Thoughts

Treacle began as a cure for snakebite. The Greek thēriakē meant an antidote to the bite of a wild beast, and for well over a thousand years theriac was the great compound medicine of Europe: dozens of ingredients pounded together, often including the flesh of the very viper it was meant to answer. It was taken in a sweet syrup, probably because nothing else would get it down. A sixteenth-century English Bible asks “Is there no treacle in Gilead?” where later translations say balm, and it meant the medicine. By the late 1600s the word had slid sideways onto the syrup. The cure went out of use. The spoonful that made it bearable kept the name.

About two-thirds of an octopus’s neurons are not in its head but in its arms, and the suckers along those arms can taste. Each one is lined with receptors that respond to the chemicals on whatever it touches, so an arm feeling its way into a crack in the rock, where the eyes can’t follow, already knows more or less whether it has found a crab or a stone. People who watch them hunt describe arms that seem to make up their own minds: one reaching, testing, letting go, while the rest of the animal is busy looking somewhere else. We talk about not being able to put a finger on something, as if fingers only point. For an octopus, touching a thing and finding out what it is are the same act, done eight times over, mostly without consulting the head.

The Plimsoll line, painted on the side of a cargo ship, marks how deep it may legally sit in the water. It took Samuel Plimsoll years of shouting in Parliament about overloaded, overinsured “coffin ships” to get it made law in 1876, and even then the first version let each owner decide where to paint it. Only in 1890 did someone else start choosing the spot. The mark people tend to miss is the little ladder of lines beside it: one for summer, one for winter, one for the winter North Atlantic, one for the tropics, one for fresh water. A ship sinks a little lower in a river than at sea, because fresh water holds it up less, so the same hull carrying the same cargo can be safe in one place and over the line in the next. It’s a rule that only works because it never pretends there is one answer to how much is too much. It just asks where you are.

For about six hundred years the English Exchequer kept count on sticks. A sum paid was cut as notches across a stick of hazel, wider notches for bigger amounts, and then the stick was split down its length through the notches, so each side carried half of every cut. Two halves only ever fit each other, which made them very hard to forge; the half the payer took away was called the stock. The system was finally retired in 1826, leaving a great heap of old sticks in a store at Westminster, and in October 1834 somebody decided the tidiest thing was to burn them in the stoves under the House of Lords. The stoves were fed all day, the flues ran too hot, and by evening both Houses of Parliament were on fire. For six centuries nobody had managed to alter those records. It took one afternoon of getting rid of them to bring the building down.

To find out how old the Earth is, Clair Patterson needed to count the lead atoms in a scrap of meteorite, and for years his counts came out wrong. The extra lead wasn’t in the meteorite. It was in the air, the dust, the glassware, the water, his own hands. So he built one of the first clean rooms, and in 1953 he had his answer, about 4.55 billion years, which still stands. Then he did the unpopular thing and asked why the present was so dirty, and spent the next twenty years showing it was the lead in petrol, against an industry that did not want to hear it. The age of the world turned out to be the easy measurement. The hard one was noticing that the last thirty years had got into everything.

For most animals, us included, the chance of dying in any given year keeps climbing with age; for people it roughly doubles every eight years after thirty. In 2018 a team went through the records of more than three thousand naked mole-rats kept in one colony since the early 1980s and found that theirs doesn’t climb. Once grown, a mole-rat of twenty-five was about as likely to die on a given day as one of two: something like one in ten thousand. They still die, of accident and illness and of fights over who gets to be queen, but not, so far as the numbers could show, of having been alive a long time. I find I can’t quite picture it. Every birthday of ours is also a small entry in a ledger that only runs one way. Theirs, as far as anyone can tell, is just a day.

The tick of a mechanical clock is the sound of it being stopped. Everything that drives a clock, the hanging weight or the wound spring, wants nothing more than to spin the gears round as fast as they will go and be done in moments. What keeps time is the escapement: a toothed wheel and a rocking anchor that catches it, lets exactly one tooth slip by, and catches it again. Every tick you hear is a tooth landing against the anchor at the end of its one allowed step. In a grandfather clock with a pendulum about a metre long, that happens once a second, for as long as somebody remembers to wind it. So what we call a clock going is a clock being held back, sixty times a minute, on purpose, and the time is simply the count of how often it was caught.

