It was former US Secretary of Defense Donald Rumsfeld who once said that there are known knowns, known unknowns, and unknown unknowns. It was a clumsy way of saying that there are things we know, things we know that we don’t know, and things that we’re unaware of not knowing. The latter category could describe everything you’re about to see in this video - they’re things we didn’t know to exist until we found them, and we’re still unsure about them now!