August 23, 2024: Pupil size is linked to cognition, another galaxy is on a collision course with ours, and new COVID vaccines are on the way. —Andrea Gawrylewski, Chief Newsletter Editor | | | A pair of far-distant colliding spiral galaxies, as seen by NASA's Hubble and Spitzer space telescopes. NASA, ESA, and The Hubble Heritage Team (STScI) | | | The Andromeda galaxy appears to be on a collision course with the Milky Way. Currently about 2.5 million light-years away from our galaxy, it is speeding toward us at about 110 kilometers per second. Yet some of that movement could be lateral, and Andromeda may end up whizzing by instead of colliding. Astronomers created computer simulations of the motions of both galaxies and ran them over and over, changing various variables each time, and calculated that the odds of Andromeda and Milky Way colliding is about 50 percent.
How it works: The collision of two galaxies is a long dance that takes about a billion years to complete. Two galaxies usually pass closely to each other, each stretching like taffy as their gravitational pulls clutch at each other, writes astronomer and columnist Phil Plait. That stretching decreases their orbital energy, so that they circle back around and slam into each other some time later, merging into a new elliptical galaxy.
What the experts say: Such a collision would not occur for 8 billion years, so rest easy, Plait says. Plus, many variables (like the gravitational pull of other galaxies in the area) may prevent collisions. "Collisions and mergers such as this are how galaxies grow. The Milky Way is a bruiser among galaxies, and we got here by what is essentially galactic cannibalism." | | | Pupil size can indicate cognitive power. In a recent study, participants looked at a sequence of numbers that each flashed on a screen for 2.5 seconds. They then had to indicate whether the current digit matched a number they had seen two digits earlier in the sequence. Participants whose pupils dilated more performed better on the task.
How it works: People who were better able to identify the correct number devoted more intense attention (indicated by their increased pupil diameter) more consistently (indicated by less variation in their pupil size). The results align with the so-called intensity-consistency framework: People who more consistently and intensely devote their attention toward a task perform that task better.
What the experts say: Tracking the link between cognitive performance and pupil size could be a useful research tool since it's noninvasive, says neuroscientist Andreas Tolias of Stanford University. "Finding these correlations with performance is yet another indication that pupil measurement is very important." | | | A chinstrap (Pygoscelis antarcticus) and a gentoo (Pygoscelis papua) penguin. Juan Barreto/AFP via Getty Images | | | • An analysis of almost 50,000 brain scans reveals five distinct patterns of brain atrophy associated with aging and neurodegenerative disease. | 3 min read | | | • The Polaris Dawn space mission is set to launch next week. If successful, the four-person crew will complete the first commercial space-walk. | 6 min read | | | • The FDA just approved the latest COVID vaccines. It's just in time to meet the current high case rate. | 7 min read | | | • In a non-peer reviewed analysis, Sam Wyatt and Gary N. Smith, a student and professor of economics at Pomona College, respectively, found that only 10 of the 43 partly AI-powered investment funds in the market have done better than the S&P 500 during their lifetimes. And the average annual return for all 43 funds was about five percentage points per year worse than the S&P 500. Funds fully powered by AI performed even worse. "The Achilles' heel of AI systems is that while they are unparalleled at finding statistical patterns, they have no way of judging whether the patterns they find are plausible or pointless," they write. | 4 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 Louise from Montreal, Lisa from Belgium, and Lisa Rowley all found occipital (which is also a pangram!). Well done, Spellementers! | | | MOST POPULAR STORIES OF THE WEEK | | | • Something Is Wrong with Dark Energy, Physicists Say | 5 min read | • The Paradox of 1 – 1 + 1 – 1 + 1 – 1 + … | 6 min read | • People Are Overdosing on Semaglutide Drugs like Ozempic and Wegovy | 5 min read | | | • An analysis of 2,845 adults—ages 22 to 77 at the start— for more than 20 years found that people seem less stressed as they grow older. As our life experiences accumulate we learn how to cope with things and stress less. | 5 min read | • The great tits are some of the most recognizable birds in Europe and Asia. They evolved in deciduous forests but survive remarkably well in urban environments, thanks to their cleverness and adaptability. There seem to be no limits for this species when it comes to inventing new ways of acquiring food from people. | 5 min read | | | For school kids and families with school-age children, summer is sadly coming to an end in the next week or two. For others, fall officially begins on September 22, the autumnal equinox. Daylight will start dwindling quickly here in the Northern Hemisphere after that date, as the Earth's northern axis starts angling away from the sun. My advice is to soak up the last late sunsets, beach reads and ice cream cones (what am I saying, ice cream is a year-round food). | Savor your weekend--relax, restore and email me anytime: newsletters@sciam.com. See you back here on Monday! | —Andrea Gawrylewski, Chief Newsletter Editor | | Subscribe to this and all of our newsletters . | | | | Scientific American
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