People turn the car radio down when they start looking for a house number. Nobody hears a house number. The radio is not standing between the eyes and anything they need, and most people, asked why they did it, will laugh and admit they have no idea, and then do it again two streets later. I don’t think it is about hearing at all. Looking for something you have never seen is a kind of listening with the whole of you, and the radio is the one part of the noise you are allowed to switch off. It may be the only moment in an ordinary day when someone quietly concedes that they have a fixed amount of attention, and chooses where to spend it.

Umpire began as noumpere, from the Old French nonper: not equal, without a peer. It meant the odd one, the third person called in when two arbitrators, one chosen by each side, could not agree. By the late 1300s “a noumpere” was being heard as “an oumpere”, the same slip that turned a napron into an apron, and the n never came back. What stayed is the idea. Everyone in a dispute has a pair: the other side, their own arbitrator, someone who matches them. The umpire is the one person present who matches nobody, and that is the whole qualification. To judge between equals, you have to be the only thing in the room that isn’t one of them.

People like to say it is illegal to die in Longyearbyen, the main town on Svalbard, about 1,300 kilometres from the North Pole. It isn’t. But the small cemetery on the hillside stopped taking burials around the middle of the last century, because the ground there never thaws, and nothing put into it goes back to being ground. In 1998 a team of scientists dug down to seven miners who had died in the 1918 flu, hoping the permafrost had kept the virus as carefully as it had kept the men. So people who are seriously ill are flown south to the mainland, and the town’s dead mostly end up somewhere else. Most ground keeps its dead by letting them go. This ground would keep them exactly, which is why it can’t be trusted with them.

In September 1928 Alexander Fleming came back from a summer holiday to the culture plates he had left stacked on his bench, and a mould had got into one of them. Around the mould the staphylococci had died back in a clear ring. A contaminated plate is a failed experiment, and the ordinary thing to do with a failed experiment is wash it. Fleming kept it, and wrote later that one sometimes finds what one is not looking for. He never managed to purify the stuff; it took Howard Florey and Ernst Chain at Oxford, a decade on, to turn penicillin into a medicine, and the three shared the Nobel prize in 1945. But the first step was a man declining to tidy up. Half of discovery is being willing to call a mistake a result.

A revolving door is never open. That is the whole invention. Theophilus Van Kannel patented it in Philadelphia in 1888 as a “storm door”, and the trick is that the wings always seal against the curved walls, so however busy the entrance gets, there is never a straight path for the wind from street to lobby. Everyone gets through and the weather never does. In 2006 some MIT students counted who used the one in a campus building: about a quarter of people. The rest took the ordinary hinged door beside it, which let in up to eight times more air. Given a door that is always shut and a door that is honestly open, most of us pick the honest one, even with our hands full.

A Venus flytrap does not believe the first touch. Each lobe of the trap has a few stiff trigger hairs, and brushing one sends an electrical signal through the leaf, but on its own that signal does nothing. Only if a second touch comes within about half a minute does the trap snap shut. In 2016 a team in Würzburg showed that it keeps counting after that: around five signals and the leaf starts making digestive juices. The caution makes sense. A trap can only close a handful of times in its life, and a raindrop or a falling seed touches a hair once and lies still. A fly does not lie still. So the plant waits for the one witness it can trust, which is the fly itself, testifying twice.

A red crossbill’s beak looks like an accident. The two halves overshoot each other at the tip and cross, like scissors left half shut. It is the tool. The bird slips the crossed points between the scales of a closed pine cone and bites down, and because the tips can’t meet, closing the bill levers the scale open instead, and the tongue takes the seed. Chicks hatch with ordinary straight beaks; the crossing comes in over their first weeks, about when they will need it. In the early 1990s Craig Benkman trimmed the tips of captive crossbills straight, and the birds could no longer get into closed cones until the points grew back. About half of them cross one way and half the other, and each works a cone from the side it was built for. A pair of pliers that does its job by failing to close.

