Three students and graduate students of the Faculty of Philosophy of Moscow State University displayed several stalls with hats in and around Red Square in the center of Moscow. This is how the “Popper Test” took place - a small social experiment conceived by three students of the Faculty of Philosophy 5 years ago. Then, standing in line at the US Consulate and discussing the search for income, they decided to try to exchange their clothes for tickets to a Yevgeny Yevtushenko concert. It turned out that American tourists are quite willing to exchange hats and jeans for tickets and souvenirs from Moscow. Two experiments ended quite successfully, one without an exchange, but with a photo shoot for Rolling Stone magazine.