Engineers figured out how to cook 3D printed chicken with lasers

Creative Machines Lab at Columbia Engineering have developed a system of software-controlled lasers to cook food with precision, retain moisture with the final-cooked product, brown food within its original packaging, and create an entirely new meal creation process for a consumer.

Who hasn’t dreamt of coming home after a long day and simply pressing a few buttons to get a hot, home-cooked 3D-printed meal, courtesy of one’s digital personal chef? It might make microwaves and conventional frozen TV dinners obsolete. Engineers at Columbia University are trying to make that fantasy a reality, and they’ve now figured out how to simultaneously 3D print and cook layers of pureed chicken, according to a recent paper published in the journal npj Science of Food. Sure, it’s not on the same level as the Star Trek Replicator, which could synthesize complete meals on demand, but it’s a start.

Co-author Hob Lipson runs the Creative Machines Lab at Columbia University, where the research was conducted. His team first introduced 3D printing of food items back in 2007, using the Fab@Home personal fabrication system to create multi-material edible 3D objects with cake frosting, chocolate, processed cheese, and peanut butter. However, commercial appliances capable of simultaneously printing and cooking food layers don’t exist yet. There have been some studies investigating how to cook food using lasers, and Lipson’s team thought this might be a promising avenue to explore further.

“We noted that, while printers can produce ingredients to a millimeter-precision, there is no heating method with this same degree of resolution,” said co-author Jonathan Blutinger. “Cooking is essential for nutrition, flavor, and texture development in many foods, and we wondered if we could develop a method with lasers to precisely control these attributes.” They used a blue diode laser (5-10 W) as the primary heating source but also experimented with lasers in the near- and mid-infrared for comparison, as well as a conventional toaster oven.

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#engineering, #food-science, #laser-cooking, #lasers, #physics, #science

Astronomers solve centuries-old mystery of supernova observed in 1181

Hubble Space Telescope mosaic image of the Crab Nebula, a six-light-year-wide expanding remnant of a star's supernova explosion in 1054 CE

Enlarge / Hubble Space Telescope mosaic image of the Crab Nebula, a six-light-year-wide expanding remnant of a star’s supernova explosion in 1054 CE (credit: NASA/ESA/J. Hester & A. Loll (Arizona State University)

In August 1181, astronomers in China and Japan witnessed a bright “guest star” in the night sky that we now know to have been a supernova—one of just a handful of recorded supernovae in our Milky Way that were visible to the naked eye. It shone brightly for a full six months before it disappeared. Astronomers haven’t been able to identify the remnant of the source for SN 1181 for centuries, and that detail is crucial to determine which class the supernova belongs to. Now, an international team of astronomers think they have pinpointed that source as one of the hottest stars in the galaxy within the Pa30 nebula, according to a new paper published in the Astrophysical Journal Letters.

As we’ve written previously, there are two types of known supernova, depending on the mass of the original star. An iron-core collapse supernova occurs with massive stars (greater than ten solar masses), which collapse so violently that it causes a huge, catastrophic explosion. The temperatures and pressures become so high that the carbon in the star’s core begins to fuse. This halts the core’s collapse, at least temporarily, and this process continues, over and over, with progressively heavier atomic nuclei. When the fuel finally runs out entirely, the (by then) iron core collapses into a black hole or a neutron star.

Then there is a thermonuclear supernova. Smaller stars (up to about eight solar masses) gradually cool to become dense cores of ash known as white dwarfs. If a white dwarf that has run out of nuclear fuel is part of a binary system, it can siphon off matter from its partner, adding to its mass until its core reaches high enough temperatures for carbon fusion to occur. 

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#astronomy, #astrophysics, #nebula, #physics, #science, #supernovae

It’s all in the ink: Vinland Map is definitely a fake, new analysis finds

The Vinland Map purports to be a 15th-century map with a pre-Columbian depiction of the North American Coast. A new analysis has confirmed that the map is, in fact, a modern-day forgery.

Enlarge / The Vinland Map purports to be a 15th-century map with a pre-Columbian depiction of the North American Coast. A new analysis has confirmed that the map is, in fact, a modern-day forgery. (credit: Yale University)

Scholars have questioned the authenticity of a purported 15th-century map housed in Yale University’s Beinecke Rare Book & Manuscript Library since it was first unveiled to the public in 1965. About the size of a placemat, the Vinland Map is an intriguing document because, in addition to Africa, Asia, and Europe, the map depicts a section of the North American coastline identified as “Vinlandia Insula” just southwest of Greenland. This suggested that Norsemen may have been the first Europeans to discover the Americas, well before the first voyage of Christopher Columbus.

That would have major historical significance, if proven. But evidence that the map is a hoax has been steadily accumulating, particularly over the last few years. And the latest scientific analysis has definitively put an end to the controversy once and for all: the inks used to draw the map are of modern origin.

“The Vinland Map is a fake,” said Raymond Clemens, curator of early books and manuscripts at the Beinecke. “There is no reasonable doubt here. This new analysis should put the matter to rest.”

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#gaming-culture, #history, #medieval-manuscripts, #physics, #science, #vinland-map

Fusion startup builds 10-foot-high, 20-tesla superconducting magnet

Image of a large metal oval being lowered into a tank by a crane as people observe.

Enlarge / The assembled magnet gets lowered into its testing apparatus. (credit: Commonwealth Fusion Systems)

In 2015, a group of physicists at MIT did some calculations to rethink how we’re approaching the problem of fusion power. High-temperature, nonmetallic superconductors were now commercially available and could allow the generation of stronger magnetic fields, enabling a simpler, more compact fusion reactor. But the physicists behind the work didn’t stop when the calculating was done; instead, they formed a company, Commonwealth Fusion Systems, and set out to put their calculations to the test.

