Indholdsfortegnelse for July/August 2023 i Discover

ALMOST TWO centuries ago, in 1831, paleontologist Georg August Goldfuss was working with a fossilized pterosaur — a flying reptile that lived in the Mesozoic Era alongside the dinosaurs — and found a trait that no one had ever seen before. The specimen was covered in what looked like a strange halo of fuzz all around its body. Whether the fluff represented fur or something else entirely, experts of the time couldn’t agree. The discovery of feathers on dinosaurs in the 1990s renewed interest in that pterosaur fuzz. Then, in 2009, paleontologists coined a new term for the pterosaur filaments — pycnofibers — and proposed that they were different from the true feathers found on dinosaurs and birds. It seemed that feathers and pycnofibers were similar body coverings that evolved…

VINCENT VAN GOGH moved to Nuenen, in the south of the Netherlands, in 1883. There, still in the early stages of his career as an artist, he carefully immortalized the facial features and simple clothes of a local woman in a painting, aptly titled Head of a Peasant Woman. But on the flip side of the work, hidden behind layers of glue and cardboard, is another painting: a bearded man in a brimmed hat and loose handkerchief. His stare is unyielding and, although the right side of his face is in shadow, his left ear is clearly visible. Art conservators at the National Galleries of Scotland discovered the mysterious image in 2022 using an X-ray, as part of a routine examination. They speculate that van Gogh, who often reused his canvases…

THE IDEA OF humans making a new home on Mars is mind-bending enough on the surface. What’s even more wild is that human colonization of the Red Planet’s harsh and exotic atmosphere — if we can achieve it — might accelerate our species’ evolution. “Given how different the martian environment is, you’d expect strong natural selection,” says Scott Solomon, an evolutionary biologist at Rice University in Houston. Mars sits about 34 million miles away from Earth (depending on the orbital position of both planets), and Earthlings still face plenty of obstacles before we even reach it. But if we do (somehow) get to Mars and establish a colony of permanent residents, factors like comparatively higher radiation, lower gravity and a vast change in lifestyle could prompt significant evolutionary changes in our…

Rhonda Underhill was 34 years old when she started getting massive headaches. She felt fatigued and couldn’t stop vomiting, but what came up didn’t look like anything she’d ever seen before. It resembled dried-up coffee beans, black and goopy. Rhonda, who had just started a new job in Maryland, didn’t yet have insurance or coverage to see her primary care doctor. When she went to urgent care, the doctor diagnosed her with vertigo, which is most often caused by a problem with the balance-controlling inner ear and can result in dizziness and vomiting. They prescribed her an anti-nausea medication. But Rhonda’s symptoms didn’t subside. As time went on, she did her best to mask them, taking aspirin for the headaches and blaming the fatigue on stress from work and the…

Transplanting animal hearts and kidneys into humans could end the dire shortage of donor organs. But researchers must still prove they can defeat the specter of long-term rejection. On a warm fall day in 2021, University of Alabama at Birmingham (UAB) surgeon Jayme Locke peered into a sliced-open abdomen and braced for the task ahead of her: transplanting two pig kidneys into a brain-dead human recipient for the first time in history. Locke had done experimental surgeries before, even putting pig kidneys into baboons. But this new procedure danced closer to the edge of the surreal, and unknowns leapt out at her. She had no idea, for example, if the porcine organs would survive the rigors of stronger human blood flow. And though the pig kidneys had been genetically tweaked…

ONE IN A MILLION+? (“Mapping the Multiverse,” Mar/Apr 2023) In the article about the multiverse, an important argument in favor of the existence of multiple universes, an argument that a number of physicists accept, was left out. The various constants of nature (such as the masses of particles and the strengths of their interactions) are barely in the right range to allow planet formation and life. It seems unlikely that this is just lucky. Under the assumption of a huge number of universes, each with its own constants of nature, some will have their constants in the right range for planet formation and life. This includes our universe. Ronald Fagin WELL-AGED (“Michio Kaku’s Lifelong Quest,” Jan/Feb 2023) In the first paragraph, it is stated that the cosmos is 93 billion…

