Wonder: Something new to discover. - Page 3

Editor’s note

Wonder

For the pleasure of learning something you did not know, from an unfamiliar artist to a surprising discovery.

WonderHistory

Britain's National Health Service (NHS) opened on 5 July 1948. It brought hospitals, family doctors and other services into one system, paid for mainly through taxes, so that anyone could be treated without paying at the time of care.

The plan grew out of the 1942 Beveridge Report, in which the economist William Beveridge proposed a comprehensive health service as part of a welfare system for post-war Britain. Aneurin Bevan, a former coal miner from Wales and health minister in Clement Attlee's Labour government, pushed it through despite opposition from many doctors. On its first day the NHS took over some 2,700 hospitals in England and Wales. Before 1948 people relied on charity hospitals, council hospitals and insurance schemes, but coverage was patchy and many women and children were left out. The care did not stay entirely free: charges for glasses and false teeth came in 1951, leading Bevan to resign, and prescription charges followed in 1952.

Ikigai DailyRead card

WonderHistory

In the American South, “Jim Crow” laws separated Black and white people in schools, buses and restaurants and kept many Black citizens from voting. From the 1950s the civil rights movement fought them with lawsuits, boycotts and marches, winning the Civil Rights Act of 1964 and the Voting Rights Act of 1965.

The laws took their name from “Jim Crow”, a racist stage character of the 1830s. In 1896 the Supreme Court had allowed segregation as long as facilities were “separate but equal”; in Brown v. Board of Education, on 17 May 1954, it ruled unanimously that separate schools were unequal by their nature. In December 1955 Rosa Parks was arrested in Montgomery, Alabama, for refusing to give up her bus seat to a white passenger, and the bus boycott that followed, lasting more than a year, made Martin Luther King Jr. a national figure. At the March on Washington in August 1963 he gave his “I Have a Dream” speech. After state troopers attacked peaceful marchers at Selma, Alabama, in March 1965, Congress passed the Voting Rights Act. The laws ended legal segregation, though discrimination in daily life did not disappear with them.

Ikigai DailyRead card

WonderHistory

In 1960 the US Food and Drug Administration approved Enovid, the first birth control pill. Taken daily, its hormones stop the release of eggs. It gave many women reliable control over when to have children and helped change education, work and family life.

The pill was developed in the 1950s by the biologist Gregory Pincus and the gynaecologist John Rock, with research funded largely by the philanthropist Katharine McCormick at the urging of the birth control campaigner Margaret Sanger. Enovid was first approved in 1957 for menstrual disorders, and in 1960 for contraception. In Britain the pill became available through the NHS in 1961. In the US access widened slowly: in 1965, in Griswold v. Connecticut, the Supreme Court struck down a state ban on contraception for married couples, and it extended the right to unmarried people only in 1972. The first pills held far higher doses of hormones than today's. The first report of a blood clot in a pill user appeared in 1961, and concern about such risks led to lower-dose versions.

Ikigai DailyRead card

WonderHistory

In the early hours of 28 June 1969, police raided the Stonewall Inn, a gay bar in New York's Greenwich Village. Customers and local people fought back, and several nights of protest followed. The uprising became a turning point for the LGBTQ rights movement, and Pride marches around the world mark its anniversary.

In the 1960s New York police regularly raided gay bars, and serving gay customers could cost a bar its licence. Stonewall was not the first act of resistance: the Mattachine Society had campaigned since 1950 and the lesbian organisation Daughters of Bilitis since 1955, and in 1966 customers at Compton's Cafeteria in San Francisco had fought back against police harassment. But Stonewall drew far wider attention and moved the movement from quiet persuasion to open protest. Within weeks new groups such as the Gay Liberation Front had formed. On 28 June 1970, the first anniversary, thousands took part in the Christopher Street Liberation Day march, named after the street where the bar stands and now counted among the first Pride marches. In 2016 the site became the Stonewall National Monument.

Ikigai DailyRead card

WonderScience

A 2025 Finnish study found that men who had suffered severe abuse or neglect as children showed some differences in the chemical tags on their sperm DNA and in the small RNA molecules their sperm carry. In mice such changes can affect offspring; in humans that has not been shown.

