Long-time Slashdot reader fahrbot-bot shares a story that all started with a high school student's innocuous question on TikTok, leading academic mathematicians and philosophers to weigh in on "a very ancient and unresolved debate in the philosophy of science," reports Smithsonian magazine.

"What, exactly, is math?" Is it invented, or discovered? And are the things that mathematicians work with — numbers, algebraic equations, geometry, theorems and so on — real? Some scholars feel very strongly that mathematical truths are "out there," waiting to be discovered — a position known as Platonism.... Many mathematicians seem to support this view. The things they've discovered over the centuries — that there is no highest prime number; that the square root of two is an irrational number; that the number pi, when expressed as a decimal, goes on forever — seem to be eternal truths, independent of the minds that found them....

Other scholars — especially those working in other branches of science — view Platonism with skepticism. Scientists tend to be empiricists; they imagine the universe to be made up of things we can touch and taste and so on; things we can learn about through observation and experiment. The idea of something existing "outside of space and time" makes empiricists nervous: It sounds embarrassingly like the way religious believers talk about God, and God was banished from respectable scientific discourse a long time ago. Platonism, as mathematician Brian Davies has put it, "has more in common with mystical religions than it does with modern science." The fear is that if mathematicians give Plato an inch, he'll take a mile. If the truth of mathematical statements can be confirmed just by thinking about them, then why not ethical problems, or even religious questions? Why bother with empiricism at all...?

Platonism has various alternatives. One popular view is that mathematics is merely a set of rules, built up from a set of initial assumptions — what mathematicians call axioms... But this view has its own problems. If mathematics is just something we dream up from within our own heads, why should it "fit" so well with what we observe in nature...? Theoretical physicist Eugene Wigner highlighted this issue in a famous 1960 essay titled, "The Unreasonable Effectiveness of Mathematics in the Natural Sciences." Wigner concluded that the usefulness of mathematics in tackling problems in physics "is a wonderful gift which we neither understand nor deserve."

Slashdot reader the_newsbeagle writes: At the beginning of the pandemic, modelers pulled out everything they had to predict the spread of the virus. This article explains the three main types of models used: 1) compartmental models that sort people into categories of exposure and recovery, 2) data-driven models that often use neural networks to make predictions, and 3) agent-based models that are something like a Sim Pandemic.
"Researchers say they've learned a lot of lessons modeling this pandemic, lessons that will carry over to the next..." the article points out: Finally, researchers emphasize the need for agility. Jarad Niemi, an associate professor of statistics at Iowa State University who helps run the forecast hub used by the CDC, says software packages have made it easier to build models quickly, and the code-sharing site GitHub lets people share and compare their models. COVID-19 is giving modelers a chance to try out all their newest tools, says biologist Lauren Ancel Meyers, the head of the COVID-19 Modeling Consortium at the University of Texas at Austin. "The pace of innovation, the pace of development, is unlike ever before," she says. "There are new statistical methods, new kinds of data, new model structures."

"If we want to beat this virus," says Mikhail Prokopenko, a computer scientist at the University of Sydney, "we have to be as adaptive as it is."

"The service branch protecting U.S. interests outside the stratosphere may use blockchain to render its computer systems, on earth and in space, unhackable," reports CoinDesk: Last week, Xage Security won a contract from the United States Space Force to develop and roll out a blockchain-based data protection system across its networks. Called the Xage Security Fabric, the blockchain verifies data and protects the network from third party intervention, so confidential data sent from satellites to earth isn't intercepted en-route.

It also ensures security remains consistent across the entire United States Space Force network, preventing hackers and other malicious entities from identifying and exploiting any weak spots.
And UPI reports: The U.S. Space Force will start to fly missions on reused SpaceX rockets next year to save millions of dollars, the service announced Friday.

The Space Force will fly two GPS satellites into orbit on a Falcon 9 first-stage booster. The lower cost that SpaceX charges for reused rockets will save taxpayers $52.7 million, a statement from the military branch said... Gwynne Shotwell, SpaceX's president and chief operating officer, said in a news release that the company was pleased the Space Force saw "the benefits of the technology."

