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I’LL level with you: a part of me didn’t want to write this story. When I first realised that I was losing my hair, I found it important to mention it often in conversation. I was so embarrassed about it that I was trying some sort of reverse psychology. But I soon realised that if there was one thing less attractive than my balding head, it was how much I was talking about it. I am joking, of course: there is nothing wrong with being bald. Still, for me, the prospect is terrifying. My hair is a big part of my identity, so to lose it is crushing.
So although I have dialled down the discussion of my growing bald patch, I have been quietly digging into the science of hair loss – and what I found is worth shouting about. It is common knowledge that some treatments can slow hair loss. What is less known is that as we are coming to understand the reasons why male pattern baldness causes people to lose their hair, we are finding new strategies to restore it. There may soon be a way to not just slow balding, but reverse it.
Searching for superheavies — Science News, September 8, 1973
Physicists and chemists have been actively searching for superheavy elements, substances with atomic weights and numbers greater than the 105 [elements] now known. Results of two searches are reported … none were found…. Future searches will have to involve direct fusion of heavy nuclei by driving one against another in heavy-ion accelerators.
Update
Particle accelerators have been crucial for creating superheavies beyond elements 104 and 105. Just a year later, element 106, seaborgium, emerged from collisions of oxygen ions and californium atoms — though its discovery wasn’t officially confirmed until two decades later (SN: 3/19/94, p. 180). Elements 107 through 118 have since made their debut, with several joining the periodic table as recently as 2016. Scientists are now trying to create elements 119 and 120 (SN: 3/2/19, p. 16). Forming heavier elements and pushing known superheavyweights to their limits could reveal insights into the forces that bind atoms together and the bizarre chemistry of the most extreme elements.
AS YOUR eyes scan these words and absorb this sentence, do you feel you are resting? There is good reason to think you might. In 2016, more than 18,000 people responded to a survey called The Rest Test, which asked them how they unwind, and the top answer was by reading.
This comes with caveats. Sat in your sunny garden fondly perusing a copy of New Scientist, you may respond in the affirmative. But if you are a student researching an essay due tomorrow, the answer is probably a definite no. Whether an activity is restful is clearly contextual. It is also hugely subjective: in The Rest Test, many people reported that their favoured forms of rest were either exercise or becoming absorbed in work.
Such challenges are one reason why this topic has been rather neglected scientifically. In the past, researchers had preferred to study the body or brain engaging in active tasks rather than in difficult-to-define downtime. “In psychology and cognitive neuroscience, scientists can be blind to the importance of something like rest,” says Erin Wamsley, a psychologist at Furman University in South Carolina.
Sleep studies have been a bona fide branch of neuroscience for decades, but only now are a host of new studies from multiple disciplines beginning to explain why waking rest is also important. When we choose the right activities in the right doses, rest can be a vital process for the optimal functioning of our bodies and minds. This includes our capacity to recover from illnesses such as covid-19, whether we can maintain self-control and our ability to form stronger memories of…
Article amended on 31 August 2023
This article has been amended to reflect Claudia Hammond’s role in The Rest Test.
The time may be coming to wash our hands of plastic trash. Literally.
About 60 percent of all plastic ever made ends up in landfills or littering the environment. Only about one-tenth of plastic waste is ever recycled, and much of that ends up being low-quality material reused in things like park benches (SN: 1/27/21). So chemists are searching for ways to “upcycle” plastic into more valuable raw materials.
Now, there’s a way to turn old plastic into surfactants, researchers report in the Aug. 10 Science. Surfactants make up the key ingredients in dozens of products like lubricants, ski wax, detergents and soap.
“To me, plastic waste basically [is] aboveground crude oil,” says chemist Guoliang Liu of Virginia Tech in Blacksburg. “We don’t have to go deep into the ocean or underground to mine [it] anymore” to make valuable chemicals.
Surfactants and the two most used kinds of plastic, polyethylene and polypropylene, are made of molecular chains of carbon atoms. But surfactants’ chains are far shorter than those of plastics and are capped with groups of water-attracting atoms.
