Latest from Scientific American
Scientific American
a day ago
- Science
- Scientific American
Cover Art Jigsaw: April 1954
Sarah Lewin Frasier is Scientific American 's senior news editor. She plans, assigns and edits the Advances section of the monthly magazine, as well as editing online news. Before joining Scientific American in 2019, she chronicled humanity's journey to the stars as associate editor at (And even earlier, she was a print intern at Scientific American.) Frasier holds an A.B. in mathematics from Brown University and an M.A. in journalism from New York University's Science, Health and Environmental Reporting Program. She enjoys musical theater and mathematical paper craft.
Scientific American
2 days ago
- Health
- Scientific American
Organs Age in Waves Accelerating at 50 Years Old
It is a warning that middle-aged people have long offered the young: ageing is not a smooth process. Now, an exhaustive analysis of how proteins change over time in different organs backs up that idea, finding that people experience an inflection point at around 50 years old, after which ageing seems to accelerate. The study, published 25 July in Cell, also suggests that some tissues — especially blood vessels — age faster than others, and it identifies molecules that can hasten the march of time. The findings add to mounting evidence that ageing is not linear, but is instead pockmarked by periods of rapid change. Even so, larger studies are needed before scientists can label the age of 50 as a crisis point, says Maja Olecka, who studies ageing at the Leibniz Institute on Aging — Fritz Lipmann Institute in Jena, Germany, and was not involved in the study. On supporting science journalism If you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today. 'There are these waves of age-related changes,' she says. 'But it is still difficult to make a general conclusion about the timing of the inflection points.' Showing their age Previous work has shown that different organs can age at different rates. To further unpick this, Guanghui Liu, who studies regenerative medicine at the Chinese Academy of Sciences in Beijing, and his colleagues, collected tissue samples from 76 people of Chinese ancestry aged 14 to 68 who had died from accidental brain injury. The samples came from organs representing eight of the body's systems, including the cardiovascular, immune and digestive systems. The researchers then created a compendium of the proteins found in each of the samples. They found age-related increases in the expression of 48 disease-associated proteins, and saw early changes at around age 30 in the adrenal gland, which is responsible for producing various hormones. This tracks well with previous data, says Michael Snyder, a geneticist at the Stanford University School of Medicine in California. 'It fits the idea that your hormonal and metabolic control are a big deal,' he says. 'That is where some of the most profound shifts occur as people age.' Between the ages of 45 and 55 came a turning point marked by large changes in protein levels. The most dramatic shift was found in the aorta, the body's main artery, which carries oxygenated blood out of the heart. The team tracked down one protein produced in the aorta that, when administered to mice, triggers signs of accelerated ageing. Liu speculates that blood vessels act as a conduit, carrying molecules that promote ageing to remote destinations throughout the body. The study is an important addition to others that have analysed molecules circulating in the blood, rather than tissue samples taken from individual organs, as a way to monitor age-related changes, says Snyder. 'We're like a car,' he says. 'Some parts wear out faster.' Knowing which parts are prone to wear and tear can help researchers to develop ways to intervene to promote healthy ageing, he says. Halfway to 100 Last year, Snyder and his colleagues found ageing inflection points around the ages of 44 and 60. Other studies have found accelerated ageing at different times, including at around 80 years old, which was beyond the scope of the current study, says Olecka. Discrepancies with other studies can emerge from their use of different kinds of samples, populations and analytical approaches, says Liu. As data build over time, key molecular pathways involved in ageing will probably converge across studies, he adds. These data will accumulate rapidly, says Olecka, because researchers are increasingly incorporating detailed time series in their studies, rather than simply comparing 'young' with 'old'. And those results could help researchers to interpret these periods of rapid change. 'Currently, we do not understand what triggers this transition point,' she says. 'It's a really intriguing emerging field.'
