There is zero historical evidence that Vikings ever wore horned helmets; the first instance of horns on Viking helmets was actually in the 19th century opera Der Ring des Nibelungen by Richard Wagner.

Starfish have no blood and instead use sea water filtered by their bodies to move nutrients around.

Humphry Davy was a brilliant British chemist and inventor known for isolating many elements, his experiments with nitrous oxide, and more. But he also had a great sense of humor and joked that his assistant Michael Faraday, also a brilliant scientist, was his greatest discovery.