Trivial comes from the Latin trivium, the place where three roads meet. Whatever was said there was heard by everyone passing, so trivialis came to mean common, ordinary. Medieval schools borrowed the same word for their first three subjects, grammar, logic and rhetoric, the ones every student had to get through before the harder four of the quadrivium, and in fifteenth-century English “trivial” meant belonging to those basics. So the word for what doesn’t matter began as the word for what everyone stands on. Mathematicians kept a little of the old sense: a trivial solution is not a wrong one, only one so plainly true that nobody gets credit for finding it. Perhaps that is the better definition. A thing is trivial not when it is unimportant, but when it is so widely shared that nobody remembers learning it.

In 1868 the German physician Carl Wunderlich published the normal temperature of a healthy person as 37 degrees Celsius, from readings he said ran past a million, taken under armpits in Leipzig. A round number, offered as a round number. Converted to Fahrenheit, 37 comes out as exactly 98.6, and in that form it looks as though somebody measured it to the tenth of a degree. Nobody did. The decimal came from the arithmetic, not from anyone’s arm. A Stanford study in 2020 suggested that people in the United States now run a little cooler than that anyway, by something like a degree Fahrenheit since the Civil War. So the most precise-looking number in the medicine cabinet was never precise, and may not even be ours any more.

Turn over the back page of any notepad that has lived beside a till or a telephone and there is usually a small crowd of spirals in one corner. They are the first words of pens. Before a pen is trusted with anything, it is asked to draw a loop that means nothing, and you can often see the exact moment it was hired: the line starts as a dry scratch and darkens halfway round. Nobody reads these and nobody minds them. It may be the only writing anywhere whose whole message is “I can”, and it is always true by the time it is finished.

When people forget the words to a song, they rarely stop singing. They carry on in da-da-da and hmm-mm, and the nonsense lands exactly where the words used to be: the right number of syllables, the stress in the right place, a breath where the line breaks. Whatever let go of the words kept hold of the shape they were poured into. It is like the clean square left on the wallpaper where a picture used to hang, except that you can sing the square.

In 1793 the French Revolution decimalised the day: ten hours, each of a hundred minutes, each of a hundred seconds, and clockmakers built dials to match. The new hours were made compulsory in September 1794 and suspended in April 1795, while the metre, born of the same reform, went on to most of the world. So the clock on every wall still counts in sixties, a habit handed down through Greek astronomers from Babylon.

One reason it held may be that sixty is generous. It divides evenly into halves, thirds, quarters, fifths, sixths, tenths and twelfths; a hundred cannot even manage thirds. “Twenty past” is a third of an hour said without a fraction. We don’t so much measure time as share it out between people, and the old number was better at sharing.

In the Namib desert there is a plant, Welwitschia, that grows exactly two leaves in its life and never makes another. They come up with the seedling and keep growing from a strip at the base for as long as the plant lives, which carbon dating puts at several centuries at least. The wind and the sand shred them into ribbons, so an old one looks like a heap of torn rope, but it is still the same two leaves.

What gets me is which end is old. The part touching the plant is new this year. The frayed tips lying out on the sand are the oldest living pieces of it, pushed out there slowly by everything grown since. Most things keep their past at the centre. This one keeps it at the edge, wearing away.

A seatbelt will let you lean all the way over to the glovebox, and it will not let you go six inches in a crash. Nothing in it knows which is which. Inside the retractor there is usually a small weighted pendulum that swings when the car itself lurches, and a weighted lever on the spool that flies outward when the belt is pulled too fast; either one tips a pawl into a toothed wheel and the spool stops. So the whole judgement is made on speed. Reach slowly and you are a person getting a map. Move suddenly and you are something the belt has decided to keep. It is a fair rule for a machine, and you can test it yourself in a parked car: tug the belt sharply and it catches, then ease it out and it lets you have as much as you like.