First, PetaPixel reminds us that Estee Lauder's products will be launching into space this week: The cosmetics giant Estee Lauder is paying NASA $128,000 for a product photography shoot onboard the International Space Station. Bloomberg reports that the company will be paying the space agency to fly 10 bottles of its Advanced Night Repair skin serum to the orbiting space station on a cargo run that will launch from Virginia on Tuesday and dock on Saturday. Once the product is on board, astronauts will be tasked with shooting product photos of the serum floating in the cupola module, which has sweeping panoramic views of Earth and space.

NASA charges a "professional fee" of $17,500 per hour for the astronauts' time.
In a possibly-related story, the same flight will also be carrying a new $23 million space toilet to the station as part of a routine resupply mission "to test it out before it's used on future missions to the moon or Mars."

Newsweek reports: Pharmaceutical manufacturer Johnson & Johnson announced Friday that early trials of a COVID-19 vaccine showed a 98 percent success rate in showing a boost in the immune system. According to research from Johnson & Johnson, the vaccine enabled 98 percent of those who took it to create antibodies that fight off the coronavirus infection. Those neutralizing antibodies were present 29 days after receiving the vaccination...

Currently, four U.S. vaccines are in the final trial stages. Vaccines from other pharmaceutical companies such as Pfizer and Moderna are administered in two doses while the Johnson & Johnson vaccine only requires one.
"Based on the current results, Johnson & Johnson on Wednesday kicked off a final 60,000-person trial," reports Reuters, "which could pave the way for an application for regulatory approval. The company said it expects results of that so-called Phase 3 trial by the end of the year or early next year."

The New York Times reports: Vaccine maker Novavax said Thursday that it would begin the final stages of testing its coronavirus vaccine in the United Kingdom and that another large trial was scheduled to begin next month in the United States. It is the fifth late-stage trial from a company supported by Operation Warp Speed, the federal effort to speed a coronavirus vaccine to market, and one of 11 worldwide to reach this pivotal stage.

Novavax, a Maryland company that has never brought a vaccine to market, reached a $1.6 billion deal with the federal government in July to develop and manufacture its experimental vaccine, which has shown robust results in early clinical trials. The new study, known as a Phase 3 trial, is expected to enroll up to 10,000 people in the United Kingdom. Half of the volunteers will receive two doses of the experimental vaccine, 21 days apart, and the others will receive a placebo.

Although Novavax is months behind the front-runners in the vaccine race, independent experts are excited about its vaccine because its early studies delivered particularly promising results. Monkeys that were vaccinated got strong protection against the coronavirus. And in early safety trials, published early this month in The New England Journal of Medicine, volunteers produced strikingly high levels of antibodies against the virus. It is not possible to make a precise comparison between early clinical studies of different vaccines, but John Moore, a virologist at Weill Cornell Medicine, said that the antibodies from Novavax were markedly higher than any other vaccine with published results. "You just can't explain that away," he said. The Phase 3 trials will determine if Novavax can live up to that promise.

An anonymous reader quotes a report from The New York Times: The medal awarded on Friday lauded the "lifesaving bravery and devotion to duty" for work detecting land mines in Cambodia. Its recipient: a rat named Magawa. Magawais the first rat to receive the award -- a gold medal bestowed by the People's Dispensary for Sick Animals, a British charity, that is often called the "animal's George Cross" after an honor usually given to civilians that recognizes acts of bravery and heroism. Not since the fictional Remy of the 2007 Disney-Pixar film "Ratatouille" has a rat done so much to challenge the public's view of the animals as creatures more commonly seen scuttling through sewers and the subway: Magawa has discovered 39 land mines and 28 pieces of unexploded ordnance, and helped clear more than 1.5 million square feet of land over the past four years.

More than five million land mines are thought to have been laid in Cambodia during the ousting of the Khmer Rouge and internal conflicts in the 1980s and 1990s. Parts of the country are also littered with unexploded ordnance dropped in United States airstrikes during the Vietnam War, a 2019 report from the Congressional Research Service found. Since 1979, more than 64,000 people have been injured by land mines and other explosives in Cambodia, and more than 25,000 amputees have been recorded there, according to the HALO Trust, the world's largest humanitarian land mine clearance charity.

