Every day, billions of products are scanned at checkouts around the world, but few shoppers stop to think about the stripes on the package.
The barcode was invented by two graduate students, Norman Joseph Woodland and Bernard Silver, in the late 1940s.
According to the story, Silver had overheard the head of a grocery chain asking a dean at the college for a way to record products automatically at checkout.
Woodland, who had learned Morse code years earlier, came up with an answer while he was sitting on a beach in Miami.
He pushed his fingers into the sand and pulled them toward himself, turning dots and dashes into thin and thick lines.
The invention was patented in 1952, but it was not used in stores for more than twenty years because the equipment was too large and expensive.
In the early 1970s, the Universal Product Code, or UPC, was developed by a team at IBM, and stores finally began to adopt it.
The first product ever scanned with a UPC barcode was a pack of chewing gum, which was sold in a supermarket in Troy, Ohio, on June 26, 1974.
That pack of gum is now kept at a Smithsonian museum in Washington.