On Tuesday, Commonwealth Fusion Systems announced that it had hit a key milestone on its roadmap to having a demonstration fusion plant operating in 2025. The company used commercial high-temperature superconductors to build a three-meter-tall magnet that could operate stably at a 20-tesla magnetic field strength. This magnet is identical in design to the ones that will contain the plasma at the core of the company’s planned reactor.

Aggressive roadmap

Giving yourself less than 10 years to solve a problem that an entire research field has been struggling with for decades is ambitious, but it reflects how relevant fusion could be to the climate crisis we’re facing. Several of the company’s leaders mentioned climate change as an inspiration for their work.

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#fusion, #fusion-power, #physics, #science

Forensic tracking could verify uranium cube came from Nazi nuclear effort

Extreme close-up photograph of a bluish cube.

Enlarge / This is likely one of 664 uranium cubes from the failed nuclear reactor that German scientists tried to build in Haigerloch during World War II. (credit: John T. Consoli/University of Maryland)

For decades, the Pacific Northwest National Laboratory (PNNL) has been home to an unusual artifact from World War II: a small cube of solid uranium metal, measuring about two inches on each side and weighing just under 2.5 kilograms. Lab lore holds that the cube was confiscated from Nazi Germany’s failed nuclear reactor experiments in the 1940s, but that has never been experimentally verified.

PNNL scientists are developing new nuclear forensic techniques that should help them confirm the the pedigree of this cube—and others like it—once and for all. Those methods could also eventually be used to track illicit trafficking of nuclear material. PNNL’s Jon Schwantes and graduate student Brittany Robertson presented some of their initial findings this week at the fall meeting of the American Chemical Society (a hybrid virtual/in-person event).

University of Maryland physicist Timothy Koeth is among the outsider collaborators in this ongoing research. He has spent over seven years tracking down these rare artifacts of Nazi Germany’s nuclear research program, after receiving one as a gift. As of 2019, he and a UMD colleague, Miriam Herbert, had tracked down 10 cubes in the US: one at the Smithsonian, another at Harvard University, a handful in private collections—and of course, the PNNL cube.

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#history, #history-of-physics, #manhattan-project, #pacific-northwest-national-laboratory, #physics, #science, #uranium-cubes, #werner-heisenberg

When the Big Bang Was Just a Theory

In “Flashes of Creation,” Paul Halpern offers a dual biography of George Gamow and Fred Hoyle, two midcentury physicists who debated the origins of the universe.

#books-and-literature, #flashes-of-creation-george-gamow-fred-hoyle-and-the-great-big-bang-debate-book, #gamow-george, #halpern-paul-1961, #hoyle-fred, #physics, #space-and-astronomy, #stars-and-galaxies

Study: Ants create stable tunnels in nests, much like humans play Jenga

Two ants in a clear, greenish tunnel.

Enlarge / Two ants tunneling in green gel. A new Caltech study found that ants search for and remove loose grains of soil when digging their tunnels, much like humans remove loose blocks while playing Jenga. (credit: Kimberly Hosey/Getty Images)

Ants are prodigious diggers, constructing elaborate nests with multiple layers connected by an intricate network of tunnels, sometimes reaching depths of 25 feet. Now, a team of scientists from Caltech has used X-ray imaging to capture the process of how ants construct their tunnels. The scientists found that the ants have evolved to intuitively sense which grain particles they can remove while maintaining the stability of the structure, much like removing individual blocks in a game of Jenga. The team described their work in a new paper published in the Proceedings of the National Academy of Sciences.

Scientists interested in collective behavior have been studying ants for decades. That’s because, as a group, ants behave like a form of granular media. A few ants spaced well apart behave like individual ants. But pack enough of them closely together, and they behave more like a single unit, exhibiting both solid and liquid properties. You can pour fire ants from a teapot, for instance, or the ants can link together to build towers or floating rafts. Ants may be tiny critters with tiny brains, but these social insects are capable of collectively organizing themselves into a highly efficient community to ensure that the colony survives.

Several years ago, behavioral biologist Guy Theraulaz of the Institute for Advanced Study in Toulouse, France, and several colleagues combined laboratory experiments with Argentine ants and computer modeling to identify three simple rules governing the ants’ tunneling behavior. To wit: (1) the ants picked up grains at a constant rate (about 2 grains every minute); (2) the ants preferentially dropped their grains near other grains to form pillars; and (3) ants typically chose grains marked with a chemical pheromone after being handled by other ants. Theraulaz et al. built a computer simulation based on those three rules and found that, after a week, their virtual ants built a structure that closely resembled real ant nests. They concluded that those rules emerge from local interactions between individual ants, with no need for central coordination.

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#ant-tunnels, #ants-are-awesome, #biology, #engineering, #granular-materials, #physics, #science

The Miracle Cure for All Our Energy Woes?

In “The Star Builders,” Arthur Turrell explores the attempt to produce clean and abundant energy through nuclear fusion.

#books-and-literature, #fusion-nuclear-reaction, #nuclear-energy, #physics, #the-star-builders-nuclear-fusion-and-the-race-to-power-the-planet-book, #turrell-arthur

MIT scientists reveal why water drops move faster on a hot, oil-coated surface

Side-by-side photographs of teeny-tiny explosions.