TO COMBAT WILDFIRES, A SUBURB OF DUBLIN IS RELYING ON TRADITIONAL GRAZING METHODS FOR GOATS. IT’S NOT WHAT you’d expect from one of the rainiest countries in Europe: In the summer of 2021, wildfires burned for six weeks in Howth, an outer suburb of Dublin, before firefighters could get them under control. That was a particularly bad summer for wildfires on the Howth peninsula, but damaging fires are a major challenge for people and wildlife there almost every year. The local municipality has tried setting up firebreaks and raising public awareness about the dangers of campfires and littering, with little success. But some unlikely helpers are on the case: a herd of goats. The village’s residents hope the animals will make this heathland less vulnerable to fire by munching their…

MONIKA SCHLEIER-SMITH, an experimental physicist and associate professor at Stanford University, entangles atoms in her lab to ask big questions: How does gravity work? What happens to information when it falls into black holes? What problems can quantum computing help us solve? In a nutshell, quantum physicists study how atom-sized particles interact. At this scale, the classical rules of physics fail. That’s where counterintuitive phenomena like quantum entanglement — a phenomenon where two tiny particles share information over great distances — come in. Schleier-Smith compares entanglement to tossing a coin. The results will be random; half the time you’ll get heads, and half the time you’ll get tails. But imagine if someone else was also flipping a coin, and every time you landed on heads, they landed on heads, and…

WHEN IT comes to cleanliness, the Middle Ages were far from consistent. For most medieval townsfolk, whether they made their living as merchants, artisans or agriculturalists, or passed their time at local universities, the sanitation systems consisted solely of filth-filled cesspits, cavities dug out of the ground for the collection of feces and other forms of garbage. Yet the tiniest minority of people — the residents of friaries, monasteries and nunneries — had access to running water and an emphasis on hygiene as part of monastic life. The differences in the lifestyles and living conditions of these individuals translated into differences in their susceptibility to disease. As such, some scientists have speculated that the residents of these religious institutions — who tended to have access to washing stations and latrine blocks…

The dry, deciduous terrain in and around Gir National Park and Wildlife Sanctuary, located near India’s western tip, is the proud — and only — home of the Asiatic lion. As part of his work for the Wildlife Institute of India, Kausik Banerjee spent countless hours tracking the big cat there between 2005 and 2016. With the aid of a spotting scope, he would draw sketches, take photos and meticulously note each lion’s characteristics: a notch on the left ear at the 11 o’clock position, a defining scar, the distinctive row of dots on its upper lip from which whiskers sprout. Back at his desk, Banerjee would then pore over old notes and photos to identify the individuals he’d spotted. His efforts went beyond those of the average wildlife hobbyist;…

The term executive functions refers to a set of cognitive processes and mental skills that help you control and coordinate your other cognitive abilities and behavior. (Think of them like an executive monitoring all the departments within their company, or an air traffic control system helping planes take off and land on different runways while avoiding mid-air collisions.) You use these skills every day to plan ahead, meet goals, exhibit self-control, follow directions, stay focused and more. Here are the three main executive functions that allow you to succeed — and thrive — in everyday life. Cognitive flexibility: Also known as thinking outside the box, this refers to the ability to see problems from different angles — and adapt your behavior and thinking to new situations. Inhibitory control: This executive function is…

Many readers can point back to televised science fiction as their first introduction to the universe. For some — like me — it was The Outer Limits, which had a brief run starting in 1963. Others may have been influenced by The Twilight Zone (1959), Lost in Space (1965) or The Invaders (1967). By far, however, the TV show that gave the most astronomy buffs their start exploring space was Star Trek, which began a three-season run at 8:30 P.M. EDT on Thursday, Sept. 8, 1966. This groundbreaking television show was followed by Star Trek: The Next Generation (1987), Star Trek: Deep Space Nine (1993), Star Trek: Voyager (1995), Star Trek: Enterprise (2001), Star Trek: Discovery (2017), Star Trek: Picard (2020), and Star Trek: Strange New Worlds (2022), along with…

