Blog
The Optical Telegraph: France’s 18th‑Century Internet
• Claude Chappe launched a tower network in 1790s France; messages hopped 30 km at a time.
• Mechanized shutters/arms encoded alphabetic codes; operators relayed in minutes.
• Killed by electric telegraph (wires, all‑weather) and labor cost; lives on as naval semaphore and in HCI metaphors. 🏰📡 (more…)
Morse Code: The First Global Digital Language
• Morse mapped letters to short/long pulses—a human‑parseable binary.
• Born in the 1830s–40s with Samuel Morse and Alfred Vail, optimized by letter frequency.
• Powered news, finance, railways, and distress signaling (⚠️ SOS).
• Lives on in amateur radio, assistive tech, and aviation IDs; teaches compression & latency thinking.
Caloric Theory: The Useful Wrong Turn in Heat
The Caloric That Melted Away: How a Fictional Fluid Heated the 18th Century
Before energy and entropy reigned, scientists pictured heat as a fluid—caloric—that flowed from hot bodies to cold, conserved like water in pipes (see Caloric theory). The model was wrong; it was also productive. It guided apparatus design, inspired Sadi Carnot’s engine insights (1824), and set the stage for thermodynamics. 🔥 (more…)
Phrenology: The Beautiful Wrong Map of the Mind
Phrenology: The Map That Never Was
In the early 1800s, Franz Joseph Gall and Johann Spurzheim popularized phrenology—the idea that mental faculties live in discrete brain “organs” whose development bulges the skull. Practitioners palpated heads, read bumps, and claimed to diagnose character, talent, even criminality (see Phrenology). 🧠🪨 (more…)
Feature Flags: The Safety Switch of Modern Software
Feature Flags: Shipping Without Fear
Feature flags let teams deploy code dark and turn it on later for chosen users. That simple ability—decouple deploy from release—changed how software moves. Done well, flags are safety rails for experiments and rollouts; done poorly, they’re a tangle that slows everything (see Feature toggle). 🚦 (more…)
Repro Steps or It Didn’t Happen
Bug Reports That Fix Themselves: The Art of Reproducibility
A good bug report is a time machine. It takes an engineer from “I can’t see it” to “I can ship a fix” in one read. Yet issue trackers overflow with vibes—“it’s broken”—instead of evidence. This essay traces the history of bug culture from punch cards to continuous delivery, then nails down a reproducibility ritual that makes teams faster and kinder (see Software bug, Debugging). 🐞🧪 (more…)
Let’s Encrypt: The Day HTTPS Went Free
“Free as in Certs”: How Let’s Encrypt Made HTTPS the Default
For years, small sites treated HTTPS as optional—expensive certificates, manual renewals, and mysterious CSR rituals kept it rare. Then Let’s Encrypt launched public beta in 2015 and scaled in 2016 with the ACME protocol: automated, free TLS certificates on cron‑like schedules. Within a few years, web telemetry flipped: more than half of page loads arrived over HTTPS, then most (see Let’s Encrypt, Transport Layer Security). 🔐 (more…)
1/1/1983: When TCP/IP Ate ARPANET
January 1, 1983: The Flag Day That Built the Internet
At midnight on January 1, 1983, engineers did something rare: they coordinated a global protocol flip. The ARPANET, stitched together by experimental protocols like NCP, adopted TCP/IP in a planned cutover dubbed Flag Day. It was the moment many historians mark as the Internet’s birth (see History of the Internet, Transmission Control Protocol). 🌐🚩 (more…)
Aérotrain: France’s Hovertrain That Nearly Won
Hovering on Rails: The Aérotrain That Almost Floated France into the Future
In the 1960s, France courted a frictionless dream: the Aérotrain, a concrete guideway where trains skimmed on air cushions and rocketed forward with propellers or jet engines. In tests, prototypes hit 430 km/h—decades before commercial TGV speeds (see Aérotrain, Hovertrain). 🚄💨 (more…)
Pneumatic Mail: The Air‑Powered Internet of 1865–1984
When Cities Breathed Letters: The Rise and Fall of Pneumatic Mail
In the late nineteenth century, you could drop a note at lunchtime and have a typed reply before coffee. No radio, no fiber—just air. Cities from Paris to Prague, Vienna to New York, built pneumatic mail networks: underground tubes that blasted brass capsules between post offices using alternating pressure and vacuum. The idea reads like steampunk fiction; it was everyday infrastructure for more than a century (see Pneumatic tube, Pneumatic post). ✉️💨 (more…)