To turn plastic into surfactants, Liu and colleagues developed a special reactor that carefully heats and condenses plastic into a wax with short carbon chains. By capping the wax’s chains with groups of oxygen atoms and treating them with an alkaline solution, the researchers turned the wax into surfactant. Combining the surfactant with a bit of dye and fragrance produced tiny bars of soap.
Still, upcycled plastic probably won’t be washing away messes any time soon. The researchers can make only about half a gram of surfactant at a time. If Liu and his team can figure out a way to scale up the process, they hope to partner with industry to make plastic waste a bit cleaner.
A new “smart rust” could one day help pull pollutants out of waterways, leaving cleaner water behind.
Researchers adorned tiny particles of iron oxide, better known as rust, with “sticky” molecules that grab on to estrogen and similar hormones in water samples. A magnet can then remove both the particles and the trapped pollutants from the water, materials scientist Lukas Müller reports August 16 in San Francisco at a meeting of the American Chemical Society.
The new technology could potentially limit excess estrogen’s harmful effects on animals, especially those that live in waterways.
With the nanoparticles, “we are able … to clean very different kinds of environmental pollutants,” says Müller, of Friedrich-Alexander-Universität Erlangen-Nürnberg in Germany.
Estrogen hormones typically enter waterways through humans’ and other animals’ waste (SN: 1/2/02). Even low concentrations can have harmful chronic effects on aquatic life, like higher instances of cancer or reproductive issues, says Konrad Wojnarowski, a biologist at Ludwig-Maximilians-Universität München who was not involved in the study. Wastewater treatment plants can remove some estrogen hormones, he says, but the process isn’t cheap or energy efficient.
For now, “we still don’t have an ideal way of dealing with estrogen pollution in the environment,” but nanoparticles could help, Wojnarowski says.
To build the estrogen-catching particles, Müller and Marcus Halik, a chemist also at Friedrich-Alexander-Universität, drew on prior experience designing iron oxide nanoparticles that can catch other kinds of pollutants like oil or herbicides (SN: 7/25/08). The tiny iron oxide cores are each about 10 nanometers in diameter. Each core is then covered in phosphonic acid molecules, which act like sticky hairs that scoop up contaminants.
The new version of the nanoparticles specifically targets estrogen by including two types of phosphonic acid. One kind is long, repels water and attaches to the neutrally charged part of the estrogen molecule. The other is positively charged to attract parts of estrogen hormones that carry a slight negative charge.
The smart rust removed much of the estrogen from small water samples prepared in the lab, the researchers found. Their next step is to test the nanoparticles on samples from actual waterways.
And the team is investigating exactly how the molecules on the nanoparticle surfaces grab and hold on to estrogen at the atomic scale. With this information, Halik says, they can improve the estrogen binding even more.
TRUDGING through hot, red sand is hard work, especially in temperatures above 40°C (104°F). After about 40 minutes, I am drenched, dehydrated and drained. I can’t imagine doing this for 40 days, dragging all my gear behind me – including 40 litres of water, enough for five days – on a two-wheeled trolley. But that is exactly what the people I am travelling with have just done.
I am in the Nafud desert, a vast tract of sandy and rocky wilderness in northern Saudi Arabia, to experience levels of heat that I am not built to endure – and to meet 20 people participating in an expedition called Deep Climate, dedicated to understanding how humans respond to extreme conditions. “The idea is to study how human beings can adapt to a new kind of environment,” says Christian Clot, the leader of the expedition and director of the Human Adaptation Institute in France.
As the climate warms, the issue is becoming increasingly pressing. Even under the most optimistic scenarios, the scorching heat seen in southern Europe and across the US over the past couple of months, with temperatures exceeding 40°C, will become the norm in many parts of the world.
