Today in Science: Our first glimpse of dark stars

Science, insight, inspiration July 20, 2023: We may have discovered dark stars, how our imagination lacks detail and mind-melting nighttime heat. Read it all below! —Andrea Gawrylewski, Chief Newsletter Editor TOP STORIES The First Dark Stars At least three far-off objects observed by the James Webb Space Telescope (JWST) could be stellar objects called "dark stars." These stars might not be fueled by nuclear fusion but by the self-annihilation of dark matter—the invisible stuff that is thought to make up about 85 percent of the matter in the universe. Dark stars could have formed soon after the big bang, from the collapse of helium and hydrogen clouds that annihilated the particles within. Why this is so cool: Dark stars have never been definitively observed before–astronomers weren't even sure they really existed. To prove these objects are indeed dark stars will take many months of observation–particularly, watching their electromagnetic spectrums for a particular isotope of helium only found in dark stars, not in galaxies.  What the experts say: "Finding a dark star would not only provide a new look into the early formation of the universe," says Pearl Sandick, a theoretical particle physicist at the University of Utah, "but would also be a unique opportunity to directly observe dark matter interactions. JWST initially identified these three objects (JADES-GS-z13-0, JADES-GS-z12-0, and JADES-GS-z11-0) as galaxies in December 2022. Now, astronomers think they might be "dark stars," theoretical objects powered by particles of dark matter annihilating. Credit: NASA/ESA Incomplete Pictures Do you have a memory, or even a fantasy, that feels so real to you, so vivid, that summoning it up can be like truly living in that moment? Mental images activate the same brain pathways as visual perception, but surprisingly, they lack detail. In a series of experiments, neurocognitive researchers found that, when asked to imagine a scene, the majority of participants left out key details in their mind. Why this matters: Scientists have long debated the role of mental images in the study of cognition–whether imagining vivid scenes serves to help us reason our way through things, or whether such images are just visual aftershocks, with no role in cognition. And these latest findings add to the growing body of evidence of the unreliability of eyewitness memory; not only can the mind fail to register large details in a scene (check out this wild story on how some people don't notice a gorilla entering their field of vision), but it can unintentionally conjure things that didn't happen.  What the experts say: "Mental images fill our daydreams, fuel our fancies, and color our memories," write the authors of the new study. "Our results suggest that while the imagination may indeed be a good artist, it's on a deadline, and stingy about paint." TODAY'S NEWS • The overnight LOW for Tuesday night in Phoenix was a record-setting 97 degrees F. Here's why that's so dangerous. | 3 min read • Researchers have partially deciphered the "unknown Kushan script" — a writing system that has puzzled linguists since it was first found in the 1950s. | 3 min read • Carrying some extra weight later in life is not a bad thing, but lack of movement is. | 6 min read • The United States is within reach of cutting its carbon pollution in half by 2035 — if it's able to install enough renewable energy projects. | 5 min read More News EXPERT PERSPECTIVES • So called "synthetic embryos" generated from stem-cells could yield advancements in assisted and unassisted reproduction, as well as provide insight into pregnancy failures and the causes of developmental disorders. Fears around using such a technology are not warranted, writes Insoo Hyun, from Harvard University. | 5 min read More Opinion What is it that's so compelling about the idea of a dark star? The concept has inspired song lyrics, spy novels and sci-fi comedy movies. Perhaps the imagery of a powerful burning sun shrouded in shadow (though the real things aren't dark at all) harkens to the powerful and dark things we encounter, and maybe struggle with, throughout our human lives. We all have dark stars of our own.  Reach out any time and let me know what you like (or don't!) about Today in Science: newsletters@sciam.com. Until tomorrow! —Andrea Gawrylewski, Chief Newsletter Editor Subscribe to this and all of our newsletters here. Scientific American One New York Plaza, New York, NY, 10004   Support our mission, subscribe to Scientific American here   Unsubscribe Email Preferences