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Technology

1,389 cards. Each one is a 40-second story with a five-minute read behind it. Page 21 of 24.

1201. Modern detergent was born from a wartime shortage of soap fatsSoap has washed clothes since Sumerian times, around 2,500 BC. But when the First World War left Germany short of fats, chemists turned to coal tar for substitutes. Those early ef…
1202. A carpenter was originally a maker of carriages, not housesCarpenter traces back through Old French to the Latin carpentarius, a maker of carriages. English once had its own word for a builder in wood, wright, related to work, and it surv…
1203. People fired clay figurines thousands of years before they made potsThe oldest known ceramics, from southern central Europe and at least 26,000 years old, are sculpted figures rather than dishes. Everyday pottery became common only around 10,000 y…
1204. Henry Ford turned car-factory sawdust into the Kingsford charcoal briquetteBackyard barbecue briquettes owe a debt to the car industry. Ellsworth Zwoyer of Pennsylvania patented the American briquette in 1897, but Henry Ford popularised it by feeding lef…
1205. Fewer than one in a hundred chemical plant designs ever gets builtBefore a new chemical plant rises, engineers sketch dozens of alternatives, and typically under 1 percent of design ideas reach commercial use. Cost studies kill most of them earl…
1206. A Roman recipe for underwater concrete still matches modern practiceWriting around 25 BC, the Roman architect Vitruvius advised mixing one part lime with two parts volcanic ash from Pozzuoli, near Naples, for concrete meant to sit underwater. That…
1207. Those giant power station towers are breathing out mostly water vapourThe huge waisted towers beside power stations look like smokestacks, and many people assume they pour out fumes. What rises from them is almost entirely water vapour. Their job is…
1208. Whether biofuel helps the climate depends on where its crops are grownBurning biofuel releases carbon that the crops pulled out of the air only months before, which is why it is often called carbon-neutral. Yet if forests or grasslands are cleared t…
1209. Bleaching linen once took six months and involved sour milkIn 17th-century Western Europe, whitening cloth was a slow industry. Fabric was soaked in alternating baths of lye and acid, the acid often lactic acid from soured milk, and the w…
1210. Modern candle wicks are designed to trim themselves as they burnBefore the 19th century, anyone burning a candle had to keep trimming the wick with scissors or snuffers, or it would smoke and gutter. Today's wicks are built to curl over as the…
1211. Your toothpaste and a glacier both work as abrasivesAn abrasive does not strictly need to be harder than what it wears down. Any two solids rubbed together long enough will erode each other: soft shoe soles hollow out stone steps o…
1212. Neanderthals were making glue from birch bark 200,000 years agoThree stone tools found in central Italy, about 200,000 years old, still carry traces of birch bark tar used to fix them to wooden handles. They are the oldest known hafted tools …
1213. Aqueducts are older than Rome by well over a thousand yearsAqueducts call to mind Roman arches, but the Minoans of Crete were probably building them around 2000 BC. By the 7th century BC the Assyrians had run an 80-kilometre limestone cha…
1214. Ford's moving assembly line was inspired by a Chicago slaughterhouseThe idea behind the Model T production line came from a place that took things apart. After watching carcasses glide along a conveyor at a Chicago meatpacker, with each worker cut…
1215. Ancient Egyptian jewellers made wire by pulling metal strips through stone beadsLong before anyone drew wire through a steel die, Egyptian craftsmen of the 2nd Dynasty, nearly 5,000 years ago, cut strips from metal sheet and tugged them through holes in stone…
1216. Signal processing quietly cleans up almost every sound and picture you consumeWhen a phone call sounds clear despite a noisy street, or a night photo comes out less grainy than it should, signal processing is doing the work. The field treats sound, images, …
1217. Signal-to-noise ratio measures how far a message stands out from the hissEvery radio broadcast, radar echo, photograph and recording carries some unwanted background along with the part you care about. Engineers boil the contest down to one number, the…
1218. A flicked switch bounces several times before it settles, and organists love itPress a light switch and it seems to snap cleanly from off to on. Inside, the springy metal contacts actually slam together and rebound a few times, sending a stutter of pulses be…
1219. Aircraft run on 400 hertz power because it makes transformers lighterPlanes and much military gear use electricity alternating 400 times a second, far faster than household mains. The reason is weight. A transformer handling a given amount of power…
1220. The vacuum tube grew out of the light bulb and created electronicsHeat a filament inside an airless glass bulb and it sheds electrons. Add a positively charged plate and they flow one way only. That trick, first packaged as a practical device in…