Enlarge / Researchers have determined why droplets are propelled across a heated oily surface 100 times faster than on bare metal. The images above reveal the mechanisms that cause the rapid motion. (credit: Kripa Varanasi/MIT News)

There’s a classic 2009 Mythbusters episode in which the hosts demonstrate how someone could wet their hand and dip it ever so briefly into molten lead without injury. The protective mechanism is known as the “Leidenfrost effect,” and it could one day prove useful for microfluidic devices, particularly in microgravity environments, among other applications. We’re one step closer to achieving those applications, thanks to new insights into the phenomenon uncovered by MIT scientists. They described their findings in a recent paper published in the journal Physical Review Letters.

As we’ve reported previously, the Leidenfrost effect dates back to 1756. That’s when German scientist Johann Gottlob Leidenfrost observed that, while water splashed onto a very hot pan sizzles and evaporates very quickly, something changes when the pan’s temperature is well above water’s boiling point. When that happens, Leidenfrost discovered, “gleaming drops resembling quicksilver” will form and will skitter across the surface.

In the ensuing 250 years, physicists came up with a viable explanation for why this occurs. If the surface is at least 400 degrees Fahrenheit (well above the boiling point of water), cushions of water vapor, or steam, form underneath the droplets, keeping them levitated. The droplet can skitter across the surface with very little friction. The Leidenfrost effect also works with other liquids, including oils and alcohol, but the temperature at which it manifests (the “Leidenfrost point”) will be different.

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#leidenfrost-effect, #physics, #science

Study: These ancient straight-shelled cephalopods lived the vertical life

Reconstruction of the orthocone ammonite <em>Baculites compressus</em>. A new study reveals that the creatures likely lived a vertically oriented lifestyle.

Enlarge / Reconstruction of the orthocone ammonite Baculites compressus. A new study reveals that the creatures likely lived a vertically oriented lifestyle. (credit: David Peterman)

The fossil record is chock-full of the fossilized remains of spiral-shelled ammonoids, whose shapes are reminiscent of rams’ horns. But there was another type of ammonoid with long, straight, uncoiled shells, known as orthocones, that particularly flourished during the early Paleozoic. Prior reconstructions have depicted these creatures as being horizontal swimmers, similar to today’s squid.

But a new investigation that involved dropping 3D-printed models into water tanks reveals that most species of orthocones would not have been able to swim well horizontally. Instead, the creatures likely led a vertically oriented lifestyle, moving leisurely up and down through the water column to hunt and sometimes executing rapid upward dodges as needed to avoid predators, according to a recent paper published in the journal PeerJ.

Co-authors David Peterman and Kathleen Ritterbush are paleontologists at the University of Utah. They previously developed digital models of ammonoids with coiled shells to investigate the evolution and lifestyle of these creatures. This time, they’ve turned their attention to a species of orthocone cephalopods (Baculites compressus) that lived during the Cretaceous Period. The authors hypothesized that there must be some adaptive benefit to having a straight shell, since the spiral shell of the orthoconic ammonoids has evolved several times in different lineages found in the fossil record.

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#ammonoids, #biology, #biomechanics, #cephalopods, #paleobiology, #physics, #science, #virtual-paleontology

There’s new evidence of a large cold spot partly causing dimming of Betelgeuse

Two images, the earlier one showing an orange sphere, and the second showing an orange sphere with much of one hemisphere partially eclipsed.

Enlarge / Astronomers continue to ponder the strange, dramatic dimming in the light from Betelgeuse, a bright red star in the Orion constellation, first observed in December 2019. (credit: ESO/M. Montargès et al.)

Back in June, we reported on a likely explanation for the strange, dramatic dimming of Betelgeuse, a bright red star in the Orion constellation: The star burped out a massive gas bubble, resulting in lower temperatures that condensed heavier elements into dust that temporarily obscured the starlight. Now, a team of Chinese scientists has found evidence of a large, dark, cooler spot on the star—consistent with those earlier findings—based on spectral analysis, according to a recent paper published in the journal Nature Communications.

As Ars’ John Timmer reported last year, Betelgeuse is one of the closest massive stars to Earth, about 700 light-years away. It’s an old star that has reached the stage where it glows a dull red and expands, with the hot core only having a tenuous gravitational grip on its outer layers. The star has something akin to a heartbeat, albeit an extremely slow and irregular one. Over time, the star cycles through periods when its surface expands and then contracts.

Astronomers noticed the pronounced dimming of the light from Betelgeuse in December 2019; the difference was even visible to the naked eye. And the dimming persisted, decreasing in brightness by 35 percent in mid-February before brightening again in April 2020. Astronomers puzzled over the phenomenon and wondered whether it was a sign that the star was about to go supernova. 

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#astronomy, #astrophysics, #betelgeuse, #physics, #science, #variable-stars

Physicists discover new kind of tetraquark—the longest-lived yet found

An artist’s impression of Tcc+, a tetraquark composed of two charm quarks and an up and a down antiquark.

Enlarge / An artist’s impression of Tcc+, a tetraquark composed of two charm quarks and an up and a down antiquark. (credit: CERN)

The exotic family of particles known as tetraquarks has a surprising new member. Dubbed Tcc+, it’s the first tetraquark to contain two heavy quarks and two light antiquarks, and it’s the longest-lived exotic matter particle yet discovered. Representatives for the LHCb collaboration at CERN’s Large Hadron Collider made the announcement last week at the European Physical Society Conference on High Energy Physics in Germany, hosted jointly by Universität Hamburg and DESY.

