#numbers
Questions about “numbers”.
128 articles
What is the oldest money in Japan?
Generations of Japanese students learned one coin as “Japan’s oldest money.” Then a single excavation shook its claim to the title.
How many times a day do we blink?
You have almost certainly closed your eyelids at least once while reading this sentence. Have you ever stopped to count how often?
Are you taller in the morning than at night?
The same person can measure a different height in the morning and at night. About 300 years ago, an English clergyman who noticed this is said to have saved several soldiers from being discharged for being too short.
How many meals a day did people eat in Edo-period Japan?
Breakfast, lunch and dinner feel like the natural order of things. But when did that “natural order” actually begin?
What’s the difference between magnitude and seismic intensity?
Two numbers come up in every earthquake report. They look alike, but they actually measure completely different things.
Can a Venus flytrap count?
What if a plant with no brain and no nerves were “counting” something as its prey crept closer? A look inside the intricate workings of a carnivorous trap.
Where does the Japanese phrase “ichika bachika” come from?
Japanese speakers say it when they leave everything to luck. But why “one” and “eight”? Why not two, or seven? The answer leads into the gambling dens of old Edo.
When was zero discovered?
Zero, the number for nothing at all, seems utterly obvious. Yet it took humanity a very long time to get hold of it.
How hot is lightning?
For the briefest instant, a single streak of light carves a path hotter than the Sun. And that deafening roar comes from the very same heat.
Why do volcanic eruptions make lightning?
Bolts of lightning flash through a towering black plume of ash. There is no thundercloud, so why does lightning strike above a volcano? The phenomenon appears even in Japanese records from the eighth century.
Is an atom mostly empty space?
Desks, air and our own bodies are all made of atoms. Peer inside an atom, though, and you find a landscape nothing like what you might imagine.
Is it true that no two snowflakes are alike?
“No two snowflakes are alike,” people say. But has anyone actually checked? Each flake, it turns out, carries a record of its journey through the sky.
Where does the word “OK” come from?
“OK” is one of the most widely understood words on Earth. It started out as a bit of wordplay among nineteenth-century newspapermen.
Was a swimsuit really banned for being too fast?
There was a time when swimming world records fell one after another, as if a dam had burst. The real star, many said, was not the swimmers but their swimsuits.
Why do auroras glow?
Curtains of light rippling across the night sky. We think of them as a polar sight, yet they were recorded in Japan as far back as the seventh century.
Where does the term “hat-trick” come from?
When a soccer player scores three goals in a game, it is a hat-trick. But what does a hat have to do with it? The answer lies in a different sport altogether.
Why is tennis scored 15, 30, 40?
Not 1, 2, 3, but 15, 30 and then 40. Behind tennis’s puzzling way of keeping score lies a mystery nearly 600 years old.
Why are rainbows round?
A rainbow in the sky is always a half circle or a smaller arc. But that shape is only part of the picture. Where did the rest of the rainbow go?
How much space junk is there?
Roughly 70 years after humanity first reached space, the things we’ve “dropped” keep piling up around Earth, mostly too small to see.
Is there really a planet where a day is longer than a year?
Right next door to Earth is a planet where our sense of time is turned upside down. There, the Sun rises in the west.
Did people in the past really die young?
Hear that life expectancy in Edo-period Japan was in the thirties, and it sounds as if 40 was already old age. But was it really?
Is the wasabi at conveyor-belt sushi the real thing?
The packet beside your plate, the pot on the counter: that nose-tingling kick may not come from a Japanese mountain stream. The ingredients list holds a surprise.
Why do magnets stick to things?
A magnet clings to the fridge door yet ignores aluminum cans and copper coins. How does a magnet choose what it sticks to?
How many hearts does an octopus have?
A heart that stops when it swims, blue blood built on copper, arms that think. The more you learn about the humble octopus, the more alien it seems.
How do bats fly in the dark?
They dart through pitch-black caves without hitting a thing and snatch tiny insects out of the air. How they do it puzzled scientists for more than 200 years.
How many hours a day do giraffes sleep?
Ever heard that giraffes hardly sleep at all? Look into it, and the answer depends a great deal on how you count sleep, and where the giraffe lives.