Scientific American
2 days ago
- Science
- Scientific American
The Sky Is Falling—From Another Star
Aliens are visiting our solar system. Not little green men, sadly, but natural alien objects —cosmic bodies such as comets and asteroids born elsewhere in the galaxy that zip by the sun as they drift through the Milky Way. They're not so much visiting as just passing through. Though these objects were speculated to exist for a long time, we didn't know they were out there for sure until October 2017, when astronomers noticed a small body moving through space at exceptionally high speed. Observations over just a few nights showed it was moving far too quickly to be orbiting the sun and thus must have come from some other star. It was our first known interstellar visitor. On supporting science journalism If you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today. Eventually designated 1I/'Oumuamua, it was 30 million kilometers from Earth and already outward bound from the solar system when it was discovered, offering scant time for follow-up studies. But then, less than two years later, a second such object was found, also moving far faster than usual. 2I/Borisov turned out to be a comet very similar to those we're familiar with, except for its trajectory, which clearly showed it came from interstellar space. And now a third such alien body is barreling through the solar system: 3I/ATLAS, moving so rapidly its path is barely bent at all by the sun's gravity as it zooms past. In science, one is an anomaly and two might be coincidence, but three is a trend. Clearly, objects like this are passing by on the regular. Roughly speaking, there could be ones 100 meters in size or larger passing through the inner solar system at any time. Given their speed and intrinsic faintness, though, they're difficult to detect. We also know that when it comes to things such as asteroids and comets, nature tends to make many more smaller ones than bigger ones. In our own solar system, for example, only a couple of dozen main-belt asteroids are bigger than 200 km wide, but more than a million are 1 km across or larger. This generalization should hold for interstellar interlopers as well. For every kilometer-scale one that we see, there should be far more that are smaller. In fact, there could be millions of sand-grain-sized alien objects whizzing past us right now. And we already know that they're out there: in 2014 astronomers announced they had found seven grains of cosmic dust brought down to Earth from the Stardust space probe, which was designed to catch material ejected from a comet. Also, embedded in some meteorites that have hit Earth are tiny bits of material, called presolar grains, that are so old they actually formed around other stars. They got here after being blown across the void of space into the collapsing cloud of gas and dust that formed the sun and planets 4.6 billion years ago. Larger material could be ejected from an alien planetary system if it's given a gravitational assist when passing by a planet there, or it could be torn away from its parent star by another star passing closely to that system. So it seems certain interstellar jetsam would occasionally hit our planet. Earth is a small target, but with so many galactic bullets, you'd think some would actually find their way to our planetary bull's-eye. The problem is detecting them. Every day Earth is hit by very roughly 100 tons of locally grown interplanetary debris—material ejected from asteroids and comets native to our solar system—which translates into billions of tiny specks zipping across our sky daily. Detecting the tiny fraction that have an interstellar origin is tough. And the difficulty is not just in the sheer numbers. It's in tracing the trajectories of that small handful across the sky back up into space to calculate their orbits. When an object such as a planet or an asteroid orbits the sun, we say it's gravitationally bound to our star. That orbit in general is an ellipse, an oval shape. These can be defined mathematically, with the key factor being the eccentricity: how much the ellipse deviates form a circle. A perfect circle has an eccentricity of 0, and the higher the eccentricity, the more elliptical the orbit, up to a value of just under 1. An orbit with an eccentricity of 0.99, say, is extremely elongated; you might find that an object dropping down very close to the sun from the outer solar system has an eccentricity that high. It's possible to have an eccentricity higher than 1 as well. That kind of trajectory is called hyperbolic—named after the mathematical curve, not because it's exaggeratedly over-the-top—and an object on this path is not bound to the sun gravitationally. Once it's heading out, it's gone forever. It ain't coming back. This is how we know 'Oumuamua, Borisov and ATLAS are from interstellar space; each has an eccentricity greater than 1—'Oumuamua's is about 1.2 and Borisov's 3.4, which is quite high, but ATLAS has them both beat with an astonishing eccentricity of 6.2. That's extraordinarily high and also indicates it's hauling asteroid (or, more accurately, it's not comet back). Do we see any meteors with eccentricities like these? If the exact path of a meteoroid (the term for the solid bit that burns up in the air and becomes a meteor) through Earth's atmosphere can be determined, that can be backtracked up into space, allowing the object's trajectory, including its eccentricity, to be calculated. This can be done with multiple sky cameras set up in various locations; if a meteor streaks across their field of view, the multiple vantages can allow astronomers to triangulate on the rock and measure its path. There are quite a few such camera networks. It's actually difficult getting good enough data to determine solid orbits for meteoroids, though. Many do have eccentricities very close to 1; these likely come from long-period comets that originate out past Neptune. NASA's Jet Propulsion Laboratory maintains a database of bright fireballs —exceptionally luminous meteors—at the Center for Near-Earth Object Studies (CNEOS). The earliest recorded meteors in the database date back to 1988, so there is a rich hunting ground in the data. Are any of the meteors listed hyperbolic? Unfortunately, no. At least, not unambiguously —there have been false positives but nothing clear-cut. Additionally, a study from 2020 looked at 160,000 measurements by the Canadian Meteor Orbit Radar covering 7.5 years. The researchers found just five potential interstellar meteors. The results aren't quite statistically strong enough to claim detections for sure, but they're very compelling. What we need are more eyes on the sky, more meteor camera networks that can catch as many of these pieces of cosmic ejecta burning up in our atmosphere as possible. It's a numbers game: the more we see, the more likely we'll see some that are not from around here. The science would be, well, stellar: these meteors can tell us a lot about the environments around other stars, the ways they formed and perhaps even the stars they come from. We're getting physical samples from the greater galaxy for free. We should really try to catch them.
