Innholdsfortegnelse for January/February 2024 i Discover

THE ASTROPHYSICIST AND SCIENCE COMMUNICATOR REFLECTS ON HIS FAVORITE SCI-FI FLICK, HIS FIRST MEETING WITH CARL SAGAN, AND THE FUTURE OF SPACE TRAVEL. STARING UP at the moon through a pair of binoculars as a young child, Neil deGrasse Tyson found himself inspired by the cosmos that unfolded above him. “If you look at the moon through good binoculars or even through a simple telescope, oh my gosh,” says Tyson. “It’s not just this thing in the sky. It’s a world with mountains and valleys and craters and shadows and gullies. And, all of a sudden, the moon goes from this object that you ignored most of your life [to] a place [that makes you say], ‘Hey, I want to visit that. I want to know more about what’s in…

Aortic dissection! Coming back!” Amanda, the triage nurse, cried as she slalomed a gurney down the corridor. “Sixty-five-year-old, history of hypertension,” she panted. “Sudden chest and back, 10-over-10 pain. Started an hour and a half ago. Headache, too.” Eight pairs of hands eased a grimacing woman off the stretcher onto our resuscitation bed. Clenching her eyes shut, the woman moaned. “Head hurts, head hurts.” “Which side?” I asked. She raised a hand to her left ear. “Here,” she mumbled. “Hurts.” “Chest pain, back pain?” I added. “Hurts. Please. Head,” was all she managed. The team speed-started IVs, applied EKG leads to the patient’s chest and hooked up monitors. “She sounds confused,” Emily, a physician’s assistant, said softly. “Stroke?” “Is she already dissecting up her neck into the carotids?” I wondered…

FEW AILMENTS are as fearsome as Alzheimer’s disease, the most common form of dementia, which robs patients of their minds and memories before it takes their lives. So, when the U.S. Food and Drug Administration approved a new treatment for Alzheimer’s in July, the event made front-page news. But it also generated heated arguments. Lecanemab, branded as Leqembi by pharma companies Esiai and Biogen, is the first drug targeting the disease’s underlying mechanisms to receive full approval from the FDA. The medication — an engineered molecule known as a monoclonal antibody — works by removing the sticky plaques of amyloid beta protein that gum up the brain as Alzheimer’s progresses. In that respect, it resembles an earlier drug: aducanumab (marketed by Biogen as Aduhelm), which in 2021 was granted “accelerated”…

FOR DECADES, cancer vaccines have been touted as a technology with transformative potential — a promise that always seemed to lie beyond some distant horizon. In 2023, however, the results of two clinical trials hinted that the transformation may be near. The first report came in April, at the annual meeting of the American Association for Cancer Research (ASCO). It concerned melanoma, the deadliest form of skin cancer. In patients whose tumors had been surgically removed, researchers announced, an experimental therapeutic vaccine cut the risk of recurrence by 44 percent compared with the immunotherapy drug pembrolizumab alone — the standard therapy in such cases. These findings have “absolutely breathed new life into the cancer vaccine field,” declared lead author Jeffrey Weber, deputy director of NYU Langone’s Laura and Isaac Perlmutter…

WHILE TEMPERATURES in Phoenix soared above 110 degrees Fahrenheit for a record-shattering 31 straight days in July, people began turning up in emergency rooms with third-degree burns they’d suffered after falling — their skin seared by blistering hot pavement. Although not unprecedented, burn specialists said the number and severity of injuries were much higher than ever before. Meanwhile, 30,000 feet up, the jet stream had become deranged. Its wavy, loopy and swirling pattern helped lock heat domes in place, like the one over south-central Arizona. Meteorologist Jeff Berardelli called the pattern “insane.” University of Pennsylvania climate scientist Michael Mann likened it to a Vincent Van Gogh painting. In Canada, by midsummer, wildfire season was already twice as bad as any other on record, thanks to abnormally warm and dry conditions.…

