estrada-Belli said. “Everything was done with a purpose, and every inch of the ground has been manipulated in some form. The amount of investment is unprecedented.”

And that, maybe more so than the knowledge of the Mayan civilization’s scale, could be a radical shift in our sense of history. Through these techniques, the Maya were able to preserve soils and control the flow of water in a way that maintained the soil’s richness. They withstood droughts and other natural disasters as a result. Could it be that we might rule out climate disaster as the culprit in Mayan cities’ mysterious decline?

“We’re going to have to rethink our ideas about how they were not good stewards of the environment and therefore they might have caused their own collapse,” Estrada-Belli said.

Canuto says all civilizations share one trait: that they eventually decline and crumble. What we could be seeing in this new data, then, are lessons—evidence of infrastructural blunders, say. “Perhaps all of this manipulation and intensification was in an attempt to extend, expand, and maintain something that was, in the long-term, not sustainable,” Canuto said.

Estrada-Belli noted one theory that hasn’t received much traction, but which could become more plausible with this new data: These robust changes in the northern part of Mayan territory—trade routes, canals, and so on—may have starved the southern cities of resources. Ultimately, they were the first to die.

“It could have made the south irrelevant,” he said.

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Psychiatry’s biggest breakthrough in decades might come from machines that don’t need to understand the mind at all. Our friends at NEO.LIFE reported a story on the potentially groundbreaking new field of computational psychiatry. Don’t miss it .

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On Tuesday, SpaceX successfully launched the world’s most powerful rocket. PBS NewsHour science correspondent Miles O’Brien talked with NewsHour’s John Yang about this historic moment in an interview, which you can listen to here . NOVA’s own senior producer, Chris Schmidt, wrote a piece on the mission. Here’s an excerpt:

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It’s worth noting that three years ago, when SpaceX attempted a similar landing on a drone ship, the world still hailed the near-miraculous near miss. Yesterday’s failed attempted drone ship landing was far more difficult.

The Falcon Heavy could usher in a new era in space exploration—and a new space race. While NASA explores like no other agency, in the 50 years since the first moon landing, it has not matched that singular achievement. The Falcon Heavy not only spurs NASA to complete SLS, but it also gives the agency another option to send humans to the Moon and beyond.

For now, though, consider the firsts that today’s launch embodies. Just a few years ago, SpaceX was the first to fly a reusable, tail-landing rocket that can deliver a satellite or replenish the space station. Now they have successfully flown a rocket capable of taking humans beyond Earth orbit, a system that is totally reusable. In fact, SpaceX is the first to attempt such a thing.

—Chris Schmidt, NOVA senior producer

WHAT’S ON YOUR MIND

In response to our post last week of the NOVA Lens newsletter on Cape Town’s water crisis, Gary Clatt wrote :

gary-clatt
Here’s what the asteroid’s path looks like.

Thanks, Gary! You’re smart to think of overpopulation as a concern. This issue is a bit nuanced! Certainly increased urbanization is hard on cities that have limitations when it comes to water and other resources. However, population growth as a whole plays only a small role in the climate situation altogether. Here’s an article from Vox that might interest you.

WHAT’S ON OUR MIND

NOVA’s Education and Outreach Manager, Ralph Bouquet, offers this salute to Black History Month:

Last year, I created a Twitter thread of 28 black scientists who made contributions to a variety of scientific disciplines—from designing the first moon-based space observatory to creating treatments for leprosy. There were common themes in many of their stories. Many of the scientists were barred from attending top university and research institutions, forced to take entry-level jobs despite their education and experience, and many died without their contributions to science being fully acknowledged and celebrated.

Despite the narrative that we often hear of brave individuals successfully overcoming racism and segregation, the reality is that they accomplished what they did despite the combination of systemic and social barriers that hampered every aspect of their work and personal lives.

Alice Ball’s treatment for leprosy was credited to a white chemist for over 80 years, Charles Drew organized the first large-scale blood bank and then resigned when he was told that black people were excluded from donating blood, and Percy Julian had to go overseas to complete his PhD in chemistry after Harvard would not allow him to teach white students. And for every one of these success stories, there were so many others with similar talents and passion who never even got a chance to begin their scholarly pursuits.

Where would we be now if there were more Patricia Baths, and Jane C. Wrights, and William Hintons? Black History Month is an opportunity to reflect on the stories and achievements that are often left uncelebrated in science, but it should also remind us that many of the traditional narratives of who “does” science were largely shaped by the deliberate and systemic exclusion of many groups of people.

—Ralph Bouquet, NOVA Education and Outreach Manager

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