Quarks are the most fundamental building blocks of matter, first proposed in 1964 by Murray Gell-Mann and George Zweig. Quarks come in six different flavors, all differing in mass and charge: up, down, strange, charm, bottom, and top (from lightest to the heaviest), along with their corresponding antiquarks. They typically clump together in groups of two or three to form hadrons, held together by force-carrying particles known as gluons. Ordinary baryons are hadrons that include the proton and neutron of an atom, each made up of three-quark combinations, while hadronic particles known as mesons are formed from quark-antiquark pairs. Think of quarks as the LEGO bricks of the subatomic world, mixing and matching in various combinations to form more complicated structures.

Gell-Mann thought there might be more exotic hadrons formed from quark combinations of four or even five quarks, but these existed solely in the realm of theory until quite recently. That’s because such exotic heavy particles decay very rapidly into more stable byproduct particles within fractions of a second. It’s those byproducts that show up in particle accelerator detectors, amounting to distinctive signatures for their heavier precursor particles. But it’s extremely difficult to tease out those signatures from all the noise in the vast amounts of data produced in particle collisions.

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#cern, #large-hadron-collider, #lhcb, #particle-physics, #physics, #science, #tetraquark

Touring Trinity, the Birthplace of Nuclear Dread

A recent visit to the site of the first atomic bomb explosion offered desert vistas, (mildly) radioactive pebbles and troubling reflections.

#albuquerque-nm, #defense-and-military-forces, #hiroshima-japan, #manhattan-project, #miller-robert-j, #missiles-and-missile-defense-systems, #nagasaki-japan, #nuclear-weapons, #oppenheimer-j-robert, #petrov-stanislav-1939, #physics, #plutonium, #radiation, #space-and-astronomy, #united-states-defense-and-military-forces, #white-sands-missile-range-nm, #your-feed-science

Learning to Live in Steven Weinberg’s Pointless Universe

The late physicist’s most infamous statement still beguiles scientists and vexes believers

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#physics, #the-sciences

Event Horizon Telescope captures birth of black hole jet in Centaurus A

Highest-resolution image of Centaurus A obtained with the Event Horizon Telescope on top of a color composite image of the entire galaxy.

Enlarge / Highest-resolution image of Centaurus A obtained with the Event Horizon Telescope on top of a color composite image of the entire galaxy. (credit: Radboud University/ESO/WFI/MPIfR//APEX/NASA/CXC/CfA/EHT/M. Janssen et al.)

The Event Horizon Telescope (EHT) collaboration made headlines in 2019 by capturing the very first direct image of a black hole at the center of galaxy. Now, the EHT is back with another exciting breakthrough: images of the “dark heart” of a radio galaxy known as Centaurus A that enable the EHT to pinpoint the location of the supermassive black hole at the galaxy’s center, according to a new paper published in the journal Nature Astronomy. The image also captures the birth of a powerful jet emitting from the black hole. The jet’s unusual characteristics could help astronomers answer a few nagging questions about how such jets are produced in the first place.

“This allows us for the first time to see and study an extragalactic radio jet on scales smaller than the distance light travels in one day,” said co-author Michael Janssen, an astronomer at Max Planck Institute for Radio Astronomy in Bonn and Radboud University Nijmegen. “We see up close and personally how a monstrously gigantic jet launched by a supermassive black hole is being born.”

Centaurus A (aka NGC 5128) is one of the largest and brightest objects in the night sky, making it especially popular with amateur stargazers, although it is only visible from the Southern Hemisphere and low northern latitudes. Located in the constellation Centaurus, the galaxy was discovered in 1826 by James Dunlop. John Herschel noted its peculiar shape—it looks elliptical when viewed from Earth, with a lane of dust superimposed across it—in 1847.

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#astronomy, #black-holes, #centaurus-a, #event-horizon-telescope, #physics, #science

Finger wrap could one day let you power up wearables while you sleep

A new wearable device turns the touch of a finger into a source of power for small electronics and sensors. (video link)

Wearables are so hot right now, with consumers scooping up more than 100 million units of smartwatches, fitness trackers, augmented reality glasses, and similar tech in the first quarter of 2021 alone. Sales in the category increased 34.4 percent in the second quarter from Q2 2020, making it one of the fastest-growing categories of personal electronics.

That rise comes with an increased demand for practical and efficient energy harvesters capable of continuously powering those wearables. Now, a team of engineers at the University of California San Diego has designed a new type of biofuel cell that harnesses energy from the sweat of your fingertips, according to a recent paper published in the journal Joule. It can also be integrated with piezoelectric generators to harvest energy from the pressing of the fingertip. The breakthrough could one day make it possible to power up your wearables as you type or sleep.

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#biofuel-cells, #energy-harvesting, #physics, #science, #thermodynamics, #wearable-electronics

China Is Pulling Ahead in Global Quantum Race, New Studies Suggest

The competition between the U.S. and China over development of quantum technology has implications for both the future of science and the two countries’ political relations

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#physics, #the-sciences

Star Trek’s Warp Drive Leads to New Physics

Researchers are taking a closer look at this science-fiction staple—and bringing the idea a little closer to reality

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#physics, #the-sciences

Plasma Particle Accelerators Could Find New Physics

The next big collider will likely rely on novel technology

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#features, #physics, #the-sciences

Highest-Energy Particles Yet Arrive from Ancient Crab Nebula

Astronomers have observed record-breaking photons that strain classical theories of acceleration

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#physics, #space, #the-sciences

Cauliflower and Chaos, Fractals in Every Floret

Scientists take a crack at recreating the hypnotic fractal spirals of the Romanesco cauliflower.