BY THE MIDDLE of August 2023, one of Joey Lawrence’s videos on TikTok had over 3 million views — and it wasn’t a viral dance or recipe. Lawrence, a psychologist who also happens to be autistic, had posted the video about a month prior to talk about a new autism assessment on monotropism, when a person’s attention is dedicated to a narrow range of interests. The views on Lawrence’s video aren’t entirely surprising: TikTok has exploded with content on neurodiversity since the app’s surge in popularity during the pandemic. Now there are over 11 billion views on TikTok’s hashtag #neurodivergent, and Google searches for the term have increased steadily over the past year. Neurodiversity is a term that refers to the natural range of differences in people’s brains. The neurodiversity…

DEEP BENEATH our feet, under 1,800 miles of rock, the planet’s core is undergoing profound change. How quickly it is changing, however, has long remained a mystery. In a January 2023 study published in Nature Geoscience, Yi Yang and Xiaodong Song of Peking University in China used the seismic waves produced by many sets of nearly identical earthquakes to deduce the motion of Earth’s inner core. This dense center appears to have consistently spun faster than the outer layers of the planet from the 1970s to the early 2000s. Much to the researchers’ surprise, however, they also found evidence that core motion may have slowed to match — and then fall behind — the speed of Earth as recently as 2009. The core is still rotating in the same direction but,…

PALEONTOLOGISTS KNOW a lot about Tyrannosaurus rex from the abundance of fossilized specimens they’ve found throughout North America. They know, for instance, that the theropod had sharp, serrated teeth, each the size of a banana, and a bite force over a hundred times that of a human. They also know that the species had a huge head, almost 5 feet from front to back. But, in the absence of brain tissue, what was inside that massive skull has remained a mystery. In a study published in the June 2023 issue of the Journal of Comparative Neurology, Suzana Herculano-Houzel, a neuroscientist and associate professor of psychology at Vanderbilt University, took a controversial first stab at calculating the neuronal count of several species of dinosaur, including T. rex. Neuronal numbers are difficult to…

Paleontologist Michael D’Emic also analyzed how sauropods, the long-necked herbivores, evolved to such staggering sizes. In a paper published in Current Biology in 2023, D’Emic estimated the mass of nearly 200 species of sauropod and plotted the estimates onto an evolutionary tree, visualizing their transformations over time. He found that sauropods maxed out dozens of times. Over the course of 100 million years, at least 36 different lineages surpassed the maximum size achieved by the largest land mammals, which topped out at almost 53,000 pounds. “I was really surprised to find that sauropodss exceeded terrestrial mammalian size so many times,” D’Emic says. “I thought I’d find five or six examples, not 36.” Members of these supersized lineages included Jurassic icons, like Diplodocus and Brachiosaurus, which lived when a splintering supercontinent…

THE YEAR 2023 brought a flurry of pivotal advancements to the field of genomics. Three large databases — one of humans, one more broadly of mammals, and one of primates (see sidebar on page 54) — are promising brand new revelations about the source code of life, especially as it pertains to our own species. A notable milestone for a one-of-a-kind repository of ancient DNA could hold similar insights from our ancestors, as well. These massive genomic repositories will grant scientists novel tools for comparing DNA between humans, between humans and animals, and between us and our ancestral relatives. While genome sequencing has been a reality for decades, much of the value of genomics lies in comparing different genomes to one another to understand how they differ, and why those…

AROUND 2,600 years ago, a small ceramic bowl sat in a subterranean workshop. Carrying hints of cedar and honey, the bowl was used by Egyptian embalmers to blend essential oils and beeswax for the multimonth process that transformed corpses into mummies. Reciting incantations, removing organs, and applying substances that made bodies dry, fragrant, and microbe-free, the embalmers employed a multifaceted set of skills. “They knew the ritual practices, but also [a] kind of chemistry,” says Maxime Rageot, a biomolecular archaeologist at the University of Tübingen in Germany. Over the past four years, Rageot and colleagues have gained unprecedented insights into the substances and steps involved in ancient Egyptian mummy-making. Their analysis of molecules trapped in pottery, as published in a Nature paper from February 2023, revealed that embalmers sourced ingredients…

