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Earth’s inner core is ‘superionic’, a state of matter somewhere between solid and liquid

Earth’s inner core is ‘superionic’, a state of matter somewhere between solid and liquid, study suggests core is ‘superionic’, a state of matter somewhere between solid and liquid, study suggests We’ve known for a while that Earth’s deepest depths, its “solid iron” inner core, isn’t made of pure iron — and now scientists say it might not be solid either. Key points: The structure of Earth’s inner core has been a mystery since its discovery in 1936 Physicists originally thought it was solid, but a new study suggests it’s somewhere between solid and liquid Such studies potentially shed light on some, but not all, of our planet’s deepest secrets Simulations by a team of researchers in China suggest our planet’s innards are somewhere between solid and liquid in a “superionic” state. The research has been published in the journal Nature. Yu He, a physicist at the Chinese Academy of Sciences and co-author of the study, said the calculations were “a new starting point to understand the inner core”. This study, and others like it, Dr. He added, might one day help earth scientists solve some fundamental but complex problems, such as when the inner core started to take shape. But the new study can’t completely explain all the inner core’s quirks. Why states of matter matter On the surface of the Earth, we generally deal with three states of matter: solid, liquid, and gas. Take water, for instance. As the ice in a cool drink, water molecules are arranged in a regular, 3D crystal. When that ice melts to become liquid water, those molecules can now move around but are still in close proximity. And like a gas, like the water vapor that gives humid days their oppressive stickiness, those mobile water molecules are free to move far away from each other. But when substances are subjected to intense pressure or heat, they can switch into other, weirder states of matter. Such as superionic matter, which is somewhere between liquid and solid. In superionic water, molecules split apart into oxygen and hydrogen atoms. The oxygen atoms crystallize into a 3D structure — like you’d see in a solid — while hydrogen atoms move freely around, like a liquid. Superionic water ice could make up the bulk of giant icy planets, such as Neptune and Uranus. And some geophysicists think the very center of Earth, its inner core, is superionic too. Instead of water, though, the inner core is made of a metal alloy: mostly iron, a bit of nickel, and a few other much lighter elements, such as hydrogen and carbon, mixed in there too. It’s the iron atoms that form the 3D “solid” structure in a superionic state and the lighter elements that flow around it like liquid. Earthquakes used to probe Earth’s core Earth’s inner core reaches temperatures similar to the surface of the Sun and pressures 3.7 million times what we experience at sea level. Physically digging to the inner core is impossible, and we can’t yet recreate its conditions in the lab. So to get an idea of what the inner core is like, scientists measure how seismic waves, generated by earthquakes, change in speed and direction as they rumble through the center of the planet. This information can tell scientists how dense the inner core’s iron alloy is, as well as its stiffness, said Hrvoje Tkalcic, a geophysicist at the Australian National University who was not involved in the work. “And then we also have mineral physics, geodynamics, and mathematical geophysics trying to work together to figure out what the heck is happening at the center of our planet,” Professor Tkalcic said. Dr. He and his crew used computer simulations to see how seismic waves might travel through an alloy made of iron, hydrogen, carbon, and oxygen under immense pressure and heat. They’re not the first to do this: other studies have done similar, albeit with fewer lighter elements included. The new study’s conclusions are in line with what scientists have deduced from earthquakes: that the core is less dense than pure iron, so lighter elements must be mixed in, and it’s relatively soft. But there’s still a mystery Something the new study can’t fully explain is a peculiar but distinct feature of the inner core. The speed at which a seismic wave moves through the inner core depends on its direction through the planet. For instance, a wave traveling between north and south magnetic poles will ripple faster through the inner core than a wave traveling across the globe from the equator to the equator — even if they’re traveling the same distance. It’s a phenomenon called seismic anisotropy, and why it happens, no one’s really sure. Dr. He and colleagues suggest lighter, liquid-like elements are not evenly distributed through the superionic inner core. Instead, they’re concentrated into a flattened sphere around the middle, which puts the brakes on waves passing through. But how exactly how — and why — lighter elements might accumulate that way is not specified. In any case, the middle of the planet definitely requires more scrutiny, Dr. He said. “I think more studies are needed to explain other seismic features, such as seismic anisotropy, in the inner core.” Source: abc.net.au