#biology-and-biochemistry, #cauliflower, #flowers-and-plants, #genetics-and-heredity, #physics, #research, #science-journal, #vegetables, #your-feed-science

Electrons Can Form Bizarre 2-D ‘Flatland’ in Superconductor

This property could reveal new secrets of superconductivity

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#advances, #physics, #the-sciences

Black Holes, Quantum Entanglement and the No-Go Theorem

New research shows that there are problems even quantum computers might never be able to solve

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#physics, #the-sciences

German scientists built a high-resolution microscope out of Lego bricks

Photograph and schematic representation of the LEGO microscope built by scientists at Göttingen University.

Enlarge / Photograph and schematic representation of the LEGO microscope built by scientists at Göttingen University. (credit: Bart E. Vos et al., 2021)

German scientists have built a high resolution microscope out of Lego parts and components salvaged from a mobile phone, according to a recent paper published in The Biophysicist. They found that children who undertook the project—including building their microscopes and conducting several at-home experiments—gained enhanced understanding of how microscopy works. It’s part of an ongoing “frugal science” trend: using cheap consumer hardware and open-source software to build low-cost scientific instruments. The DIY tools are perfect for educational environments and for field use in developing countries.

“An understanding of science is crucial for decision-making and brings many benefits in everyday life, such as problem-solving and creativity,” said co-author Timo Betz of the University of Göttingen. “Yet we find that many people, even politicians, feel excluded or do not have the opportunities to engage in scientific or critical thinking. We wanted to find a way to nurture natural curiosity, help people grasp fundamental principles, and see the potential of science.” 

Perhaps the best known low-cost DIY instrument to date is the Foldscope, an optical microscope easily assembled out of a sheet of paper and a lens. It comes as a kit, which includes magnets so users can attach a smartphone to the Foldscope and take pictures of the magnified samples. It’s robust enough to survive being dropped or getting wet, and the magnification is strong enough to view E. coli and malarial parasites in a sample.

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#diy-science, #frugal-science, #microscopes, #optics, #physics, #science, #science-education

AI Designs Quantum Physics Experiments Beyond What Any Human Has Conceived

Originally built to speed up calculations, a machine-learning system is now making shocking progress at the frontiers of experimental quantum physics

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#physics, #tech, #the-sciences

Physicists confirm two cases of “elusive” black hole/neutron star mergers

The successful gravitational-wave detections just keep coming for the LIGO-Virgo-KAGRA collaboration, which has now confirmed two separate “mixed” mergers between black holes and neutron stars, sending powerful gravitational waves rippling across spacetime. Those signals were detected last year by the collaboration, just 10 days apart. A year and a half later, the events officially constitute the first confirmed detection of mixed mergers, as described in a new paper published in The Astrophysical Journal Letters.

“With this new discovery of neutron star-black hole mergers outside our galaxy, we have found the missing type of binary,” said co-author Astrid Lamberts of CNRS, a researcher on the Virgo collaboration in Nice. “We can finally begin to understand how many of these systems exist, how often they merge, and why we have not yet seen examples in the Milky Way.”

LIGO detects gravitational waves via laser interferometry, using high-powered lasers to measure tiny changes in the distance between two objects positioned kilometers apart. LIGO has detectors in Hanford, Washington state, and in Livingston, Louisiana. A third detector in Italy, Advanced VIRGO, came online in 2016. In Japan, KAGRA is now online, and it’s the first gravitational-wave detector in Asia and the first to be built underground. Construction began on LIGO-India earlier this year, and physicists expect it will turn on sometime after 2025.

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#astronomy, #astrophysics, #black-holes, #gravitational-waves, #ligo-virgo, #multi-messenger-astronomy, #neutron-stars, #physics, #science

See the Highest-Resolution Atomic Image Ever Captured

Scientists achieved a record level of visual detail with an imaging technique that could help develop future electronics and better batteries

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#computing, #electronics, #physics, #tech

Physicists show that flying beer coasters will flip 0.45 seconds into flight

University of Bonn physicists were inspired to investigate the aerodynamics of flying beer mats after traveling to Munich with a German physics demonstration show.

Enlarge / University of Bonn physicists were inspired to investigate the aerodynamics of flying beer mats after traveling to Munich with a German physics demonstration show. (credit: sheck / iStock / Getty Images Plus)

Many a pub crawler has engaged in the time-honored tradition of throwing beer mats—those round cardboard coasters that are ubiquitous in bars—as if the mats were frisbees, often competing to see who can throw one the farthest. But unlike frisbees, beer mats tend to flip in the air and fly with a backspin. Now physicists at the University of Bonn have come up with a theoretical model to explain the phenomenon, according to a new paper submitted to the physics arXiv preprint server.

Thanks to their natural curiosity, physicists are fascinated by the physics of beer, and lead author Johann Ostmeyer is no exception. A couple of years ago, he became intrigued by the physics of so-called “beer tapping”: a common prank where the perpetrator, holding an open bottle of beer, finds a target in the bar holding another open bottle. The prankster strikes the top of the target’s bottle with the bottom of their own, then savors the sight of beer explosively foaming all over the target’s hands and clothes.

Back in 2013, Javier Rodríguez-Rodríguez, a physicist at Carlos III University of Madrid, and several colleagues presented experimental and computer-simulation findings of why beer cans foam up so much after being shaken. They concluded that the foaming-over stemmed from a series of waves. Apparently the physics is similar to the development of the cloud in an atomic bomb, although the source of the “explosion” is very different.

