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Science

1,585 cards. Each one is a 40-second story with a five-minute read behind it. Page 21 of 27.

1201. A Delft cloth merchant found microbes and hid how he did itAntonie van Leeuwenhoek sold linen and ribbon in Delft and wanted a better look at his thread. His homemade lenses revealed bacteria, sperm cells and red blood cells, yet he guard…
1202. Handed fourteen open problems, a stateless student solved them all within monthsAround 1949, two leading mathematicians in Nancy showed a newcomer their latest paper, which closed with 14 unsolved questions. Within a few months Alexander Grothendieck had inve…
1203. Before crossing the Americas, Humboldt was a mine inspector who paid for a miners' schoolLong before he climbed higher than any Westerner had gone, Alexander von Humboldt inspected Prussian mines. In his first year, gold ore output beat the previous eight years combin…
1204. Alfred Kinsey spent two decades measuring gall wasps before he studied peopleSome 5 million of the insects in the American Museum of Natural History are gall wasps, all gathered by one man. Alfred Kinsey took 26 measurements of each of hundreds of thousand…
1205. The famous merchant of death obituary may never have been printedThe tale goes that a French paper mistook his brother's death for Alfred Nobel's in 1888 and branded him the merchant of death, shaming him into founding the prizes. Historians ca…
1206. Wallace lost his Amazon collection to fire at sea, then sailed eastIn 1852, twenty-five days out from Brazil, the cargo of Alfred Russel Wallace's ship caught fire. Two years of his finest Amazon specimens went down, and he drifted ten days in an…
1207. A lecture invitation put Alfred Tarski on the last ship from PolandIn August 1939 the logician Alfred Tarski sailed for a congress at Harvard on what proved the final ship from Poland to America before the invasion. He went reluctantly, leaving h…
1208. Avogadro's big idea was ignored until four years after he diedIn 1811 a provincial physics teacher proposed that equal volumes of any gas, at the same temperature and pressure, hold equal numbers of molecules. Almost nobody paid attention. O…
1209. For 1,400 years anatomists kept finding holes in the heart that weren't thereGalen's theory needed tiny openings between the heart's two ventricles, and generation after generation of anatomists dutifully reported seeing them. Andreas Vesalius simply admit…
1210. Every algorithm carries the name of a ninth-century scholar from KhwarazmWhen Europeans translated a Baghdad arithmetic book into Latin in the 12th century, its author's name came out as Algoritmi. That garbled label became our word algorithm, and the …
1211. A monkey chewing lute strings pointed a Cordoba surgeon toward dissolving stitchesAl-Zahrawi, a tenth-century surgeon in Cordoba, reportedly noticed that his pet monkey had eaten the gut strings of his oud and digested them. Catgut, he realised, was a natural m…
1212. Alexander Graham Bell's telephone began with a book he misreadAs a teenager, Alexander Bell struggled through a French edition of Helmholtz's work on sound and wrongly concluded the German scientist had sent vowels electrically. If vowels co…
1213. Before cracking Enigma, a teenage Turing cycled 60 miles to reach schoolHis first day at Sherborne School fell during the 1926 General Strike, with no trains running. Thirteen-year-old Alan Turing simply got on his bicycle and rode alone from Southamp…
1214. Michelson chased the speed of light for fifty years because it was funAsked why he devoted his life to light, Albert Michelson reputedly answered that it was so much fun. He timed beams bouncing between California mountains 22 miles apart, fought fo…
1215. Einstein promised his Nobel money to his ex-wife before he had won itWhen Albert Einstein and Mileva Marić divorced on 14 February 1919, part of the settlement said that if he ever won a Nobel Prize, the cash would go to her. It was a bet on his ow…
1216. The first battery grew out of an argument about frogs' legsLuigi Galvani believed twitching frog legs revealed a special animal electricity. Alessandro Volta suspected the frog was merely a detector and the real source was the two differe…
1217. Fleming paid lab staff threepence per tear, years before penicillinIn 1921 Alexander Fleming noticed that a drop of his own runny-nose mucus dissolved bacteria on a culture plate. To test other fluids, his team spent weeks squeezing lemons into t…
1218. The Baghdad doctor who chose a hospital site by watching meat rotAsked to build the largest hospital of the Abbasid Caliphate, the Persian physician al-Razi reportedly hung pieces of fresh meat around Baghdad and picked the spot where they spoi…
1219. For two centuries, the famous portrait of Legendre showed the wrong manTextbooks, paintings and articles long illustrated the mathematician Adrien-Marie Legendre with a profile sketch labelled simply Legendre. In 2005 someone noticed it actually depi…
