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.
Description
One smoot is equal to Oliver Smoot's height at the time of the prank, . The bridge's length was measured to be "+/− 1 εar" with the "+/−" showing
measurement uncertainty
In metrology, measurement uncertainty is the expression of the statistical dispersion of the values attributed to a measured quantity. All measurements are subject to uncertainty and a measurement result is complete only when it is accompanied by ...
and spelled with an
epsilon
Epsilon (, ; uppercase , lowercase or lunate ; el, έψιλον) is the fifth letter of the Greek alphabet, corresponding phonetically to a mid front unrounded vowel or . In the system of Greek numerals it also has the value five. It was der ...
to further indicate possible error in the measurement.
Over the years the "+/−" portion and "ε" spelling have gone astray in many citations, including some markings at the site itself, but the "+/−" is recorded on a 50th-anniversary plaque at the bridge's end.
History

Oliver Smoot was selected by the fraternity pledgemaster because he was the pledge deemed shortest (thereby making measuring the bridge the most labor-intensive), and "most scientifically named."
To implement his use as a unit of measure, 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 so much exercise and was carried thereafter by the fraternity brothers to each new position.
[MIT Celebrates 50th Smoot-aversary with Party, Volunteerism, & Plaque. Oct. 4, 2008]
/ref>
Oliver Smoot graduated from MIT with the class of 1962, became a lawyer, and later became chairman of the American National Standards Institute
The American National Standards Institute (ANSI ) is a private non-profit organization that oversees the development of voluntary consensus standards for products, services, processes, systems, and personnel in the United States. The organi ...
(ANSI, 2001–02) and then, president of the International Organization for Standardization (ISO, 2003–04). He is a "distant relative" of Nobel Prize in Physics winner George Smoot.
Public knowledge and interest in the story began when ''Holiday
A holiday is a day set aside by custom or by law on which normal activities, especially business or work including school, are suspended or reduced. Generally, holidays are intended to allow individuals to celebrate or commemorate an event or tra ...
'' investigated the marks on the bridge years later, and published an interview with Smoot. The prank's fiftieth anniversary was commemorated on October 4, 2008, as Smoot Celebration Day at MIT, which Smoot attended.
In 2011, "smoot" was one of the 10,000 new words added to the fifth edition of the '' American Heritage Dictionary''.
A 2016 April Fools' Day article by the MIT Alumni Association announced that MIT would recalibrate the smoot to and the ear to , and the bridge would thus be 372 smoots give or take 11 ears.
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.
Practical use
The bridge is marked with painted markings indicating how many smoots there are from where the sidewalk begins on the Boston river bank, and with a number every ten smoots. The marks are repainted each semester by the incoming associate member class (similar to pledge class) of Lambda Chi Alpha.
Markings typically appear every , but additional marks appear at other numbers in between. For example, the mark is accompanied by a mark for 69. The mark is accompanied by the words "Halfway to Hell" and an arrow pointing towards MIT. In recent years graduating classes have begun to paint a special mark for their graduating year.
The markings are recognized as milestones on the bridge, to the degree that during bridge renovations in the 1980s, the Cambridge police department requested that the markings be restored, as they were routinely used in police reports to identify locations on the bridge. The renovators at the Massachusetts Highway Department also scored the concrete surface of the sidewalk on the bridge at intervals instead of the conventional . The Lambda Zeta (MIT) chapter of Lambda Chi Alpha, which created the smoot markings, continues to repaint the markings once or twice per year.
Starting in 2011, Google Earth
Google Earth is a computer program that renders a 3D computer graphics, 3D representation of Earth based primarily on satellite imagery. The program maps the Earth by superimposition, superimposing satellite images, aerial photography, and geog ...
enabled the ability to measure distance using smoots, with the standard length of 5 feet 7 inches.
MIT's student-run college radio
Campus radio (also known as college radio, university radio or student radio) is a type of radio station that is run by the students of a college, university or other educational institution. Programming may be exclusively created or produced ...
station, WMBR
WMBR is the Massachusetts Institute of Technology's student-run college radio station, licensed to Cambridge, Massachusetts, and broadcasting on 88.1 FM. It is all-volunteer and funded by listener donations and MIT funds. Both students and commun ...
, broadcasts at a wavelength of , ''i.e.'' 88.1 MHz.
See also
* List of humorous units of measurement
* List of unusual units of measurement
References
External links
The smoot as a unit of length
*
The Smoot story, in Oliver Smoot's own words
*
A December, 2005 National Public Radio Interview with Oliver Smoot upon his retirement
What's A Smoot?
NPR.org
{{MIT
Units of length
Human-based units of measurement
Massachusetts culture
Massachusetts Institute of Technology student life
Lambda Chi Alpha
Eponyms
1958 introductions
University folklore