Scientific American
2 days ago
- Sport
- Scientific American
The Surprising Math and Physics behind the 2026 World Cup Soccer Ball
Every four years, soccer fans eagerly await the sport's biggest event: the International Federation of Association Football (FIFA) World Cup. But before each dramatic kickoff, artists and researchers spend years designing, testing and revising the official match ball. Recently images of the planned ball for the 2026 competition were leaked, and its design incorporates math, physics and style in some surprising ways. Called the Trionda (Spanish for 'triwave'), the new ball celebrates the three host nations—the U.S., Mexico and Canada—for the first multinational-hosted World Cup. The ball is stitched together from just four panels, the smallest number yet for a FIFA World Cup ball. And it represents a significant reduction from the 20-paneled Al Rhila ball that was used in 2022. The design of any soccer ball hinges on an age-old question: How can one make rounded shapes out of flat material? Every FIFA World Cup ball so far has borrowed inspiration from some of math's simplest three-dimensional shapes: the platonic solids. These five shapes are the only convex polyhedrons built from copies of a single regular polygon. On supporting science journalism If you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today. The icosahedron, which has 20 triangle faces and a relatively ball-like appearance, seems promising, but it's still a bit too pointy to roll around. If we cut off (or truncate) the points of an icosahedron, each of the triangles becomes a hexagon, and each of the points becomes a pentagon. This is the shape of the classic soccer ball, originally called the Telstar ball and used in the official FIFA World Cup match in 1970. The stark black-and-white color scheme was meant to increase visibility on black-and-white TVs, which were still prevalent at the time. The Trionda ball is also based on a platonic solid—the tetrahedron—which at first seems the least ball-like of all the famous shapes. A tetrahedron is made of four triangles, three of which meet at every point. The trick in the Trionda design is in the shape of the panels. Though they have three points like a typical triangle, the panels' edges are curves that fit together to give the ball a more rounded exterior. This method of making a pointy platonic solid rounder by curving the edges of the faces may be familiar to soccer fans; in fact, the design of the Trionda ball strongly evokes the Brazuca, a six-paneled ball based on a cube that starred in the 2014 World Cup. Basing the Trionda ball on a tetrahedron might be a risky choice; the last match ball based on that shape was highly controversial. The Jabulani ball, whose name means 'rejoice' in Zulu, might have been a bit too joyful. Players complained it was unpredictable in the air and didn't react the way they expected it to. The design of the Jabulani combined both methods of turning a platonic solid into a sphere: cutting off the corners to make eight faces and turning the edges of the faces into curves. It also had a unique feature, shared with none of the official match balls before or since: three-dimensional, spherically molded panels. The Jabulani may have been the roundest ball yet. So why didn't it work as intended? The answer has to do with 'drag'—the force of air particles pushing back on the ball as it flies through space. Typically, the faster a ball moves, the more drag it experiences, which can slow it down and change its trajectory. But each ball also has a 'critical speed' past which the drag on the ball decreases significantly. The smoother a ball is, the higher the critical speed barrier becomes. This is why the surfaces of golf balls have dimples: they lower the critical speed and help the balls move faster through the air. These effects mean that rounder and smoother isn't always better—and may explain the Jabulani's unpredictable behavior. The minimization of drag is likely why the Trionda ball has divots in its surface and offers another reason for its meandering seams. Ball designers use a combination of surface texture, seam length and seam depth to achieve just the right amount of 'roughness' so that players are comfortable with the ball when they step onto the field. While the amount of roughness is important, the placement of seams and surface texture can also affect a ball's reliability in the air. In particular, researchers are concerned about the 'knuckleball effect,' named after a kind of baseball pitch. When a ball spins quickly through the air, the placement of its rough elements matters less; the ball moves as if these features are evenly distributed. But if the ball is pitched or kicked in a way that minimizes spin, its rougher areas will feel different amounts of drag than smoother sides, causing it to move unpredictably. This effect is good for a baseball pitcher, who wants to make the ball more difficult for the batter to hit, but not so much for a soccer player, who wants the ball to go precisely where they aim it. To avoid this effect, soccer ball designers often try to make balls as symmetrical as possible; they want a ball to look the same from