Magawa, the most successful rat to have taken part in the program, was trained to detect TNT, the chemical compound within explosives. The ability to sniff out TNT makes him much faster than any person in searching for land mines, as he can ignore scrap metal that would usually be picked up by a metal detector. He can search an area the size of a tennis court in 30 minutes, whereas a person with a metal detector would usually take four days to search an area of that size. When he finds a mine, he signals to his handler by scratching at the earth above it. Unlike humans, Magawa is too light to detonate a mine, so there is minimal risk of injury.

sciencehabit writes: A number of animals, from dogs to chimpanzees, can imitate human behavior. Now scientists have shown that cats can too. Under controlled conditions, a Japanese cat named Ebisu copied the movements of her owner when she touched a cardboard box and rubbed her face against it. Researchers say it's evidence of complex cognition, because the cat must be able to "map" the human's body parts onto her own. The finding may also suggest that the ability to imitate arose earlier in mammalian evolution than previously thought. The study has been published in the journal Science.

An anonymous reader quotes a report from The Guardian: Doctors believe they are closer to a treatment for multiple sclerosis after discovering a drug that repairs the coatings around nerves that are damaged by the disease. A clinical trial of the cancer drug bexarotene showed that it repaired the protective myelin sheaths that MS destroys. The loss of myelin causes a range of neurological problems including balance, vision and muscle disorders, and ultimately, disability.

While bexarotene cannot be used as a treatment, because the side-effects are too serious, doctors behind the trial said the results showed "remyelination" was possible in humans, suggesting other drugs or drug combinations will halt MS. "It's disappointing that this is not the drug we'll use, but it's exciting that repair is achievable and it gives us great hope for another trial we hope to start this year," said Prof Alasdair Coles, who led the research at the University of Cambridge. The drug had some serious side-effects, from thyroid disease to raised levels of fats in the blood, which can lead to dangerous inflammation of the pancreas. But brain scans revealed that neurons had regrown their myelin sheaths, a finding confirmed by tests that showed signals sent from the retina to the visual cortex at the back of the brain had quickened. "That can only be achieved through remyelination," said Coles.

Research unveiled on Thursday in Science finds that crows know what they know and can ponder the content of their own minds, a manifestation of higher intelligence and analytical thought long believed the sole province of humans and a few other higher mammals. STAT reports: "Together, the two papers show that intelligence/consciousness are grounded in connectivity and activity patterns of neurons" in the most neuron-dense part of the bird brain, called the pallium, neurobiologist Suzana Herculano-Houzel of Vanderbilt University, who wrote an analysis of the studies for Science, told STAT. "Brains can appear diverse, and at the same time share profound similarities. The extent to which similar properties present themselves might be simply a matter of scale: how many neurons are available to work."

The study shows that neurons in the most complex part of the crows' brain, the pallium, "do have activity that represents not what was shown to them, but what they later report," said Herculano-Houzel. Neurons "represent what the animals next report to have seen -- whether or not that is what they were shown," she said. The neurons figure this out, so to speak, during the time lapse between when Nieder tells the birds the rule and when they peck the target to indicate their answer. "That's exactly what one would expect from neurons that participated in building the thoughts that we later report," she said, suggesting that corvids "are as cognitively capable as monkeys and even great apes." A second study, also in Science, looked in unprecedented detail at the neuroanatomy of pigeons and barn owls, finding hints to the basis of their intelligence that likely applies to corvids', too. STAT reports: Specifically, the pigeons' and owls' neurons meet at right angles, forming computational circuits organized in columns. "The avian version of this connectivity blueprint could conceivably generate computational properties reminiscent of the [mammalian] neocortex," they write. "[S]imilar microcircuits ... achieve largely identical cognitive outcomes from seemingly vastly different forebrains." That is, evolution invented connected, circuit-laden brain structure at least twice. "In theory, any brain that has a large number of neurons connected into associative circuitry ... could be expected to add flexibility and complexity to behavior," said Herculano-Houzel. "That is my favorite operational definition of intelligence: behavioral flexibility." That enables pigeons to home, count, and be as trainable as monkeys. But for sheer smarts we're still in the corvid camp.

