June 21, 2024: Time dilation at the edges of the universe, "dark fungi" lurk everywhere, and treasures from the oldest deep-sea shipwreck recovered. —Andrea Gawrylewski, Chief Newsletter Editor | | | Time ticks slower for objects moving at extremely high speeds. Called time dilation, this effect (first proposed by Albert Einstein) grows in intensity the closer to the speed of light that something travels. Hypothetically, since objects in the far-distant universe are speeding up as the expanding cosmos sweeps them farther away from Earth, they should also show more time dilation (which, oddly, should look like they're slowing down to observers. Ahh, physics). By examining measurements from 1,504 stellar explosions called Type 1a supernovae, which have relatively consistent brightness, scientists have shown that these events are neatly displaying time dilation–the farther out they are in the universe, the slower their apparent motion.
Why this matters: Measuring time dilation is "one of the most direct pieces of evidence of the expansion of the universe," says Amitesh Singh of the University of Mississippi. Our best reckoning of the state of the cosmos–that it is expanding–appears to be holding true.
What the experts say: "I love the fact that we can actually see time dilation happening," says Tamara Davis of the University of Queensland, a co-author of the paper. "It's a pretty definitive measurement." | | | An artist's visualization of an imminent Type 1a supernova, a cataclysmic cosmic explosion that can occur when a white dwarf star (left) detonates after siphoning a fixed amount of material from a companion star (right). NASA's Goddard Space Flight Center Conceptual Image Lab | | | The land, water and air around us are brimming with genetic material from fungi that scientists can't identify, and dubbed "dark fungi" (a nod to the mysterious dark energy and dark matter that we know fills the universe but haven't yet identified). Scientists detect dark fungi in environmental DNA (eDNA for short) as fragments of base pairs floating in soil or water samples. A single eDNA study can reveal 20,000 yet-to-be-identified fungal species--and they are often the most abundant DNA fragments in the sample. "I don't think I ever saw an environmental sequencing study with less than 30 percent unknowns," says Henrik Nilsson, a mycologist at the University of Gothenburg in Sweden, and the ratio is typically much higher.
Why this matters: The millions of predicted fungi on Earth play vital, if often unseen, roles. They form symbiotic relationships with plants and decompose organic molecules into carbon and nitrogen that other organisms can utilize. Without these services whole ecosystems could collapse. And yet taxonomists have only identified about 150,000 species of fungus.
What the experts say: Identifying all the dark fungi is crucial to protect the intricate, life-supporting processes they support. "Capturing that diversity," Rosling says, "can help us have a more informed perspective on conservation." | | | Archaeologist Jacob Sharvit, left, and Energean environmental lead Karnit Bahartan, examine two Canaanite storage jars after their retrieval from the seafloor of the Mediterranean on May 30, 2024. Ilan Ben Zion | | | • The oldest deep-sea shipwreck, dating from the Bronze Age, was discovered a mile below the surface of the Mediterranean Sea. | 6 min read | | | • As the patents on various weight-loss drugs near expiration, companies in India and China are vying to make cheaper versions. | 5 min read | | | Heat wave news: • Emergency departments in New England and the Midwest have seen a spike in heat-related visits, as the heat dome in the region refuses to budge. | 3 min read
| | | • The prevalence of sexual harassment in the sciences hasn't improved meaningfully since the 1980s. Science-backed training methods and new laws can make a difference, but research institutions must adopt them rather than carry on simply protecting themselves, write Jenny Morber and Starre Vartan, both professional writers and former scientists. "How harassment is handled can make the difference between substantial trauma and healing for the survivors—and a trauma-informed response can also encourage others to speak out," they say. | 9 min read | | | Can you solve this puzzle? A traveling salesman who lives in city A wants to visit all cities from B to P over the course of a week, though not necessarily in alphabetical order, and return to A at the end. He plans to enter each city exactly once. The blue lines are the only roads connecting the 16 cities. The traveling salesman may use only a straight route between any two cities; he is not allowed to turn at the intersection of two streets. How many different routes are possible? Click here to see the solution. | | | MOST POPULAR STORIES OF THE WEEK | | | • We've Hit Peak Denial. Here's Why We Can't Turn Away From Reality | 6 min read | • Voyager 1 Is Back! NASA Spacecraft Safely Resumes All Science Observations | 3 min read | • Vermont Will Be Hotter Than Miami This Week—Blame the Heat Dome | 4 min read | | | • Island in peril: The Indian government, which inherited Great Nicobar Island from British colonizers, is about to build a massive transshipment terminal there. The island is a UNESCO biosphere reserve and part of the Sundaland biodiversity hotspot. Of the 2,500 plant and animal species so far identified, 17 are only found there. | 18 min read | • The recycling icon is omnipresent—the green knot of arrows is found on plastic bottles, cereal boxes, and bins curbs across the country. But in the decades since it was introduced, the symbol has duped people into buying more plastic. | 18 min read | | | If you enjoy puzzles and games, we've got some fun stuff planned for this summer, so stay tuned! Let me know if you were able to crack the above salesman's dilemma. Test your smarts with this head-scratcher:
What number is missing from this sequence?
1 3 4 3 9 5 16 4 25 _ 36 3 | I'll include the answer in the next Today in Science. Thank you for being part of our circle of science-curious readers! 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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