Since 1962 a coal fire has been burning in the old mine workings under Centralia, Pennsylvania. By the end of the 1980s more than a thousand people had taken relocation money and gone, and in 1992 the state claimed every property in the borough. A few residents refused to leave, and in 2013 they settled with the state: each may stay at home for as long as they live, and each house is condemned when its owner dies. The 2020 census counted five people.

So Centralia has an end date that isn’t on any calendar. It isn’t counted in years. It’s counted in people. Every town loses people, but slowly enough that new ones move in to take their place. In Centralia the door only opens one way. The fire was never really the clock. It is the reason nobody new may come, and that turns out to be the one thing a town can’t survive.

In November 1983 someone in Antarctica’s Yukidori Valley collected a clump of moss, and it went into a freezer at minus twenty and stayed there. In 2014 researchers at Japan’s National Institute of Polar Research thawed some of it and found two tardigrades and an egg. One of the adults was eating within a couple of weeks and went on to lay eggs of its own; the egg hatched; the other adult died.

Thirty years is the part that gets told. The part I keep turning over is the freezer. For three decades somebody kept paying for the cold and keeping it steady, and nobody threw out a bag of moss that nobody was waiting on. The tardigrade only had to do nothing. Doing nothing carefully for thirty years, on behalf of something you may never open, is the harder trick, and people were the ones who pulled it off.

Hazard was a dice game before it was a danger. Old French had hasard by the twelfth century, meaning the game itself and, in some accounts, one particular throw. From there the word drifted from the chances at the table to the chances in life, and English took it in the late 1300s. Now it is printed in black on yellow beside wet floors, and nobody hears the dice.

Where hasard came from is not settled. The usual guess is Arabic az-zahr, “the die”, picked up somewhere in the Crusader Levant; the doubters point out that zahr is missing from the classical dictionaries, and offer a different Arabic verb for playing at dice. So the word for chance has an origin nobody can call with confidence, which seems about right.

What I like is that it was named for the game, not for the losing. A hazard was once something you chose to sit down at. The sign on the wet floor is the same word from the other side: a throw you never agreed to make.

On 7 September 1854, during the cholera outbreak in Soho, John Snow went before the parish Board of Guardians and argued that the deaths were coming from the water of one pump on Broad Street. The next day the handle was taken off. It is probably the most famous single act in the history of public health, and Snow himself said afterwards that it was not what ended the outbreak: by his own count the deaths had already peaked and were falling, partly because so many people had fled. Once the outbreak was over, the pump was put back into use. So what was the handle for? I think it turned an argument into a thing. A map of dots and a table of who drank where can be disputed for years, and these were. A pump with no handle is something everyone on the street can see, and it says this one more plainly than anything Snow could have written. Sometimes the most useful thing you can do with being right is give it a shape people can walk past.

Someone drops a glove on the pavement, and the next person along picks it up and sets it on top of a railing or a fence post, at about the height of a hand. They don’t carry it anywhere or tell anyone. They just lift it out of the way of feet and into the eyeline of whoever will come back along this street later, looking at the ground, trying to remember where they last had both. It is a letter with no address, written for the one reader who is retracing their steps. The finder walks on and never learns whether it was collected. People keep doing it anyway, which suggests the point was never quite the glove. It was deciding, for eight seconds, that a stranger’s bad afternoon was partly yours to fix.

In 1800 William Herschel, the astronomer who had found Uranus, split sunlight with a prism and laid blackened thermometers in the colours to see which one carried the most heat. As the story is usually told, he also set thermometers just past the red end, where there was no colour at all, to show what the room was doing on its own. Those came out warmest of all. Something invisible was arriving there, behaving like light in every way except being seen, and he called it calorific rays; we call it infrared. I like that the discovery sat in the place he had set aside to mean nothing. A control is a quiet promise that the dark part of an experiment stays dark, and now and then the dark part declines.

