This week CNN published an article chronicling how 35 countries "have come together to try and master nuclear fusion, a process that occurs naturally in the sun — and all stars — but is painfully difficult to replicate on Earth.

"Fusion promises a virtually limitless form of energy that, unlike fossil fuels, emits zero greenhouse gases and, unlike the nuclear fission power used today, produces no long-life radioactive waste. Mastering it could literally save humanity from climate change, a crisis of our own making." If it is mastered, fusion energy will undoubtedly power much of the world. Just 1 gram of fuel as input can create the equivalent of eight tons of oil in fusion power. That's an astonishing yield of 8 million to 1. Atomic experts rarely like to estimate when fusion energy may be widely available, often joking that, no matter when you ask, it's always 30 years away. But for the first time in history, that may actually be true....

The main challenge is sustaining it. The tokamak in the UK — called the Joint European Torus, or JET — held fusion energy for five seconds, but that's simply the longest that machine will go for. Its magnets were made of copper and were built in the 1970s. Any more than five seconds under such heat would cause them to melt. ITER uses newer magnets that can last much longer, and the project aims to produce a 10-fold return on energy, generating 500 megawatts from an input of 50 megawatts.... The dimensions are mind-blowing. The tokamak will ultimately weigh 23,000 tons. That's the combined weight of three Eiffel towers. It will comprise a million components, further differing into no fewer than 10 million smaller parts.

This powerful behemoth will be surrounded by some of the largest magnets ever created. Their staggering size — some of them have diameters of up to 24 meters — means they are are too large to transport and must be assembled on site in a giant hall.... Even the digital design of this enormous machine sits across 3D computer files that take up more than two terabytes of drive space. That's the same amount of space you could save more than 160 million one-page Word documents on. Behind hundreds of workers putting the ITER project together are around 4,500 companies with 15,000 employees from all over the globe... Now commercial businesses are preparing to generate and sell fusion energy, so optimistic they are that this energy of the future could come online by mid-century.

But as ever with nuclear fusion, as one challenge is overcome another seems to crop up. The limited stocks and price of tritium is one, so ITER is trying to produce its own. On that front, the outlook isn't bad. The blanket within the tokamak will be coated with lithium, and as escaped plasma neutrons reach it, they will react with the lithium to create more tritium fuel... First plasma is now expected in 2025, and the first deuterium-tritium experiments are hoped to take place in 2035, though even those are now under review — delayed, in part, by the pandemic and persistent supply chain issues.
"This article has some nice photography," writes Slashdot reader technology_dude. "It really makes it hit home on the incredible amount of design and planning work that is required."

The article notes that when Stephen Hawking was asked which scientific discovery he'd like to see in his lifetime, Hawking answered, "I would like nuclear fusion to become a practical power source."

Amateur astronomers are preparing for a heavenly treat from Friday as the five planets visible to the naked eye line up in order of their distance from the sun across the pre-dawn sky. From a report: For those who can face the early start, and have an unobstructed view of the horizon to the east and south-east, Mercury, Venus, Mars, Jupiter and Saturn, could all be visible before the faintest, Mercury, vanishes in the glare of sunrise. It is not uncommon to see two or three planets close together, but the five that can be spotted with the naked eye have not appeared in order, as viewed from the northern hemisphere, since December 2004.

"This is really cool," said Prof Beth Biller, personal chair of exoplanet characterisation at Edinburgh University's institute for astronomy. "We now know of many other stars hosting multiple planets. This is a rare opportunity to see the same thing closer to home, with all five 'naked eye' planets in our solar system visible at once." The planets of the solar system orbit the sun in a remarkably narrow plane, meaning that when viewed from Earth, they appear to lie close to an imaginary line in the sky called the ecliptic. The five planets will rise above the horizon in the early hours of Friday, though it may be hard to see them all until later in the month.

Nearly a third of Hawaii's single-family houses have rooftop solar panels -- more than twice the percentage in California -- and officials expect many more homes to add panels and batteries in the coming years. From a report: Even before energy prices surged globally this year, homeowners, elected leaders and energy executives in Hawaii had decided that rooftop solar panels were one of the best ways to meet demand for energy and tame the state's high power costs. Russia's invasion of Ukraine has only strengthened the state's embrace of renewable energy. Electricity rates in Hawaii jumped 34 percent in April from a year earlier because many of its power plants burn oil, about a third of which came from Russia last year.

