In the early 18th century, the citizens of Konigsberg had a puzzle. Their city, a prosperous Prussian trading hub on the Pregel River, in what is now Kaliningrad, Russia. Was built across two islands connected to each other and to the river’s north and south banks by seven bridges. The…

In 1801, a book appeared in Leipzig that almost no one could read. It was written in Latin, ran to over 400 pages, and was so dense that even accomplished mathematicians struggled to follow its arguments. Its author was twenty-four years old. He had been working on it, on and…

Ask most people what Albert Einstein won the Nobel Prize for, and they will say relativity. They are wrong. Einstein received the 1921 Nobel Prize in Physics “for his services to Theoretical Physics, and especially for his discovery of the law of the photoelectric effect.” Not a word about relativity.…

When On the Origin of Species was published in 1859, Charles Darwin expected backlash. He got it. But he also got something he had not expected: a young German zoologist who would become his most enthusiastic, most prolific, and most controversial champion on the European continent. Ernst Haeckel read Darwin’s…

In February 1962, just hours before John Glenn was set to become the first American to orbit the Earth, the astronaut made an unusual request. The electronic computers at NASA had calculated his orbital trajectory, but Glenn did not entirely trust them. The IBM machines were new, prone to glitches,…

Somewhere in your house right now, there is a device built according to a plan written in 1945. It might be the phone in your pocket. It might be the laptop on your desk. It might be the thermostat on your wall or the chip inside your car. Every one…

Sometime in the 13th century, a monk in Jerusalem needed parchment. Parchment was expensive. But there was an old book in the monastery library, written in Greek, filled with strange diagrams and dense mathematical text that nobody cared about anymore. So the monk did what monks routinely did: he scraped…

Before 1656, the best clocks in Europe drifted by about fifteen minutes every day. Think about what that means. By the end of a week, your clock was off by nearly two hours. Scheduling a meeting across town was an act of optimism. Coordinating anything at sea was essentially impossible.…

Picture a forensic investigator arriving at a crime scene. Among the first things they do – after securing the area and documenting the surroundings – is take the body’s temperature. Then they take it again thirty minutes later. From these two readings, combined with the ambient temperature of the room,…

Charles Darwin had a problem with human faces. Not his own, though his enormous beard certainly obscured most of it by the 1870s. The problem was scientific. Darwin believed that human emotions – fear, joy, anger, disgust, surprise – were not uniquely human. He believed they were inherited from our…