A middle-aged man a couple of seats away leans in to ask the pair what they are doing. Every once in a while they land on a photograph that piques their interest, enter into a brief discussion, and move on. Behind me, two men in their 20s are scrolling through images of the Earth taken from space. I’d arrived an hour earlier and found a chair six or seven rows back from the stage. I’m in central Birmingham, at the UK’s first Flat Earth convention, a weekend of lectures and workshops designed to provide believers with opportunities to engage with others who subscribe to the same hypothesis: that the Earth is not a globe, as most of us think, but some kind of plane, with edges. Few are able to explain why a conspiracy might exist, why scientists might go to such great lengths to create false evidence.

“And I’m a Flat Earther.” Other audience members offer similar anecdotes: epiphanies, followed by a complete rebuttal of their previous beliefs. A 40-something woman approaches the stage. The woman who asks another, “If they’ve lied about this, what else are they lying about?” The various conversations peter out as the open-mic session gets under way. The man at the bar chastising an acquaintance for holding on to the science he was taught at school.

The clique in the corner discussing the moon landings. Middle managers on a staff team-building exercise, perhaps.

To the casual observer, there is nothing remarkable about the crowd gathered in a convention room at a central Birmingham hotel.

Conspiracy theories about flat earth