One Universe at a Time
Quasars are supermassive black holes that are very far away. This means the study of quasars allow us to understand the earliest examples of active black holes, but it also means they can be difficult to observe. But for one quasar, its location behind a closer galaxy allows us to better determine its properties. In particular we now know it rotates very quickly.
When quantum theory is presented in popular science, it is often presented as a strange or spooky thing where particles can act like waves and waves can act like particles. It usually focuses on experiments such as the double-slit experiment where the photon or electron “knows” how the experiment is done and alters its behavior accordingly. This is rather unfortunate, because although quantum theory can seem strange, it is hardly mysterious. It basically comes down to a concept known as duality.