In 1948, the war had ended, and Joseph Woodland was back on campus. After spending a couple of years working on the Manhattan Project, he had come back to Drexel to finish his bachelor's degree and start life as a grad student. Almost as soon as he had started academic work again, though, he left school to work on a new secret project.

Woodland's fellow grad student, Bernard Silver, had heard a grocery executive say that his industry needed a way to track the products that they sold. Together, Silver and Woodland started working on an answer. Their first prototype worked fine, but it was too expensive to scale. Woodland had a little money saved up so he cashed it and left school in the winter of 1948.

He set up shop in Miami Beach—perhaps a self-serving choice, given its climatic advantages over Philadelphia in the winter, but a fortuitous one. One day on the beach, he had an idea for how to visually code items's identities. As he told The New York Times:

I poked my four fingers into the sand and for whatever reason—I didn't know—I pulled my hand toward me and drew four lines. I said: 'Golly! Now I have four lines, and they could be wide lines and narrow lines instead of dots and dashes.'

In 1952, he and Silver would patent a "classifying apparatus and method"—what today we'd call a bar code. Woodland and Silver's design wasn't quite like the barcodes on produce now though. The two of them stretched the lines into a circle, which could be scanned from any angle. But the machine they rigged up to read it required a hugely bright lamp—500 watts—and a special tube to convert the light into code. They tried to get a grocery store interested, but no one bit. The patent was sold for next to nothing—$15,000, or about $115,000 in 2014 dollars—and ended up with RCA.

A decade later, however, lasers existed, and grocery manufacturers were begging tech companies for something exactly like what Silver and Woodland had already invented. RCA trotted out the old design. Woodland now worked for IBM. Woodland told the grocery stores: "That was a very good idea when I had it back in 1949." But IBM now had a better one—a rectangular product code system that took up less space on packaging and would be easier on printers. In 1974, a cashier at Marsh's supermarket, a UPC test facility, scanned a pack of gum—the first item sold with a UPC code.

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