In social psychology or science in general, a theory cannot get proved, only confirmed until someone else will disprove it later. Due to this, the statistical relations between corruption and the quality of education, quality of democracy or company behavior are confirmed, but not proven.
Black swans had been unknown in the Roman Empire and due to this, for its citizens it would had been a complete unexpected event to find such a bird. This is why the poet Juvenal used this picture in the early 2nd Century A.D. to call ironically a faithful wife a black swan.
Only in the late 17th Century, the Dutch explorer Willem de Vlamingh discovered such swans at the west-coast of Australia. The theory that black swans not exist had been disproved and since that day, it became furthermore a synonym for an unexpected event.
What about unicorns? They really only exist in fairy-tales or we just looked at the wrong places? These legendary animals had been reported from all over the world, in the antique India and Greece, in the Bible, and of course, since the Medieval Age furthermore in Europe. Literature described them mostly as a romantic symbol for the good, as in “The Last Unicorn” and in the dark science fiction movie “Blade Runner” it is a symbol for life and freedom.
The ancestor of our modern whale, the Cetancodonta, lived on the land, before a part of this group decided to return to the sea around 30 Million years ago. Interesting, the part who stayed on land became our today’s hippos. So these land animals are the closest living family member of whales and dolphins. The whale-family has many sub-members, one of them had been discovered in 1758 by the Danish zoologist Carl Linnaeus: the Narwhal.
This medium-sized white whale lives in the North (similar to different books, which define the unicorn as animal of the winter-land); in the Canadian Arctic, around Greenland and in Russian waters. Its horn, also known as tusk, is a type of tooth, what grows outside the mouth. It can get up to three meters, what confirms the existence of the Narwhal as the unicorn, even if it is a black swan.