1221. Whale song and microwave ovens both rely on waveguidesA layer of ocean called the SOFAR channel traps sound so well that whale calls can travel enormous distances through it. Engineers build the same kind of trap on purpose. A wavegu…
1222. Why people call the TV remote a clicker: early ones really clickedThe first popular wireless TV remote had no batteries for its signal. Pressing a button made a tiny hammer strike a metal bar, which rang at a pitch too high for people to hear, a…
1223. The humble resistor spans more than nine orders of magnitude in valueFew components are plainer than a resistor, a two-legged part whose whole job is to get in the way of current. Yet commercial resistors are made in values ranging across more than…
1224. Roughly 13 sextillion MOSFETs were made between 1960 and 2018One kind of switch dominates the modern world so thoroughly that it makes up at least 99.9 percent of all transistors ever built. An estimated 13 sextillion of these MOSFETs were …
1225. Every sensor nudges the very thing it is trying to measureDrop a room-temperature thermometer into hot coffee and the reading is already slightly wrong, because the glass has cooled the drink while the drink warms the glass. Sensors alwa…
1226. Every electronic filter is a compromise between flat, sharp and smoothAn ideal filter would let wanted frequencies through untouched and block everything else instantly. No real circuit can. Engineers instead pick a family, such as Butterworth, Cheb…
1227. A fuse protects a circuit by deliberately destroying itselfInside a fuse sits a thin strip of metal designed to be the weakest link. Normal current barely warms it. Too much current heats it until it melts, breaking the circuit before wir…
1228. An inductor is a coil of wire that resists any change in currentWind a wire into a coil and it gains a stubborn streak. Try to push more current through and it pushes back; try to cut the current and it fights to keep it flowing. That electric…
1229. White LED lighting had to wait decades for someone to crack blueRed LEDs glowed on gadgets for decades, but bright white lighting needed a blue one, and blue proved stubbornly hard. When Shuji Nakamura, Hiroshi Amano and Isamu Akasaki finally …
1230. The oscilloscope lets engineers watch electricity change in real timeA multimeter tells you a voltage. An oscilloscope shows you its whole life story, drawing the signal as a moving line against time so you can see spikes, wobbles and distortion. T…
1231. The humble power brick exists mainly to keep mains voltage out of your gadgetsThat bulky box halfway along a laptop cord is doing a safety job. It steps hazardous 120- or 240-volt household current down to something gentle before any of it reaches the devic…
1232. Before circuit boards, electronics were hand-wired tangles bolted to metal pansOld radios were built by soldering each component lead to the next inside a sheet-metal pan, sometimes with a wooden base. The results were heavy, fragile and expensive. The print…
1233. The relay let a feeble telegraph pulse travel as far as anyone wantedTelegraph signals faded over long wires until someone had a clever idea: let the weak incoming current flip a switch that sends a fresh, strong copy down the next stretch. That sw…
1234. Unplugging and replugging a connector really can fix it, and here is whyThe old trick of pulling a plug out and pushing it back in has a physical basis. Metal contacts slowly grow a thin film of corrosion that raises resistance and causes flaky connec…
1235. The 160-character text limit came from an engineer counting letters at homeIn 1984, Friedhelm Hillebrand of Deutsche Telekom sat at his home typewriter writing random sentences and tallying every letter, digit, space and punctuation mark. Nearly every me…
1236. The first capacitor was a jar of water that delivered a brutal shockIn October 1745, Ewald Georg von Kleist ran a wire from an electrostatic generator into water held in a glass jar. When he touched the wire, the jolt was far worse than anything t…
1237. The hard part of a circuit breaker is killing the sparkOpening a switch sounds simple, yet pulling two contacts apart while a large current flows makes the electricity leap the gap as a glowing arc. Left alone, that arc can vaporise m…
1238. Designing an electronic circuit starts with boxes whose insides are ignoredBefore an engineer picks a single resistor, a new circuit usually exists as a diagram of empty boxes. Each box states a job, such as amplify, filter or power, with no thought yet …
1239. Why shops once sorted gadgets into black, brown and white goodsWalk into an American electronics shop decades ago and the radios, televisions and stereos were black goods, named for their dark casings. British sellers called the same things b…
1240. The diode is an electrical one-way valve with a two-path nameA diode lets current flow one way and all but blocks it the other, much like a check valve in plumbing. That humble trick turns household alternating current into the steady direc…