Epigenetics studies chemical tags and molecules that help switch genes on or off without changing the DNA code itself. One such tag is DNA methylation, small chemical groups attached to DNA; small RNAs are short molecules that fine-tune which genes are used. The study, by researchers at the universities of Turku and Copenhagen, compared sperm from fathers in FinnBrain, a Finnish study that follows families from pregnancy, who reported high or low levels of childhood maltreatment. It was small, with fewer than 60 men, and found differences in three regions of DNA, including areas near genes that help control brain development, and in 68 small RNAs. The idea comes from animal work: in 2014 Swiss researchers injected RNA from the sperm of mice stressed early in life into fertilised eggs, and the pups showed changes in behaviour and metabolism.

Ikigai DailyRead card

WonderScience

Deliberately smiling can make people feel slightly happier. In 2022 a study of nearly 4,000 people in 19 countries found that posing a smile, or copying a smiling face, raised reported happiness a little; a subtler method, holding a pen between the teeth, gave less clear results.

The idea that the face can feed back into feelings, called the facial feedback hypothesis, goes back to Charles Darwin and William James. In a famous 1988 experiment, Fritz Strack and colleagues had people hold a pen in their teeth, which forces a smile, or between their lips, which prevents one, and those in the first group rated cartoons as funnier. In 2016, seventeen laboratories repeated that experiment exactly and found no effect. A 2019 review of 138 studies concluded that the effect is real but small and varies from study to study. The 2022 Many Smiles Collaboration, led by Nicholas Coles and designed jointly by supporters and sceptics of the idea, found that deliberate smiling could both strengthen and start feelings of happiness, while the pen method remained inconclusive.

Ikigai DailyRead card

WonderScience

In a cave in Jujuy, northern Argentina, archaeologists found two pipes carved from puma bone, with seeds of cebil, a tree whose seeds are psychoactive, lying beside them. Chemical traces inside the pipes point to plant smoking more than 4,000 years ago, among the oldest evidence of such use in South America.

Cebil, Anadenanthera colubrina, is a South American tree whose seeds contain tryptamines, compounds that strongly alter perception; further north in the Andes it is called vilca. The pipes come from Inca Cueva 7, a small rock shelter near the Humahuaca valley at the edge of the high Andean plateau, where seeds of cebil and of mesquite lay in the same layer. Radiocarbon measurements, which gauge how much of the carbon-14 in once-living material has decayed, give ages of about 4,000 years, roughly 2100 BC. The residue shows that a tryptamine-bearing plant was smoked, but it cannot prove exactly which one. Cebil use continued in the region for thousands of years: Wichí healers in northern Argentina still used its seeds, which they call hatáj, in the 1990s.

Ikigai DailyRead card

WonderScience

A 2016 estimate found that a typical adult man weighing 70 kg has about 30 trillion human cells and 38 trillion bacteria. That overturned the old claim that bacteria outnumber our own cells ten to one: the two numbers are roughly equal.

The estimate comes from Ron Sender, Shai Fuchs and Ron Milo of the Weizmann Institute of Science in Israel. Their reference man is 20 to 30 years old, 170 cm tall and weighs 70 kg. The ten-to-one figure, they found, went back to a single rough calculation from 1972 that had been repeated for decades. Almost all the bacteria live in the colon, the last part of the gut, and together they weigh only about 0.2 kg. Among human cells, red blood cells dominate the count, making up about 84 per cent, while fat and muscle cells, far fewer but much larger, make up most of the body's cell mass. The balance also shifts through the day: a single trip to the toilet empties a quarter to a third of the colon's contents.

Ikigai DailyRead card

WonderScience

An adult body replaces about 330 billion cells every day, around 80 grams of cells, according to a 2021 estimate by scientists at the Weizmann Institute of Science. Close to nine in ten of those cells are blood cells.

Ron Sender and Ron Milo combined the number, mass and lifespan of every major cell type in the body. Short-lived cells dominate the count. Red blood cells live about four months, and neutrophils, the most common white blood cells, only days, so the bone marrow must make vast numbers of them every day. By mass, the largest shares come from blood cells and from the cells lining the gut, which are shed and replaced within days. At this pace, a number of cells equal to all the roughly 30 trillion human cells in the body is replaced in about three months. That does not mean the whole body is renewed: most nerve cells in the brain last a lifetime, and heart muscle cells are replaced only very slowly.

Ikigai DailyRead card

WonderScience

Bone is living tissue. In adults about a tenth of the skeleton is broken down and rebuilt each year, so most of it is renewed over roughly ten years; in a baby's first year, almost all of it is.

