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The Guardian
a day ago
- Science
- The Guardian
‘Boiling frog' effect makes people oblivious to threat of climate crisis, shows study
Surveys show that the increasing number of extreme climate events, including floods, wildfires and hurricanes, has not raised awareness of the threats posed by climate change. Instead, people change their idea of what they see as normal. This so-called 'boiling frog effect' makes gradual change difficult to spot. Researchers at Carnegie Mellon University in Pennsylvania wondered if climate change could be made more obvious by presenting it in binary terms. Local newspaper archives describing ice skating on Lake Carnegie when it froze in winter inspired a simple experiment. Some test subjects were shown temperature graphs of a fictional town's winter conditions; others had a chart showing whether or not a fictional lake froze each year. The result, published in Nature, showed those who receiving the second graphic consistently saw climate change as more real and imminent. Binary data gives a clearer impression of the 'before' and 'after'. The disappearing ice is more vivid and dramatic than a temperature trace, even though the underlying data is the same. 'We are literally showing them the same trend, just in different formats,' says Rachit Dubey, a co-author of the study. These results should help drive more effective ways of communicating the impact of climate change in future by finding simple binary, black-and-white examples of its effects.
The Guardian
2 days ago
- Science
- The Guardian
‘Boiling frog' effect makes people oblivious to threat of climate crisis, shows study
Surveys show that the increasing number of extreme climate events, including floods, wildfires and hurricanes, has not raised awareness of the threats posed by climate change. Instead, people change their idea of what they see as normal. This so-called 'boiling frog effect' makes gradual change difficult to spot. Researchers at Carnegie Mellon University in Pennsylvania wondered if climate change could be made more obvious by presenting it in binary terms. Local newspaper archives describing ice skating on Lake Carnegie when it froze in winter inspired a simple experiment. Some test subjects were shown temperature graphs of a fictional town's winter conditions; others had a chart showing whether or not a fictional lake froze each year. The result, published in Nature, showed those who receiving the second graphic consistently saw climate change as more real and imminent. Binary data gives a clearer impression of the 'before' and 'after'. The disappearing ice is more vivid and dramatic than a temperature trace, even though the underlying data is the same. 'We are literally showing them the same trend, just in different formats,' says Rachit Dubey, a co-author of the study. These results should help drive more effective ways of communicating the impact of climate change in future by finding simple binary, black-and-white examples of its effects.
Yahoo
2 days ago
- Science
- Yahoo
Physicists Blast Gold to Astonishing Temperatures, Overturning 40 Years of Physics
Physicists superheated gold to 14 times its melting point, disproving a long-standing prediction about the temperature limits of solids Gold usually melts at 1,300 kelvins—a temperature hotter than fresh lava from a volcano. But scientists recently shot a nanometers-thick sample of gold with a laser and heated it to an astonishing 19,000 kelvins (33,740 degrees Fahrenheit)—all without melting the material. The feat was completely unexpected and has overturned 40 years of accepted physics about the temperature limits of solid materials, the researchers report in a paper published in the journal Nature. 'This was extremely surprising,' says study team member Thomas White of the University of Nevada, Reno. 'We were totally shocked when we saw how hot it actually got.' The measured temperature is well beyond gold's proposed 'entropy catastrophe' limit, the point at which the entropy, or disorder, in the material should force it to melt. Past that limit, theorists had predicted solid gold would have a higher entropy than liquid gold—a clear violation of the laws of thermodynamics. By measuring such a blistering temperature in a solid in the new study, the researchers disproved the prediction. They realized that their solid gold was able to become so superheated because it warmed incredibly quickly: their laser blasted the gold for just 45 femtoseconds, or 45 quadrillionths of a second—a 'flash heating' that was far too fast to allow the material time to expand and thus kept the entropy within the bounds of known physics. 'I would like to congratulate the authors on this interesting experiment,' says Sheng-Nian Luo, a physicist at Southwest Jiaotong University in China, who has studied superheating in solids and was not involved in the new research. 'However, melting under such ultrafast, ultrasmall, ultracomplex conditions could be overinterpreted.' The gold in the experiment was an ionized solid heated in a way that may have caused a high internal pressure, he says, so the results might not apply to normal solids under regular pressures. The researchers, however, doubt that ionization and pressure can account for their measurements. The extreme temperature of the gold 'cannot reasonably be explained by these effects alone,' White says. 'The scale of superheating observed suggests a genuinely new regime.' [Sign up for Today in Science, a free daily newsletter] To take the gold's temperature, the team used another laser—in this case, the world's most powerful x-ray laser, which is three kilometers (1.9 miles) long. The machine, the Linac Coherent Light Source at the SLAC National Accelerator Laboratory in California, accelerates electrons to more than 99 percent the speed of light and then shoots them through undulating magnetic fields to create a very bright beam of one trillion (1012) x-ray photons. When this laser fired at the superheated sample, the x-ray photons scattered off atoms inside the material, allowing the researchers to measure the atoms' velocities to effectively take the gold's temperature. 'The biggest lasting contribution is going to be that we now have a method to really accurately measure these temperatures,' says study team member Bob Nagler, a staff scientist at SLAC. The researchers hope to use the technique on other types of 'warm dense matter,' such as materials meant to mimic the insides of stars and planets. Until now, they've had no good way to take the temperature of matter in such toasty states, which usually last just fractions of a second. After the gold trial, the team turned its laser thermometer on a piece of iron foil that had been heated with a laser shock wave to simulate conditions at the center of our planet. 'With this method, we can determine what the melting temperature is,' Nagler says. 'These questions are super important if you want to model the Earth.' The temperature technique should also be useful for predicting how materials used in fusion experiments will behave. The National Ignition Facility at Lawrence Livermore National Laboratory, for example, shoots lasers at a small target to rapidly heat and compress it to ignite thermonuclear fusion. Physicists can now determine the melting point for different targets—meaning the whole field could be heating up in the near future. Solve the daily Crossword