FOR SEVERAL days in June, millions around the globe were gripped by news of five people missing 12,500 feet under the ocean, lost while attempting to catch a glimpse of the wreckage of the RMS Titanic. By the time evidence confirmed that their poorly designed submersible, the Titan, had imploded under the immense pressure of the deep, their fate was hardly a surprise. Following the disaster, information came to light that the Titan did not meet industry safety standards: The carbon fiber cylinder making up the Titan’s hull was known to be inappropriate for deep sea craft, and OceanGate, the company that developed and operated the submersible, had a history of safety-related allegations. Interview footage resurfaced of OceanGate CEO Stockton Rush, who was aboard at the time and died in…

REFRIGERATION INNOVATION (“Cold Comfort,” Sep/Oct 2023) Thank you for Amy Brady’s excellent article about John Gorrie and building refrigeration. A shout-out is also needed to Frederick McKinley Jones (May 17, 1893–Feb. 21, 1961), an African American inventor. Jones innovated mobile refrigeration technology, which allowed for the transportation of food and blood during World War II. He received 61 patents, 40 for refrigeration technology. He also co-founded Thermo King; I started my engineering career at there in 1972 and worked with many brilliant managers, engineers, and workers. Jim Holstein (TELE)MEDICAL MYSTERIES In each issue, your Vital Signs column focuses on patients [with medical mysteries who are] fortunate enough to have face-to-face medical consultation in which the doctor diagnoses based on visual examination. What’s a person to do when their health plan…

IT’S NO SECRET that our gut microbiomes — the trillions of bacteria, viruses and fungi that inhabit our gastrointestinal tracts — play a vital role in our lives. In the past decade, researchers have found that these microorganisms help us perform an array of bodily functions and, notably, that they can profoundly affect our mental health. Still, we’re only beginning to learn how those interactions work, and how they might be harnessed to treat or prevent disease. In a study published in February 2023 in PLOS Biology, for example, researchers at the University of Virginia found that a protein called aryl hydrocarbon receptor, or AHR, which regulates immune cells’ response to chemicals produced by the gut microbiome, may play an important role in multiple sclerosis (MS). The disease causes the…

HERE’S A SHORT story: “I got up from the air mattress and pressed my face against the glass of the bedroom window expecting to see eyes staring back at me, but instead finding only darkness.” Now here’s another: “I just continued to walk up to the window and open the glass I stood on my toes and peered out I didn’t see anything and looked up again I saw nothing.” The first is a snippet that a person heard while in a functional magnetic resonance imaging (fMRI) machine, which measures blood flow in the brain. The second is what artificial intelligence (AI) recreated, based on that brain activity. In a study published in May 2023 in Nature Neuroscience, a team of researchers from the University of Texas at Austin showed…

ON THE topic of dinosaur sounds, there’s a whole lot of silence. And it’s no wonder, since most of their sound-producing structures were made of fragile tissues that usually failed to fossilize. But in February 2023, an analysis of the first dinosaur larynx fossil ever discovered provided new insights into their vocalization. Taken from an ankylosaur that lived in Mongolia between 84 million and 72 million years ago, the voice box suggests that the dinosaur may have tweeted, twittered, and cooed rather than roared. Comparing the fossil to the sound-producing anatomy of birds and reptiles, researchers found that the ankylosaur’s larynx was much more avian than reptilian. Though the ankylosaur — a member of the species Pinacosaurus grangeri — possessed some of the same laryngeal structures as both birds and reptiles,…

AFTER DECADES of stumbling, humankind has taken a big step forward in the ongoing quest to return to the moon — and to travel beyond. The journey has been a long time in the making: Our last visit was more than 50 years ago, during the Apollo 17 mission in 1972. In April 2023, NASA named the four astronauts in the crew for Artemis II, the upcoming mission that could launch as early as November 2024. During the 10-day journey, the spacecraft will circle the moon, traveling deeper into space than any crewed spacecraft has ever gone before. It will help pave the way for Artemis III, which is planned to touch down on the lunar surface in 2025, and Artemis IV, a future mission to both land on the…

