WASHINGTON — The tale of the first horseback riders may be written on the bones of the ancient Yamnaya people. Five excavated skeletons dated to about 3000 to 2500 B.C. show clear signs of physical stress that hint these Yamnaya individuals may have frequently ridden horses, researchers reported March 3 at the American Association for […]
A form of lightning with a knack for sparking wildfires may surge under climate change. An analysis of satellite data suggests “hot lightning” — strikes that channel electrical charge for an extended period — may be more likely to set landscapes ablaze than more ephemeral flashes, researchers report February 10 in Nature Communications. Each 1 […]
When New Zealand Prime Minister Jacinda Ardern, who garnered international praise for how she handled the pandemic in her country, recently announced her intention to resign, here’s how she summed up her surprise decision: “I know what the job takes, and I know that I no longer have enough in the tank to do it […]
Scientists have identified the stem cells behind the liver’s legendary ability to replenish its tissue. Stem cells not only bolster their own numbers but also become other kinds of cells through a process called differentiation, thereby keeping an organ populated as mature cells die off. The stem cells underpinning this process in the liver had […]
Among some killer whale moms, lifelong feeding for adult sons but not daughters could be a long-term investment play. The delayed payoff? Greater grandmotherly glory. Females in a quirky population of killer whales off the Pacific Coast of North America let their grown mama’s boys share fish that mom catches. Biologists have known that this […]
High-tech shrink art may be the key to making tiny electronics, 3-D nanostructures or even holograms for hiding secret messages. A new approach to making tiny structures relies on shrinking them down after building them, rather than making them small to begin with, researchers report in the Dec. 23 Science. The key is spongelike hydrogel […]
A 120-million-year-old fossil bird found in China could offer some new clues about how landbound dinosaurs evolved into today’s flying birds. The dove-sized Cratonavis zhui sported a dinosaur-like head atop a body similar to those of today’s birds, researchers report in the January Nature Ecology & Evolution. The flattened specimen came from the Jiufotang Formation, […]
Supercooled water is two of a kind, a new study shows. Scientists have long suspected that water at subfreezing temperatures comes in two distinct varieties: a high-density liquid that appears at very high pressures and a low-density liquid at lower pressures. Now, ultrafast measurements have caught water morphing from one type of liquid to the […]
2022 was the year many people decided the coronavirus pandemic had ended. President Joe Biden said as much in an interview with 60 Minutes in September. “The pandemic is over,” he said while strolling around the Detroit Auto Show. “We still have a problem with COVID. We’re still doing a lot of work on it. […]
A group at the National Bureau of Standards at Boulder, Colo., now reports an extremely accurate [speed of light] measurement using the wavelength and frequency of a helium-neon laser.… The result gives the speed of light as 299,792.4562 kilometers per second. UpdateThat 1972 experiment measured the two-way speed of light, or the average speed of […]