Why do orchestras tune to an A?
Just before a concert begins, a single note stretches out through the chatter. That ritual-like moment holds both the design of the instruments and 300 years of history.
Was the QR code invented in Japan?
From ordering at restaurants to paying at the register, those black-and-white squares are everywhere now. Their birthplace is not where you might expect.
Is the Moon really drifting away from Earth?
At about the pace your fingernails grow, the Moon is slowly taking its leave. And the price Earth pays for it turns out to be time itself.
Is it true that the specks on a strawberry aren’t seeds?
That glossy red on top of a strawberry shortcake. Through a botanist’s eyes, the part we eat as the “flesh” of the fruit turns out to be something rather unexpected.
What is the fastest animal in the world?
There is a bird that falls through the sky faster than a bullet train. But change how you compare “fast,” and some surprising creatures turn up.
Why doesn’t the stomach digest itself?
Your stomach turns meat and fish into mush. Yet the stomach itself is an organ made of flesh. How does it keep from dissolving?
Does air have weight?
You can’t see air or hold it in your hand. But if you gathered up all the air in the room you’re sitting in and put it on a scale, how far would the needle swing?
How thick is the ice in Antarctica?
Antarctica, the white continent. How much thickness lies hidden beneath its snow and ice? The latest map, built from some 60 years of surveys, also reveals surprising terrain under the ice.
Do babies really have more bones than adults?
As we grow, our bodies get bigger but our bone count goes down. Behind that curious subtraction lies a reason that helps babies survive.
How hot is the center of the Earth?
More than 6,000 kilometers beneath your feet lies a place no one has ever been. How did scientists work out its temperature?
How rare is a four-leaf clover?
Remember crouching in the grass, searching intently? We unpack the rarity of this lucky charm through numbers and genes.
What is the coldest place in the universe?
Empty space is already bitterly cold. Yet astronomers found a place that dips below even that cosmic floor.
What is the longest-living animal in the world?
When this clam was born, Japan was entering an age of civil war. In the northern seas live creatures that seem to have watched human history unfold.
Will the Sun burn out someday?
Even the Sun that rises faithfully every morning has a lifespan. Follow the life story of a star, and the Sun’s surprising “final days” come into view.
Does bamboo really flower only once every 120 years?
Bamboo is everywhere in Japan, yet almost no one has seen it bloom. And when it finally does, whole groves can wither away.
How many stitches are on a baseball?
A curve of red thread racing across white leather. You have seen it countless times, but chances are you have never stopped to count the stitches.
Why do we have a dominant hand?
The hand that holds a pen, the hand that throws a ball. Our dominant hand seems settled before we notice—so when, and how, does it take shape?
Where do curling stones come from?
A round stone with a handle, gliding across the ice. You see them at every Winter Olympics, but where does the rock actually come from, and what kind of rock is it?
Why does a piano have 88 keys?
Rows of black and white keys stretch across every piano, and the count is almost always the same, whoever made it. So who decided?
Was Napoleon really short?
His name is still shorthand for the short man with big ambitions. But the record of his height hides a surprising trap.
How many elements are there?
Water, air and our own bodies are all made of combinations of elements. So how many elements are there in total? The latest count includes one that was born in Japan.
Where is the rainiest place in the world?
Where in the world can you never put your umbrella away? In one place, more than 10,000 millimeters of rain a year has shaped the way people live.
Is glass a liquid?
“Old church windows in Europe are thicker at the bottom, because glass is a slow-flowing liquid.” You’ve probably heard it. But is it true?
What is the longest river in the world?
Your atlas has an answer. But some researchers aren’t convinced by it—because measuring a river turns out to be far harder than it sounds.
Would Saturn float in water?
Drop the solar system’s second-largest planet into a giant bathtub: would it sink or bob? The more you think about it, the more fun the thought experiment gets.
What is the figure in Munch’s “Scream” screaming about?
Under a blood-red sky, a figure presses its hands to its face, mouth wide open. What that famous pose means is spelled out in a note the painter wrote himself.
How many smells can humans tell apart?