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#aerodynamics, #beer-physics, #physics, #science

George Stranahan, Benefactor of Physicists and Bar Flies, Dies at 89

A venturesome millionaire, he forged an only-in-America career in fields ranging from craft beer to free speech activism to scientific research.

#alcoholic-beverages, #aspen-colo, #aspen-center-for-physics, #bars-and-nightclubs, #beer, #deaths-obituaries, #freedom-of-speech-and-expression, #nonprofit-organizations, #physics, #stranahan-george-1931-2021

A Modest Proposal: Let’s Change Earth’s Orbit

What’s the worst that could happen?

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#math, #physics, #space, #the-sciences

Researchers cool a 40 kg object to near its quantum ground state

A researcher in protective gear examines an impossibly futuristic mirror.

Enlarge / One of the 40 kg mirrors that has approached its quantum ground state. (credit: Matt Heintze/Caltech/MIT/LIGO Lab)

Objects that obey the rules of quantum mechanics behave very differently from those in the familiar world around us. That difference leads to an obvious question: is it possible to get an everyday item to start behaving like a quantum object?

But seeing quantum behavior requires limiting an object’s interactions with its environment, which becomes increasingly difficult as objects get larger. Still, there has been progress in increasing the size of the objects we can place in a quantum state, with small oscillators and even grains of sand being notable examples.

So far, researchers have approached this challenge largely by scaling up systems that were relatively easy to work with. But in today’s issue of Science, researchers report that they’ve gotten close to putting a big object into its quantum ground state—a really big object: the 40 kilogram mirrors of the gravitational-wave observatory known as LIGO.

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#gravity, #ligo, #physics, #quantum-mechanics, #science

Can Science Survive the Death of the Universe?

Three physicists envision ways in which the quest for knowledge can last forever

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#physics, #the-sciences

A cold spot and a stellar burp led to strange dimming of Betelgeuse

Thanks to a new study conducted with ESO telescopes, we now know that Betelgeuse’s dip in brightness was the result of a “dusty veil” that formed from material that emerged from the star. Credit: ESO/L. Calçada.

In December 2019, astronomers noticed a strange, dramatic dimming in the light from Betelgeuse, a bright red star in the Orion constellation. They puzzled over the phenomenon and wondered whether it was a sign the star was about to go supernova. Several months later, they had narrowed the most likely explanations to two: a short-lived cold patch on the star’s southern surface (akin to a sun spot), or a clump of dust making the star seem dimmer to observers on Earth. We now have our answer, according to a new paper published in the journal Nature. Dust is the primary culprit, but it is linked to the brief emergence of a cold spot.

As Ars’ John Timmer reported last year, Betelgeuse is one of the closest massive stars to Earth, about 700 light years away. It’s an old star that has reached the stage where it glows a dull red and expands, with the hot core only having a tenuous gravitational grip on its outer layers. The star has something akin to a heartbeat, albeit an extremely slow and irregular one. Over time, the star cycles through periods when its surface expands and then contracts.

One of these cycles is fairly regular, taking a bit over five years to complete. Layered on that is a shorter, more irregular cycle that takes anywhere from under a year to 1.5 years to complete. While they’re easy to track with ground-based telescopes, these shifts don’t cause the sort of radical changes in the star’s light that would account for the changes seen during the dimming event.

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#astronomy, #astrophysics, #betelgeuse, #physics, #science, #stardust

Mysterious Fast Radio Bursts Come in Two Distinct Flavors

A trove of new detections suggests that the bursts could be the result of at least two separate astrophysical phenomena

— Read more on ScientificAmerican.com

#physics, #space, #the-sciences

New Radioactivity Measurement Could Boost Precision of Dark Matter Experiments

The process finds minuscule amounts of radioactive material in metals

— Read more on ScientificAmerican.com

#advances, #physics, #the-sciences

Physicists find “definitive evidence” of mechanism behind brightest auroras

Physicists report definitive evidence that auroras that light up the sky in the high latitudes are caused by electrons accelerated by a powerful electromagnetic force called Alfvén waves.

Enlarge / Physicists report definitive evidence that auroras that light up the sky in the high latitudes are caused by electrons accelerated by a powerful electromagnetic force called Alfvén waves. (credit: Austin Montelius, University of Iowa)

In August and September 1859, there was a major geomagnetic storm—aka, the Carrington Event, the largest ever recorded—that produced dazzling auroras visible throughout the US, Europe, Japan, and Australia. Scientists have long been fascinated by the underlying physical processes giving rise to such displays, but while the basic mechanism is understood, our understanding is still incomplete. According to a new paper published in the journal Nature Communications, electrons in the Earth’s ionosphere catch a plasma wave in order to accelerate toward Earth with sufficient energy to produce the brightest types of auroras.

The spectacular kaleidoscopic effects of the so-called northern lights (or southern lights if they are in the Southern Hemisphere) are the result of charged particles from the Sun being dumped into the Earth’s magnetosphere, where they collide with oxygen and nitrogen molecules—an interaction that excites those molecules and makes them glow. Auroras typically present as shimmering ribbons in the sky, with green, purple, blue, and yellow hues. The lights tend to only be visible in polar regions because the particles follow the Earth’s magnetic field lines, which fan out from the vicinity of the poles.

