Today in Science: The universe keeps rewriting cosmology

A daily read for science lovers, the endlessly curious and inquiring minds. ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏  ͏ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­

August 26, 2025—Is the universe expanding, contracting or something else entirely? Plus, humans are not as special as we think and new data on exoplanets around Proxima Centauri.  —Andrea Gawrylewski, Chief Newsletter Editor TODAY'S NEWS An artist's impression of the Proxima Centauri system, with the planets Proxima b and Proxima d. Gabriel Pérez Díaz (IAC) New near-infrared instruments release data on exoplanets around our nearest red dwarf star Proxima Centauri. | 6 min read Secretary of Health and Human Services RFK, Jr., called for the retraction of a paper that showed no link between aluminum in vaccines and disease. The journal that published the paper rejected the request. | 4 min read  Exposure to repeated heat waves can age you as much as smoking or drinking, a new long-term study has found. | 3 min read The first human case of flesh-eating screwworms in the U.S. has been detected in a patient in Maryland. | 6 min read  Microplastics are breeding grounds for bacteria and could be turning them into drug-resistant superbugs. | 4 min read More News Want to dive deeper into the science that interests you? Consider a subscription to Scientific American. Today in Science readers get special discounts! TOP STORIES The Cosmos, Revised Earlier this year, the Dark Energy Spectroscopic Instrument in Arizona provided evidence that dark energy may evolve over time, that is, it's not a constant as physicists had thought for decades. This isn't the first time that a reversal in thinking has threatened to strike cosmology.      The backstory: To astronomers in the 1990s, three facts seemed clear: all the matter in the universe is gravitationally attracting all the other matter in the universe; therefore, the expansion of the universe is slowing. In 1998, two independent research groups found the opposite: the universe's expansion is not decelerating at all, it's accelerating. Dark energy, which scientists believe constitutes about 70 percent of everything in the universe, was later predicted to be at the heart of this acceleration. How the latest dark energy finding will amend its role in cosmic expansion is the next question in physics.    Why this matters: Cosmology has often lent itself to assumptions that turn out to be dead wrong. Going back to the flawed assumption that the sun orbited the Earth, what seems obvious to our eyes is not necessarily true, and with the progress of technology scientists continue to gather data to reveal the nature of the universe. Reversals in cosmology are always possible, and should be expected.  Sam Falconer Humans Aren't Special At the end of last year, Tahlequah the killer whale birthed a female calf. After only a few days the calf died, and Tahlequah was seen carrying her lost baby draped over her snout for at least 11 days in the Puget Sound. In 2018 the orca displayed similar behavior when she lost her previous calf. She carried the 300-pound body on her head for 17 days while swimming 1,000 miles. Researchers characterize the mother orca's reaction to these losses as grief.   Why this is interesting: Virtually every trait that anthropologists have identified as one that might have set humans apart from other animals has subsequently been found in another species. Orcas display grief. Elephants mourn their lost relatives. Chimpanzees use tools. Mice and dogs can detect suffering in other animals and respond. The Eurasian Magpie can recognize itself in the mirror–a sign of consciousness. And early evidence for consciousness has emerged in fish, reptiles, insects and other invertebrates. Even plants seem to behave in ways that suggest memory and advanced sensing of their environment.   Why this matters: A 2023 study by researchers at Northeastern University found that human exceptionalism—the idea that humans are somehow separate from nature and not inherently linked to (or even like) nature— discourage environmental action and decreases how much humans value the natural world. In his book, A Sand County Almanac, Aldo Leopold urges humans to see ourselves not as conquerors but as members of ecological communities. Ethical consideration must extend to soils, waters, plants, animals—and prioritize the integrity, stability and beauty of ecosystems—not just human benefit, he says. "We abuse land because we regard it as a commodity belonging to us. When we see land as a community to which we belong, we may begin to use it with love and respect."   The Top Stories today are part of our 180th anniversary package, which is all about reversals in scientific thinking (180-degree turns. Get it?). Check out the rest of them here.   This week, our Science Quickly podcast explores some of the wildest U-turns in science. Listen here.

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EXPERT PERSPECTIVES "We need fundamental change to our economic systems so that financial incentives go to those whose activities result in the conservation of nature rather its destruction," Elizabeth Bennett, the vice president of the Wildlife Conservation Society, wrote in 2021. Halting the loss of habitats and biodiversity that result from human action is not enough, she says. "We will never succeed in restoring our balance with nature unless we fundamentally change the ways in which we do business." | 3 min read More Opinion PUZZLER Can you unscramble this image of our December 1987 cover? This image depicts a strong magnetic field, generated by a molten iron core, that might have once been present on the moon. ​ More Jigsaw Puzzles Revolutionary discoveries can happen in nearly every field and have been for centuries. Here are some of my favorites we've covered over the years: Dinosaurs, long thought of as drab-looking creatures, were anything but—research on fossilized melanin cells shows that dinosaurs were feathered in bright colors; some even sported spots and stripes.  Our solar system did not establish itself slowly, as was long thought, but was born of a violent blur of impacts and destruction. Women in Viking society likely controlled the money through their creation and trade of textiles.    If you're interested in reversals in scientific thinking, read our 180th anniversary issue, and a collector's edition on scientific U-turns. And send feedback on this newsletter to: newsletters@sciam.com. Thanks for reading.   —Andrea Gawrylewski, Chief Newsletter Editor

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