Fresh coffee, earth after rain, bread straight from the oven. Just how many different smells can our noses tell apart?
Why are soccer balls made of pentagons and hexagons?
The black-and-white patchwork is still the very symbol of a soccer ball. Behind that combination lies an answer settled by mathematics.
What is the hardest material in the world?
Scratch it, press it, hit it: “hard” can be measured in many ways. The race for the world title turns out to be surprisingly tangled.
Is Japan moving?
The ground beneath our feet seems perfectly still. But measure it precisely, and the Japanese archipelago turns out to be on the move, a little every day.
What exactly is a shooting star?
A flash across the night sky, the kind people make wishes on. What causes it turns out to be nothing like the stars shining overhead—and astonishingly small.
How long does sunlight take to reach Earth?
The Sun you see overhead isn’t the Sun as it is right now. Even for the fastest thing in the universe, the journey is a long one.
Who invented instant noodles?
Just add hot water and wait. The world now eats more than 120 billion servings of instant noodles a year, but whose bright idea were they, and where did it come from?
Why do golf balls have dimples?
A smooth ball seems like it should slice through the air better, yet golf balls are covered in little hollows. The reason goes back to battered old balls.
What do the colors of the Olympic rings mean?
Blue, yellow, black, green and red: everyone knows the Olympic symbol. But trace what its designer actually wrote about the colors, and a surprising answer emerges.
What is the largest animal in the world?
An animal heavier than any dinosaur is swimming in Earth’s oceans right now. Learn about its heart and its appetite, and “big” starts to mean something new.
Why is seawater salty?
River water isn’t salty. Rainwater isn’t salty. Yet the sea is. So where did all that salt come from in the first place?
How do tornadoes form?
A slender vortex reaches down from the sky to the ground. What conditions have to come together to create a tornado, the source of nature’s most violent winds?
Are Olympic gold medals made of solid gold?
Gleaming on the podium, it is the crystallized dream of every athlete. Learn what makes it shine, and you may never see a medal the same way again.
Why doesn’t ice cream in Japan have a best-before date?
Pick up a tub of ice cream from the freezer and search the lid and the bottom: there’s no date anywhere. Did the maker simply forget?
Do astronauts get taller in space?
Is it really true that going to space makes you taller? A Japanese astronaut’s “9-centimeter incident” offers a good place to start.
How does a microwave oven heat food?
No flame, no hot plate, yet your food is steaming in minutes. What on earth is going on inside that box?
Why do bullet trains have such long noses?
The newer the bullet train, the longer and sleeker its nose. And it isn’t just because a long nose looks cool or fast.
How much does hair grow in a day?
It must be growing every day, yet the mirror never shows a change. So how fast is your hair actually growing?
How many times a day does the International Space Station circle Earth?
A huge laboratory flies 400 kilometers over our heads. For the astronauts who live there, a “day” runs to a rhythm completely unlike ours on the ground.
Why does metal feel colder than wood?
On a winter morning, playground bars feel icy but the wooden bench doesn’t. Yet a thermometer says they’re the same temperature. So what is your hand feeling?
Why does popcorn pop?
Little kernels leaping out of the pan with a pop. Ordinary corn won’t do this. Inside each kernel lies something like a pressure cooker, and an unexpected “leg.”
What was the first computer?
Computers now fit in our pockets. Try to name the very first one, though, and the trail runs from 19th-century blueprints to wartime secrets and into a courtroom.
Why can’t we see the far side of the Moon?
For thousands of years, humanity has looked up at the same lunar markings. There’s a good reason the Moon’s other half stays hidden.
Why does ice float on water?
Most substances sink in their own liquid once they solidify. Yet the ice in your glass bobs happily at the top. What makes water so different?
Why is a marathon 42.195 kilometers?
Not 40 kilometers, not 42, but an odd number with a tail of meters. The marathon’s awkward distance carries the story of one particular race.
How many cells are in the human body?
The number you learned in school and the number in today’s reference books don’t match. In the 21st century, scientists sat down and counted the body’s cells again.
Why does static electricity give you a shock?
In winter, touching a doorknob or a car door becomes a little nerve-racking. That sudden sting is a tiny lightning bolt driven by thousands of volts.
