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Cutting the Glare

Katharine Burr Blodgett’s “invisible glass” helps us see.

Camera lenses, telescopes and a host of other optical devices owe their efficiency to glare-proof glass. The material has been dubbed “invisible glass,” but its inventor, as the first female research scientist at General Electric, was very visible indeed.

Katharine Burr Blodgett was born in Schenectady, New York, in 1889, the second child of a G.E. patent attorney who died before his daughter’s birth. On a Christmas vacation at age 18, she visited the Schenectady research facilities of her father’s former employer, where her tour guide was the chemist (and future Nobel Laureate) Irving Langmuir. Langmuir encouraged the teenager to pursue her studies in science, and she did; earning a master’s degree from the University of Chicago the following spring helped Blodgett earn a spot in Langmuir’s lab. After that, except for the two years she took off to get the first physics PhD ever awarded to a woman by Cambridge University, Blodgett spent the whole of her 45-year career at G.E.

Witty and gregarious, the petite researcher-known to all at G.E. as Katie-made a big splash in the last week of 1938. That’s when the company announced Blodgett had found a way to treat glass so that 99 percent of the light hitting it would penetrate, rather than reflecting off the surface. Blodgett’s process grew from Langmuir’s discovery years earlier that when he spread certain substances on water, a film one molecule thick formed; by dipping a plate through the film and then pulling it out again, Blodgett found she could deposit single-molecule layers on solid surfaces. Coating a sheet of ordinary glass with 44 layers of liquid soap molecules virtually eliminated glare.

What the press called “invisible glass” landed Blodgett in Time, Life and The New York Times. Though the soap coating was too soft for commercial application, G.E. made Blodgett’s findings public; other researchers soon found ways of making durable films that to this day coat lenses, shop windows, picture glass and windshields. In the meanwhile, spurred by the Second World War, Blodgett turned her attention to such military applications as airplane de-icing and smokescreen machines.

Though her contributions to science, technology and G.E. have been recognized by a multitude of citations and awards, there was at least one critical omission: The author of a 1953 Science article titled “Seventy-five years of research in General Electric” admiringly mentioned almost every man to pass through the company’s labs-but not Katie Blodgett.