There are different kinds of auroral displays, such as “diffuse” auroras (a faint glow near the horizon), rarer “picket fence” and “dune” displays, and “discrete aurora arcs”—the most intense variety, which appear in the sky as shimmering, undulating curtains of light. Discrete aurora arcs can be so bright, it’s possible to read a newspaper by their light. (Astronomers have concluded that the phenomenon that earned the moniker STEVE (Strong Thermal Emission Velocity Enhancement) several years ago is not a true aurora after all, since it is caused by charged particles heating up high in the ionosphere.) Scientists believe there are different mechanisms by which precipitating particles are accelerated to produce each type.

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#alfven-waves, #astronomy, #auroras, #physics, #plasmas, #resonance-acceleration, #science

Physicists unlock multispectral secrets of earliest color photographs

French physicist Gabriel Lippmann pioneered color photography and snagged the 1908 Nobel Prize in Physics for his efforts. But according to a recent paper published in the Proceedings of the National Academy of Sciences, Lippmann’s technique distorted the colors of the scenes being photographed. Physicists at the Ecole Polytechnique Federale de Lausanne (EPFL) in Switzerland were able to determine the nature of that distortion and developed a means of reconstructing the original spectrum that created the plates.

“These are the earliest multi-spectral light measurements on record so we wondered whether it would be possible to accurately recreate the original light of these historical scenes,” said co-author Gilles Baechler. “But the way the photographs were constructed was very particular, so we were also really interested in whether we could create digital copies and understand how the technique worked.”

A physics professor at the Sorbonne, Lippmann became interested in developing a means of fixing the colors of the solar spectrum onto a photographic plate in 1886, “whereby the image remains fixed and can remain in daylight without deterioration.” He achieved that goal in 1891, producing color images of a stained-glass window, a bowl of oranges, and a colorful parrot, as well as landscapes and portraits—including a self-portrait. (Fun fact: Lippmann’s laboratory protégés included a promising Polish physics student named Marie Skłodowska, who went on to marry Pierre Curie and win two Nobel Prizes of her own.)

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#chemistry, #color-photography, #gabriel-lippmann, #gaming-culture, #history-of-science, #optics, #physics, #science

What the physics of skipping stones can tell us about aircraft water landings

Experiments by Chinese physicists have shed further light on the intricate physics involving in skipping a stone across the water's surface. Their findings revealed key factors that could influence spaceflight water landings after re-entry.

Enlarge / Experiments by Chinese physicists have shed further light on the intricate physics involving in skipping a stone across the water’s surface. Their findings revealed key factors that could influence spaceflight water landings after re-entry. (credit: Colin Anderson Productions / Getty Images)

Learning how to skip stones across a lake or pond is a time-honored childhood tradition. The underlying physics of skipping stones could also be a useful model for landing aircraft or spacecraft on water, according to a recent paper published in the journal Physics of Fluids. Chinese physicists have built just such a model, and they used it to further clarify the key determining factors behind how many times a stone (or spacecraft) will bounce upon hitting the water.

Skipping stones is just the sort of natural everyday phenomenon that would fascinate physicists, even though at first glance the basic concepts seem simple. It all comes down to spin, speed, shape of the stone, and angle. As the stone hits the water, the force of impact pushes some of the water down, so the stone, in turn, is forced upwards. If the stone is traveling fast enough to meet a minimum velocity threshold, the stone will bounce; if not, it will sink. A round, flat stone is best, simply because its surface area displaces more water as it skips.

Experiments in 2004 by French physicists Lyderic Bocquet and Christophe Clanet demonstrated as much. They built a catapult device to toss aluminum disks at a tank of water and then recorded the splashes with high-speed video. They learned that the bouncing stone must be spinning at a minimal rate of rotation (at least once during its collision time) in order to be stable. In other words, a skipping stone relies on the gyroscopic effect, in which a body rotating around its own axis tends to maintain its own direction. (It’s also what stops a spinning top from tipping over.) Experienced stone-skippers typically apply this rotation to the stone with a simple flick of the finger.

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#fluid-dynamics, #gyro-effect, #magnus-effect, #physics, #science, #spacecraft-water-landings

The Top Unsolved Questions in Mathematics Remain Mostly Mysterious

Just one of the seven Millennium Prize Problems named 21 years ago has been solved

— Read more on ScientificAmerican.com

#math, #physics, #the-sciences

What to Name a Bunch of Black Holes? You Had Some Ideas.

Recently, astronomers asked aloud which plural term would best suit the most enigmatic entity in the cosmos. The responses were plentiful.

#black-holes-space, #european-space-agency, #gravitation-and-gravity, #national-aeronautics-and-space-administration, #physics, #space-and-astronomy, #vanderbilt-university, #your-feed-science

The Subatomic Keys to the Universe

Surprising new data from the Muon g-2 experiment are turning the classical model on its head

— Read more on ScientificAmerican.com

#from-the-editor, #physics, #space, #the-sciences

Wormhole Tunnels in Spacetime May Be Possible, New Research Suggests

There may be realistic ways to create cosmic bridges predicted by general relativity

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#physics, #space, #the-sciences

First Nuclear Detonation Created ‘Impossible’ Quasicrystals

Their structures were once controversial. Now researchers have discovered quasicrystals in the aftermath of a 1945 bomb test

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#physics, #the-sciences

New analysis confirms hypothesis for source of mysterious auroral “dunes”

Revisiting the aurora “dunes”: A time-lapse video recorded by a Scottish aurora borealis hobbyist Graeme Whipps was used to determine the speed of the phenomenon at over 200 m/s.