How much does a cloud weigh?
Clouds look as light as cotton candy. If you could set one on a scale, how far would the needle swing? And why don’t clouds fall out of the sky?
Which is colder, the Arctic or the Antarctic?
Both are frozen worlds at the ends of the Earth. The two polar regions seem like twins, but what lies beneath their ice could hardly be more different.
Where did the stones of Stonehenge come from?
A ring of colossal stones about 5,000 years old stands on an English plain. Where were stones weighing tens of tonnes hauled from? Modern science has been answering that question piece by piece.
Why does a round of golf have 18 holes?
Not 10, not 20, but 18. The number written into every golf course plan grew out of a small decision by the golfers of one Scottish seaside town.
Why does water boil at a lower temperature on a mountain?
Water boils at 100°C—or so we learned in school. That rule doesn’t hold everywhere. High on a mountain, a pot of water behaves very differently.
Who invented braille?
Station handrails, can lids, elevator buttons: the tiny rows of raised dots found all over town began with one boy’s ingenuity.
How many times can you fold a piece of paper?
“No matter how hard you try, you can’t fold paper more than eight times.” The person who took on that old saying was a high school student given a math assignment.
How many feathers are on a badminton shuttlecock?
A badminton shuttle looks simple, a neat ring of white feathers on a cork. But that little projectile is governed by surprisingly exact rules, and a lot of fuss over birds’ wings.
Is blood type linked to personality?
“You’re so organized—you must be type A.” In Japan this is everyday small talk. But when, and from where, did the idea take hold?
How fast does a hummingbird’s heart beat?
A tiny bird hangs perfectly still in front of a flower, sipping nectar. Inside that jewel-like body, a heart is beating at an almost unimaginable pace.
Is there sound in space?
In sci-fi movies, spaceships explode with a deafening roar. Is real space silent? Mostly, yet in some places an unimaginably deep “song” rings out.
Was basketball really born from peach baskets?
Why does a basketball hoop hang at exactly 3.05 meters, such an oddly specific height? The answer lies in a gym more than 130 years ago.
Do naked mole-rats never grow old?
Wrinkled, hairless and decidedly odd-looking, this small rodent has become a favorite of aging researchers around the world. Why do some call it the animal that doesn’t age?
What is the nearest star to the Sun?
Of all the countless stars in the night sky, which one is our closest neighbor? Surprisingly, it is a star you cannot see with the naked eye.
How fast do fingernails grow?
You just trimmed them, and somehow they’re already long again. One doctor spent 35 years recording that tiny change on his own thumb.
What makes the sound when you crack your knuckles?
Plenty of us were warned that cracking our knuckles would make them swell. Scientists have pursued the source of that satisfying pop with surprising determination.
Why do you float in the Dead Sea?
Lie back on the water and open a newspaper. A lake famous for photos like that lets even non-swimmers stay afloat. How does it work?
Can tardigrades survive in space?
A tiny animal about half a millimeter long that lives in moss. Sometimes called the toughest creature on Earth, it has actually been sent into space. What happened when it got there?
Why does baseball have nine innings?
Most ball games are timed, but baseball has no clock. So when, and how, did the game come to be measured in nine innings?
Why is Uranus tipped on its side?
Every planet in the solar system spins like a top as it circles the Sun. Every planet, that is, except one, which rolls along lying flat on its side.
How many ants are there in the world?
Ants bustle around underfoot almost everywhere. If you could count every ant on Earth, what would the total be? Here is what a serious attempt at an “ant census” found.
How many Sunflowers paintings did Van Gogh make?
London, Amsterdam, Munich, Tokyo: museums around the world display Van Gogh’s Sunflowers. So just how many of them are there?
Why does the Leaning Tower of Pisa lean?
Some people assume the tower was built leaning on purpose. The real story is an 800-year saga of whether it would fall or stand.
What percentage of the human body is water?
People often say the human body is mostly water. But how much, exactly? It turns out the share varies surprisingly with age and sex.
Why does bowling use ten pins?
Knock down all ten pins in their triangle with one ball and it’s a strike. But that familiar number “ten” comes with a rather dubious legend attached.