While Hawaii faces unique challenges, the state's reliance on solar carries lessons for other states and countries looking to fight climate change and bring down energy costs. The state has increased the use of renewable energy in large part by getting electric utilities to accept rooftop solar rather than fight it, as energy companies in California, Florida and other states have been doing. "In Hawaii, we've come to the recognition that rooftop solar is going to be an important part of our grid, has to be part of our grid," said Shelee Kimura, president and chief executive of Hawaiian Electric Company, the state's largest power provider. "Some people think we're crazy. Some people think we're pretty amazing."

Researchers may have pinpointed the source of a famous supposed alien broadcast discovered nearly a half century ago. Space.com reports: The prominent and still-mysterious Wow! Signal, which briefly blared in a radio telescope the night of Aug. 15, 1977, may have come from a sun-like star located 1,800 light-years away in the constellation Sagittarius. "The Wow! Signal is considered the best SETI (or the search for extraterrestrial intelligence) candidate radio signal that we have picked up with our telescopes," Alberto Caballero, an amateur astronomer, told Live Science. [...] The Wow! Signal most likely came from some kind of natural event and not aliens, Caballero told Live Science, though astronomers have ruled out a few possible origins like a passing comet. Still, Caballero noted that in our infrequent attempts to say hello to E.T., humans have mostly produced one-time broadcasts, such as the Arecibo message sent toward the globular star cluster M13 in 1974. The Wow! Signal may have been something similar, he added.

Knowing that the Big Ear telescope's two receivers were pointing in the direction of the constellation Sagittarius on the night of the Wow! Signal, Caballero decided to search through a catalog of stars from the European Space Agency's Gaia satellite to look for possible candidates. "I found specifically one sun-like star," he said, an object designated 2MASS 19281982-2640123 about 1,800 light-years away that has a temperature, diameter and luminosity almost identical to our own stellar companion. Caballero's findings appeared May 6 in the International Journal of Astrobiology. "I think this is perfectly worth doing because we want to point our instruments in the direction of things we think are interesting," Rebecca Charbonneau, a historian who studies SETI at the Harvard-Smithsonian Center for Astrophysics and who wasn't involved in the work, told Live Science. "There are billions of stars in the galaxy, and we have to figure out some way to narrow them down," she added.

But she wonders if looking for only sun-like stars is too limiting. "Why not just look at a bunch of stars?" she asked.

New research explains how meteorites called aubrites may actually be shattered pieces of the planet closest to the sun from the early days of the solar system. From a report: Mercury does not make sense. It is a bizarre hunk of rock with a composition that is unlike its neighboring rocky planets. "It's way too dense," said David Rothery, a planetary scientist at the Open University in England. Most of the planet, the closest to the sun, is taken up by its core. It lacks a thick mantle like Earth has, and no one is quite sure why. One possibility is that the planet used to be much bigger -- perhaps twice its current bulk or more. Billions of years ago, this fledgling proto-Mercury, or super Mercury, could have been hit by a large object, stripping away its outer layers and leaving the remnant we see behind.

While a nice idea, there has never been direct evidence for it. But some researchers think they have found something. In work presented [PDF] at the Lunar and Planetary Science Conference in Houston in March, Camille Cartier, a planetary scientist at the University of Lorraine in France, and colleagues said pieces of this proto-Mercury may be hiding in museums and other meteorite collections. Studying them could unlock the planet's mysteries. "We don't have any samples of Mercury" at the moment, said Dr. Cartier. Gaining such specimens "would be a small revolution" in understanding the natural history of the solar system's smallest planet. According to the Meteoritical Society, nearly 70,000 meteorites have been gathered around the world from places as remote as the Sahara and Antarctica, finding their way into museums and other collections. Most are from asteroids ejected from the belt between Mars and Jupiter, while more than 500 come from the moon. More than 300 are from Mars.