"Every musician knows that when the performers can hear one another, the performance is always better than otherwise," writes Slashdot reader nightcats. "This principle applies in nature as well, and has been anecdotally witnessed amid the quiet imposed by COVID-19 on cities around the world. In San Francisco, behavioral ecologist Liz Derryberry has been able to deliver a dramatic scientific demonstration of the changes to the songs of the white-crowned sparrow amid the quiet of 2020." National Geographic reports: With most San Franciscans staying at home due to the coronavirus pandemic, she decided to seize an unprecedented opportunity to study how this small, scrappy songbird responded when human noises disappeared. By recording the species' calls among the abandoned streets of the Bay Area in the following months, Derryberry and colleagues have revealed that the shutdown dramatically improved the birds' calls, both in quality and efficiency. The research, published today in Science, is among the first to scientifically evaluate the effects of the pandemic on urban wildlife. It also adds to a burgeoning field of research into how the barrage of human-made noise has disrupted nature, from ships drowning out whale songs to automobile traffic jamming bat sonar.

Rose Pastore reporting via Gizmodo: A new way of producing powerful X-ray beams -- the brightest on Earth -- is now making it possible to create 3D images of matter at astounding resolutions. This "Extremely Brilliant Source" officially opened last month at the European Synchrotron Radiation Facility in France, and scientists are already using it to study the coronavirus behind covid-19. These X-ray beams will image the interiors of fossils, brains, batteries, and countless other interesting items down to the atomic scale, revealing unprecedented information and supercharging scientific research.

A typical medical X-ray, like you would get for a broken bone, can show doctors details about your particular fracture and the tissue around it. X-rays penetrate the body and are absorbed at different rates by different tissue; once they've passed through you, they hit a detector, creating the familiar black-and-white X-ray image. The Extremely Brilliant Source produces X-rays 10 trillion times more powerful than those used in hospitals. With such a beam, scientists could create a 3D image of your broken bone so detailed that they could see the individual atoms in the blood cells surrounding your fracture. Of course, you wouldn't want to be hit with this particular beam -- the dose of radiation would be fatal.

The possibilities that the Extremely Brilliant Source opens up feel endless. One area that particularly excites Francesco Sette, director general of the ESRF, is research into the structure and functioning of brains, which could eventually enable brain-like electronics. "It would be a major revolution, not only for neuroscience, but also for all those applications that are coming up to use possibly the human brain architecture for a new generation of devices," he said.

Saad Bhamla, an undergraduate in Mumbai, India, has invented a do-it-yourself hearing aid made from inexpensive, easy-to-find parts. "At bulk rates, Bhamla says, it would cost just under $1 to make," reports Science Magazine. "But anyone with the freely available blueprints and a soldering iron can make their own for not much more -- maybe $15 or $20, Bhamla says." From the report: Inspired by his grandparents and a hearing-impaired colleague -- who is the first author on the new paper -- Bhamla and his team set out to develop a cheap hearing aid built with off-the-shelf parts. They soldered a microphone onto a small circuit board to capture nearby sound and added an amplifier and a frequency filter to specifically increase the volume of high-pitch sounds above 1000 hertz. Then they added a volume control, an on/off switch, and an audio jack for plugging in standard earphones, as well as a battery holder. The device, dubbed LoCHAid, is the size of a matchbox and can be worn like a necklace.

Next, Bhamla and his colleagues tested the device. They found that it boosted the volume of high-pitch sounds by 15 decibels while preserving volumes at lower pitches. It also filtered out interference and sudden, loud sounds like dog barks and car horns. Finally, tests with an artificial ear revealed that LoCHAid might improve speech recognition, by bringing conversations closer to the quality heard by healthy individuals. It complied with five out of six of the World Health Organization's preferred product recommendations for hearing aids, the researchers report today in PLOS ONE. There are some drawbacks. The device can't be fine-tuned for individual needs, and the researchers anticipate that LoCHAid's parts will wear out after about a year and a half. It's also bulky, though a smaller version is in development.