The work is done by two kinds of cells. Osteoclasts dissolve small patches of old or damaged bone, and osteoblasts then fill the gap with new bone, which hardens as calcium and phosphate are laid down in it. This cycle, called remodelling, repairs the tiny cracks caused by everyday movement and lets bone adapt to the loads it carries: in the 19th century the German surgeon Julius Wolff described how bone grows stronger where it is stressed. Bone is also the body's calcium store: bones and teeth hold about 99 per cent of it. In space, without gravity loading the skeleton, astronauts lose more than 1 per cent of their bone mass a month. From middle age, breakdown slowly outpaces rebuilding, which is why osteoporosis, the thinning of bone, becomes more common with age.

Ikigai DailyRead card

WonderScience

Mitochondria, the parts of your cells that turn food into usable energy, very probably began as free-living bacteria. Well over a billion years ago one was taken inside another cell, where it went on living and dividing, and the partnership became permanent.

This is the endosymbiotic theory: endo means inside, and symbiosis means two different living things living closely together. Early versions of the idea date from the early 1900s, but it was the American biologist Lynn Margulis who gathered the microbiological evidence in a 1967 paper, and many scientists at first rejected it. The evidence is now strong. Mitochondria have their own DNA, a small ring like a bacterium's, which in humans holds 37 genes. They have two membranes, make some of their own proteins with bacteria-like machinery, and multiply by splitting in two, as bacteria do. Their closest living relatives are a group of bacteria called alphaproteobacteria. Because a baby's mitochondria come from the mother's egg, mitochondrial DNA is used to trace ancestry through the female line.

Ikigai DailyRead card

WonderScience

Your gut and brain communicate through nerves, hormones, immune signals and microbes, which is why stress and digestion can affect each other.

Scientists call this link the gut–brain axis. The gut has its own network of about 500 million nerve cells, the enteric nervous system, sometimes called the “second brain”, which can run digestion largely by itself. It is connected to the brain mainly through the vagus nerve, a long nerve running from the brainstem down to the abdomen, and most of its fibres carry messages upwards, from the gut to the brain. More than 90 per cent of the body's serotonin, a chemical messenger, is found in the gut. Gut bacteria play a part too: in a 2004 Japanese study, mice raised entirely free of germs overreacted to stress. Stress can speed up or slow down the gut, one reason it often worsens irritable bowel syndrome, a common gut disorder. Most research on the microbes' role has been in animals, and human evidence is still limited.

Ikigai DailyRead card

WonderScience

A placebo is a dummy treatment, such as a sugar pill. In pain studies, placebos can reduce the pain people report and also dampen activity in the brain areas that process pain, even though they contain no active drug.

The word placebo is Latin for “I shall please”. One of the first clues that the effect is physical came in 1978, when Jon Levine and colleagues studied patients recovering from wisdom tooth removal. They gave them a placebo and naloxone, a drug that blocks the effect of endorphins, the body's own painkilling chemicals. In patients who had responded to the placebo, naloxone increased the pain, which suggested that the placebo relief came from endorphins. In 2004 Tor Wager and colleagues used brain scans to show that a placebo painkiller reduced activity in pain-processing regions during a painful stimulus. Expectation works the other way too: in the nocebo effect, from the Latin for “I shall harm”, expecting harm makes symptoms worse. None of this means the pain was imaginary, or that placebos can replace effective treatment.

Ikigai DailyRead card

WonderScience

Memory does not work like a recording. Each time we recall an event, the brain rebuilds it from stored fragments, filling gaps with what we know and what we have heard since, so a memory can change without our noticing.

Psychologists call this reconstructive memory. In his 1932 book Remembering, the British psychologist Frederic Bartlett described asking people to retell “The War of the Ghosts”, a Native American folk tale unfamiliar to them; each retelling drifted towards what felt familiar in their own culture. In 1974 Elizabeth Loftus and John Palmer showed people films of car accidents and asked how fast the cars were going when they “hit” or “smashed” into each other. Those asked with “smashed” gave higher speeds, and a week later were more likely to remember broken glass that was never there. This is known as the misinformation effect. It matters in court: according to the Innocence Project, mistaken eyewitness identification played a part in most US convictions later overturned by DNA evidence.

Ikigai DailyRead card

WonderScience

The Dunning–Kruger effect describes how people who do worst at a task tend to overestimate their own performance the most. The psychologists David Dunning and Justin Kruger described it in 1999, after testing students on logic, grammar and humour. It does not mean that every beginner is confidently wrong.

