How did lines drawn in beach sand become the barcode?

The barcode began as lines drawn in beach sand. In 1948, a Drexel graduate student named Bernard Silver overheard the president of a local food chain asking a dean to find a way to read product information automatically at checkout. Silver told his friend Norman Woodland, and Woodland, convinced the problem could be solved, moved into his father's apartment in Florida to work on it. His inspiration came from Morse code: on the beach, he formed his first barcode in the sand. "I just extended the dots and dashes downwards and made narrow lines and wide lines out of them," he said. To read the pattern, he adapted technology from movie soundtracks, shining a 500-watt bulb through the paper onto a light-sensing tube from a movie projector.

Woodland and Silver filed their patent in 1949 and received it in 1952, but making real use of it took more than twenty years. Woodland moved to IBM in 1951 and kept trying to interest the company; an IBM report found the idea feasible and interesting, but said processing the information would need equipment that didn't exist yet. IBM offered to buy the patent, but the offer was not accepted, and it went to Philco and then RCA. In the early 1970s RCA tested Woodland's circular 'bullseye' version in a Kroger store, and it ran into a problem: printers sometimes smeared the ink, making the circles unreadable in most orientations. A straight-bar design by George Laurer coped better, since extra ink only made the bars taller while they stayed readable, and in 1973 the grocery industry chose it.

On 26 June 1974, at a Marsh supermarket in Troy, Ohio, a ten-pack of Wrigley's Juicy Fruit gum became the first item ever scanned at a checkout, ringing up at 67 cents. Murray Eden, a consultant on the team that created the code, came up with the idea of printing the digits in plain numbers underneath the stripes, a fail-safe for whenever a scanner couldn't read the code.

Research indicates that the code's adoption stimulated innovation and contributed to the growth of international retail supply chains; decades later, their square 2D cousin, the QR code, rode the smartphone boom to an everyday ubiquity of its own.