Researchers from the University of Gottingen have published new calculations of the physics of the sun's atmosphere that resolve the apparent contradiction between the modern standard model of solar evolution and the "tried-and-true" method called spectral analysis. "The new calculations of the physics of the sun's atmosphere yield updated results for abundances of different chemical elements, which resolve the conflict," reports Phys.Org. "Notably, the sun contains more oxygen, silicon and neon than previously thought. The methods employed also promise considerably more accurate estimates of the chemical compositions of stars in general." From the report: Highly accurate helioseismic measurements gave results about the sun's interior structure that were at odds with the solar standard models. According to helioseismology, the so-called convective region within our sun where matter rises and sinks down again, like water in a boiling pot, was considerably larger than the standard model predicted. The speed of sound waves near the bottom of that region also deviated from the standard model's predictions, as did the overall amount of helium in the sun. To top it off, certain measurements of solar neutrinos -- fleeting elementary particles, hard to detect, reaching us directly from the sun's core regions -- were slightly off compared to experimental data, as well. Astronomers had what they soon came to call a "solar abundances crisis," and in search of a way out, some proposals ranged from the unusual to the downright exotic. Did the sun maybe accrete some metal-poor gas during its planet-forming phase? Is energy being transported by the notoriously non-interacting dark matter particles?

The newly published study by Ekaterina Magg, Maria Bergemann and colleagues has managed to resolve that crisis, by revisiting the models on which the spectral estimates of the sun's chemical composition are based. [...] In this study they tracked all chemical elements that are relevant to the current models of how stars evolved over time, and applied multiple independent methods to describe the interactions between the sun's atoms and its radiation field in order to make sure their results were consistent. For describing the convective regions of our sun, they used existing simulations that take into account both the motion of the plasma and the physics of radiation ("STAGGER" and "CO5BOLD"). For the comparison with spectral measurements, they chose the data set with the highest available quality: the solar spectrum published by the Institute for Astro- and Geophysics, University of GÃttingen. "We also extensively focused on the analysis of statistical and systematic effects that could limit the accuracy of out results," notes Magg. The new calculations showed that the relationship between the abundances of these crucial chemical elements and the strength of the corresponding spectral lines was significantly different from what previous authors had claimed. Consequently, the chemical abundances that follow from the observed solar spectrum are somewhat different than stated in previous analysis.

"We found, that according to our analysis the sun contains 26% more elements heavier than helium than previous studies had deduced," explains Magg. In astronomy, such elements heavier than helium are called "metals." Only on the order of a thousandth of a percent of all atomic nuclei in the sun are metals; it is this very small number that has now changed by 26% of its previous value. Magg adds: "The value for the oxygen abundance was almost 15% higher than in previous studies." The new values are, however, in good agreement with the chemical composition of primitive meteorites ("CI chondrites") that are thought to represent the chemical make-up of the very early solar system. When those new values are used as the input for current models of solar structure and evolution, the puzzling discrepancy between the results of those models and helioseismic measurements disappears.

After traveling 300 miles on the underbelly of the Perseverance rover, the "Ingenuity" helicopter has made 28 different flights over the surface of Mars, reports the Washington Post, staying aloft for a total of nearly one hour, flying 4.3 miles with a maximum speed of 12.3 miles per hour and a top altitude of 39 feet. "It's traversed craters, taken photos of regions that would be hard to reach on the ground, and served as a surprisingly resilient scout that has adapted to the changing Martian atmosphere and survived its harsh dust storms and frigid nights.

"Now the engineers and scientists at NASA's Jet Propulsion Laboratory are worried that their four-pound, solar-powered drone on Mars, may be nearing the end of its life." Winter is setting in on Mars. The dust is kicking up, coating Ingenuity's solar panels and preventing it from fully charging its six lithium-ion batteries. This month, for the first time since it landed on Mars more than a year ago, Ingenuity missed a planned communications session with Perseverance, the Mars rover that it relies on to send data and receive commands from Earth. Will a dust-coated Ingenuity survive a Martian winter where temperatures routinely plunge below minus-100 degrees Fahrenheit? And if it doesn't, how should the world remember the little helicopter that cost $80 million to develop and more than five years to design and build? Those closest to the project say that as time winds down for Ingenuity, it's hard to overstate its achievements....

