October 21, 2024: Birds practice singing when they sleep, how the brain processes "zero," and gamma rays might trigger lightning. —Andrea Gawrylewski, Chief Newsletter Editor | | | Stuart Westmorland/Getty Images | | | • Some thunderstorms may emit gamma rays that trigger lightning to strike. | 6 min read | | | • Oregon decriminalized hard drugs in 2021 and recriminalized them last month. A new analysis shows the laws likely had little effect on opioid deaths. | 6 min read | | | Great Kiskadee. David Plummer/Alamy Stock Photo | | | Birds sing in their sleep. Scientists implanted electrodes into birds' brains to compare their neuron and muscle activity when they're asleep and awake. Zebra finches do something like lip-syncing while asleep and they seem to silently practice singing a few notes as if learning a new instrument. A similar study in Great Kiskadees showed that those slumbering birds don't seem to practice songs while asleep, but mimic sharp staccato notes and puff their head feathers as if defending their territory.
What the experts say: We shouldn't rush to call the activities of sleeping finches and kiskadees "dreaming," says University of Chicago neuroscientist Daniel Margoliash. First scientists need to examine bird sleep cycles–their REM cycles, for example–to determine what role the neuronal activity plays during sleep. | | | Neuroscientists recruited 17 people with epilepsy who had microelectrodes inserted into their temporal lobes in preparation for an operation. The scientists showed the participants two sets of numbers, from zero to nine--either an image of a cloud containing dots that represented the number (an empty cloud being zero) and the Arabic number. The researchers saw neurons that reacted specifically to the empty cloud and others that reacted to the number zero.
Why this is interesting: People can conceptualize "zero" in several ways, including as an "absence," a special category of emptiness, a quantity, or as a number used in mathematical calculations. Though humans and other animal species like crows are born with a sense of numbers, the concept of the numeral zero must be taught, and human children don't quite understand it until age 6.
What the experts say: "When you look closely based on behavioral data or neuronal data, zero is still slightly different; it is still special," says Andreas Nieder of the University of Tübingen in Germany. "It is this eccentric uncle in the family of the numbers." | | | • Nobel Prizes in physics and chemistry this year went to scientists who developed machine learning or used AI tools to make their landmark discoveries. A debate ensued over whether AI has taken over science. But scientists have a long history of integrating new tools and technology into their work, writes science journalist Dan Garisto. AI has "a crucial limitation tied to something wonderful about science: its empirical dependence on the real world, which cannot be overcome by computation alone," he says. | 5 min read | | | We might think of scientific mysteries as obscure or esoteric questions relating to topics like dark matter in the universe or the strong force that holds atoms together. But plenty of unanswered questions exist in commonplace events. Although lightning strikes the planet some eight million times a day, scientists are still searching for what prompts that tremendous surge of energy. It's usually safe to assume, in science and life in general, that we know less than we think we know. | Thanks for being on this journey of discovery with me. If you like this newsletter and want to dive deeper, consider a subscription to Scientific American! We have special discounts for Today in Science readers. And email me anytime with feedback or comments: newsletters@sciam.com. See you tomorrow. | —Andrea Gawrylewski, Chief Newsletter Editor | | Subscribe to this and all of our newsletters . | | | | Scientific American
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