Space lasers starting forest fires. A pizza parlor serving as the front for a pedophiliac cabal. Chinese bamboo-paper ballots taking the place of the real thing. The world is full of strange ideas, and it seems they get stranger by the day.

Daily Beast reporter Kelly Weill has been tracking the wacky world of conspiracy theories and what she calls “fringe cultures” for years. “I got interested in niche ideas when I was in high school,” she tells Kirkus in a by telephone, “and I never got away from them.”

That fascination has yielded the absorbing—and often disturbing—debut book Off the Edge: Flat Earthers, Conspiracy Culture, and Why People Will Believe Anything (Algonquin, Feb. 22). As its subtitle suggests, the book looks not just at the present culture’s willingness to swallow poppycock, but also at the flimflammery of bad ideas that swept the world nearly 200 years ago, rejecting Enlightenment science for superstition and anti-intellectualism.

Weill’s primary case study is the notion, disproven since the days of the Greek mathematician Eratosthenes, that the Earth is flat. There are wrinkles in that theory: Some adherents today say that the world is ringed in ice, others that the plane on which humankind dwells is infinite and just needs willing explorers to go have a look and bring back the good news.

Samuel Birley Rowbotham, the Englishman who concocted the flat Earth theory in 1838 at the young age of 22, would probably be content with either interpretation, so long as adherents contributed to his upkeep. He was a haphazardly educated idealist who, Weill writes, “liked to get high and litigate obscure political arguments.” He was also a small-scale con man who once “made steady money as a phosphorus grifter,” holding soda water to be a panacea for whatever ailed a person, before he hit on an even better idea: claiming that the Earth was flat. He turned that claim, preposterous on its face, into something approaching a religion.

It worked, and Rowbotham found intellectual—well, pseudo-intellectual—heirs who shared several attributes with him: They liked to argue, they imagined that they knew more than scientific experts (think Marjorie Taylor Greene versus Anthony Fauci), and they were often to be found on the fringes of academia or at the gates of colleges flogging their contrarian, frequently dyspeptic treatises.

Rowbotham’s heirs are still at work today, as Weill shows. One of her cases in point, figuring on Page 1 of her book, is an “offbeat guy, but a good one,” whom she met at a Flat Earth Society conference. Mike Hughes was convinced that the world was flat, of course. He was also a pretty good tinker and mechanic who spent much of his time drumming up support for a rocket by which he would launch himself into space and get a look at the pancake of a planet for himself. It would spoil the story to say what happened except to note, as Weill details, that things didn’t work out well for him.

At such conferences, Weill tells Kirkus, she observed that attendees were of all social classes, distributed broadly across age cohorts, variously educated, not outwardly unbalanced. But, she adds, they were almost all White, almost all Protestant, almost all conservative—and they tended to be an older demographic. (“Those are the people who can afford to travel to conferences,” she hazards.) And most, “despite decades of mockery,” are reasonably good-natured about the people they call “Globe Earthers” and consider to be simply misled by scientists who have their own nefarious reasons for thinking that the planet is round.

That mockery is an important element, says Weill, in the making of a flat-earther, or indeed anyone intractably wedded to just about any conspiracy theory. Mockery for their beliefs pushes people away from others who are not like-minded, and, Weill observes, “loneliness and isolation are really powerful vectors into conspiracy thinking.” Take the case of the writer Eve Babitz, who died last December at the age of 78. A one-time counterculture icon who was everywhere on the scene, she became a recluse after suffering extensive burns in a terrible accident—and, in her loneliness, found that right-wing radio was just about her only friend, a font of oddly comforting fear and anger.

“There’s more than just radio,” Weill says. “Social media is much more powerful as a hook.” Indeed, her book takes a hard view of the algorithmic manipulation by which tech giants such as Facebook and Twitter privilege bad ideas over good ones, as long as they lure eyeballs and advertising dollars. And that’s to say nothing of Alex Jones and his legion of imitators.

Therein lies one of the most disturbing aspects of Off the Edge. Flat-earthers don’t just believe in a flat Earth. There’s a Venn diagram of outlandish thinking to chart what Weill calls “a whole package of beliefs” conveniently assembled for easy wholesale adoption. While not every flat-earther is a right-winger, she notes, most are. Most accept the premise that the 2020 presidential election was rigged against Donald Trump. Many buy the view that storming the Capitol wasn’t such a bad thing. Many are doomsday preppers, convinced that some sort of apocalypse is fast upon us and the unready will be obliterated. Most are opposed to vaccinating against Covid. Most are sympathetic to, if not believers in, the cluster of improbabilities that constitutes QAnon.

On the further end of the spectrum are the Holocaust deniers and neo-Nazis. Flat Earth may be, as Weill writes, “the ultimate incarnation of conspiratorial thinking,” rejecting science and authority in favor of what Kellyanne Conway was fond of calling “alternate facts,” but there are degrees of conspiratorial thinking that go far beyond geographical ignorance and descend into truly dark realms.

“It’s all very challenging,” Weill says. “It’s hard to deal with people who have ideas that are racist and antisemitic at the core, whose valorization is close to sociopathy.”

Still, Weill takes pains to remind her readers that conspiracy theories at their most basic level are a means by which people try to explain the inexplicable, at least to themselves: “They let us shape our fears into something we understand.” Given how many things there are to be afraid of out there, it’s small wonder that conspiracy theories and believers in them have grown logarithmically.

If isolation is the trigger by which fear becomes conspiratorial thinking, then, Weill urges, it’s important to remain open to those whose ideas have not yet metastasized into evil. “One of the best ways to help people out of a conspiratorial mindset is probably the most frustrating of all to those who have to do it,” she says, “and that’s maintaining a human connection with them.…The flat-earthers I’ve spoken to who have left the movement tell me that what helped them was to have the truth explained to them in a nonconfrontational, noncondescending way—not in the format of a debate, but with someone they know saying, ‘Let’s talk this through.’ People who love them can bring them back, and we have to make space for them to return.”

That may seem a big job with no end in sight, but it’s a necessary one. Off the Edge makes a powerful argument for why that’s so, and it’s an intriguing tour of the fun-house world that exists alongside our own.

Gregory McNamee is a contributing editor.