Bhamla notes that it needs to be clinically tested before his device can be sold as a "hearing aid" in the United States.

The supermassive black hole at the center of the M87 galaxy has a shadow crescent that moves, like a dancer in the dark. From a report: Over a year ago, scientists unleashed something incredible on the world: the first photo of a black hole ever taken. By putting together radio astronomy observations made with dishes across four continents, the collaboration known as the Event Horizon Telescope managed to peer 53 million light-years away and look at a supermassive black hole, which is 6.5 million times the mass of the sun and sits at the center of the galaxy Messier 87 (M87). The fiery historic image showed off a bright crescent of ultra-hot gas and debris orbiting the black hole's event horizon, the pitch-black central point-of-no-return that traps anything that goes over, even light. The EHT team had just made one of the most impressive achievements in the history of astronomy, but this was only the beginning. On Wednesday, members of the EHT collaboration published new findings in the Astrophysical Journal about M87's supermassive black hole (known as M87*), revealing two new major insights.

First, the shadow diameter of the event horizon doesn't change over time, which is exactly what Einstein's theory of general relativity predicts for a supermassive black hole of M87*'s size. However, the second insight is that the bright crescent adorning this shadow is far from stable: it wobbles. There's so much turbulent matter surrounding M87* that it makes sense the crescent would bug out and get fidgety. But the fact that we can watch it over time means we now have an established method for studying the physics of one of the most extreme kinds of environment in the entire universe.

An anonymous reader quotes a report from Scientific American: Stomach ulcers and other gastric wounds afflict one in eight people worldwide, but common conventional therapies have drawbacks. Now scientists aim to treat such problems by exploring a new frontier in 3-D printing: depositing living cells directly inside the human body. [...] In their effort to treat stomach lesions less invasively, scientists in China wanted to develop a miniature bioprinting robot that could enter the human body with relative ease. The researchers used existing techniques for creating dexterous electronic devices, such as mechanical bees and cockroach-inspired robots, says the study's senior author Tao Xu, a bioengineer at Tsinghua University in Beijing.

The resulting micro robot is just 30 millimeters wide -- less than half the width of a credit card -- and can fold to a length of 43 millimeters. Once inside a patient's body, it unfolds to become 59 millimeters long and can start bioprinting. "The team has constructed clever mechanisms that make the system compact when entering the body yet unfurl to provide a large working area once past the tight constrictions at entry," says David Hoelzle, a mechanical engineer at the Ohio State University, who did not take part in the study. In their experiments, the researchers in China fitted the micro robot onto an endoscope (a long tube that can be inserted through bodily openings) and successfully snaked it through a curved pipe into a transparent plastic model of a stomach. There, they used it to print gels loaded with human stomach lining and stomach muscle cells (which were grown in culture by a commercial laboratory) onto a lab dish. The printed cells remained viable and steadily proliferated over the course of 10 days. "This study is the first attempt to combine micro robots and bioprinting together," Xu says. The study has been published in the journal Biofabrication.

A team of scientists from the Singapore University of Technology and Design discovered that, using simple chemistry, the organic polymer chitin -- contained in the exoskeletons of insects and crustaceans -- can easily be transformed into a viable building material for basic tools and habitats. The findings have been published in the journal PLOS ONE. Ars Technica reports: "The technology was originally developed to create circular ecosystems in urban environments," said co-author Javier Fernandez. "But due to its efficiency, it is also the most efficient and scalable method to produce materials in a closed artificial ecosystem in the extremely scarce environment of a lifeless planet or satellite." [T]he authors of the current paper point out that most terrestrial manufacturing strategies that could fit the bill typically require specialized equipment and a hefty amount of energy. However, "Nature presents successful strategies of life adapting to harsh environments," the authors wrote. "In biological organisms, rigid structures are formed by integrating inorganic filler proceed from the environment at a low energy cost (e.g., calcium carbonate) and incorporated into an organic matrix (e.g., chitin) produced at a relatively high metabolic cost."