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Types of Bikes: The Ultimate Bike Buying Guide

Welcome to the Co-op’s own ‘I’m new to cycling and I don’t know what type of bike I should buy’ guide. Here you’ll find the main types of bikes that people tend to speak about, demystified. Think of it as the ultimate bike types guide for beginners! Bike Buying Guide: Different bikes for different activities We usually recommend that you buy a bike for the kind of activity you want it for – although if you want to buy a bike just because you like the way it looks, that’s fine too! Do you want a bike mostly for commuting? Do you want a versatile bike that can handle both tarmac and dirt tracks well? Do you want to dress head-to-toe in lycra and attempt the land speed record? Many people who are new to cycling often opt for a mountain bike, purely because it somehow sounds like the most familiar. However, there’s really no need to buy a mountain bike unless you a) really like mountain bikes for whatever reason or b) want to go mountain biking. Here at the Co-op we tend to divide our bike types into the following categories based on the activity they’re used for: Road bikes: Roads. Mountain bikes: Off road. Hybrid or Commuter bikes: A bit of everything. Cyclocross bikes: A bit of everything, but with a road bike feel. Folding bikes: Commuting, leisure or touring for the short-on-space. Electric bikes: An electric-assisted bit of everything. Touring bikes: designed for carrying loads over longer distances while remaining comfortable for the rider. Women’s bikes: All of the above, designed specifically for women. Kids bike: bikes for kids We’ll look at each of these in turn so you can get a better idea of what bikes are used for what. Road Bikes As the name suggests, road bikes are designed to ride on the road. Can’t all bikes ride on the road, you wonder? They absolutely can. But road bikes are optimised to make road cycling as efficient as possible, and because of that they’d perform terribly on a mountain dirt track. Instead, road bikes are designed to help cyclists get the most out of the road, including the particular geometry (i.e. frame shape) of the bike, the width of the tyres, and the weight of the components. And just in case you were wondering; You won’t be able to buy a road bike with skinny tyres and transform it into a mountain bike by putting big, knobbly tyres on. Mountain bike tyres just won’t fit on, full stop. Defining characteristics: A lightweight frame, skinny tyres, drop handlebars (those are handlebars which curve back down underneath themselves) and a high gear ratio (i.e. The gears are set up to favour the ones that help you go really fast, if your legs and lungs are up to it.) Get a road bike if: You want fast, efficient cycling on tarmac roads for commuting, competing, or for fun. Don’t get a road bike if: You want to take it off the road. Skinny tyres means you won’t really be able to use a road bike on anything other than tarmac. Icy roads can also be a problem for road bikes. If you’re after a road bike, reading up on What Kind of Road Bike Should I Get? might be a useful five-minute read. Mountain Bikes Mountain bikes are designed to go on mountains or on off-road trails, which means they’re chunkier, have knobbly tyres on them, and a frame geometry which makes them better suited for seriously uneven terrain. Defining characteristics: Wide, knobbly tyres for traction, and a wide range of gears to help you get up and over mountains or across fields. Some bikes have front suspension but are rigid at the back (‘hardtail’), and some have front and rear suspension for cushioning jumps and drops (‘full suspension’ or ‘full sus’). Others have neither. Here’s our Guide to full suspension vs hardtail. Get a mountain bike if: You want to go mountain biking or mainly off road. Don’t get a mountain bike if: You want to go fast on tarmac roads, cycle long distances, or mostly knock about town. Hybrid or Commuter Bikes Hybrid bikes, or commuter bikes as they’re also known, are essentially a mixture between road bikes and mountain bikes. They give you the versatility to do a bit of everything. What you sacrifice in terms of speciality, you gain by being able to do what you want, when you want. Defining characteristics: Hybrid bikes have flat handlebars instead of drop handlebars. Some models have front suspension to cushion bumps in the road or on the track, and others don’t. They’re designed with versatility and comfort in mind, so they have the comfortable geometry of mountain bikes but with slicker, narrower tyres. The tyres can be changed for super knobbly tyres if you want to do a bit of off-roading, or slicker tyres if you’re commuting on tarmac, or something in between. Get a hybrid/commuter bike if: Your main use for the bike will be commuting and/or knocking about town, as well as occasionally going off road or mountain biking. Don’t get a hybrid/commuter bike if: You want to go full lycra and ride as fast as possible on roads, or tear down mountain bike trails as dexterously as possible. Cyclocross bikes Also simply known as ‘Cross Bikes’, these are bikes which follow the tradition of road cyclists in the olden days, who would swap their slick road tyres for knobblier tyres and continue to train during the winter months. A cyclocross bike could be the perfect year-round bike for you if you’re looking for a fast road bike that will cope with off-road excursions. Defining characteristics: The easiest to spot is the drop handlebars like a road bike, instead of the flat handlebars of a hybrid. Like a hybrid, there’s also enough clearance (space around the wheel) for knobblier tyres and mudguards. A cross bike has more of a road bike feel >>Read more
