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 […]
Some immune defenses of the brain may have their roots in the gut. A new study in mice finds that immune cells are first trained in the gut to recognize and launch attacks on pathogens, and then migrate to the brain’s surface to protect it, researchers report online November 4 in Nature. These cells were […]
It’s official: 2020 now has the most named storms ever recorded in the Atlantic in a single year. On November 9, a tropical disturbance brewing in the northeastern Atlantic Ocean gained enough strength to become a subtropical storm. With that, Theta became the year’s 29th named storm, topping the 28 that formed in 2005. With […]
When some bacteria manage to escape being killed by a virus, the microbes end up hamstringing themselves. And that could be useful in the fight to treat infections. The bacterium Shigella flexneri — one cause of the infectious disease shigellosis — can spread within cells that line the gut by propelling itself through the cells’ […]
The twilight time between fully awake and sound asleep may be packed with creative potential. People who recently drifted off into a light sleep later had problem-solving power, scientists report December 8 in Science Advances. The results help demystify the fleeting early moments of sleep and may even point out ways to boost creativity. Prolific […]
2021 was the year the COVID-19 vaccines had to prove their mettle. We started the year full of hope: With vaccines in hand in record-breaking time and their rollout ramping up, we’d get shots in arms, curb this pandemic and get life back to normal. That was too optimistic. Roughly 200 million people in the […]
Brains are like sponges, slurping up new information. But sponges may also be a little bit like brains. Sponges, which are humans’ very distant evolutionary relatives, don’t have nervous systems. But a detailed analysis of sponge cells turns up what might just be an echo of our own brains: cells called neuroids that crawl around […]
As the chill of autumn encroaches on Siberia’s grasslands, Richard’s pipits usually begin their southward trek to warmer latitudes. But a growing number of the slender, larklike songbirds seem to be heading west instead, possibly establishing a new migratory route for the species. This would be the first new route known to emerge on an […]
In a remote corner of Brazil’s Amazon rainforest, researchers have spent decades catching and measuring birds in a large swath of forest unmarred by roads or deforestation. An exemplar of the Amazon’s dazzling diversity, the experimental plot was to act as a baseline that would reveal how habitat fragmentation, from logging or roads, can hollow […]
Regenerating body parts is never easy. For instance, some lizards can grow back their tails, but these new appendages are pale imitations of the original. Now, genetically modified stem cells are helping geckos grow back better tails. Tweaking and implanting embryonic stem cells on the tail stumps of mourning geckos (Lepidodactylus lugubris) allowed the reptiles […]