Is your earwax type decided by your genes?
Some people’s earwax comes out in dry flakes, while others’ is soft and sticky. Where does that difference come from? Hidden behind it is a trace of humanity’s long journey across the globe.
Did vending machines exist in ancient times?
Drop in some coins, press a button, and out comes a cold drink. Trace the idea behind the vending machine back far enough and you end up nearly 2,000 years ago.
Did people in Edo-period Japan bathe every day?
In Japanese period dramas, the cramped tenement houses have kitchens but no bathrooms. Even so, the people of old Tokyo seem to have been remarkably fond of keeping clean.
What is the “curse of the ninth”?
Beethoven, Bruckner, Dvořák, Mahler: one great composer after another left a Ninth Symphony as his last. Is it really a curse?
Why do sumo wrestlers throw salt?
Before the bout, a white spray arcs from a wrestler’s hand. It’s a familiar sight, but that handful hides a long history—and a surprising amount of salt.
Why has Roman concrete lasted so long?
Modern concrete can start to crumble within decades, yet ancient Roman buildings are still standing after nearly 2,000 years. The secret was hidden in the material itself.
How do batteries make electricity?
The little batteries in our remote controls and clocks are packed with a discovery that began more than 200 years ago, with a twitching frog’s leg.
Why does a soccer match last 90 minutes?
Forty-five minutes each way, everywhere on Earth. Who decided that, and when? The story begins in a London park, in rain and hail.
How many digits of pi have been calculated?
3.14159… and on forever. For more than 2,000 years, people have chased the next digits of pi. How far has the record gone?
When was the toothbrush invented?
We pick up a toothbrush every morning and night without a second thought. Before it existed, how did people keep their teeth clean?
Is there an upper limit to temperature?
Cold has a floor, a point below which nothing can go. But what about heat? The hottest thing humans have made was over 300,000 times hotter than the Sun’s core.
When were eyeglasses invented?
We wear them every day as if they were part of our face. Thanks to one friar’s sermon, we know surprisingly well when this little device was born.
Was the Palace of Versailles really built without toilets?
Behind the glittering facade, the story goes, courtiers relieved themselves in the gardens and hallways. What was it really like at Versailles?
Why are railway tracks 1,435 mm apart?
Much of the world’s railway network runs on tracks an oddly specific 1,435 mm apart. Have you heard that the measurement goes back to the chariots of ancient Rome?
Was the barcode born on a beach?
The black-and-white stripes that beep at every checkout are everywhere. But when, and how, did someone first think of them?
Why do we replace our teeth only once?
Sharks go through tens of thousands of teeth in a lifetime, yet we swap ours only once, in childhood. Here’s why, and where research into regrowing teeth stands today.
Where does the Japanese phrase “pin kara kiri made” come from?
Japanese speakers use “pin” and “kiri” all the time, yet both are written in katakana and few can say what they mean. In fact, neither may have started out as Japanese at all.
Why do some people’s faces turn red when they drink?
One glass of beer turns some people bright red; others drink round after round without changing color. The difference lies in a tiny variation in a single gene.
Were the pyramid workers paid in beer?
There’s a story that in ancient Egypt, beer served as a paycheck. Peek into the records of the craftsmen who built the royal tombs, and a surprising picture of daily life emerges.
Which is older, the Kojiki or the Nihon Shoki?
Japan’s two oldest books carry its myths and the early history of its emperors. Which of the pair came first? The answer depends a little on how you look at it.
Who invented the red card?
A single red card held high by the referee. Even people who know nothing about soccer understand it. The idea was born on a street corner, after one chaotic sending-off.
Why is human body temperature around 36–37°C?
The idea that “normal” is 37°C was popularized by a German doctor more than 150 years ago. Now it seems that normal itself has been slowly slipping.
When did the rank of yokozuna begin?
Yokozuna is the summit of professional sumo. Today it is the highest rank on the ladder, yet it started out as something that was not a rank at all: a single rope.
How much can bamboo grow in a day?
A bamboo shoot that wasn’t there yesterday is as tall as a person today. In a spring bamboo grove, growth that hardly seems plant-like is quietly under way.