"We built it as an experiment," Lori Glaze, the director of NASA's planetary science division, told The Washington Post. "So it didn't necessarily have the flight-qualified parts that we use on the big missions like Perseverance." Some, such as components from smartphones, were even bought off-the-shelf, so "there were chances that they might not perform in the environment as we expected. And so there was a risk that it wasn't going to work.... What happened was, and this is really key, after Ingenuity performed so well on those first five flights, the science team from Perseverance came to us and said, 'You know what, we want this helicopter to keep operating to help us in our exploration and achieving our science goals,' " Glaze said.

So NASA decided to keep flying....

On April 29, it took its last flight to date, No. 28, a quarter-of-a-mile jaunt that lasted two-and-a-half minutes. Now NASA wonders if that will be the last one. The space agency thinks the helicopter's inability to fully charge its batteries caused the helicopter to enter a low-power state. When it went dormant, the helicopter's onboard clock reset, the way household clocks do after a power outage. So the next day, as the sun rose and began to charge the batteries, the helicopter was out of sync with the rover: "Essentially, when Ingenuity thought it was time to contact Perseverance, the rover's base station wasn't listening," NASA wrote.

Then NASA did something extraordinary: Mission controllers commanded Perseverance to spend almost all of May 5 listening for the helicopter.

Finally, little Ingenuity phoned home.

The radio link, NASA said, "was stable," the helicopter was healthy, and the battery was charging at 41 percent.

But, as NASA warned, "one radio communications session does not mean Ingenuity is out of the woods. The increased (light-reducing) dust in the air means charging the helicopter's batteries to a level that would allow important components (like the clock and heaters) to remain energized through the night presents a significant challenge."

Maybe Ingenuity will fly again. Maybe not.

"At this point, I can't tell you what's going to happen next," Glaze said. "We're still working on trying to find a way to fly it again. But Perseverance is the primary mission, so that we need to start setting our expectations appropriately."
For Ingenuity's "Wright Brothers moment" — when it flew for the first time on another planet — it was actually carrying a postage-sized bit of fabric from the Wright Brothers original 1903 aircraft.

Astronomers announced today that they had pierced the veil of darkness and dust at the center of our Milky Way galaxy to capture the first picture of "the gentle giant" dwelling there: A supermassive black hole, a trapdoor in space-time through which the equivalent of 4 million suns have been dispatched to eternity, leaving behind only their gravity and a violently bent space-time. From a report: The image, released in six simultaneous news conferences in Washington, D.C., and around the globe, showed a lumpy doughnut of radio emission framing an empty space as dark and silent as death itself. The new image joins the first ever picture of a black hole, produced in 2019 by the same team, which photographed the monster at the heart of the M87. The new image shows new details of the astrophysical violence and gravitational weirdness holding sway at the center of our placid-looking hive of starlight.

Black holes were an unwelcome consequence of Albert Einstein's general theory of relativity, which attributes gravity to the warping of space and time by matter and energy, much as a mattress sags under a sleeper. Einstein's insight led to a new conception of the cosmos, in which space-time could quiver, bend, rip, expand, swirl and even disappear forever into the maw of a black hole, an entity with gravity so strong that not even light could escape it. Einstein disapproved of this idea, but the universe is now known to be speckled with black holes. Many are the remains of dead stars that collapsed inward on themselves and just kept going. But there seems to be a black hole at the center of nearly every galaxy, ours included, that can be millions or billions of times as massive than our sun. Astronomers still do not understand how these supermassive black holes have grown so big.

An anonymous reader quotes a report from Gizmodo: Helga and Zohar are headed for a trip around the Moon on an important mission, measuring radiation risks for female astronauts for the first time. The inanimate pair are manikins modeled after the body of an adult woman. For the Artemis 1 mission, in which an uncrewed Orion capsule will travel to the Moon and back, one of the manikins will be outfitted with a newly developed radiation protection vest. Helga and Zohar, as they're called, won't be alone, as they'll be joined by a third manikin that will collect data about flight accelerations and vibrations. Artemis 1 is scheduled to blast off later this year. The Artemis program aims to return humans to the Moon for the first time in over 50 years, but this time the space agency has vowed to land the first woman on the dusty lunar surface. [...]

