Number of the Day - "369" This podcast is produced by Klassic Studios. Check out our other podcasts there! Learn more about your ad choices. Visit megaphone.fm/adchoices

Benjamin Banneker, autodidacte contre l’oubli

Number of the Day - "368"This podcast is produced by Klassic Studios. Check out our other podcasts there! Learn more about your ad choices. Visit megaphone.fm/adchoices

We journey through the Gudermannian (often called Gutermannian) function, the elegant link that ties circular angles to hyperbolic angles without complex numbers. We explore how its antiderivative is the hyperbolic secant, while its inverse comes from the circular secant, and why this makes the function a natural bridge between two geometries. We'll trace its history—from Lambert’s transcendent angle to Mercator’s meridional part and the stereographic projection that underpins map projections...

Number of the Day - "367" This podcast is produced by Klassic Studios. Check out our other podcasts there! Learn more about your ad choices. Visit megaphone.fm/adchoices

Dive into the Mesozoic oceans and meet the ichthyosaurs—air-breathing, warm-blooded reptiles that redefined life underwater with dolphin-like shapes, giant eyes, and live birth. We trace their 160-million-year reign from early Triassic pioneers to their abrupt decline near the Cenomanian-Turonian boundary, and explore how climate upheaval and shifting ecosystems reshaped ancient seas, paving the way for mosasaurs. Note: This podcast was AI-generated, and sometimes AI can make mistakes. Please...

Number of the Day - "366" This podcast is produced by Klassic Studios. Check out our other podcasts there! Learn more about your ad choices. Visit megaphone.fm/adchoices

A half-century tale of a metal that was once the pinnacle of opulence and is now everywhere. Aluminum’s abundance in ore didn’t matter—refining it was brutally hard until the Hall–Héroult breakthrough in 1886. Coupled with the rise of cheap electricity, this unlocked mass production and crashed the price, transforming aluminum from precious parlorware into a universal building material. From Napoléon III’s special cutlery to airplanes, engines, and soda cans, the episode traces how utility an...

Number of the Day - "365" This podcast is produced by Klassic Studios. Check out our other podcasts there! Learn more about your ad choices. Visit megaphone.fm/adchoices

We explore Armenia’s colossal Vizhapakar dragonstones—basalt megaliths dating to the Chalcolithic around 4200–4000 BCE. Shaped as fish and cowhide figures, these markers sit at springs and irrigation corridors, revealing a sophisticated, region‑wide ritual system that tied water management to monumental labor. Through new dating and spatial analysis, we see how these 4,000+ year‑old stones encode social organization, sacred geography, and a worldview where water, ritual, and survival were dee...