Katharine Burr Blodgett made a breakthrough when she discovered invisible glass

scientificamerican.com · Feb 26, 2026 · Collected from GDELT

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The 1930s prove to be an exceptional decade for research at the General Electric Company. Katharine Burr Blodgett works closely alongside her boss, Irving Langmuir, who wins the Nobel Prize in Chemistry in 1932. In 1938 Blodgett’s meticulous experiments with thin film coatings on solid surfaces lead to her most important breakthrough: nonreflecting glass. GE’s public relations machine kicks into high gear. Blodgett becomes an overnight sensation in both the scientific community and the press, which dubs her discovery “invisible glass.” The assistant to the Nobel Prize winner, long invisible herself, takes center stage.LISTEN TO THE PODCASTTRANSCRIPTOn supporting science journalismIf you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today.Episode 4 – The Breakthrough Katie Hafner: This is our fourth episode in our season about Katharine Burr Blodgett. If you haven't heard the other episodes, please do go back to the first one and start there.At 1:00 p.m. on November 10th, 1932, Irving Langmuir got a phone call. It was a reporter calling from Sweden, who said he’d heard a rumor that Langmuir was to be awarded the Nobel Prize in Chemistry.Langmuir was cautious. He’d heard nothing official. But within hours the rumor became fact. The prize was awarded for the work Langmuir had done sixteen years earlier on molecular monolayers, work that essentially invented the field of surface chemistry.A month later, Langmuir was in Stockholm with his wife and children to accept the prize.There was a whirlwind of pomp and ceremony. Banquets. Speeches. The medal.By then, Irving Langmuir was already a familiar figure inside the Nobel system. He’d been nominated again and again since 1916 — five times in physics and nine times in chemistry — by the same small circle of senior men who dominated science at the time. On his tenth chemistry nomination, the Nobel committee finally said yes .It was an old boys’ network in the most literal sense: professors nominating professors, Nobel laureates nominating future laureates, the same names circulating year after year. Langmuir belonged to that system. And the 1932 prize was Langmuir's moment - the system’s recognition of one of its own and the public affirmation of a man who had always believed in his own brilliance.After that, Langmuir’s career entered a different orbit. Still, he was a scientist through and through. And when he returned to Schenectady, he had already decided what to pursue next… or rather, what he would go back to: molecular monolayers.The Nobel Prize had cast a clarifying light backward. Monolayers were something he had set aside in favor of flashier problems, including, as we saw last week, his failed attempt to describe the inner workings of atoms.Now monolayers stood at the center of his reputation -- and they had his full attention. As soon as he got back to the lab, Langmuir suggested to Katharine Blodgett that they circle back to monolayers.And for Katharine, that decision would shape the most important science of her career.I’m Katie Hafner and this is Lost Women of Science. Today on Layers of Brilliance, what happens when the humble assistant becomes the star?The idea that oil spreads across water is ancient.Fishermen knew it.Sailors knew it.So did Benjamin Franklin, who in 1774 reported that he poured a teaspoon of oil onto a pond in England and watched it spread -- smooth as a looking glass, shimmering with color.What Franklin didn’t know—but what scientists would later begin to suspect—was just how thin that film really was.Here's Michael Petty, an engineering professor at the University of Durham in England and author of a book on Langmuir and Blodgett's work in material science.Michael Petty: If you look at, uh, the paper, uh, that, uh, Benjamin Franklin wrote describing his experiment, he says he took a teaspoon of oil and it spread out into an area of, uh, about a half an acre, something like that.And if you actually do the sums,Katie Hafner: Which is what Irving Langmuir did in 1916…Michael Petty: You can work out that his film was probably about a molecule in thickness.Katie Hafner: Langmuir found ways not only to measure that layer, but to compress it, to study how it behaved under controlled conditions — which was part of the research that earned him the Nobel Prize.Langmuir also showed that when oil spreads across water, it doesn’t thin out endlessly. The molecules spread out onto a surface to form a film just one molecule thick. Then they stop. And sit there. This process in which molecules stick to a surface rather than sinking into it, called adsorption, is as you might remember, the same one Katharine studied in her graduate work at the University of Chicago and continued to play with when she arrived at GE.Back when Katharine and Langmuir first worked