The Independent
2 days ago
- Science
- The Independent
Earth is spinning faster and is about to see one of its shortest days ever
The Earth is spinning at its fastest rate since records began, and astronomers predict that 5 August will be one of the shortest days ever measured. New estimates released this month suggest that the first Tuesday of August will be around 1.25 milliseconds shorter than it should be. The average rotation of our planet is 24 hours, or 86,400 seconds, however there are several variables that cause Earth to spin faster or slower. The Moon's gravitational influence on Earth typically causes it to slow time over time and for days to lengthen. There is no conclusive reason for why Earth's rotation is accelerating, though a 2024 study suggested that melting polar ice caps and rising sea levels could be influencing it. The shortest day ever recorded was on 5 July, 2024, measuring 1.66 milliseconds shorter, with recent years seeing the rotation speeding up. Scientists have proposed a negative leap second to compensate for the lost time, meaning all of the world's clocks will need to be adjusted. 'This is an unprecedented situation and a big deal,' said geophysicist Duncan Agnew from the University of California, who wrote about the issue in a paper published in the journal Nature last year. 'It's not a huge change in the Earth's rotation that's going to lead to some catastrophe or anything, but it is something notable. It's yet another indication that we're in a very unusual time.' There have been 27 leap seconds added to Coordinated Universal Time (UTC) since 1972, when the present form of the time standard was adopted, in order to match atomic time to astronomical time. This would be the first time that a second has been subtracted, and it is not clear how current computing infrastructure would cope with the shift. Patrizia Tavella from the Time Department at the International Bureau of Weights and Measures, wrote in an accompanying article to the Nature paper that any potential risks should be assessed before a negative leap second is applied. 'A negative leap second has never been added or tested,' she said, 'so the problems it could create are without precedent.'
Gizmodo
2 days ago
- Health
- Gizmodo
Newly Discovered Gut ‘Sense' Could Change How We Think About Hunger and Health
There really is something to the concept of having a gut feeling. New research out today suggests our bodies can directly sense and communicate with the many bacteria lining our digestive tract. Scientists at Duke University led the study, published Wednesday in Nature. They found that nerve cells can respond in real time to bacterial signals from the gut—including signals that tell us to curb our appetite. The findings suggest the relationship we have with our microbial neighbors is even more complex than thought, the researchers say. Humans are well known for having five basic senses (sight, hearing, touch, smell, and taste). But according to the study researchers, growing evidence points to other senses that react specifically to cues from our digestive system, the 'gut sense.' Some of the researchers had previously discovered that certain cells lining the gut can sense specific stimuli and directly communicate with nearby nerve cells that lead back to the brain, called neuropods. And they reasoned that one type of stimuli these cells detect would be the gut microbiome, the trillions of normally harmless, often helpful bacteria and other microbes that live inside us. Study Says U.S. Babies Are Missing a Key Gut Microbe, Fueling Allergy Risk 'We had previously found that neuropod cells in the small intestine sense and rapidly respond to nutrients,' co-lead author Maya Kaelberer, a sensory neuro-gastroenterologist, told Gizmodo. 'It seemed natural to think that neuropod cells of the colon could sense the gut microbiome; therefore, we set out to find out how.' The team focused on an ancient protein found in the tail, or flagella, of many gut bacteria, aptly named flagellin. Gut bacteria appear to produce more flagellin when we eat, and neuropods can detect flagellin through a receptor called the Toll-like receptor 5 (TLR5), the researchers found. In experiments with mice, they also showed that this interaction seems to be key to regulating our hunger. When the researchers gave fasting mice flagellin directly through the colon, for instance, the mice ate less than usual. They then knocked out the TLR5 receptor in neuropods and ran the same experiment, finding that the mice now kept eating and gained weight. The findings indicate that increased levels of bacterial flagellin act as a real-time signal for the brain to tamp down our hunger. Neuropods catch this signal through the TLR5 receptor and then quickly transmit it to the brain via the vagus nerve. If the neuropods' ability to detect nutrients could be considered a sixth sense, then its detection of gut microbes might be a distinct, seventh sense, the researchers argue. 'We discovered that our colon has a sense for microbes, the neurobiotic sense,' Kaelberer said. Bizarre Virus-like 'Obelisks' Found in Human Mouths and Guts More research is needed to confirm and better understand how this neurobiotic sense operates in people, of course. But assuming it's genuine, the discovery would have important scientific and medical implications. Certain health conditions might alter the communication between gut bacteria, neuropods, and the brain, for instance, as might things like our diets or environment. And perhaps someday, we'll be able to safely influence this sense to treat or prevent such conditions. 'If you lived in a world where everything you saw was blue—blue walls, blue ground, blue computers, blue cars… Then you come home to see a yellow/orange peach on your blue table; it would have a profound effect on your experience. Knowing this, can we target this sense to have that same profound experience without the peach?' Kaelberer said. This is still just the beginning of the team's exploratory work. They next hope to uncover whether neuropods can also detect immune-related signals. In the meanwhile, I'll be sure to thank my gut bacteria from now on for helping me have at least some restraint when it's time for dessert.