That means the question of what happens to our brains and bodies, and the extent to which human physiology can cope with extreme heat, matters for millions of people. “You’re going to see a great big swathe of very densely populated areas go up to unprecedented temperatures that nobody experienced in the historical climate,” says Tim Lenton at the University of Exeter, UK, who recently co-authored a research paper called “…
The Pacific “cold tongue”, an area of ocean that stretches West from Ecuador is cooler than expected
Harvepino/shutterstock
FOR years, climate models have predicted that as greenhouse gas emissions rise, ocean waters will warm. For the most part, they have been correct. Yet in a patch of the Pacific Ocean, the opposite is happening. Stretching west from the coast of Ecuador for thousands of kilometres lies a tentacle of water that has been cooling for the past 30 years. Why is this swathe of the eastern Pacific defying our predictions? Welcome to the mystery of the cold tongue.
This isn’t just an academic puzzle. Pedro DiNezio at the University of Colorado Boulder calls it “the most important unanswered question in climate science”. The trouble is that not knowing why this cooling is happening means we also don’t know when it will stop, or whether it will suddenly flip over into warming. This has global implications. The future of the cold tongue could determine whether California is gripped by permanent drought or Australia by ever-deadlier wildfires. It influences the intensity of monsoon season in India and the chances of famine in the Horn of Africa. It could even alter the extent of climate change globally by tweaking how sensitive Earth’s atmosphere is to rising greenhouse gas emissions.
Given all this, it isn’t surprising that climate scientists are trying to find out what is going on with increasing urgency. Like any good mystery, this is a tale of intrigue, confusion and competing theories. We haven’t quite…
Though perhaps better known for its newspapers and almanacs, Benjamin Franklin’s printing business also churned out paper money to support the colonial economy. Now, scientists are confirming some of the ways that Franklin and his associates thwarted counterfeiters to help early American paper currency succeed, including by adding a reflective mineral to bills.
Franklin’s bills “served as an archetype for printed money” to come, says Khachatur Manukyan, a physical chemist at the University of Notre Dame in Indiana. “It was very sophisticated for that time.”
In past studies, Manukyan and his colleagues have analyzed ancient Roman coins, medieval manuscripts and other artifacts using nuclear imaging techniques. When the researchers realized that Notre Dame housed paper money bills dating to the early colonial days of North America, the team decided to take a closer look. They examined about 600 paper notes.
By using techniques such as infrared, electron energy loss spectroscopy, and X-ray analysis, the researchers could see features such as colored threads and muscovite — a crystalized mineral — incorporated into the paper. The blue threads are visible to the naked eye, and the muscovite produces a glimmer that reflects light — features most knock-offs wouldn’t have been able to reproduce, the team reports July 17 in the Proceedings of the National Academy of Sciences.
The muscovite, found in about 95 percent of the analyzed Franklin bills produced after 1754, was probably sourced from the same geologic area, the team says. The mineral was also probably used to increase the durability of the notes so they could hold up better during circulation.
It’s wonderful that scientists are using these techniques to analyze these bills, says Jessica Linker, a historian at Northeastern University in Boston who studies early moneymaking. Still, she says, historians have known for some time from historical documents that muscovite — also known as mica — and blue threads were incorporated into old paper money to fight counterfeiting.
What’s more, while Franklin contracted with the colonial governments to print money, others were involved in the decisions about its manufacture — not just Franklin, she says.
Franklin’s operations incorporated elements like blue thread (left) and muscovite (microscope image, right) in their paper money in an effort to make it difficult to counterfeit.K. Manukyan et al/PNAS 2023
The new analyses also showed that Franklin’s operations used graphite in their black ink. Other money printers of the time, including Paul Revere, generally used a type of black ink that had a higher proportion of chemicals that came from burnt bones like phosphorus and calcium. Counterfeiters had figured out how to fake the bone black ink, and some knock-off Franklin notes are distinguishable by the fact they use this bone black rather than graphite.
Franklin’s operations may have used graphite to one-up the counterfeiters, the researchers say. But Franklin wasn’t the first printer to use graphite in ink, Linker says. Black lead — the historical term for graphite — is listed in some 18th century ink recipes, she says.
“Even if it was unique to the money or new in the mid-Atlantic, it’s possibly not a Franklin innovation, but something he read about, experimented with and used to improve the quality of the ink generally,” she says — not necessarily something to fight counterfeiting.