Several years ago, amateur astronomers first spotted a rare type of aurora nicknamed “the dunes” because of its luminous, rolling wave patterns. Last year, astronomers proposed a possible underlying mechanism—an increase in the density of oxygen atoms—although the theory was admittedly speculative. Now, a new analysis by researchers at the University of Helsinki provides evidence to confirm that explanation, according to a recent paper published in the journal AGU Advances.

Most people have a passing familiarity with the atmospheric phenomenon known as aurora borealis, aka the northern lights (or the southern lights if they appear in the southern hemisphere). The spectacular kaleidoscopic effects are the result of charged particles from the Sun being dumped into the Earth’s magnetosphere, where they collide with oxygen and nitrogen molecules—an interaction that excites those molecules and makes them glow. Auroras typically present as shimmering ribbons in the sky, with green, purple, blue, and yellow hues. The lights tend to only be visible in polar regions because the particles follow the Earth’s magnetic field lines, which fan out from the vicinity of the poles.

Discoveries of possible new types of auroras are rare. Back in 2016, enthusiasts observed a different kind of aurora that was visible at more southern latitudes. The aurora looked like a ribbon of pink or mauve light, sometimes with “picket fence” columns of green light passing through the ribbon.

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#astronomy, #astrophysics, #atmospheric-physics, #atmospheric-waves, #aurora-borealis, #auroral-dunes, #mesosphere, #northern-lights, #physics, #science

Better than holograms: 3D-animated starships can be viewed from any angle

Inspired by the displays of science fiction like the holodeck from Star Trek and the Princess Leia projector from Star Wars, a BYU electrical and computer engineering team is working to develop screenless volumetric display technologies.

Scientists at Brigham Young University (BYU) have created tiny 3D animations out of light. The animations pay homage to Star Trek and Star Wars with tiny versions of the USS Enterprise and a Klingon battle cruiser launching photon torpedoes, as well as miniature green and red light sabers with actual luminous beams. The animations are part of the scientists’ ongoing “Princess Leia project“—so dubbed because it was partly inspired by the iconic moment in Star Wars Episode IV: A New Hope when R2D2 projects a recorded 3D image of Leia delivering a message to Obi-Wan Kenobi. The researchers described the latest advances on their so-called screenless volumetric display technologies in a recent paper published in the journal Scientific Reports.

“What you’re seeing in the scenes we create is real; there is nothing computer generated about them,” said co-author Dan Smalley, a professor of electrical engineering at BYU. “This is not like the movies, where the lightsabers or the photon torpedoes never really existed in physical space. These are real, and if you look at them from any angle, you will see them existing in that space.”

The technology making this science fiction a potential reality is known as an optical trap display (OTD). These are not holograms; they’re volumetric images, as they can be viewed from any angle as they seem to float in the air. A holographic display scatters light across a 2D surface, and microscopic interference patterns make the light look as if it is coming from objects in front of, or behind, the display surface. So with holograms, one must be looking at that surface to see the 3D image. In contrast, a volumetric display consists of scattering surfaces distributed throughout the same 3D space occupied by the resulting 3D image. That means when you look at the image, you are also viewing the scattered light.

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#lasers, #optical-trap-displays, #optics, #physics, #science

Physicists Edge Closer to Taming the Three-Body Problem

A new model cuts through the chaos to reach the best-yet predictions of complex gravitational interactions

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#physics, #the-sciences

Scientists Supersize Quantum Effects with Entangled Drum Duet

Two teams have demonstrated new degrees of quantum measurements in micron-sized metal drums

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#physics, #the-sciences

“Agricomb” is the perfect tool for measuring gases from cow burps

It's a myth that cows fart methane; they actually burp out the greenhouse gas. Agriculture now has a new tool for measuring that methane, which could help design cleaner and more productive farms.

Enlarge / It’s a myth that cows fart methane; they actually burp out the greenhouse gas. Agriculture now has a new tool for measuring that methane, which could help design cleaner and more productive farms. (credit: BerndBrueggemann/iStock/Getty Images)

Optical frequency combs are essentially high-tech “rulers” for measuring different colors of light; they’re useful for making better atomic clocks and hunting for exoplanets, among other things. Now scientists at the National Institute of Standards and Technology (NIST), collaborating with researchers at Kansas State University (KSU), have introduced the “agricomb,” an optical frequency comb that measures the gassy emissions from cow burps—the first use of frequency combs in an agricultural setting. The tool could one day help boost agricultural yields and enable the design of cleaner farms, according to a recent paper published in the journal Science Advances.

According to the authors, the so-called “digestive processes” of livestock account for the largest US source of methane and ammonia emissions. (The former is a major greenhouse gas, while ammonia is an atmospheric pollutant.) A single cow belches about 220 pounds of methane every year.

That’s one reason why there are calls in some quarters to drastically cut down on consumption of beef. However, some scientists—notably Frank M. Mitloehner of the University of California, Davis—have pointed out that cows and other ruminants nonetheless currently account for just 4 percent of all greenhouse gases produced in the US, thanks to better breeding, genetics, and nutrition, among other advances.

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#agriculture, #cattle-emissions, #cow-farts, #measurement, #metrology, #nist, #optical-frequency-comb, #physics, #science

The Fermilab Muon Measurement Might or Might Not Point to New Physics, But…

It was important either way, because the experiment that generated it was breathtakingly precise

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#physics, #the-sciences

The Fermilab Muon Measurement May or May Not Point to New Physics, But …

It was important either way, because the experiment that generated it was breathtakingly precise

— Read more on ScientificAmerican.com

#physics, #the-sciences