Famed dancer Gus Solomons raises his arms through a 50 cycles/second strobe in a single photographic exposure (1960; photograph by Harold Edgerton).

Consider the strobe light.

Anyone who has partied in the past few decades should be familiar with the device. It flashes incessantly, transforming a living room into a night club.

And the party animal who developed the strobe?

Harold Edgerton in the lab with a stroboscope.

Harold "Doc" Edgerton was an engineer at MIT for the better part of the 20th century. As a graduate student in the 1920's, Edgerton perfected a method for creating repeated bright pulses of light: an electronic stroboscope.

Edgerton wasn't concerned with getting his groove on, though. He was interested in machines, and by the 1920's machine makers had a problem. Motors were capable of spinning so quickly their rotation could not easily be measured.

Stroboscopes illuminate a subject at intervals, allowing a moving object to appear momentarily frozen in place. When set fast enough they appear as constant light, and become particularly handy when synced to the same interval as a rotating subject.

When set to the right speed, the strobe appears to stop the subject in its tracks- a useful illusion. Deviations from stationarity indicate an object is spinning faster or slower than the strobe. Thus, the strobe is also a tachometer.

Edgerton took earlier stroboscopic instruments and improved on them by developing a particularly effective electronic version, one that interspersed long unlit intervals with a brief intense flash. His device found immediate popularity in industrial applications:

The Edgerton Stroboscope, because of its brilliant, short flash, has readily found its way into fields where older types of stroboscopes were not acceptable, and it is used today in some part of the design or manufacture of machines, automobiles, engines, instruments, cameras, electric motors, metal products, and textiles. The fact that some twenty engineering schools and universities are users of this instrument is further evidence of its utility in mechanical and electrical engineering.

-Radio Experimenter (1935)

Edgerton further recognized that his invention had photographic potential. An open camera will record an object moving in strobed light as an overlayed set of still images.

Golfer Densmore Shute tees off at 100 flashes/second. (1938; photograph by Harold Edgerton).

Ballet by strobelight (photograph by Harold Edgerton)

Charles Batterman diving (1955-56; photograph by Harold Edgerton)

These are technical images, insofar as one can take the flash interval as a basis for computing velocity and acceleration. But they are also art, and Edgerton is perhaps more remembered for the aesthetic qualities of his images than for the engineering prowess. I consider the stroboscope as among the finest stories of industrial technology being coopted for artistic expression*.

Pigeon in flight (1965; photograph by Harold Edgerton)

Images © 2011 Massachusetts Institute of Technology, courtesy of MIT Museum and used with permission.


*For excellent recent examples, see images by Kim Taylor and Christian Ziegler.