"364.4 SMOOTS ± 1 EAR" painted on the Harvard Bridge sidewalk
|Named after||Oliver R. Smoot|
|1 smoot in ...||... is equal to ...|
|imperial/US units||5 ft 7 in|
|SI units||1.702 m|
The smoot // is a nonstandard, humorous unit of length created as part of an MIT fraternity prank. It is named after Oliver R. Smoot, a fraternity pledge to Lambda Chi Alpha, who in October 1958 lay down repeatedly on the Harvard Bridge (between Boston and Cambridge, Massachusetts) so that his fraternity brothers could use his height to measure the length of the bridge.
One smoot is equal to Oliver Smoot's height at the time of the prank, 5 feet 7 inches (1.70 m). The bridge's length was measured to be 364.4 smoots (2,035 ft; 620.1 m) plus or minus one ear, with the "plus or minus" intended to express uncertainty of measurement. Over the years the "or minus" portion has gone astray in many citations, including the markings at the site itself, but is recorded on a plaque by Smoot's college class.
To implement his use as a unit of measure, Oliver Smoot repeatedly lay down on the bridge, let his companions mark his new position in chalk or paint, and then got up again. Eventually, he got tired from all this exercise and was carried thereafter by the fraternity brothers to each new position.
Oliver Smoot graduated from MIT with the class of 1962, became a lawyer, and later became chairman of the American National Standards Institute (ANSI, 2001–02) and then, president of the International Organization for Standardization (ISO, 2003–04). He is the cousin of Nobel Prize winner George Smoot. The prank's fiftieth anniversary was commemorated on October 4, 2008 as Smoot Celebration Day at MIT, which Smoot attended.
On May 7, 2016, Oliver Smoot served as Grand Marshal of the alumni parade across the bridge, celebrating the 100th anniversary of MIT's move from Boston to Cambridge.
The bridge is marked with painted markings indicating how many smoots there are from where the sidewalk begins on the Boston river bank. The marks are repainted each semester by the incoming associate member class (similar to pledge class) of Lambda Chi Alpha.
Markings typically appear every 10 smoots, but additional marks appear at other numbers in between. For example, the 70-smoot mark is accompanied by a mark for 69. The 182.2-smoot mark is accompanied by the words "Halfway to Hell" and an arrow pointing towards MIT. Each class also paints a special mark for their graduating year.
The markings are recognized as milestones on the bridge, to the degree that during the bridge renovations that occurred in the 1980s, the Cambridge police department requested that the markings be restored, as they were used routinely in police reports to identify locations on the bridge. The renovators at the Massachusetts Highway Department went one better, scoring the concrete surface of the sidewalk on the bridge at 5-foot-7-inch (1.70 m) intervals instead of the conventional 6 feet (1.8 m). The Lambda Zeta (MIT) chapter of Lambda Chi Alpha, which created the smoot markings, continues to repaint the markings once or twice per year.
Google Calculator also incorporates smoots, which it reckons at exactly 67 inches (170.18 cm). Google also used the smoot as an optional unit of measurement in their Google Earth software and Google Maps distance measurement tool. In 2014, Google introduced a new Maps interface with a measurement tool that gives distances only in feet/miles and meters/kilometers.
Specifically noting the bridge's length of 364.4 Smoots (+/− 1 ear), the plaque, a gift of the MIT Class of 1962, honors the prank's 50th anniversary.