There’s a woman in Sweden I think about sometimes. We’ve never met, but I’ve seen enough of her to know how brave she is. Her star turn happens halfway through Ten Meter Tower, a short documentary that features one or two people at a time standing on a diving-board platform that’s ten meters high, or almost 33 feet, trying to talk themselves, or one another, into jumping off. She’s blonde, fit, and the eldest of the bunch by far. Like many others that day who were part of the Gothenburg swimming-hall experiment — “a portrait of humans in doubt,” according to the directors — she’s up there alone, surrounded by a handful of cameras and microphones capturing the slightest of reactions and reflexes. Bent over, hands clasped over knees, she does some breathwork before stepping forward, all the way to the edge, meaning she’ll now receive the roughly $30 participation prize no matter what follows. Then she weighs whether the long drop into the pool is worth it. After dangling a few toes over …