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When Oliver Smoot ‘62 talks to prospective MIT students, he likes to share a thing or two that he’s learned over the years. “One message,” he says, “is you really have no way of knowing what long-term impact any hour and a half’s worth of work is going to have.” He should know: as a freshman, he spent about that much time measuring the Harvard Bridge, using his body as a yardstick. What began as a pledge task for Lambda Chi Alpha (LCA) in 1958 has become permanently etched, not only into the bridge, but into MIT lore as well.

Smoot will return to MIT on October 4 to participate in a Smoot 50th-­anniversary cele­bration for students and alumni. Although he won’t be remeasuring the bridge, the festivities will include a Charles River cleanup, a plaque installation on the bridge, and a 1950s-theme bash at the MIT Museum, where Smoot will be presented with an official unit of measure: a Smoot stick. Check event details at

Anointing the Shortest Pledge

As Smoot tells it, Tom O’Connor ‘60, the LCA pledgemaster, came up with the measurement idea. He was tired of making the half-mile trek across the bridge to campus from LCA’s home in Boston without an inkling of how far he had to go at any given point. O’Connor chose Smoot because he was, at 5’ 7”, the shortest pledge, thereby making the measurement more labor-intensive. Plus, the name Smoot sounded scientific, like ampere or watt.

So on a crisp Thursday night in October, seven freshmen set to work. They planned to calibrate the bridge with a few actual Smoot lengths–having Smoot lie down and marking off the distance with chalk–and then use a string to measure the rest of the bridge. But a sophomore LCA brother happened by. He was so amused that he stayed to watch, so they had to abandon the idea of using the string altogether.

They painted marks every 10 Smoots; by the end of the bridge, Smoot was so exhausted he had to be carried along. But they finished the job. According to their calculations, the bridge was 364.4 Smoots, plus or minus an ear. They knew they couldn’t come up with a precise number, Smoot explains, so they added the plus or minus, and wrote the e in ear as an epsilon. “The epsilon referred in a cutesy way to this error measurement,” he says. And therein lies another detail that has evolved over time: the epsilon has been lost from written accounts of the story, Smoot says, and the minus sign is often omitted as well.

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Credit: courtesy of the MIT Museum

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