on monolayers—with Katharine running most of the experiments, of course—they'd studied not just the properties of monolayers, but how to manipulate them. Like how to transfer a monolayer of oil resting on the surface of water, to a metal plate.All of this work came before the Nobel Prize.So when Langmuir returned home in the summer of 1933, the question before them was: What else can we do with these layers?Katharine got to work. She was using a metal trough that was invented in 1882 by Agnes Pockels, a self-trained German chemist. Pockels developed her trough to study what happens when substances interact on the surface of water. (We’re going to devote a whole episode to Agnes in March, by the way.)Using a modified version of Pockels’ trough, Katharine dipped solid plates in and out of the water, observing the water’s surface tension and the light reflecting from the plates. She concocted every possible type of problem to explore surface chemistry, attempting to manipulate the monolayer as it transferred from water to the solid surface.What could she do with just one monolayer, one molecule thick, other than examine how it behaved on the surface of water? She was stuck.Time and again, for about six months, Katharine was left with her invisible film staring back at her. What wasn’t she seeing?These were not experiments you could rush. They were unforgiving. They demanded steadiness, repetition, and a tolerance for failure that few people possessed. The films Katharine was working with were almost impossibly delicate.Over the years, when people who worked with Katharine Blodgett or knew her work described her, they didn’t reach first for words like brilliant or visionary.They talked instead about HOW she worked.About what it took to do the kind of science she did.And there was one word that cropped up over and over again:Michael Petty: Katharine Blodgett was a very, very patient scientist,Vincent Schaefer: In addition to her patience, of course,Eric Furst: She just had tremendous patiencePeggy Schott: PatienceGuy Suits: Persistence and patienceVincent Schaefer: One of the most important things I learned from Katie was patience.”Katie Hafner: Katharine paid attention to the smallest details, not because she was fussy – okay, maybe she was a little fussy – but because she knew that at the scale she worked on, everything mattered.But it’s at this point that we encountered a problem. And it’s not a scientific one – it’s a historical one. So far, we don’t have Katharine Blodgett’s laboratory notebooks from this period where she would have detailed the results of each experiment. We have Irving Langmuir’s notebooks, of course, and a handful of recollections from colleagues. And we have a brief description by Katharine herself, years after the fact.But what’s missing, most of all, is the real-time record of her hands at work.So the story has to be pieced together. It’s an act of reconstruction – necessarily incomplete. In effect, we have to imagine the endlessly repetitive experiments that led to the discoveries.Here’s Katharine’s co-worker of many years, Vincent Schaefer, talking about the process of doing science.Vincent Schaefer: What science is all about and how you go about doing it. And it is so different than the conception that most young people have. A lot of them think that you set out a problem. And you head toward it and you solve it. And that isn't the way it works at all. You blunder along, and you don't head for the objective. You go this way and you go that way. And very frequently a serendipitous event occurs and you have something much more important than the thing you're looking forKatie Hafner: Indeed, in an interview after her retirement, Katharine described her research process overall. She said, “You keep barking up so many wrong trees in research. It seems sometimes as if you’re going to spend your whole life barking up wrong trees. And I think there is an element of luck if you happen to bark up the right one.”And with luck, genius, and relentless patience, eventually, Katharine found the right tree to bark up. Dipping her metal plate in and out of a water trough, months after she began this set of experiments, she noticed something new. Here’s Peggy Schott.Peggy Schott: In December, 1933 when Katharine one day was working in the laboratory, she's using talcKatie Hafner: That’s ordinary talcum powder, which she used for a very simple, but important reason: the films themselves were so thin as to be invisible.Peggy Schott: She needs a visual aid to see movement, like physical movement of the layers as they're going onto the plate.Katie Hafner: In other words, she needed a way to see motion without needing to see the molecules themselves. If you sprinkle a very fine powder like talcum powder onto the surface, something magical happens:The talc grains don’t dissolve. They float on the water. And they get pushed around by changes in surface tension.So when a molecular film spreads, compresses, or gets tra