Dunning and Kruger, then at Cornell University, published the study as “Unskilled and Unaware of It”. Students who scored in the bottom quarter did better than only about 12 per cent of their peers, yet guessed that they had beaten 62 per cent. The authors called this a dual burden: the knowledge needed to do something well is often the same knowledge needed to notice that it has been done badly. In one experiment, a short lesson in logic helped the weakest scorers judge their own results more accurately. Later researchers argued that much of the pattern may be statistical: when almost everyone rates themselves a little above average, the lowest scorers are bound to show the biggest gap, and computer simulations produce a similar curve. Dunning replies that the misjudgements are real, whatever their cause.

Ikigai DailyRead card

WonderScience

Predictive processing, an influential theory in neuroscience, says the brain does not simply wait for information from the senses. It keeps guessing what is out there and uses the incoming signals mainly to check and correct those guesses.

The idea goes back to the German physicist Hermann von Helmholtz, who argued in the 1860s that seeing involves “unconscious inference”: the brain fills in what the eyes cannot fully tell it. In 1999 the researchers Rajesh Rao and Dana Ballard turned this into a computer model of vision. Higher brain areas send predictions down, and lower areas send back only the difference between prediction and input, called the prediction error. The philosopher Andy Clark and the neuroscientist Karl Friston later helped develop it into a broad theory of the mind. A well-known illustration is the hollow-mask illusion: the inside of a mask still looks like a face bulging outwards, because the brain's expectation of a normal face outweighs the evidence. The theory is widely used but still debated, and critics ask how some of its claims could be tested.

Ikigai DailyRead card

WonderScience

Going over a problem again and again can feel like working on it. Psychologists call this rumination: dwelling on why something went wrong and what it means, without reaching a decision or a next step. Studies link it to low mood and to poorer problem-solving.

The American psychologist Susan Nolen-Hoeksema made rumination a major research topic from 1991, describing it as passively and repeatedly focusing on distress and its possible causes and consequences. In a 1995 study with Sonja Lyubomirsky, people in a low mood who were asked to dwell on their feelings came up with less effective solutions to problems with other people than those who were first given something else to think about. Edward Watkins at the University of Exeter later showed that the style of thinking matters. Abstract “why” questions, such as “Why does this always happen to me?”, tend to keep people stuck, while concrete “how” questions, such as “How did this happen, and what can I do next?”, helped depressed patients solve problems better. Some therapies now teach people to notice when they are asking why and to switch to how.

Ikigai DailyRead card

WonderScience

In a 1999 experiment, people asked to count basketball passes in a short video were so focused that about half failed to notice a person in a gorilla suit walking through the middle of the scene. Psychologists call this inattentional blindness: missing something in plain sight because attention is busy elsewhere.

The psychologists Daniel Simons and Christopher Chabris ran the study at Harvard and published it in the journal Perception as “Gorillas in our midst”. It built on experiments by Ulric Neisser in the 1970s, in which viewers often missed a woman with an umbrella strolling through a similar ball game. The term inattentional blindness was coined by Arien Mack and Irvin Rock in 1992. Expertise does not protect against it. In 2013 researchers at Harvard Medical School inserted a gorilla, 48 times the size of the small nodules the doctors were looking for, into a lung scan. Of 24 radiologists, 83 per cent did not see it, although eye tracking showed that most of those who missed it had looked straight at it. A British road-safety advert later used the same trick, with a moonwalking bear, to warn drivers that they can miss cyclists.

Ikigai DailyRead card

WonderScience

Emotions are not only feelings in the head. Fear speeds up the heart and breathing, grief can take away appetite and sleep, and joy changes posture and expression. These bodily changes are part of the emotion itself, and sensing them may be part of how we come to feel it.

In 1884 the American philosopher and psychologist William James turned the usual order around in an essay called “What Is an Emotion?”. We do not tremble because we are afraid, he argued; we feel afraid because we tremble. The physiologist Walter Cannon attacked the idea in 1927, and the debate ran for decades, but modern research keeps finding the body at the heart of emotion. In 2014 Lauri Nummenmaa and colleagues in Finland asked 701 people to colour in body outlines to show where they felt activity rise or fall with different emotions. Most emotions showed up in the chest, where breathing and heartbeat change; anger and happiness also lit up the arms, sadness appeared as weakened arms and legs, and disgust centred on the throat and stomach. The maps were similar for Finnish, Swedish and Taiwanese participants.

Ikigai DailyRead card

WonderScience

Memories of your own life help give you a sense of who you are, yet they are not fixed recordings. Each time you recall an event the brain rebuilds it, and later knowledge and feelings can reshape the story without you noticing.

