It’s back to school season, so here’s a short primer in Technology 101.

In 1948, Drexel graduate students Bernard Silver and Norman Woodland overheard their dean talking to the president of a local retail chain. He needed a better way to inventory all the products in his stores. The two students kicked some ideas around, and then Woodland moved home to Florida. One day while sitting on the beach, he drew some Morse code in the sand, and then expanded the dots and dashes upwards and downwards, creating a pattern of thin and fat lines separated by spaces. He then realized that if one reproduced the lines on paper and used a bright light to scan across them, one was essentially creating the inverse of an optical movie soundtrack (wherein a stationary light has alternating sized lines passed over it to transmit musical data). Flickering Lines = Coded Data. Hmmm.

Silver and Woodland refined the idea and realized that if they created these alternating lines in concentric circles, rather than straight parallel lines, data could be scanned off them in any direction. In 1952, the students applied for and received a patent for both the linear and circular data patterns, and for the equipment needed to decode them. They tried to sell it to IBM, but IBM felt the technology was too far ahead of its time. So the students sold the patent to Philco, who later sold it to RCA.

Meanwhile, a third graduate student from MIT named David Collins had spent his summers working for the Pennsylvania Railroad. After graduating, he joined GTE Sylvania and developed a system called KarTrak which used yellow and blue reflective stripes to mark and identify each car in the rail system. It was adopted by the Association of American Railroads, and became the national standard. It was later abandoned, but by then the U.S. Postal Service was testing a similar system to mark all their trucks. Finally, the Kal Kan pet food company raised their hand, asking if anyone could help them more efficiently label and track their products.

In 1970, the National Association of Food Chains, working with McKinsey, developed an 11-digit coding paradigm for every grocery product, and challenged the big technology companies to develop a universal “bar code” labeling system. The winner? RCA’s circular bulls eye pattern. It went into an 18-month test in a Kroger’s store in Cincinnati. But, in a case of old-school technology taking down a cutting-edge idea, the printing of the circular labels often resulted in smears that rendered them unreadable. So IBM came up with a simplified version using straight lines that was easier to print and handle, and it tested successfully. On June 26, 1974, in a Marsh’s Supermarket in Troy, Michigan, Mr. Clyde Dawson pulled a pack of Juicy Fruit out of his grocery basket and handed it to Ms. Sharon Buchanan, who was working the checkout. She scanned it at 8:01 AM, and successfully completed the world’s first transaction by Universal Product Code.

This morning, you may be looking at your credit card statement and wondering, “how do these college students buy all this stuff so fast?” And now you know who to blame.