People carved it into the beams of barns to protect livestock from disease. It was scratched onto the walls of churches and houses to ward off witches. In Renaissance Europe, the square was a cure for rabies: you would write it on a piece of barley bread and feed it to the sick animal (or person).
Next time you see the word (thanks to Christopher Nolan’s film, it’s having a pop culture moment), remember: that word is the center of a 2,000-year-old puzzle that holds the universe in balance—at least according to the baker who carved it into his oven to stop it from catching fire. sator squares
Why? Because medieval Christians discovered a hidden acrostic. If you take the letters of the square and rearrange them into a cross, you can spell (Our Father) twice—once vertically and once horizontally—with the leftover letters being two A and two O (Alpha and Omega, the beginning and the end). People carved it into the beams of barns