Still, the discovery of the graphite in Franklin’s notes is intriguing, she says. “I don’t think historians of colonial American printing would expect it to be there,” mostly because graphite was relatively scarce in the colonies at the time. Linker wonders whether this ink was used more broadly in Franklin’s other imprints or used exclusively for paper money.
Efforts to thwart counterfeiters of early American money were eventually upended by the British, who figured out some of the techniques when they flooded their upstart colony with fake bills as a destabilizing tactic during the American Revolution. The value of American money tanked, and in the years following the revolution, the United States typically favored coins, only issuing treasury notes during later wars.
Even so, some of Franklin’s techniques would go on to form the basis of increasingly sophisticated methods used to combat savvier forgers, Manukyan says. “The techniques utilized in producing pre-federal American currency were refined and enhanced during the 19th century whenever new bills were printed,” he says. “For that time, [Franklin’s paper money] was really groundbreaking.”
There are TikTok hashtags with millions of followers, endless column inches over celebrities’ waistlines and streams of media coverage when trial results come out. It is rare that a new medicine gets so much attention. Then again, it is even rarer that a licensed drug causes safe and rapid weight loss with minimal effort.
A year ago, most people hadn’t heard of semaglutide, a drug developed to treat type 2 diabetes around a decade ago under the brand name Ozempic. Then, in 2021, it was approved in the US as a weight-loss aid under the name Wegovy. The medicine can cause people to lose a whopping 15 per cent of their body weight.
The impact of this new class of medicines could be unprecedented – potentially bringing to an end the world’s growing obesity epidemic. “I don’t think it’s fully sunk in yet,” says Jonathan Campbell at Duke University in North Carolina, who investigates how these drugs affect the body.
For one thing, Wegovy was just the start. The next generation of these drugs is in development and will be cheaper, easier to use and, crucially, even more potent. What’s more, emerging evidence suggests Wegovy and its ilk work better when given at a younger age, so doctors are exploring their use in teenagers and young children. This raises the prospect of switching from obesity treatment to prevention. “We have watched the obesity landscape change dramatically over the last 40 years,” says Campbell. “Now, maybe we’re at a turning point where that goes backwards.”
Why obesity is on the rise
The rise in obesity has been happening since about the 1970s…
A new material design could reduce pollution where the rubber meets the road.
Strategically adding weak points along microscopic chains called polymers actually makes them harder to tear, researchers report in the June 23 Science. Because polymers are used in car tires, the findings could help reduce plastic pollution as tires wear down over time.
When tires scrape against the road, they drop tiny particles of rubber and plastic polymers, which pollute waterways and contaminate the air (SN: 11/12/18). Every year, tires release an estimated 6 million metric tons of these microplastics into the environment. Stronger polymers that break apart less easily could limit the amount of particles shed annually.
To make such tough materials, Stephen Craig, a chemist at Duke University, and colleagues added molecules called cross-linkers to the polymers. These cross-linkers connected jumbled-up polymer chains to their many neighbors, and they were specifically designed to break apart easily. At the microscopic scale, the polymers act like a tangle of spaghetti strands with the cross-linkers holding them all together and helping them retain their shape, says Craig’s collaborator Shu Wang, a chemist at MIT.
[embed]https://www.youtube.com/watch?v=dmsznnE92w8[/embed]A rubbery plastic polymer with weak cross-linkers, shown on the left, requires more stretching force to tear than a similar polymer with stronger cross-linkers, shown on the right. Adding the weak cross-linkers to rubber could lead to tougher car tires.
When the team stretched the polymer spaghetti, the individual cross-linkers broke easily, as expected. But the bulk material required more force to rip than they expected.
The secret to the increased toughness lies in the path the tear has to take, Craig says. The tear propagates through the easy-to-break cross-linkers rather than through the tougher polymer strands. Each broken connection follows the path of least resistance but dodging the long polymer strands means breaking many cross-linkers, which requires more stretching force overall.
This isn’t the first time researchers have used weak connectors to make polymers stronger. But unlike in similar materials, the increased toughness doesn’t come at the expense of other beneficial properties like stiffness.
Craig says he hopes the findings will help extend the lifetimes of car tires and plastics, potentially limiting annual microplastic pollution.
