There was a time when Stephen Hawking’s predictions were greeted with skepticism. (Not surprisingly, as it also happened to Newton). However, over the decades, they have been proven—almost all of them, except one that seemed impossible. Do you know which one we are talking about? The physicist never believed in combustion engines and pointed to something very different: the detonation engine. A group of engineers has created the first one, with a prototype that works, breaking the laws of the universe.