history
For three centuries the mechanical calculator was the high-precision instrument of arithmetic — Pascal's adding machine, Leibniz's stepped reckoner, the Brunsviga, the Curta. The engineering that solved arithmetic in brass and steel is mostly forgotten, and the institutional coll...
physics
Sand is one of the most familiar materials on Earth and one of the most poorly understood by physics. It flows like a fluid, supports weight like a solid, exhibits force chains that physicists are still arguing about, and refuses to fit into the continuum equations that describe ...
mathematics
The relationship between simple frequency ratios and a fixed-pitch keyboard is mathematically impossible to satisfy exactly. Three thousand years of music theory has been a sequence of compromises, each of which sounds wrong in some specific way that another compromise was designed to avoid.
history
The Roman road network ran 400000 kilometers across three continents and stayed in use for fifteen centuries after the empire that built it collapsed. The engineering vocabulary it developed — surveying, drainage, aggregate layering, milestones — became the foundation of every road tradition since.
mathematics
Cellular automata are the simplest possible computational systems and they exhibit some of the deepest behavior we know how to study. The schoolroom version is Conway's Game of Life. The mathematical reality is that the simplest known universal computer fits in three lines of pseudocode.
history
The schoolroom story of windmills is Don Quixote's tilting-at-them on the plains of La Mancha. The actual story is a thousand-year arc of structural and aerodynamic engineering that quietly solved the same problems we now solve again with carbon fiber and computer modeling.
history
Before mechanical refrigeration, food had a small geography and a short timeline. The shift from local to global food systems happened in a generation, was driven by chemistry that almost killed the people who ran it, and changed the human diet more than any single agricultural innovation.
mathematics
When a dog runs at a duck swimming across a pond, the dog's path traces a pursuit curve. Pierre Bouguer worked out the mathematics in 1732. The same equations describe missile guidance, predator-prey dynamics, hot-pursuit problems in epidemiology, and the spiral arms of certain galaxies.
history
The well is the oldest piece of civic infrastructure that still works the way it did when it was invented. The Bronze Age innovations that solved problems we have largely forgotten existed, the strange persistence of medieval technology into the present, and the deep-aquifer engineering that qu
mathematics
Random numbers are simultaneously the most familiar and the most subtle objects in mathematics. The century of false starts, the philosophical puzzle of what randomness even means, the practical engineering of generators that fool sophisticated tests, and the cryptographic stakes when the engin
history
In 1942, the most beautiful woman in Hollywood patented a frequency-hopping spread spectrum system that the US Navy ignored, the FCC eventually ratified, and Bluetooth, GPS, and WiFi all use today. The story of Hedy Lamarr's other career — and what it reveals about who gets to be a scientist.
science
Glaciers are solid ice that flows downhill at speeds measured in meters per year, and the explanation involves crystal physics, pressure-melting, and the strange in-between behavior of materials near their melting point. A field guide to ice that creeps.