Friday, November 15, 2024

Today in Science: We're stuck in this reality, physicists say

Today In Science

November 14, 2024: We can't escape our current reality, says quantum mechanics. Plus, iron-toothed reptiles straight out of a nightmare, and AI crunches police bodycam footage.
Andrea Gawrylewski, Chief Newsletter Editor
TODAY'S NEWS
Buildings stand in the flood plains of the Nubra Valley, where the Nubra river flows into the Shyok river as part of the Indus River system. Prashanth Vishwanathan/Bloomberg via Getty Images
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AI analyses of tens of millions of hours of body camera footage is helping police departments enact reform. | 7 min read
More News
TOP STORIES

This is Our One and Only Reality

In troubling times, some people may wonder about the idea of multiverses–where other versions of us and our reality are playing out, but perhaps differently–and whether we're in a particularly bad iteration. The real question, writes George Musser, author and contributing editor of Scientific American, is not whether there are other so-called timelines: according to quantum physics, there almost certainly are. The real question is why we experience only one reality (for better or worse). 

On the nature of our reality: Human comprehension–and perhaps life itself–could not accommodate the knowledge of every possible outcome of existence, Musser speculates, especially considering their infinitudes.  

What the experts say: One of the key insights of physicist Hugh Everett, originator of the multiverse-spawning "many worlds" interpretation of quantum mechanics, concerned the consequences of humans being part of the reality we hope to observe. Because we are embedded in the system, Everett argued, we can never observe other branches of reality firsthand. "Rather than holding open all possibilities, a mind must settle—at least tentatively—on one," writes Musser. "The effort required to make that choice—and, from there, to act upon it—may be key to giving us at least the subjective feeling of free will." 

Iron Tooth

Close-up images showing orange serrations running down the front and back of a Komodo dragon tooth.From "Iron-coated Komodo Dragon Teeth and the Complex Dental Enamel of Carnivorous Reptiles," by A.R.H. LeBlanc et al., in Nature Ecology & Evolution. Published online July 24, 2024
Researchers took a close look at the Komodo dragon's 60 serrated teeth, each up to an inch long. They observed an orange discoloration on the outer layer of the teeth. Using chemical and structural imaging the scientists discovered that the orange coating is iron. It's the first confirmed finding of iron on reptilian teeth. (Some fish and salamanders, as well as a handful of mammals—most notably beavers—are also known to include iron in their teeth.)

How it works: The tip of each pointed Komodo dragon tooth curves back into the animal's mouth, which lets the animal tear off and swallow chunks of meat (*shudder*). The iron reinforces this structure and runs down the front and back of each tooth.

What the experts say: "Now that we're starting to actually take a closer look at different reptiles, we're finding all of these really cool adaptations," says Kirstin Brink, a paleontologist at the University of Manitoba.
EXPERT PERSPECTIVES
• Modern cannabis products are highly engineered, with THC concentrations up to 90 percent, compared with historical levels of around 2 to 4 percent. Such increased potency has serious implications for health, with some THC varieties and additives linked to mental health concerns. Though they are legalized and regulated at the state level, cannabis products would benefit from national standardized, evidence-based policies, writes Yasmin Hurd, professor of psychiatry at the Icahn School of Medicine in New York City. "I strongly urge policy makers to remove barriers to effective research on the health impacts of cannabis legalization," she says.  | 5 min read
More Opinion
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For a thought-provoking thriller about the multiverse, I recommend the sci-fi novel Dark Matter by Blake Crouch. A physics professor invents a machine that allows him to jump from one reality to the next. It gets dark fast, and certainly lends credence to George Musser's observation above that perhaps humans are not meant to see the larger fabric of the universe. If you've already read it, let me know your thoughts!
I'm always open to great sci-fi book recommendations. And of course any other feedback: newsletters@sciam.com. See you tomorrow!
—Andrea Gawrylewski, Chief Newsletter Editor
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Scientist Pankaj

Today in Science: Humans think unbelievably slowly

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