December 20, 2024: On the trail of a hidden planet beyond Pluto. Plus, how the vagus nerve influences some of the most complex health conditions, and alarming findings about black kitchen utensils. —Andrea Gawrylewski, Chief Newsletter Editor | | | • At least 860 dairy herds across 16 U.S. states have tested positive for bird flu. A sluggish federal response, deference to industry and neglect for worker safety are putting the country at risk. | 14 min read | | | About a decade ago, astronomers realized that the various icy bodies beyond Pluto's orbit were moving in strange, hard-to-explain patterns. Hard to explain, that is, unless their orbits were being influenced by an unseen world, midway in size between Earth and Neptune and residing at the edge of our solar system. The possibility of a so-called "Planet Nine" thrilled scientists and the public alike, and soon multiple intensive searches were underway.
The latest findings: Ten years on, those searches have failed to find their elusive quarry, in large part because even a big planet (estimated to be five to 10 times the mass of Earth orbiting as far as 700 astronomical units away) has plenty of places to hide in the vastness of our solar system's cold, dark hinterlands. Planet Nine remains, so far, just a hypothesis. But the circumstantial evidence supporting its existence continues to pile up.
What's next: In 2025 a revolutionary telescope, the Vera C. Rubin Observatory, will aim its 3,200-megapixel camera—the world's largest–at the sky. After nearly four decades of searching, astronomers have found about 4,000 small icy worlds beyond Pluto. "With Rubin, it should go up to about 40,000," says Mario Jurić, an astronomer at the University of Washington. Astronomers hope that Planet Nine is one of them. --Lee Billings, senior space and physics editor | | | Jen Christiansen; Source: Caltech/R. Hurt (IPAC) (ETNO and Planet Nine orbital reference) | Most of the known extreme trans-Neptunian objects (ETNOs) have much more elliptical (oval-shaped) orbits than the eight planets, and they move around the sun at a tilt. They share these features with Pluto, which also orbits at an angle and in an oval. Like the ETNOs shown in blue, the orbital path of Planet Nine is expected to be tilted at about 20 degrees from the ecliptic—the orbital plane of Earth. | | | The vagus nerve is a winding vine of two main nerve bundles running up and down both sides of the human body. Each side has up to 100,000 fibers, each contributing to specific bodily functions, from heart rate to breathing to food digestion to speech. The vagus nerve is linked to several chronic conditions. Devices implanted into the body are used to zap the vagus nerve and reduce seizures in epilepsy. A large trial of such implanted devices to treat depression showed mixed results.
Why this matters: Many wellness influencers on social media claim that you can tap, ice or zap the vagus nerve to soothe anxiety, improve memory or even cure long COVID. But scientific research on the nerve is by no means conclusive or clear. Clinicians are pressing forward with many experimental transcutaneous devices (often in combination with traditional medicines) to tackle complex, hard-to-treat conditions like major depression.
What the experts say: Because the body's most vital nerve is so interconnected with many crucial functions, some medical researchers are betting it will prove an invaluable target for treating myriad conditions. "A truly revolutionary idea can take 20 to 40 years before it's thoroughly adopted," says neurosurgeon Kevin J. Tracey of the Feinstein Institutes for Medical Research, "at which point everyone says how we needed that all along." | | | If you're enjoying all the science we cover in this newsletter, dive deeper with a subscription to Scientific American. You'll have access to all our articles and will be supporting crucial science journalism. | | | • Surveys of the public's view of LLMs, short for large language models (like the one that powers ChatGPT) find that people think the bots are more trustworthy and reliable than humans who give advice. But please seek advice from AI with caution, warns Ana Gantman, an assistant professor of psychology at Brooklyn College and the City University of New York Graduate Center. "A study published in 2023 demonstrated that LLMs will give inconsistent and sometimes contradictory moral advice from one prompt to the next," she says. | 5 min read | | | • With a possible bird flu outbreak looming, Donald Trump's choice of Jay Bhattacharya, a scientist critical of COVID policies, to lead the NIH is the wrong move for science and health, says Steven M. Albert, a professor at the University of Pittsburgh's School of Public Health. | 4 min read | | | How much Scientific American did you read this week? Test yourself with this week's science quiz. After that, try out our new Sudoku game or play today's Spellements puzzle. Remember to send any science words that are missing from the puzzle to games@sciam.com. This week, both Louise and Jan spotted phthalate, which is a chemical that plasticizes materials and is used in personal and beauty products, and to make PVC pipe. Great find, readers! | | | MOST POPULAR STORIES OF THE WEEK | | | • 78 Books Scientific American Recommends in 2024 | 34 min read | • The Perfect Beer Glass Shape, according to Math | 5 min read | • Mysterious Constant that Makes Mathematicians Despair | 5 min read | Revisiting the editors' favorite science stories from 2024. | | | The last official sighting of a grizzly bear in Washington State was in 1996. After more than a hundred years of being hunted for fur and pushed out by development, the bears disappeared. And now, federal authorities are trying to push forward with a plan to reintroduce grizzly bears to the U.S. portion of the North Cascades Ecosystem. The first phase will relocate an initial group of 25 bears over a five- to 10-year span from other regions in the U.S. and British Columbia. The hope is to establish a new population of 200 grizzlies in the North Cascades within 60 to 100 years. | 13 min read | | | Thank you for sending in your one-word descriptions of this newsletter! It was a treat to read your responses, and I made a fancy "word cloud" to share the variety of submissions (larger font sizes represent repeated words). | I'm thrilled that so many readers find this newsletter to be enlightening, informative and stimulating! Thank you for being a part of this community. You can send me one-worders any time: newsletters@sciam.com. Enjoy the weekend. | —Andrea Gawrylewski, Chief Newsletter Editor | | Subscribe to this and all of our newsletters . | | | | Scientific American
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