September 20, 2024: We're covering the new phase of searching for dark matter, seasonal morality and the tradeoffs of autism screeners. —Robin Lloyd, Contributing Editor | | | Scientists are fairly certain that the universe is filled with dark matter, the invisible stuff that exerts a gravitational pull on normal matter like stars, but physicists have struggled for decades to pin down its precise location and composition. At this point, physicists have ruled out the easiest candidates other than massless particles called neutrinos—they could only account for about 1 percent of dark matter. Most current and planned experiments are looking for either weakly interacting massive particles (WIMPs) or quantum chromodynamics (QCD) axions, particles even lighter than neutrinos, write theoretical physicists Tracy R. Slatyer and Tim M. P. Tait.
Why this matters: Many physicists hoped that big, expensive experiments, such as the Large Hadron Collider, would yield an answer to the dark matter question, but so far, no such luck. A group of optimistic physicists recently agreed that the best approach going forward in the search for dark matter is to cast a wide net, relying on many small experiments, each sensitive to a different candidate for dark matter.
What the experts say: Despite the lack of truly satisfying results to date, it's hard to write off the existence of dark matter. "Most sophisticated attempts to formulate self-consistent theories of modified gravity to explain away dark matter end up invoking a type of dark matter anyway, to match the ripples we observe in the cosmic microwave background, leftover light from the big bang," Slatyer and Tait write. | | | People are more judgmental in the shoulder seasons (fall and spring) than they are in the summer and winter, an analysis of more than 230,000 survey responses from people in the U.S., Canada and Australia. Participants were asked to make right-or-wrong calls on topics concerning loyalty to one's own group, respect for leaders and rules, and cleanliness and piety. Anxiety during seasonal swings could be behind the finding, says psychologist and study co-author Brian O'Shea, reports Anvita Patwardhan.
Why it matters: Seasonal variations in our thoughts about morality could affect jury-duty behavior, whether we get vaccinated and our voting behavior in elections.
What the experts say: "One thing that this article is showing is that we are very seasonal creatures," says psychiatrist Norman Rosenthal, who specializes in seasonal affective disorder. | | | Jasmin Merdan/Getty Images | | | • Pediatricians nowadays encourage screening children for myriad developmental and behavioral conditions, but many screening questionnaires come with tradeoffs, writes psychologist Chris Sheldrick. For instance, the thresholds or cut-points for scoring positive for a condition are somewhat subjective, depending on one's appetite for underdetection or overdetection. Both outcomes are potentially stressful for parents and children. More concerning: for autism and other conditions with low prevalence in the general population, screener thresholds typically err on the side of overdetection; that is, a large percentage of children who are scored positive for a condition do not actually have it. So-called validated screeners "can be useful and are worthy of our attention—but we should use our judgment, too," Sheldrick writes. | 5 min read
| | | • Do you know the answer to the first question of today's science quiz? Also, don't miss today's Spellements, and if you spot any science words that are missing from the puzzle, email them to games@sciam.com. This week, readers Martin, William, Bruce and Kathleen all found briar. Nice work, all! | | | MOST POPULAR STORIES OF THE WEEK | | | • The Arctic seed vault shows the flawed logic of climate adaptation. | 4 min read | • Vote for Kamala Harris to support science, health and the environment. | 7 min read | • Why is it so much harder for NASA to send people to the moon now than it was during the Apollo era? | 13 min read | • A huge tsunami caused by a thinning glacier created a seismic event for nine days. | 4 min read | | | • There's no unified theory of humor and what people find funny, but some definitions and categories of jokes capture large portions of the experience, writes freelancer Biovanni Sabato. One partial theoretical catch-all is "benign violations," in which humor follows a person's recognition that a social or physical norm has been violated. That includes the relief of laughing about misfortunes, juxtapositions of incongruous concepts or expectation violations. | 10 min read | | | —Robin Lloyd, Contributing Editor | | Subscribe to this and all of our newsletters . | | | | Scientific American
One New York Plaza, New York, NY, 10004 | | | | | | Support our mission, subscribe to Scientific American | | | | | | | | | |
