Twentieth Century
93 episodes
#6156: Why Civilization Waited 12,000 Years to Take Off
Ancient engineers built geared computers and self-healing concrete. So why did the industrial takeoff wait until 1760?
#6152: Whatever Happened to the One-Time Pad?
The math is unbreakable. The humans are the problem. Tracing the one-time pad from 1882 codebooks to quantum key distribution.
#6102: Project Cybersyn: Chile's 1972 Telex Economy
Chile ran a national economy on telex machines and hand-drawn slides fifty years before chatbots. What actually worked?
#6081: What If You Stripped Israel Down to Its Original Architecture?
The four-room house, the volute capital, and the question of whether an indigenous Judean architecture can be recovered — or only reinvented.
#5932: What the 1964 White Paper on the Twin Towers Actually Said
Three pages from 1964 concluded a 707 impact would cause only local damage. Fire was never in the analysis.
#5917: The Women Who Were Computers Before Computers Existed
Before machines did the math, people did — and most of them were women. Reconstructing the desk of the human computer.
#5890: Fifteen Miles an Hour Through a Metal Pipe
Paris ran 427 km of pneumatic tube under its streets and moved 30 million messages a year. Then the fax machine replaced it.
#5849: Who Invented Computer Science—and Was It Ever a Trade?
The founders wanted a science of computation. We built a job credential instead—and the argument hasn't changed since 1968.
#5798: Project Sundial: Teller's 10-Gigaton Doomsday Proposal
Edward Teller proposed a 10,000-megaton bomb in 1954. The physics allowed it — the delivery problem killed it.
#5797: How Many Nuclear Tests Have There Really Been?
Three credible sources, three different numbers — and the gap isn't new explosions. It's what each one decided to count.
#5795: Digging Harbors with Nuclear Bombs: Project Plowshare
From Sedan's 104-kiloton crater to a plan for 520 bombs in the Negev — how the atomic age tried to become civil engineering.
#5794: Starfish Prime: When the US Nuked Space
In 1962, the US detonated a 1.4-megaton warhead 400 km above the Pacific. The sky turned green for 90 minutes.
#5793: Little Boy: The Untested Bomb That Changed War
The gun-type bomb was never tested — yet it was the one they trusted. What Hiroshima's design and aftermath reveal about nuclear war.
#5792: Tsar Bomba: The 50-Megaton Test That Shook the World
In 1961, the Soviets dropped the largest bomb ever built — a weapon with no military purpose, designed to be seen.
#5691: When the System Feels Rigged: A 180-Year Pattern
Life expectancy is stalling across the English-speaking world. History says that signal has appeared before — and what followed was reform or rupture.
#5663: Did the Puritans Really Hate Fun?
The Puritans banned alcohol? Invented happy hour rules? A look at what they actually did — and the 1781 hoax we still quote.
#5648: Before the Break: How Rest Became a Right
The work break wasn't handed down on a tablet—it was invented in a 1915 munitions factory by a physiologist who threatened to arrest the manager.
#5615: Philadelphia, Here I Come: Friel's Split Man on Stage
One actor can't hold Gar O'Donnell — so Brian Friel used two. Inside the 1964 play that split a man in half on stage.
#5555: Five Machines That Peaked at the Wrong Moment
Concorde, Buran, Iridium: the finest machines ever built for a paradigm that vanished while they were still on the drawing board.
#5545: Jet Engines on Bicycles: The Physics of Bad Ideas
A pulsejet strapped to a bike sounds like a fighter jet — and burns 55 gallons an hour to move one guy who could have pedaled.
#5502: Clifford Hutsell and the Storybook Houses of Dallas
A listener's childhood mystery: who designed those fantastical Lakewood houses? The answer leads to Storybook architecture.
#5499: Jerusalem's Russian Compound: 17 Acres, Three Churches
A 68-dunam walled district in central Jerusalem has been a pilgrimage campus, a prison, and a city hall. Here's how it became Russian.
#5358: Ivy League Is a Sports Conference
The Ivy League is an athletic conference, not an academic body — and that tells you everything about how university rankings actually work.
#5344: Ironworking: From Rivet Gangs to Rebar Crews
Ironworking is older than the skyscraper it built. Rivet gangs, Mohawk crews, and why Israel's cranes hide the trade.