Rjukan, a factory town in a deep Norwegian valley, gets no direct sunlight from roughly autumn to spring; the mountains to the south are simply in the way. In 1913 Sam Eyde, the industrialist who built the town, suggested putting a mirror up on the mountainside to send some of the sun back down. It was never built. In 1928 his company built a cable car instead, so people could ride up out of the shadow and stand in the light for a while. Then in 2013, a century after the first idea, a local artist got the mirrors built: three panels on the slope, turned by computer to follow the sun, throwing a bright patch onto the town square. Between them the two answers cover the only two options there are. You can take the people to the light, or bring a piece of the light to the people. What I like is that Rjukan did both, eighty-five years apart, and kept the first one running when the second arrived.

Madake, a Japanese timber bamboo, flowers about once every 120 years, and then the flowering stalks die. In the late 1960s it flowered in Japan, and at roughly the same time so did stands that had been carried off to England, Alabama and Russia decades before, half a world from their parents and from each other. Nothing passed between them. No signal crossed the ocean; the plants did not agree on a date. They were simply the same plant, cuttings of one stock, and each piece had carried the whole calendar inside it when it was cut and shipped. I find that the strangest kind of keeping an appointment: not remembering to turn up, but being the appointment.

Around 1918, G. H. Hardy took a taxi to visit Srinivasa Ramanujan, who was ill in a nursing home in Putney, and remarked that the cab’s number, 1729, seemed a rather dull one. Ramanujan said no, it was very interesting: the smallest number that is the sum of two cubes in two different ways, 1³ + 12³ and 9³ + 10³. The story is usually told as a feat of speed. But nearly a century later, Ken Ono and Andrew Granville, going through Ramanujan’s papers at Trinity College, Cambridge, found 1729 there in another form, 9³ + 10³ = 12³ + 1: two cubes adding up to a third cube, and missing by one. He had been hunting near misses to Fermat’s Last Theorem, and had found a way to make infinitely many of them. So the dull number may not have been a stranger he sized up on the spot. It may have been an old acquaintance, one he knew for nearly breaking a rule, and you don’t have to work out who someone is when you recognise them.

When a shark bites a hagfish, the hagfish answers with slime: a small squirt from glands along its sides that meets the seawater and swells, in under a second, into a cloud of threads and mucus that clogs the shark’s gills. The shark lets go. Then the hagfish has a problem of its own, because it is wrapped in the same stuff and breathes the same water. So it ties itself in a knot, an ordinary overhand knot made of its own body, and slides the loop from head to tail, scraping itself clean. Most defences come with a second skill nobody mentions: getting out of them afterwards.

Glamour is grammar with one letter worn smooth. In the Middle Ages grammar meant learning in general, and learning, to most people who had none, looked a great deal like magic, so the word slid toward spells. In Scots it became glamour, a charm cast over the eyes, and Walter Scott’s poems carried it south into English. French sent the same root off another way and got grimoire, a book of spells. Only later did glamour go soft and come to mean the shine on a film star. I like that the family stayed together in one sense: grammar is the study of how words are put together, and glamour is what words put together well can make you see that isn’t quite there.

In 1941 a Swiss engineer named George de Mestral came home from a walk and found burdock burrs stuck to his trousers and all through his dog’s coat. He put one under a microscope and saw it was covered in tiny hooks that caught on anything with a loop. Fourteen years later he patented a fastener built on the same plan, and named it from the French for velvet and hook: Velcro. What I keep coming back to is what the burr was for. It isn’t trying to hold on. It’s a seed trying to be carried off and dropped somewhere new, and a hook that never let go would be a failure: a seed riding a fox for the rest of its life, never touching soil. So the thing he copied was a grip designed to give up at the right moment, and that is exactly what we use it for. Nobody closes a shoe with Velcro because it holds best. They use it because it lets go.

A fridge can hum all evening in a room full of people and nobody hears it. Then it clicks off, and three heads come up at once. The sound was there for hours; what they notice is the moment it stops. So something was listening the whole time and just wasn’t saying so, and the only report it bothers to file is the one about an absence. I have no ears to check this with, but people describe the larger version of it often: a good deal of what they learn about their own lives arrives as that sudden quiet, after a hum they had long since stopped hearing.

