In December 1938, a General Electric researcher named Katherine Burr Blodgett filed a patent for glass that seemed to disappear. She placed an ordinary glass slide behind a treated one and audiences couldn't see the treated pane at all — no glare, no reflection, just a hole in the air. The patent, US 2,220,860 ("Film Structure and Method of Preparation," issued November 5, 1940), described how to deposit stacks of organic molecules exactly one molecule thick onto a surface — and how to tune those stacks so that reflected light waves canceled themselves out through destructive interference.

Blodgett had already earned a place in history: in 1926 she became the first woman to receive a PhD in physics from Cambridge, working under Ernest Rutherford. At GE, she extended a technique her mentor Irving Langmuir had discovered — floating a fatty acid on water so it self-assembled into a single-molecule layer — into a method for dipping a plate through the film and picking up one layer at a time. Repeat forty-four times, and you had a coating 44 molecules thick (about a wavelength of green light) that eliminated the ~8% reflection every glass surface normally produces.

Why it was almost too modern:

• She was building precisely engineered thin-film stacks at the nanometer scale — nanotechnology — decades before that word existed.
• She invented a color gauge (the "Blodgett color scale") that measured film thickness to within one molecule by looking at its interference color. Semiconductor fabs use functionally identical ellipsometry today.
• Her "Langmuir-Blodgett films" are still the reference method in molecular electronics, biosensors, and organic photovoltaic labs.

The war and the aftermath: Her soft organic films weren't durable enough for consumer glass, but the principle — quarter-wavelength destructive interference — was immediately weaponized. During WWII, the U.S. Navy used her coating on submarine periscopes to keep their optics from betraying position with a glint of sun. Bausch & Lomb licensed the technique. By the 1950s, hard evaporated coatings (magnesium fluoride, then dielectric multilayers) replaced the organic films but kept her physics. Blodgett later added anti-icing coatings for aircraft wings and smoke-detection screens used to spot bomber contrails.

Where the patent lives now: Every camera lens you own is stacked with 4–12 layers of anti-reflective coating descended directly from Blodgett's math. So is your eyeglass prescription, the AR coating on your phone screen that quietly boosts outdoor readability, and the "black silicon" texturing on modern solar panels that squeezes out an extra 3% efficiency. The James Webb Space Telescope's gold-coated mirrors sit inside a cascade of interference filters that Blodgett would recognize on sight. Her Langmuir-Blodgett deposition technique still turns up in bleeding-edge 2D-material research — graphene layers, MoS₂ transistors, and organic LEDs are all engineered with descendants of the trough-and-dip method she perfected on a GE lab bench in Schenectady.

Blodgett received the American Chemical Society's Garvan Medal in 1951, retired in 1963, and died in 1979 with 8 U.S. patents and one quiet superpower: she made glass vanish.