1241. How the humble book, folded from awkward scrolls, won the ancient worldFor centuries the written word came rolled up, and finding a passage near the far end meant winding through everything before it. The fix was to fold the roll into pages and bind …
1242. A dial-up modem was secretly playing a very fast tune to send dataOld telephone lines were built for voices, not for zeros and ones, so computers talked over them by singing. A modem turned pairs of bits into distinct tones, like an instrument w…
1243. The oldest recordings of a human voice waited 150 years to be heardIn 1857 a Parisian inventor captured sound waves as wavy lines scratched through soot on paper. His machine could record but never play back; it was meant only for looking at soun…
1244. HAL's dying song in 2001 came from a real Bell Labs computer demoIn 1961 an IBM 7090 at Bell Labs sang Daisy Bell in a synthetic voice. Arthur C. Clarke happened to be visiting a friend there and heard it. He was so struck that he wrote the mom…
1245. Great Wall smoke signals could warn of armies but never spell a wordChinese signallers on the Great Wall threw wolf dung onto fires to make dark smoke by day, and by the Tang dynasty a warning could travel 1,100 kilometres in a single day. Impress…
1246. Fifteen years before Bell, a German inventor's phone said the horse won't eat cucumber saladIn October 1861 Johann Philipp Reis showed the Physical Society of Frankfurt a device that turned a voice into electrical signals, and used it to transmit a deliberately odd sente…
1247. Why a satellite dish never moves, and why rain can blank the pictureA satellite dish bolted to a wall can stay pointed at one spot forever because the satellite it listens to circles Earth exactly as fast as the planet spins. Parked about 36,000 k…
1248. Charles Babbage designed a computer printer that waited until 2000 to be builtThe first computer printer was designed in the 19th century by Charles Babbage, as a mechanical output for his difference engine. Nobody actually built it until 2000. He also sket…
1249. Medieval tricksters secretly printed amulets and sold them as handwrittenBetween roughly 900 and 1444, street magicians across the Islamic world known as the Banū Sāsān printed amulets bearing Quranic verses from wooden and tin blocks. They kept the me…
1250. Gutenberg's genius was combining four old inventions, including a wine pressThe printing press that transformed Europe around 1440 was built largely from borrowed parts: a Roman-era screw press used for grapes and olives, movable type, the book format and…
1251. The word radio started as a label on telegrams before meaning broadcastsIn December 1904, the British Post Office told telegraph operators to mark messages sent without wires with the word radio. Two years later an international convention in Berlin m…
1252. Before radio stations, Europeans heard the news down telephone linesLong before radio, some European cities had telephone newspapers that piped news and entertainment to paying subscribers. They could bill every listener but reached only one town,…
1253. The photocopier was born in a kitchen and rejected by IBMChester Carlson, a patent attorney with arthritis, hated copying documents by hand, so he experimented in his kitchen. In 1938 he made the first photocopy, the words 10-22-38 Asto…
1254. Podcasts had a 1965 ancestor: sales lessons on cassette for the carIn 1965 the scriptwriting firm Storycraft made hour-long audio programmes on then-new Philips cassettes so Westinghouse salespeople could learn while driving. Called Salespoint, i…
1255. British stamps still carry no country name, a privilege of going firstEvery nation's postage stamps must name the issuing country, with one exception: the United Kingdom. Britain launched the idea on 1 May 1840 with the Penny Black, bearing Queen Vi…
1256. How a secretive project called 'Purple' redefined the modern smartphoneIn 2004, a team of 1,000 employees began working on a confidential mission. What started as a potential tablet evolved into a device that would eventually sell over 3 billion unit…
1257. The 1984 California law that birthed a trillion-dollar digital economyLong before Amazon dominated your doorstep, a legislative milestone in California defined the rules of electronic commerce. What began as a specific state act has evolved into a g…
1258. The digital postman: how a store-and-forward system keeps us connectedBefore instant messaging, there was a system designed for reliability over speed. Email doesn't require you and your recipient to be online at the same time. By using a clever sto…
1259. How a failed insurance clerk built a global newspaper empireIn 1785, John Walter was unemployed after a Jamaican hurricane bankrupted his employer. Instead of retreating, he used a flawed new typesetting patent to launch The Daily Universa…
1260. The terrifying physics of the world's most destructive machinesFrom the 15-kiloton blast in Hiroshima to the 50-megaton Tsar Bomba, nuclear weapons harness the fundamental energy of the atom. Whether through fission or fusion, these devices c…

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