The UK’s Daily Mail published a news story last weekend speculating on the source of a “strange sound from the sky” that has been heard across the globe for nearly a decade. Witnesses told the Mail that what they heard sounded very much like the blast of a trumpet. And that it was so loud it shook the ground beneath them. In a sidebar, the Mail listed seven possible theories, from the unremarkable to the fantastical, that could account for the strange sound from the sky. The first six included (in order) tectonic plates grinding, atmospheric pressure, trains shunting, construction...