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"How to hunt for prime numbers."

Views expressed in this science and technology update are those of the reporters and correspondents.  Accessed on 27 January 2025, 2125 UTC.

Views expressed in this science and technology update are those of the reporters and correspondents.  

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Russ Roberts (https://hawaiisciencejournal.blogspot.com). 

January 27, 2025: How farmlands could absorb CO2 from the atmosphere. Plus, new tricks for hunting prime numbers and the impact of the U.S. leaving the WHO.    —Andrea Gawrylewski, Chief Newsletter Editor TODAY'S NEWS In this long exposure photo, fire smolders on a hillside during the Lilac fire in unincorporated San Diego County, California on January 21, 2025. Josh Edelson/AFP via Getty Images California fire news: • In a dark turn of irony, the L.A. fires have delayed the release of the state's newest fire hazard maps. It's an example of climate disasters making it more difficult to prepare for future disasters. | 6 min read • Uber drivers and other contractors for ride-hailing apps helped evacuate people from the L.A. fires. But those workers are excluded from state laws that require their employer provide safety measures to protect them from wildfire. | 5 min read • Southern California received some welcome rain over the weekend. But in burned landscapes, rain can lead to destructive landslides. | 3 min read Other news: • Tech giants are backing a massive government effort, dubbed the Stargate Project, to add data centers across the U.S. Here's what's in the plan. | 3 min read • On today's Science, Quickly, senior health editor Tanya Lewis discusses the potential impact of the U.S. leaving the WHO. | 10 min listen • Margarethe Hilferding was the first woman admitted to Sigmund Freud’s Vienna Psychoanalytic Society. But her work has largely been forgotten. | 41 min listen More News TOP STORIES A worker spreads pulverized basalt on a recently harvested cornfield in central Illinois. Jordan Goebig/University of Illinois Absorbing CO2? Rock On Last year, researchers in the midwest spread 190 metric tons of a crushed volcanic rock called basalt over fields that were then planted with corn crops. They found that, over four years, fields treated with crushed basalt and planted with alternating crops of corn and soy pulled 10 metric tons more CO2 per hectare out of the air than untreated plots. And crop yields were 12 to 16 percent higher. These stunning results were an early test of whether the world's farmlands could be used to suck carbon dioxide out of the air and slow global warming. How it works: Why use basalt? As it naturally weathers—gradually dissolving in soil water—volcanic basalt captures CO2, converting it into bicarbonate ions in the water, which cannot easily reenter the atmosphere. Instead, the water is carried out to the sea and the CO2 is stored in the ocean for up to 1,000 years. If such a technique were to be scaled up globally, it could remove up to two billion metric tons of CO2 from the air every year, according to experts. The catch: Enhanced rock weather, as it’s called, would require mining and crushing billions of tons of rock every year—enough to build a mountain—and transporting it to farms. The whole process would release CO2. Even so, those emissions would be small compared with the amount of CO2 that the rock stores away for centuries or longer. Prime Hunters Prime numbers appear in unpredictable and seemingly random patterns (consider the first 10 prime numbers: 2, 3, 5, 7, 11, 13, 17, 19, 23, 29. Pretty random), especially in larger sets of numbers. Mathematicians recently devised a way to hunt for primes by examining two ways of predicting prime numbers. The new tactic also reveals that there are limits to mathematicians’ ability to detect primes. What they found: To predict when prime numbers will appear, there are two types of information mathematicians commonly use to filter potential results. Type 1 information helps to remove numbers from the pool by filtering them for any multiples (if they can be divided by 2 or 3, for example). Type II information tracks how many times a number is eliminated from the pool of potential numbers. The researchers combined both Type I and Type II information to get a better guess at how many prime numbers exist in given ranges. By doing so, they also found that using these tools can only help mathematicians so much. There’s a limit to what they can predict. What the experts say: Understanding the limits for how many prime numbers mathematicians can predict is crucial for developing a complete theory of prime numbers, says Princeton University mathematician Peter Sarnak, an expert in prime sieve theory: “Uncovering what one cannot achieve is fundamental.” If you're enjoying all the science we cover in this newsletter, dive deeper with a subscription to Scientific American. You'll have access to all our articles and will be supporting crucial science journalism.  EXPERT PERSPECTIVES • For decades we have ignored dire warnings from scientists about a warming climate. And now, watching homes burn and wash away in floods and landslides, it's like we're living in a dystopian climate thriller, writes Peter H. Gleick, a hydroclimatologist, member of the U.S. National Academy of Sciences and senior fellow and co-founder of the Pacific Institute. "Refusal to acknowledge the role of climate change must stop. It hinders efforts to mitigate climate change by cutting damaging emissions. It contributes to failures to strengthen our ability to adapt to those impacts we can no longer avoid. And it massively worsens the human suffering caused by accelerating disasters." | 4 min read More Opinion It's an insidious feedback loop: The more extreme climate-change-fueled disasters that happen (wildfires, hurricanes, flooding), the more time and resources are required to recover from those disasters. While efforts are spent on recovery, preparations may not be made for the next disaster down the line (by improving infrastructure, for example), making some locations even more vulnerable to disaster. And on it goes. Perhaps recovery needs to be intricately tied in to preparation to break the cycle of vulnerability.  Email me and let me know how I'm doing: newsletters@sciam.com. See you tomorrow. —Andrea Gawrylewski, Chief Newsletter Editor Subscribe to this and all of our newsletters here. Scientific A

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