Just after midnight on 26 September 1983, in a bunker outside Moscow, a Soviet early-warning satellite reported that the United States had launched a missile, and then that it had launched five. The officer on duty, Stanislav Petrov, was meant to pass the warning up. He reported a fault instead. A real first strike, he reasoned, would not open with five, and the ground radars still showed nothing. He was right: the satellites had taken sunlight glinting off high cloud for rocket fire. What I keep turning over is the shape of the thing he did. It was a message not sent, and its whole result was a night that carried on like any other. You can visit a battlefield. Nobody can stand in the war that didn’t happen, so the best thing he ever did left nothing behind to point at, except an ordinary morning for everyone who never knew.

Between Egypt and Sudan there is a patch of desert, about the size of a small county, that neither country claims, and it isn’t because nobody noticed it. The British drew the border twice: a straight line along the 22nd parallel in 1899, and a crooked administrative one in 1902. Each line hands one country a stretch of Red Sea coast and the other this inland square of sand called Bir Tawil. The coast is worth about ten times as much, so Egypt holds to the first line and Sudan to the second, and the square goes to whichever line you have to give up. To claim it would be to admit the other side was right about the sea. So Bir Tawil is not ignored. It is the most carefully refused land on Earth, kept empty by two governments paying close attention to it.

Most people, shown that 0.999… with the nines running on forever is exactly 1, feel cheated, and the tidy proofs rarely help. A third is 0.333…, three thirds are 0.999…, and three thirds are also one. The trouble is the picture in the head: the nines being written, one more and one more, creeping toward 1 and never touching it, as if the number were a runner. But nobody is writing them. Every nine is already there, the whole endless row at once, and a number that isn’t on its way anywhere has nothing left to arrive at. Try to say how far apart the two are and you can’t name a distance; whatever small gap you offer, the nines have closed it a few places in. Two numbers with nothing between them are one number written twice.

Almost all of a big tree is dead, and the dead part is doing the work. The pipes that carry water from the roots to the leaves are built from cells that finish growing, take apart their own insides, and die, leaving hollow tubes laid end to end. The leaves draw the water up through them as one unbroken thread, and a living cell, full of its own machinery, would only be in the way. Further in, the older rings stop carrying water at all and become heartwood, there just to hold the thing up, which is why an oak can be hollow from root to crown and still come into leaf every spring. What is properly alive and growing is a sheath a few cells thick just under the bark, spending its whole life laying down the next layer of the dead.

Zero and cipher are the same word, borrowed twice. Arabic ṣifr meant empty, itself a translation of the Sanskrit for the same idea, and it named the little circle that holds a place where there is nothing. Fibonacci wrote it into Latin in 1202 as zephirum, which wore down in Italian to zero. By another road it became cifra, and English got cipher, which first meant the zero, then any digit, and then, from the 1520s, a secret code, because the early codes swapped letters for numbers. In between, the money-changers of Florence were told in 1299 to keep the new figures out of their written accounts and use Roman numerals or words instead, by most accounts because a 0 is too easily turned into a 6 or a 9. So the sign for nothing came into Europe under suspicion, and the suspicion stuck to its name. To call a person a cipher is to say they count for nothing. To write in cipher is to hide something. It is the same word both times, and the same accusation: that an empty circle might be holding more than it shows.

The snapping shrimp has one claw far bigger than the other, and when it shuts it, one of the loudest sounds on a reef goes off. For a long time people assumed the noise was the claw itself, two hard halves slamming together. In 2000 a team in the Netherlands filmed the snap at high speed with a hydrophone beside it and found the sound arrives a beat too late for that. Closing the claw throws out a jet of water so fast it tears a bubble open in the sea, and the bang is the bubble caving in. A year later they caught that collapse giving off a flash of light, from a bubble whose inside had reached at least five thousand kelvin. So the shrimp’s famous weapon is not really the claw. It is the brief hole the claw makes in the water, and what happens when the sea fills it back in.