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Road rage and auto insurance

Aggressive driving can lead to accidents—and compromised coverage Road rage incidents are not only dangerous, they are exempted from coverage by many auto insurance policies. Understand your risks and take precautionary measures to avoid being a victim—or a cause—of aggressive driving accidents. Crowded highways and traffic backups at times cause drivers to lose control and become extremely aggressive. Road rage is a real problem that can lead to serious accidents or even incidents of violence on the road. It’s important to realize that road rage is listed as an exemption in many auto insurance policies. This is because any damage or liability stemming from aggressive driving isn’t considered an accident but rather as having been caused by risky behavior. Rather than risk paying the consequences of road rage—one of which may be not having your auto insurance claim paid—it’s best to avoid a dangerous and costly aggressive driving incident in the first place. If you encounter an aggressive driver on the road… Stay as far away as possible. Slow down or change lanes if need be, let the driver pass you and give yourself room at intersections to drive away. Record a description of the car and note the license plate number if possible so that you can report him or her to the police for the sake of everyone’s safety. Do not engage with or challenge the offender in any way. Ignore the driver’s rudeness and don’t give into the temptation to react in kind or you might escalate the risky behavior. Put your safety first. If an aggressive driver starts to follow you, keep your doors locked, and head to the nearest police station. Never stop and confront an aggressive driver. If you have a short fuse yourself stay cool and… Leave plenty of time to get where you need to go. When you’re in a hurry, your patience is short and you are much more likely to become aggravated. Remember other drivers are not annoying you on purpose. People make mistakes or they might be driving more slowly for a reason—they might be lost, or their sight might be impaired by sun glare. Don’t use hand—or single finger—gestures other than a wave to someone who lets you into your lane. Don’t tailgate slow drivers. Hanging on another car’s back bumper is dangerous. If the car in front of you has to stop short and you rear-end it, the accident would be considered your fault. Don’t honk your horn insistently. Leaning on your horn is a bad practice. While it might make you feel better to express your frustration in a traffic jam, it won’t make anyone go any faster, it’s annoying to other drivers and passengers and it increases everyone’s stress level, which may lead to more aggressive behavior. Never stop to confront another driver. It could lead to a dangerous situation for all concerned.
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Papua New Guinea: only 500 doctors for 9 million people

Papua New Guinea only has about 500 doctors for 9 million people. Now it’s dealing with a Covid outbreak. Reva-Lou Reva is worried. For the first time he can remember, he says hospitals around the Pacific Island nation of Papua New Guinea (PNG) are so overburdened they are closing their doors to patients. “This is very frightening, to know that you don’t have any medical facilities open, or very limited, and you cannot easily access them because of the restriction,” says Reva, 48, PNG assistant country director of program support for humanitarian non-profit CARE International. “I’m breathless, I can’t explain how difficult it is.” Until recently, PNG had largely managed to stave off a major coronavirus outbreak. At the end of February, the country had only reported 1,275 cases, according to Johns Hopkins University. But over the past month, cases have more than tripled. PNG has now reported at least 4,660 Covid-19 cases and 39 related deaths, including that of MP Richard Mendani, who died age 53 earlier this month, according to a Radio New Zealand report. On Friday, the country reported 560 new infections — its highest for a single day — with Prime Minister James Marape admitting there is “rampant community transmission.” While those figures might not seem high compared to other countries, they pose a major issue in PNG, where the government says there are only about 500 doctors for an estimated population of 9 million people. At the best of times, the country’s health system is fragile — now NGOs are warning it could be on the “verge of collapse.” Low testing rates also mean PNG’s case load is likely much higher — something authorities acknowledge. Meanwhile, rampant misinformation in the country