different angles as it rotates. Symmetry is one concern experts have about the Trionda ball; because it is based on a tetrahedron, it has fewer symmetries than, for example, the classic Telstar ball. Whereas the Telstar ball looks precisely the same in 60 possible positions, the Trionda ball only has 12 rotational symmetries. Players will be keeping a close eye on how all these qualities might affect the way the ball plays on the field. Keeping track of the ball developments and practicing extensively with the match ball is 'very important,' says Brad Friedel, a retired goalkeeper who played on the U.S.'s respective national teams in two World Cups and two Olympic Games. When testing out a new ball, he says, 'you just go through a normal training session and [see] what little nuances it has. Does it only have good grip when it's dry? Is it good when it's wet? What's the flight like on chip crosses?' Of different ball shapes in general, Julia Grosso, a midfielder for the Chicago Stars Football Club, who has played on the Canadian team in the past two Women's World Cups, says, 'It's more about how can we work together as a team to win rather than what kind of ball we are playing with.' But she adds that practicing with a particular ball before the game 'really helps' to get a feel for how it will react and adjust accordingly. Players aren't the only ones who are eager to get their hands on new balls. 'I'm dying to hold [the Trionda] to see what it feels like and what the seam structure is like and all that,' says sports physicist John Eric Goff of the University of Puget Sound. Once the ball is officially released, he and his colleagues will do wind tunnel tests to analyze its precise physical properties. While most soccer fans will be rooting for the players, entire networks of artists, engineers and scientists will be rooting for the ball.
Scientific American
2 days ago
- Climate
- Scientific American
Scorching Heat Dome Grips Eastern U.S., with No Relief in Sight
A lingering heat dome over the eastern half of the U.S. is putting tens of millions of people in sweltering conditions, with the worst still to come. On July 25 the East Coast is bearing the brunt of the heat, with more than 80 million people at major or extreme risk of heat effects, according to the National Weather Service, a branch of the National Oceanic and Atmospheric Administration. And as the coming days unfold, the southeastern U.S. will see several days of potentially record-setting heat, with nearly 150 million people—almost half the nation's population—at major or extreme risk of heat effects on July 28. 'Even though it's midsummer, this is pretty notable,' said Bryan Jackson, a meteorologist at the NWS Weather Prediction Center in College Park, Md., in an interview with Scientific American earlier this week. On supporting science journalism If you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today. Heat domes occur when a high-pressure mass of air traps heat in place. 'Essentially, it's a cap on the atmosphere that typically leads to warmer temperatures but also leads to sunnier days and less chance of precipitation,' says Zack Taylor, also a meteorologist at the NWS Weather Prediction Center. For people under the sweltering influence of a heat dome, the weather pattern can be excruciatingly tedious to endure, Jackson told Scientific American. 'Heat domes are generally slow to form and slow to dissipate,' he said. The current event will be long-lived even for a heat dome. Although the system will only briefly raise temperatures along the East Coast on July 25, it will then settle over the Southeast and grow, with potentially record-breaking heat conditions expected to continue through around July 31. The Southeast's tendency toward high humidity at this time of year traditionally keeps air temperatures somewhat lower, Taylor adds, reducing the frequency of 100-degree-Fahrenheit (38-degree-Celsius) days. But that might not hold true this week: in the next few days, cities such as Columbia, S.C., and Tallahassee, Fla., may tie or break daily record temperatures in the low 100s F. And the high humidity will mean that temperatures can't fall much overnight, offering people little respite from the dangerous conditions. Overall, huge portions of the U.S. population will struggle with heat in the coming days. The National Weather Service's HeatRisk map includes five categories of risk, from little to none up to extreme, which it describes as 'rare and/or long-duration extreme heat with no overnight relief.' More than 24 million people will experience those conditions on July 28 and 30, with more than 30 million people facing extreme heat risk on July 29. In addition, more than 100 million people will face major heat risk on July 28 and 29. Heat can be deadly: in 2023 the Centers for Disease Control and Prevention reported 2,325 deaths as heat-related —more than double the number in 1999, according to a study published last year. And as climate change continues to unfold, dangerous heat conditions will become ever more prevalent. If you live in an affected area, check out our science-backed tips for staying healthy in extreme heat and for keeping your house cool.