Psychologists call this store of events from one's own life autobiographical memory. The British psychologist Frederic Bartlett showed in his 1932 book Remembering that recall is reconstruction, not replay: when people retold an unfamiliar Native American folk tale, “The War of the Ghosts”, they gradually reshaped it to fit their own expectations. A striking modern example followed the Challenger space shuttle disaster in 1986. The morning after, Ulric Neisser and Nicole Harsch asked students to write down how they had heard the news, then asked again two and a half years later. Many accounts had changed a great deal, yet the students were confident in their new versions. Memory is also tied to identity. When older adults look back, they recall an unusually large share of events from between about 10 and 30, the years when a sense of self takes shape; this is called the reminiscence bump.

Ikigai DailyRead card

WonderScience

Octopus suckers can taste by touch. Special receptors in them detect chemicals on a surface, so an arm can tell food from rock the moment it makes contact, much as a tongue senses taste and touch at once.

In 2020 a team led by Nicholas Bellono at Harvard identified the molecules behind this “taste by touch”. They found a family of receptors that exists only in cephalopods, the group that includes octopuses, squid and cuttlefish. Called chemotactile receptors, they respond to chemicals on contact, especially substances that do not dissolve easily in water. Such chemicals stay on surfaces instead of drifting away, so they would be hard to smell from a distance. Some cells in each sucker specialise in touch and others in taste, and much of the information is handled in the arm's own nerve cord rather than the brain. In 2025 the same group reported that the receptors also pick up molecules made by bacteria living on surfaces. Signals from the microbes on prey and on eggs helped guide an octopus's hunting and the care of its eggs.

Ikigai DailyRead card

WonderScience

Birds are living dinosaurs. They descend from theropods, the group of two-legged, mostly meat-eating dinosaurs that included Tyrannosaurus and Velociraptor, and they are the only dinosaur line that survived the asteroid impact 66 million years ago.

The link was first suggested in the 1860s. In 1861 a skeleton of Archaeopteryx, a magpie-sized animal with feathered wings, teeth and a long bony tail, was found in limestone quarries near Solnhofen in Germany, and the British biologist Thomas Henry Huxley soon argued that birds were close to dinosaurs such as Compsognathus. The idea faded, then returned after 1969, when John Ostrom of Yale described Deinonychus, a nimble predator with a strikingly bird-like skeleton. The decisive evidence came from China. In 1996 palaeontologists described Sinosauropteryx, the first of many non-flying dinosaurs found with feathers. Birds share many features with their theropod relatives, including hollow bones, a wishbone and sitting on their eggs in nests. All of today's more than 11,000 bird species belong to that surviving line.

Ikigai DailyRead card

WonderScience

Octopuses, squid and other cephalopods have camera-like eyes with a lens and a retina, much like ours, yet the two designs evolved separately. The last common ancestor of vertebrates and cephalopods had, at most, simple light-sensitive spots.

This is a classic example of convergent evolution, in which distantly related animals arrive independently at similar solutions to the same problem. The details give the separate origins away. In vertebrates the eye grows out of the developing brain, and the retina is wired back to front: light passes through nerve fibres and blood vessels before it reaches the light-sensitive cells, and where the nerves leave the eye there is a blind spot. In cephalopods the eye forms from an inward fold of the skin, the nerves run behind the retina, and there is no blind spot. In 1859 Charles Darwin admitted that the evolution of the eye by natural selection seemed “absurd in the highest possible degree”, then explained how it could happen in small steps. Simple light-sensing eyespots are thought to have evolved independently between 40 and 65 times.

Ikigai DailyRead card

WonderScience

When caterpillars or other insects chew a plant, it can release airborne chemicals, including the ones that give cut grass its smell. Nearby plants that sense them can strengthen their own chemical defences before they are attacked.

The effect was first reported in 1983. Ian Baldwin and Jack Schultz found that young poplar and sugar maple trees sharing air with damaged plants raised their levels of defensive compounds, such as tannins, within about two days, an idea soon nicknamed “talking trees”. It was met with scepticism for years, but many later studies confirmed that such airborne signals exist, although how strongly plants respond varies with species and conditions. In 2023 Masatsugu Toyota's team at Saitama University in Japan filmed the process as it happened. When thale cress, a small plant widely used in laboratories, was exposed to air from injured plants, calcium signals spread through its leaves almost at once; plant cells use such signals to raise the alarm. Two of the cut-grass compounds were enough to trigger them. The chemicals enter through stomata, the tiny pores in leaves.

Ikigai DailyRead card

Next reading modeDriveIdeas for sustained work.