Meet the flat-Earthers of the modern era

The mood of the crowd gathered alongside a highway just outside Denver is euphoric. Around 75 people stand in the brush beneath a roadside billboard with their phones out, filming one ­another and tossing around a beach ball that looks like a globe. Several of them are livestreaming the event, part of the kickoff for the Flat Earth International Conference, the largest ever summit of its kind. A drone buzzes overhead, collecting footage. Every few minutes, a passing car slows down to honk, and the crowd erupts into cheers. The billboard reads: “GOOGLE FLAT EARTH CLUES.”

This stretch of road has few landmarks beyond a Best Buy distribution center, so to direct attendees here, conference organizers gave them the coordinates on Google Earth. People seem unbothered by the apparent contradiction. They owe the rapid spread of their belief that Earth is flat to the technologies of the so-called globular world. Some speak of YouTube, a Google property, with something close to reverence.

A man named Robert Foertsch approaches me. He wears a black T-shirt and carries a large reflective sign, both urging people to “YOUTUBE TRUTH.” “Should I warm you up?” he asks. It’s a brisk afternoon, and he helpfully tilts the panel so the sun’s rays hit me. “I used to drink vodka for breakfast and smoke cigarettes in the shower,” the homeschooling dad from South Carolina tells me. First he found Jesus. Then, four years ago, came the conversion he believes was more consequential: He realized he was living on a flat disc.

I have flown to Denver to learn why a growing number of people could believe this, despite thousands of years of science showing that our planet is spherical. In the fourth century B.C., Greek scholar Aristotle observed that Earth always casts a round shadow on the moon during a lunar eclipse. He concluded the planet is round, and for the following two millennia, people mostly accepted that as truth. It took until the 1800s for the notion of a flat Earth to take hold in limited ­circles—​and until the past few years, aided largely by YouTube, for people to reject the globe in large numbers. The movement’s rise tracks with the emergence of more-dangerous conspiracy theories, like the idea that the Sandy Hook Elementary School shooting is a hoax.