means some people are still not taking the threat seriously. Onlookers warn the crisis could worsen next week as people in the predominantly Christian nation travel home for Easter — and are calling on neighboring Australia and New Zealand to do more to help. “Papua New Guinea’s health crisis has now reached the level we feared it would a year ago with a surge in cases,” Amnesty International’s Pacific researcher Kate Schuetze said earlier this month. “A combination of an ailing health system and inadequate living conditions has created a perfect storm for Covid-19 to thrive in the country’s overcrowded informal settlements.” Papua New Guinea’s outbreak For almost a year, PNG seemed to handle the outbreak well. The country confirmed its first case on March 20 last year — a man who had traveled from Spain. Within two days, the Prime Minister declared a state of emergency, stopping all incoming and domestic flights, and limiting travel between provinces. Onlookers and the government were concerned an outbreak in PNG would be disastrous. “Our country does not have a health system that is capable of defending our people in this time of emergency with the threat of the coronavirus entering and spreading in our country,” Prime Minister Marape said in Parliament on April 2. At the time, he said PNG had 500 doctors, fewer than 4,000 nurses, under 3,000 community health workers and only 5,000 hospital bed spaces. “Our existing health capacity is insufficient to fight this battle,” he added. PNG has one of the lowest ratios of doctors per 1,000 people in the world. According to 2018 World Bank figures, the country had 0.07 physicians per 1,000 people — well below the 2017 average among small Pacific Islands (0.5), the 2017 world average (1.6), or the 2017 level in the United States (2.6). For a while, PNG’s measures appeared to work. It took until February this year for the country to reach 1,000 cases. But Covid-19 was likely circulating under the radar, says Justine McMahon, PNG country director for CARE. “It’s been here for months,” McMahon said. She added that up until a month ago, people were quite ambivalent about the Covid-19 pandemic, but “there’s a growing sense of trepidation everywhere.” It’s unclear what sparked the outbreak. The country shares a land border with Indonesia, which has reported almost 1.5 million coronavirus cases, according to Johns Hopkins University data. The border between the two countries is closed, although officials said earlier in the pandemic that some people were defying the closure, according to Radio New Zealand. The outbreak may have also been exacerbated by funeral gatherings held earlier this month to honor PNG’s first Prime Minister Michael Somare, who died age 85 in late February after being diagnosed with advanced pancreatic cancer. Thousands gathered at a state funeral in Port Morseby, but few mourners wore masks at the service, Australia’s ABC reported. Crowds also gathered along the street as a hearse carried his coffin, and a number of mourning events were held for representatives from the country’s provinces. “I’m pretty concerned. The number of people who came together for the period of mourning, if it goes like any other country, it’s just going to spread like anything,” McMahon said. What’s the situation now? One year ago, PNG responded aggressively to the threat of Covid. But now cases have surged, restrictions are weak or not enforced, according to McMahon and Reva. Authorities announced restrictions on travel between provinces and mandatory mask wearing. They also said they would ban mass gatherings, close schools, and may order burials in a “designated mass grave,” according to a Reuters report. But Reva, who lives in Goroka in PNG’s Eastern Highlands province, estimated Thursday that only “about 20%” of people he sees are wearing masks. Reva also worries for his family, who live in the capital, Port Moresby, which is in the National Capital District where about 47% of the country’s cases have been reported, according to government figures. Reva said family members told him mask wearing and social distancing measures aren’t in place, and six people had died over the past week in their urban village of 30,000. So many deaths in a week is unusual for his village, Reva added — but because of limited testing, it’s unclear >>Read more
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Casu marzu: The world’s ‘most dangerous’ cheese

The Italian island of Sardinia sits in the middle of the Tyrrhenian Sea, gazing at Italy from a distance. Surrounded by a 1,849-kilometer coastline of white sandy beaches and emerald waters, the island’s inland landscape rapidly rises to form hills and impervious mountains. And it is within these edgy curves that shepherds produce casu marzu, a maggot-infested cheese that, in 2009, the Guinness World Record proclaimed the world’s most dangerous cheese. Cheese skipper flies, Piophila casei, lay their eggs in cracks that form in cheese, usually fiore sardo, the island’s salty pecorino. Maggots hatch, making their way through the paste, digesting proteins in the process, and transforming the product into a soft creamy cheese. Then the cheesemonger cracks open the top — which is almost untouched