1220. Al-Biruni reasoned his way to an unknown continent across the oceanIn 1037, centuries before Columbus sailed, the Persian scholar al-Biruni argued that land must lie in the great ocean between Asia and Europe. His logic was geometric: Afro-Eurasi…
1221. Is there really a scientific method? Some scientists call it a mythSchoolbooks present it as a neat recipe: observe, hypothesise, test, conclude. Yet in 1975 Paul Feyerabend published Against Method, denying that science follows any universal rul…
1222. Why scientists deliberately build wrong versions of the worldJohn von Neumann claimed the sciences barely try to explain anything; mostly they make models, mathematical constructs justified only because they work. Every model is a simplifie…
1223. Just a theory? In science that phrase gets things backwardsIn everyday talk a theory is a hunch. In a laboratory it means almost the opposite: an explanation that has survived repeated testing, draws on many independent lines of support a…
1224. Tree rings let scientists measure rainfall from centuries before thermometersQuantitative research runs on measurement, but some things cannot be measured directly. So researchers use proxies: the width of a tree's growth rings, for instance, reliably trac…
1225. The word scientist was coined in 1834, in a review of a woman's bookFor centuries people who studied nature were called natural philosophers or men of science. In 1834 William Whewell introduced the word scientist while reviewing On the Connexion …
1226. A scientific law tells you what happens, never why it happensNewton's laws, conservation of energy and the laws of thermodynamics all summarise what repeated observation shows, often in a single equation. Unlike theories, they offer no mech…
1227. Information science was named in 1955, but its questions date back to AssyriaThe phrase information science first appeared in 1955, yet people were analysing and organising knowledge at least as far back as the Assyrian Empire. Today the field studies how …
1228. One lab freezer can use as much power as a householdAn ultra-cold laboratory freezer held at minus 80 degrees Celsius can consume about 25 kilowatt-hours a day, roughly what a family home uses. Nudging it to minus 70 cuts energy us…
1229. Methodology is not a fancy word for method, most theorists insistA method is a planned procedure for reaching a goal, like testing a claim. Methodology, in the strict sense, is the study of such procedures: when to use which one and what hidden…
1230. The Latin root of nature literally meant birthNature comes from the Latin natura, meaning innate character and, originally, birth, and it translated the Greek physis, the root of physics. Over the centuries the idea has shift…
1231. Checking a tyre's pressure changes the pressure you are measuringTo read the air pressure in a car tyre, you have to let a little air out, so the act of measuring alters the thing measured. Scientists call this the observer effect. Every observ…
1232. Some researchers train as paramedics just to understand paramedicsQualitative researchers want to know how people experience their world, not just how often something happens. That can mean joining the group under study; one example trains as an…
1233. One of the earliest controlled trials may be a diet test in DanielIn the first chapter of the Book of Daniel, Daniel and his companions ask for ten days on vegetables and water while other young men eat from the king's table, and the steward jud…
1234. Long fieldwork reveals the gap between what people say and doA one-off survey can return neat, consistent answers. Spend months or years living alongside a community, though, and the contradictions surface: the official rules on one side, a…
1235. Data literally means things given, and it can outlast its disksThe Latin datum meant something given, and English borrowed the plural in 1645. Three centuries later, in 1946, it came to mean computer information. Now science produces so much …
1236. Magna Carta demanded one measure of ale for all of EnglandAmong the promises barons extracted from King John in 1215 was a surprisingly practical one. Clause 35 of Magna Carta required a single measure for wine, ale and corn throughout t…
1237. For decades America ran on two slightly different feetUntil recently the United States used two feet. The international foot, fixed in 1959, is exactly 0.3048 metres; the older survey foot, kept for land mapping, is a hair longer. Th…
1238. The volt was sized to match a telegraph battery cellWhen scientists fixed the volt in 1881, they chose a value close to the push of a Daniell cell, the workhorse battery of telegraph lines. Today the unit is realised with arrays of…
1239. Why the weekday planets skip around instead of following their sky orderOur days honour seven classical sky wanderers, the Sun, the Moon and five planets, yet not in their traditional order of distance. Each day's planet sits three places along that o…
1240. The words year and hour grew from the same ancient rootEnglish year, German Jahr and Old Norse ár all trace back to a Proto-Indo-European word meaning year or season. The same ancestor produced Greek hora, a season or stretch of time,…
