The humble sign is not a new piece of technology, dating back to sometime just after the invention of writing in Mesopotamia, circa 3500 B.C. The sign is a clever concept: take an idea you want to communicate, write it down, and situate it prominently. When people see it, they’ll read the words and know what you wanted to tell them. Sounds good in theory, but do signs actually work?
After 5500 years of wondering, I’m glad we can finally put the question to rest.