by maggots — to scoop out a spoonful of the creamy delicacy. It’s not a moment for the faint-hearted. At this point, the grubs inside begin to writhe frantically. Some locals spin the cheese through a centrifuge to merge the maggots with the cheese. Others like it au naturel. They open their mouths and eat everything. Casu marzu is made with sheeps’ milk If you are able to overcome the understandable disgust, marzu has a flavor that is intense with reminders of the Mediterranean pastures and spicy with an aftertaste that stays for hours. Some say it’s an aphrodisiac. Others say that it could be dangerous for human health as maggots could survive the bite and and create myiasis, micro-perforations in the intestine, but so far, no such case has been linked to casu marzu. The cheese is banned from commercial sale, but Sardinians have been eating it, jumping grubs included, for centuries. “The maggot infestation is the spell and delight of this cheese,” says Paolo Solinas, a 29-year-old Sardinian gastronome. He says some Sardinians cringe at the thought of casu marzu, but others raised on a lifetime of salty pecorino unabashedly love its strong flavors. “Some shepherds see the cheese as a unique personal pleasure, something that just a few elects can try,” Solinas adds. Archaic cuisine It’s illegal to sell or buy casu marzu When tourists visit Sardinia, they usually wind up in a restaurant that serves porceddu sardo, a slowly roasted suckling piglet, visit bakers who sell pane carasau, a traditional paper-thin flatbread, and meet shepherds who produce fiore sardo, the island pecorino cheese. Yet, if you are adventurous enough, it’s possible to find the casu marzu. It shouldn’t be seen as a weird attraction, but a product that keeps alive an ancient tradition and hints at what the future of food might look like. Giovanni Fancello, a 77-year-old Sardinian journalist and gastronome, spent his life researching local food history. He’s traced it back to a time when Sardinia was a province of the Roman empire. “Latin was our language, and it’s in our dialect that we find traces of our archaic cuisine,” Fancello says. The cheese can only be produced at certain times of year when the sheeps’ milk is right There is no written record of Sardinian recipes until 1909, according to Fancello. That’s when Vittorio Agnetti, a doctor from mainland Modena, traveled to Sardinia and compiled six recipes in a book called “La nuova cucina delle specialità regionali.” “But we have always eaten worms,” says Fancello. “Pliny the Elder and Aristotle talked about it.” Ten other Italian regions have their variant of maggot-infested cheese, but while the products elsewhere are regarded as one-offs, casu marzu is intrinsically part of Sardinian food culture. The cheese has several different names, such as casu becciu, casu fattittu, hasu muhidu, formaggio marcio. Each sub-region of the island has its own way of producing it using different kinds of milk. ‘Magic and supernatural events’ Foodies inspired by the exploits of chefs such as Gordon Ramsay often come in search of the cheese, says Fancello. “They ask us: ‘How do you make casu marzu?’ It’s part of our history. We are the sons of this food. It’s the result of chance, of magic and supernatural events.” Fancello grew up in the town of Thiesi with his father Sebastiano, who was a shepherd who made casu marzu. Facello shepherded his family’s sheep to grazing grounds around rural Monte Ruju, lost in the clouds, where magic was believed to happen. He recalls that, for his father, casu marzu was a divine gift. If his cheeses didn’t become infested with maggots, he would be desperate. Some of the cheese he produced stayed for the family, others went to friends or people who asked for it. Casu Marzu is typically produced at the end of June when local sheep milk begins to change as the animals enter their reproductive time and the grass dries from the summer heat. If a warm sirocco wind blows on the cheesemaking day, the cheese-transforming magic works even harder. Fancello says it’s because the cheese has a weaker structure, making the fly’s job easier. After three months, the delicacy is ready. Mario Murrocu, 66, keeps casu marzu traditions alive at his farm, Agriturismo Sa Mandra, near Alghero in the north of Sardinia. He also keeps 300 sheep and hosts guests in his trattoria, and keeps casu marzu traditions alive. “You know when a form will become casu marzu,” he says. “You see it from the unusual spongy texture of the paste,” Murrocu says. Nowadays, this isn’t so much down to luck as the ideal conditions that cheesemongers now use to ensure as many casu marzu as possible. They’ve also figured out a way to use glass jars to conserve the cheese, which traditionally never lasted beyond September, for years. High fines Sardinia’s unusual cheese dates back to Roman times Though revered, the cheese’s legal status is a gray area. Casu marzu is registered as a traditional product of Sardinia and therefore is locally protected. Still, it has been deemed illegal by the Italian government since 1962 due to laws that prohibit the consumption of food infected by parasites. Those who sell the >>Read more
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