1241. The sievert and the gray are both joules per kilogram, yet mean different thingsOn paper, the gray and the sievert are identical: one joule of energy per kilogram. But the gray records physical energy deposited in matter, while the sievert estimates the long-…
1242. A whole sphere contains about 12.57 steradians, the unit of solid angleA radian measures a slice of a circle; a steradian measures a cone's worth of a sphere. Stand at the centre of any sphere and the whole surrounding view spans four pi steradians, …
1243. It takes a 16-tesla magnet to make a living frog floatA fridge magnet manages about 5 millitesla. A hospital MRI scanner works at 1.5 to 3 tesla. Push to 16 tesla and the water in a frog's body is repelled strongly enough to levitate…
1244. Planck units measure the universe using nature's constants instead of metal barsMost units start with an arbitrary object, a bar or a weight. In 1899 Max Planck proposed a set built only from universal constants: the speed of light, the gravitational constant…
1245. The pound's abbreviation lb comes from a Roman word meaning balanceWhy is pound written lb? Because the unit descends from the Roman libra, a word for scales, and its full phrase libra pondo, weight measured by the balance, gave English the word …
1246. The radian is officially equal to the number one, and physics teachers hate itWrap a circle's radius around its edge and the angle you mark out is one radian. Since the 2019 update of the SI, the radian has been defined as exactly 1, a pure number. That mak…
1247. A second is officially 9,192,631,770 ticks of a caesium atomFor most of history a second was a slice of Earth's spin, one 86,400th of a day. Since 1967 it has been defined by caesium-133 atoms, whose ground-state transition oscillates exac…
1248. Before the siemens, electrical conductance was measured in mhos, ohm spelled backwardsIn 1883 Lord Kelvin suggested a joke of a name for the reciprocal of resistance: mho, ohm reversed, with an upside-down omega as its symbol. The official SI unit today is the siem…
1249. The nautical mile began as a sliver of the globe and ended as 1,852 metresSailors and pilots still measure distance in a unit that was meant to match one minute of latitude. Sixty of those minutes make a degree, so the planet's pole-to-pole girth comes …
1250. An apple weighs about two newtons, which feels like a fitting tributeHold a medium apple of 200 grams and your palm is resisting roughly two newtons of pull. The unit of force carries Isaac Newton's name because it falls straight out of his second …
1251. Before the ohm was a formula, it was a tube of mercuryFor decades the standard of electrical resistance was a slender glass tube filled with mercury, cut to a precise length and chilled to freezing point. Telegraph engineers needed a…
1252. Why astronomers measure the sky in parsecs rather than light-yearsWatch a nearby star from opposite sides of Earth's orbit and it shifts ever so slightly against the far background. Turn that tiny wobble upside down and you have its distance in …
1253. The pascal is so tiny that engineers almost never use it aloneOne pascal is the pressure of a single newton spread across a whole square metre, which is almost nothing. So the unit usually travels with a prefix: hectopascals on the weather m…
1254. A mole is just a chemist's dozen, only 602 sextillion times biggerA mole works exactly like a dozen or a pair: a name for a set number of things. The catch is the number. One mole holds precisely 602,214,076,000,000,000,000,000 particles, becaus…
1255. Astronomers count five different months, and none of them fits the calendarFrom one full moon to the next takes about 29.53 days, yet the Moon completes an orbit relative to the stars in just 27.32. Astronomers distinguish five kinds of month, most first…
1256. What happens to physics when the speed of light simply equals onePhysicists sometimes declare that the speed of light is exactly 1, with no metres or seconds attached. Einstein's famous equation then shrinks to E = m, because mass and energy be…
1257. Lord Kelvin located absolute zero with a footnote calculationIn 1848 William Thomson, later Lord Kelvin, published a temperature scale that did not work out. Tucked into a footnote, though, he calculated the coldest possible temperature at …
1258. For 130 years, the kilogram was a single metal cylinderFrom 1889 until 2019, the world's kilogram was a specific lump of platinum and iridium: whatever it weighed was, by definition, exactly one kilogram. Now the unit rests on a const…
1259. The astronomer who first measured a star's distance avoided light-yearsIn 1838 Friedrich Bessel became the first to measure the distance to another star, and noted that its light takes about 10.3 years to reach us. Yet he never used that as a unit. L…
1260. For six decades, a litre was slightly bigger than a cubic decimetreBetween 1901 and 1964, a litre was defined as the space filled by one kilogram of pure water. The trouble was that the official kilogram cylinder turned out about 28 parts per mil…

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