Variety abounds across primates. Monkeys tumble on snowy Japanese mountains, orangutans munch fruit on Sumatra, lemurs pogo between trees in Madagascar, and the naked apes — humans — strut on two legs worldwide. Scientists can now interrogate the DNA differences underlying that diversity, thanks to a databank of genomes from 233 species. To understand the good and bad of human evolution — both our extraordinary adaptations and disease-causing mutations — scientists must compare the genomes of Homo sapiens to our closest evolutionary relatives, the primates. But researchers investigating diverse topics, from contemporary genetic diseases to human origins, have long faced a roadblock when pursuing this approach: While genomic data exists from millions of people, most of the 500-plus primate species never had their genomes read. So, in 2019, Tomàs Marquès-Bonet…

IN 1827, a harpist tacked strands of hair to a page with a poem. He then folded the paper and penned “Beethovens hair” on the outside. Nearly two centuries later, researchers have used these locks to reconstruct the genome of Ludwig van Beethoven, lifting the curtain on the composer’s life and pushing the frontiers of paleogenetics. Beethoven died in Vienna at age 56, after reportedly suffering from hearing loss, jaundice, debilitating stomach pains, and suicidal ideations. Scholars seeking the causes of these maladies have previously analyzed historical documents and bits of Beethoven himself, including tufts of hair snipped as mementos for fans, to no avail. In 2014, William Meredith, the director of the Ira F. Brilliant Center for Beethoven Studies at San José State University, set out to salvage DNA from…

IN MAY 2023, a team in Switzerland announced that they had created a brain-spine interface that enabled a man who’d been paralyzed in a bicycle accident to walk naturally again. This “digital bridge” connects the brain and the spinal cord, bypassing the injured area in his neck. Electrodes implanted in the patient’s brain record activity in the part of the cortex that controls the legs. The activity patterns are then transmitted wirelessly to electrodes connected to the region of the spinal cord that governs leg movement. Machine learning, a form of artificial intelligence, is used to convert the brain signals into sequences of electrical stimulation in the spinal cord, which in turn activate leg muscles. The patient, then-38-year-old Gert-Jan Oskam, was able to control his movements naturally, standing, walking, climbing stairs,…

BY EARLY 2023, large language models (LLMs) were taking the world by storm. Arguably, ChatGPT led the revolution. The interactive chatbot allows users to make comments, ask questions, make requests, or enter into dialogue with the computer program. It is a kind of generative AI, which means that after training on enormous stores of data, it can produce something new and reads fairly convincingly — and eerily — as though it were created by a human. Despite its ability to mimic human verbiage, ChatGPT was trained to do a straightforward job: use probability and training data to predict the next text that follows a sequence of words. That ability could make it useful for people who work with text, says computer scientist Mark Finlayson of Florida International University. “It’s very good…

Humans have long nurtured the 150-year-old banyan tree at the heart of downtown Lahaina in Hawaii. In its earliest days, residents hung jars from its aerial roots to encourage the growth of additional trunks. Now, following the deadly wildfire that tore through Lahaina and thousands of acres across Maui late last summer, the largest banyan tree in the U.S. needs a different kind of care. Many arborists feared that the scorched tree, in a near comatose state, would not survive. But volunteers immediately set to work, punching air into the soil around the tree’s massive root network as trucks doused the area in hundreds of gallons of water daily. Also on the menu: a concoction of microbes and nutrients called “compost tea,” plus layers of solid compost and chopped-up alfalfa…

HIGH-FLYING LIZARD Look, up in the sky! It’s a bird! It’s a plane! It’s a … gecko? Meet Gekko mizoramensis, the newest member of the Southeast Asian parachute gecko family, discovered in India and first described by scientists last May. Like its cousins, G. mizoramensis is built for gliding, with skin flaps along its body to keep it aloft and a rudderlike tail to help the nocturnal aerial adventurer gracefully soar from tree to tree. Hidden in plain sight, this new gecko is a cryptic species — meaning that it looks incredibly similar to other species, yet has different enough DNA to be considered distinct. The discovery points to a trove of biodiversity waiting to be cataloged by researchers in the region.…