DINO FEATHERS • FIREFIGHTING GOATS • YOUR BRAIN’S FINGERPRINTS • SURPRISE SELF-PORTRAIT A SCIENTIST IN THE QUANTUM UNIVERSE • ANCIENT CAVE ART • HOW WE’LL EVOLVE ON MARS SECRETS OF MEDIEVAL FRIARS’ GUT BIOMES • IS TIME TRAVEL POSSIBLE? NATURE’S FREAKIEST FUNGUS Sitting atop a leaf in the Peruvian jungle, this dried-up carcass was once a fly. Now blooming with bulbous stems, it has been overrun by a fungus (genus Ophiocordyceps) that has just two goals: self-replication and dispersal. The fungus begins as a single spore before quickly germinating in the fly’s body and spreading to manipulate the insect’s behavior in a way that is beneficial for growth — of the fungus, that is. (Other types of zombie fungi, like the ant-afflicting Ophiocordyceps unilateralis, force their prey to climb up…

WE THINK OF fingerprints as the tiny ridges, whorls and arched patterns on the tip of each finger. They are heralded as special markers of human identity, even more individualized than DNA. And new research suggests our brains have their own “fingerprints” that are equally unchanging and unique to each person. “The same brain executing different tasks looks more similar than different brains doing the same task,” explains researcher Zack Y. Shan, head of the neuroimaging platform at the Thompson Institute at Australia’s University of the Sunshine Coast. “In other words, we can identify an individual based on how their brain’s neural connections work together.” Thanks to modern neuroimaging techniques, scientists can trace your brain’s distinct signature, an autograph composed of tens of thousands of electrical signals that communicate across the…

Over the past 25 years, archaeologists have found hundreds of abstract shapes, animals and anthropomorphs that were carved into the ceiling of a northern Alabama cave by Native Americans more than a millennium ago. But only recently did new 3D imaging techniques reveal this humanlike figure and four other creations, all too faint to be noticed by the naked eye and hidden among other carvings, according to an analysis published in Antiquity in May 2022. Each spanning between 3 and 11 feet, these immense impressions measure up to form the largest cave art in all of North America.…

WHETHER WE’RE watching Doc Brown shatter the laws of causality in Back to the Future or the Flash sprint faster than the speed of light, science fiction has long allowed us to daydream about bending physics to our will. But what if there was a fundamental particle — the building blocks of our universe — that could actually travel back in time? There is, in fact, a hypothetical particle, called the tachyon, that could travel back in time. There’s just one catch: It almost certainly doesn’t exist. BEFORE WE start talking about time travel, we need to talk about the speed of light. All objects in our universe can go no faster than light speed. (Specifically, about 186,282 miles per second.) The only particles capable of achieving light speed are massless…

On May 31, 1882, Sydney Ringer rushed into his small laboratory in the Department of Physiology at University College London. He was likely coming from a busy morning of rounds at the hospital across the street, and would soon be headed out again to attend to his duties as a successful private doctor based out of his home in Cavendish Place, London. As usual, his lab assistant had prepared the materials for that day’s experiments, including solutions of water with substances like sodium chloride and potassium chloride in various specific amounts. Under Ringer’s watchful eye, each solution was held in a reservoir and, via a double tube, flowed in and out of a frog heart. In a nearly Rube Goldberg-esque set-up that connected a vat of oil, a flexible membrane,…

The greatest achievement of nature, according to biologist Lewis Thomas, is DNA. It arrived early to the earthly party, “somewhere in the soupy water of the cooling planet three thousand million years or so ago,” he wrote in 1979, in his essay “The Wonderful Mistake.” “All of today’s DNA, strung through all the cells of the earth, is simply an extension and elaboration of that first molecule.” But that’s no longer true. Today, there is DNA that doesn’t share lineage with those primordial molecules: It’s called synthetic DNA, and it’s made in a lab. These genetic sequences don’t need to follow the rules. Where our DNA uses a language of four letters, synthetic DNA can speak a different dialect. Scientists can tinker with DNA’s canonical design and build DNA with…

At 6 feet, 5 inches tall, paleontologist Dean Lomax sticks out in a crowd — but not so much when he’s juxtaposed with this 180-million-year-old “sea dragon.” Measuring more than 32 feet long, the prehistoric ichthyosaur — a porpoiselike sea lizard — is now recognized as the biggest and most complete skeleton of its kind ever discovered in the U.K. Lomax and a team carefully unearthed the fossil in late 2021 at Rutland Water Nature Reserve, a sanctuary for birds and wildlife near Leicester, England. The dig started after a conservation worker, Joe Davis, noticed a faint pattern in a drained lagoon during routine landscaping. The specimen has since been relocated for cleaning, which is expected to last at least two years while studies are underway. After more research and…