Fernandez and his colleagues maintain that chitin is likely to be part of any planned artificial ecosystem because it is so plentiful in nature. It's the primary component of fish scales and fungal cell walls, for example, as well as the exoskeletons of crustaceans and insects. In fact, insects have already been targeted as a key source of protein for a possible Martian base. And since the chitin component of insects has limited nutritional value for humans, extracting it to make building materials "does not hamper or compete with the food supply," the authors wrote. "Rather, it is a byproduct of it."

With space junk piling up around our planet, the International Space Station needed to perform a last-minute avoidance maneuver Tuesday to steer clear of an "unknown piece of space debris expected to pass within several kilometers." From a report: Mission Control in Houston conducted the move at 2:19 p.m. PT using the Russian Progress resupply spacecraft docked to the ISS to help nudge the station out of harm's way. "Out of an abundance of caution, the Expedition 63 crew will relocate to their Soyuz spacecraft until the debris has passed by the station," NASA said in a statement prior to the move. The maneuver went off smoothly, NASA administrator Jim Bridenstine reported. "The astronauts are coming out of safe haven," he tweeted after the ISS relocated.

sciencehabit writes: A mini-arms race is unfolding in the supposed field of quantum radar, spurred by press reports in 2016 that China had built one -- potentially threatening the ability of stealthy military aircraft to hide from conventional radars. Governments around the world have tasked physicists to look into the idea. Whereas a conventional radar searches for objects by detecting pulse of microwaves reflected from them, quantum radar would utilize pulses of microwaves linked by a quantum connection called entanglement. The system would retain one pulse and measure it in concert with the one reflected from the object. Correlations between the two would make it easier to spot an object through the glare of the surroundings. Or so researchers hoped. Groups have demonstrated elements of a quantum radar, but only in limited experiments that a nonquantum system can still match. And fundamental physical limits suggest the scheme can't beat ordinary radar for long-range detection. Even one of the inventors of the basic concept thinks it won't work when applied to radar.

Plastic face shields are almost totally ineffective at trapping respiratory aerosols, according to modelling in Japan, casting doubt on their effectiveness in preventing the spread of coronavirus. From a report: A simulation using Fugaku, the world's fastest supercomputer, found that almost 100% of airborne droplets of less than 5 micrometres in size escaped through plastic visors of the kind often used by people working in service industries. One micrometre is one millionth of a metre. In addition, about half of larger droplets measuring 50 micrometres found their way into the air, according to Riken, a government-backed research institute in the western city of Kobe.

This week, senior scientists in Britain criticised the government for stressing the importance of hand-washing while placing insufficient emphasis on aerosol transmission and ventilation, factors that Japanese authorities have outlined in public health advice throughout the pandemic. As some countries have attempted to open up their economies, face shields are becoming a common sight in sectors that emphasise contact with the public, such as shops and beauty salons. Makoto Tsubokura, team leader at Riken's centre for computational science, said the simulation combined air flow with the reproduction of tens of thousand of droplets of different sizes, from under 1 micrometre to several hundred micrometres.

Last year, NASA had said that in four years, it would be landing the first woman ever on the moon, and returning to Earth's only natural satellite for the first time since 1972, through its Artemis programme. Now, in a release on September 22, NASA has shared an update outlining its plan, announcing a whopping $28 billion plan for the return to the lunar surface. From a report: The funds are all going to be used for the development of machinery; one billion dollars of the budget will go directly to the development of a commercial human lunar system that will take humans to the moon's surface. An allotment of $651 million will be used to support the Orion Spacecraft and the rocket that Boeing is building for the moon mission -- called the Space Launch System or SLS, on which NASA has already spent at least $11.9 billion.

The mission is named Artemis after the Greek goddess of the moon and the twin sister of Apollo. It's the antithesis to the NASA mission which last landed humans on the moon, Apollo 17. Only 12 humans, all male, have ever walked on the moon and they were all American, according to Bettina Inclan, NASA Communications Director. And with Artemis, they are finally planning to launch women on our satellite too. Currently, there are just 12 active women astronauts, excluding the five other female astronauts who graduated from training earlier this year. The crew for the 2024 mission, however, has not yet been named. According to NASA Administrator Jim Bridenstine, the first woman to walk on the moon would be somebody "who has been proven, somebody who has flown, somebody who has been on the International Space Station already."