IF YOU ASK a kinder-garten class to draw a rhinoceros, you’ll get an amusing variety of artistic renditions. One feature, however, will likely remain constant: a majestic horn adorning its head, defining the rhino’s distinct silhouette. Yet, in the wild, this iconic horn is disappearing — faster than the rhinos themselves, in some cases. In the ongoing battle to protect endangered rhino populations from poaching, conservationists employ a controversial practice known as “dehorning.” This process removes the rhino’s valuable horn, and with it much of poachers’ incentive to hunt them. Meticulous planning and careful execution go into dehorning to ensure a swift and safe procedure. Like a well-oiled machine, field rangers, veterinarians, researchers, helicopter pilots, and other experts coordinate to find and tranquilize the target animals. Once the rhino is…

DON’T DENY it: Sometimes, swearing just feels good. And it’s becoming clear that dropping the occasional profanity bomb is actually good for us, too — at least, according to science. Research has shown that swearing can boost pain tolerance, increase the per-suasiveness of an argument, and signal positive traits like verbal fluency and honesty. What’s more, spewing obscenities has the potential to impact our bodies, as well, providing stress relief and even a slight boost in physical performance. Given their ubiquity in society, it might seem like swear words simply sprouted into existence. But where does profane language really come from? Fromancient Rome to the Renaissance to today, there’s lots that the history of swearing can teach us about how taboos, language, and culture evolve. SIMPLY PUT, swearing is taboo…

THE STANDARD public health threats are all-too familiar: Smoking. High blood pressure. Cancer. More recently, COVID-19. But a new government advisory made headlines in 2023 by adding an unexpected major player to that list. Loneliness, stated the report from Surgeon General Vivek Murthy, is a widely underrecognized U.S. health crisis. In recent years, about 50 percent of Americans have experienced loneliness, which comes with a hefty dose of adverse effects. Lonely people, as Murthy’s report warns, run the same mortality risk as people who smoke 15 cigarettes a day. “Millions of people in America are struggling in the shadows, and that’s not right,” Murthy told the Associated Press in May. “I issued this advisory to pull back the curtain on a struggle that too many people are experiencing.” Institutions that once…

FOR A MAJOR killer of the very young and the very old, respiratory syncytial virus (RSV) gets scant public attention. Although the virus usually causes mild, coldlike symptoms, it can inflame small airways in the lungs of babies and vulnerable adults, triggering severe pneumonia. Globally, RSV is the second leading cause of pediatric deaths after malaria. Among adults, it’s responsible for up to 10,000 deaths and 160,000 hospitalizations annually in the U.S., mostly among the elderly or immunocompromised. RSV made headlines this past May, however, when the FDA approved the first vaccine for the disease. The product, known as Arexvy, was OKed for adults over 60. Its manufacturer, biopharma company GSK, beat several rivals to the finish line — including Pfizer, whose RSV vaccine Abrysvo received approval for the same…

DOWN IN THE coldest recesses of the deepest oceans, Earth’s circulatory system is pumping the brakes. Left unchecked, it threatens to halt a process that regulates the planet’s energy balance and stabilizes our climate. “Earth’s climate is fundamentally controlled by our ocean and by the ocean’s overturning circulation,” says Matthew England, an oceanographer at Australia’s University of New South Wales. In March, he and a team published the most detailed global model of Antarctic water masses and other deep-sea currents to date in the journal Nature. They found that, compared to its flow in the 1990s, this vital oceanic conveyor belt could slow by about 40 percent before 2050. Deep water circulation kicks off at the polar extremes. In the southern Antarctic seas, freezing seawater relinquishes its salt, causing the water…

BETWEEN Mexico and Hawaii, at the bottom of the Pacific Ocean, lies the Clarion-Clipperton Zone. This abyssal plain sprawls over 2.3 million square miles, over half the size of the contiguous U.S., and plunges to depths exceeding 3 miles in some places. The water here is just above freezing, and no sunlight reaches it. Yet for thousands of species that scientists know almost nothing about, the strange landscape is a happy home — for now. The creatures in the CCZ are nothing short of bizarre: long-tentacled creatures that resemble shooting stars, bristly worms that look like they’re made of ice crystals, and a sea cucumber nick-named “the gummy squirrel” because of its translucent, candy-yellow color and tail-like sail. Each represents a tiny fraction of the 5,142 unnamed species announced in…

