November 29, 2023: A mysterious cosmic ray hits Earth, on the trail of harmful "forever chemicals" and a canyon of fire on the surface of the sun. —Andrea Gawrylewski, Chief Newsletter Editor | | | On May 27, 2021, an ultrahigh-energy cosmic ray (UHECR) hit Earth's atmosphere over Utah, sparking showers of subatomic secondary particles that rained down on ground-based detectors. The event measured an estimated 244 exa-electron volts (EeV) in energy, meaning this cosmic ray packed a wallop akin to a well-pitched baseball. Dubbed "Amaterasu" (the goddess of the sun in Japanese mythology) by its discoverers, this single UHECR was the most energetic particle seen on Earth in three decades. Why this is interesting: Attempts to reconstruct Amaterasu's path to Earth traced back to the Local Void, a barren expanse of intergalactic space bordering the Milky Way that lacks stars, galaxies and most anything else that could be the ray's obvious astrophysical source. So where did it really come from? Researchers have no shortage of ideas. But for now no one can even say for sure whether this UHECR was a lightweight proton or something much heavier, like the nucleus of an iron atom—and the distinction matters for plotting Amaterasu's precise cosmic trajectory, and thus its mysterious origins.
What the experts say: Perhaps Amaterasu's source "just happens to be a galaxy where a star went fairly close to its supermassive black hole," says Glennys Farrar, professor of physics at New York University. "I think that's the most plausible explanation." | | | So-called "forever chemicals" are human-made substances composed of perfluoroalkyl and polyfluoroalkyls (PFAS) and found in products like cosmetics and shampoo, and in water-repellent coatings for nonstick cookware and food packaging. They get washed down drains and tossed into landfills, and so have become ubiquitous in the environment. A new study by researchers at Florida International University traced how precisely PFAs get into the ocean off Florida's coast.
What they found: Sewage contamination--from failed septic systems and wastewater leaks in urban areas--has become a major source of PFAs in waterways. Another is military and airport facilities, where aqueous film-forming foam washes into local waterways. PFAS concentrations were highest in the canals draining into the bays, decreased along the bays and declined as ocean water became deeper and more saline, which makes PFAS less soluble in water.
Why this matters: Knowing how the bulk of these chemicals enter the environment could help us avert their release. A recent government study estimated these chemicals were in at least 45 percent of tap water across the U.S., and a large percentage of Americans are now believed to have detectable levels of PFAS in their blood. The chemicals have been linked to immunological disorders, endocrine, developmental, reproductive and neurological disruption and increased risk of bladder, liver, kidney and testicular cancer. In marine environments they affect the immune system and liver function of fish and marine mammals. | | | • A long filament of roiling plasma arcing over the sun's surface snapped this week, leaving behind a scalding scar that has been dubbed a "canyon of fire." | 3 min read | A filament erupted from the sun on Nov. 27, 2023, and left a "canyon of fire" visible in the bottom right of this view. Credit: Courtesy of NASA/SDO and the AIA, EVE, and HMI science teams | | | • It's a popular notion of the human brain that when injury happens and one sense is lost (sight, for example), the other senses will "turn up" and compensate to give the individual enhanced smell or hearing, for example. But this idea comes from a fundamental misunderstanding of how the brain works, write neuroscientists John Krakauer and Tamar Makin. Rather than a display of brain rewiring to create function in previously unrelated neural regions, recovery from injury is "more about utilizing latent capacities that have been present since birth," they say. | 5 min read | | | • This writer got rid of the Internet from their home entirely. The results were dramatic. | The Atlantic | | | • An illuminating conversation with mathematician and educator Freeman A. Hrabowski III on how science education needs to change. | Issues in Science and Technology | | | • A beautifully illustrated contemplation of the essence of humanity while large language models like ChatGPT seem to be taking over the world. | The New Yorker | | | In the illustrated essay from The New Yorker I link to above, illustrator and cartoon artist Angie Wang grapples with the power of large language models like ChatGPT. She comes to the conclusion that "human obsolescence is not here and can never be." Most literally, the "here" she's referring to are the intimate moments with her son, in their daily activities. But she's also writing about all aspects of human life. To be sure, AI and large language models may replace many human occupations and transform work in the decades to come. But our essential humanness--emotions, imagination, connections to each other--will remain vital. | Read about AI, LLMs, ChatGPT and more here. And reach out any time with suggestions and feedback: newsletters@sciam.com. Same time tomorrow. | —Andrea Gawrylewski, Chief Newsletter Editor | | Subscribe to this and all of our newsletters . | | | | Scientific American
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