Like almost everyone I meet over the coming three days, Foertsch switched to flat Earth ideology as a result of clicking on a YouTube video. 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. 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. He concluded the planet is round, and for the following two millennia, people mostly accepted that as truth. In the fourth century B.C., Greek scholar Aristotle observed that Earth always casts a round shadow on the moon during a lunar eclipse. 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. Then, four years ago, came the conversion he believes was more consequential: He realized he was living on a flat disc. “I used to drink vodka for breakfast and smoke cigarettes in the shower,” the homeschooling dad from South Carolina tells me. It’s a brisk afternoon, and he helpfully tilts the panel so the sun’s rays hit 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. Some speak of YouTube, a Google property, with something close to reverence.Ī man named Robert Foertsch approaches me. They owe the rapid spread of their belief that Earth is flat to the technologies of the so-called globular world. People seem unbothered by the apparent contradiction. 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. The billboard reads: “GOOGLE FLAT EARTH CLUES.” Every few minutes, a passing car slows down to honk, and the crowd erupts into cheers. A drone buzzes overhead, collecting footage.

Several of them are livestreaming the event, part of the kickoff for the Flat Earth International Conference, the largest ever summit of its kind. 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. The mood of the crowd gathered alongside a highway just outside Denver is euphoric.

Flat earther gets owned