November 6, 2024: There is more than one kind of twilight, dog groups are re-ordered, and misinformation spreads like a pathogen. —Andrea Gawrylewski, Chief Newsletter Editor | | | • A second Trump term will be devastating for curbing climate change: he has vowed to promote fossil fuels, weaken pollution regulations and reverse Biden administration climate efforts. | 7 min read | | | • Astrology was considered a serious science to medieval elites. Curator Larisa Grollemond of the Getty Museum explains the medieval zodiac and how someone's sign decided their day-to-day life. | 15 min listen | | | Katrin Ray Shumakov/Getty Images | | | Astronomers have designated three phases of twilight. The first is civil twilight, which varies from place to place on Earth depending on latitude and can last anywhere from 30 minutes to many hours. The second is nautical twilight, when the sun is between six and 12 degrees below the horizon. The moon, some planets and bright stars can pop out if the sky is dark enough. Third is astronomical twilight, when the sun is 12 to 18 degrees below the horizon and the sky is black.
Why this matters: Astronomical observations are a matter of timing and light. For some objects, like planets, where and when they appear above the horizon mean the difference between not seeing them at all and having a fabulous view. The atmosphere also changes throughout the day and night, so morning twilight and evening twilight have very different visibilities.
What the experts say: "For an astronomer, twilight signals a welcoming to the universe, and the anticipation of that is one of the best things I know," writes astronomer and columnist Phil Plait. | | | An analysis of DNA sequences for more than 4,000 domesticated and wild dogs established a new way of categorizing dogs. According to the traditional system, all canines fall into one of 365 unique breeds. But the latest genetic analysis shows that there are 10 "lineage" groups of dogs that share close genetic connections.
Why this is interesting: Some breeds traditionally considered distinctive (like pinschers or schnauzers) actually share a lot in common with other dogs (terriers or sheepdogs, say). In the graphic below the opacity of the dots represents how closely a dog is related to other dogs.
What the experts say: By combining the genetic data with behavioral surveys filled out by the owners of around 46,000 purebred dogs, the researchers identified a series of genes associated with brain development in herding breeds. "That's a great jumping-off point to study how herding dogs herd," says Elaine A. Ostrander of the National Human Genome Research Institute.
Newly Established Dog Lineages | | | Credit: Emily V. Dutrow and MSJONESNYC; Source: "Domestic Dog Lineages Reveal Genetic Drivers of Behavioral Diversification," by Emily V. Dutrow, James A. Serpell and Elaine A. Ostrander, in Cell, Vol. 185; December 8, 2022 (reference) | | | • An essential principle of science is that it might change as research accumulates, write David Faigman and Jeff Kukucka, professors of law and psychology, respectively. But such change is a principle that the law has largely failed to come to grips with, they say. Fairness in law for everyone "requires the opportunity to have their cases tried in light of the best science available in the moment." | 5 min read | | | • The board of a school district in Tucson, Ariz. last week adopted a plan to cut its emissions in half by 2030 and to reach net-zero emissions by 2040. | Fast Company | | | • The world's first wooden satellite, a tiny Japanese spacecraft called LignoSat, arrived at the International Space Station (ISS) yesterday. | Space.com | | | It's an honor to connect with you every day and share in the delight, discovery, and resilience of science. Thank you for being a part of the Today in Science community. | —Andrea Gawrylewski, Chief Newsletter Editor | | Subscribe to this and all of our newsletters . | | | | Scientific American
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