SAND IS EVERYWHERE. Most people don’t take notice of the tiny grains of broken rock or shells within it, and may even curse the way it gets all over the car after a beach trip. But in that sand could lie a geological record of some of the planet’s mightiest mountains. Research published in Nature Communications in late 2022 examined the sands washed from the Andes Mountains by the Amazon River. Millions of years’ worth of this sand has accumulated in the Atlantic Ocean, thousands of miles away and on the opposite coastline from its source. The researchers, led by Cody Mason from the University of West Georgia, turned to the tiny zircon crystals found within this dusty debris to map out a part of the continent’s tectonic history. Zircon is…

FIRST SCAMPERING onto the scene around 230 million years ago, theropod dinosaurs were some of the biggest predators on the block — and also some of the smallest. From the ferocious 14,500-pound Tyrannosaurus to the feathery 2-pound Microraptor, these prehistoric beasts pushed size to the extremes. For decades, paleontologists thought the theropods evolved into giants and pipsqueaks by adjusting the pace of their growth: Only by growing more quickly than their ancestors did they bulk up, and only by growing more slowly did they trim down. But in 2023, an analysis of bones from 42 separate species of theropod put that theory to the test. Published in Science in February, the results revealed that the theropods used an assortment of developmental mechanisms to size up and size down. To understand…

THE UNIVERSE is constantly churning from the movement of its most massive objects, a 15-year survey has reported. Using pulsars as distant beacons and radio telescopes to plumb the galaxy, a collaboration of astronomers and physicists has found strong evidence of low-frequency gravitational waves undulating through the cosmos. The detection of these ripples is a long-awaited result, anticipated since the detection of highfrequency gravitational waves almost a decade ago. The ability to measure these waves directly is a major breakthrough that will inform scientists about the origin and history of the universe. The results were published in June 2023 in a series of papers in The Astrophysical Journal Letters and were based on collaborative efforts between the North American Nanohertz Observatory for Gravitational Waves (NANOGrav), the Physics Frontiers Center (PFC),…

YELLOW CRAZY ants, or Anoplolepis gracilipes, are among the most pernicious invasive insect species in the world. Still, these organisms — named for the erratic way they move when disturbed — are not what they seem. Though the long-legged insects look much like ordinary ants, males of the species are actually composed of distinct populations of cells from two separate genomes, researchers revealed in a study published in April in Science. That makes them a biological oddity known as a chimera, a name shared with a mythological creature that’s part fire-breathing lion, part goat, and part serpent. In most animals, humans included, all of our cells contain the same set of DNA. But male yellow crazy ants have two types of cells, each with a different genome, all living side by…

ROUGHLY 4,000 years ago, where the Romanian Plains border the Carpathian Mountains, mourners tucked a 30-something man into a tomb. Adorned with red pigment and faced toward the west, his body was buried in the typical fashion of the Yamnaya: within a sprawling mound of dirt. Less typical was the wear and tear on the man’s skeleton, which bore signs of repeated horseback riding. While a healed sacral fracture hinted that the man had suffered a traumatic fall, mounting horses had left him with an arthritic spine, a roughened pelvis, and a pair of accentuated thighbones. Now in scientists’ hands, this skeleton from the Strejnicu archaeological site, and other skeletons like it, have rewritten the history of horse riding. Pushing the origins of the practice back by over 1,000 years,…

ALMOST three years ago, an amateur codebreaker named Satoshi Tomokiyo discovered a cache of dozens of encrypted letters in the digital collection of the National Library of France, all dating to the 16th century. He posted them to his cryptology website, Cryptiana, under the heading “unsolved historical ciphers.” In February of 2023, Tomokiyo and codebreaker George Lasry, together with German musician Norbert Biermann, announced that they had deciphered the documents and unmasked the author as Mary Queen of Scots. The former monarch wrote the letters over a sixyear period of her life while imprisoned by her distant cousin, Queen Elizabeth I. The letters reveal insights about Mary’s life in captivity. “We see her very active, well-connected and astute,” says Lasry. Historians quickly hailed the discovery — which totaled 50,000 words…