The Helga and Zohar manikins are part of the MARE experiment, designed by the German Aerospace Center (DLR). The experiment will use two identical representations of the female body to investigate radiation exposure throughout the flight of the Artemis 1 mission, which may last up to six weeks. Artemis 1 will set the stage for Artemis 2, in which an Orion capsule carrying real humans will fly to the Moon and back (without landing), possibly as early as 2024. [...] Here's how it will work. The manikins are made from materials that mimic the bones, soft tissues, and organs of an adult woman, all of which will be tracked by more than 10,000 passive sensors and 34 active radiation detectors, according to DLR. One of the manikins, Helga, will fly to the Moon unprotected while the other one, Zohar, will wear a radiation protection vest called the AstroRad (which was developed by American aerospace company Lockheed Martin and Israeli startup StemRad).

As they travel aboard the Orion spacecraft to the Moon, Helga and Zohar will be affected by the harsh environment of space. The manikins, having traveled beyond the protective shielding of Earth's magnetosphere, will be exposed to various types of space radiation, like charged particles produced by the Sun or energy particles trapped within Earth's atmosphere. Space radiation is known to alter molecules of DNA, which is obviously not good for human health. Upon their arrival back at Earth, data collected from the two manikins will help researchers to better understand the level of protection provided by the newly developed AstroRad vest.

Several readers have shared this report: One foggy night in December 2018, David Hill was trying to land a helicopter when a beam of light suddenly overwhelmed his night vision goggles. Mr. Hill, an emergency services pilot, had been called to airlift a teenager who had been badly injured in an all-terrain vehicle crash from a village 35 miles north of Madison, Wis. But now, Mr. Hill was temporarily blinded. Flying about 500 feet above the ground, he tried to get his bearings. It was "like looking into the sun, and all I can see are bright spots," he recalled. A person had pointed a laser at his helicopter. From 2010 to 2021, close to 70,000 pilots reported similar episodes, according to the Federal Aviation Administration. Last year it recorded more than 9,700 cases, a record high, and a 41 percent increase from 2020. When a laser pointer reaches a cockpit, the light can disorient or "completely incapacitate" a pilot, who on a commercial airplane could be responsible for hundreds of passengers, the F.A.A. said. Some commercial flight paths have been disrupted, causing pilots to change course or even turn around. "What you might see as a toy has the capacity to momentarily blind the crew member," Billy Nolen, the acting administrator of the F.A.A., said. Though no plane has ever been reported to have crashed as a result of a laser strike, Mr. Nolen said in a phone interview that there was always a risk of a "tragic outcome." He added, "This is not an arcade game."

In 1972, photo prints that developed before your eyes were "downright magical," argues Fast Company — "and still meaningful today."

A new article at Fast Company points out that while Polaroid went bankrupt twice, and stopped making cameras in 2007, "Then an unexpected thing happened: It turned out that even Polaroid couldn't kill Polaroid." Even as instant photography's eulogies were being written, a band of enthusiasts known as The Impossible Project bought the last Polaroid factory that hadn't been hastily dismantled and started producing film packs again. The task required reformulating its own chemistry from scratch, and it was years until the results reached the vicinity of original Polaroid quality. Fans were very patient.

Eventually, the Impossible Project and Polaroid came under the same ownership, adopted Polaroid as the unified brand, and started making instant cameras again. The new models start at $100 and look a lot like that 1977 OneStep, even when they're adorably miniaturized. It's almost as if Polaroid's years in limbo were a bad dream.... Polaroid and several smaller companies refurbish old models, replacing worn parts and otherwise returning them to optimum performance. Repairing an SX-70 generally involves permanently removing its leather, but replacement skins are available in an array of styles, from the traditional to the psychedelic.

Increasingly, yesteryear's Polaroid cameras are springing back to life in surprising ways. Wisconsin-based Retrospekt not only revives old models, but also encases antique innards in new plastic shells, allowing it to sell branding crossovers such as Malibu Barbie and Pepsi-themed Polaroid cameras. Hong Kong's Mint offers a camera called the SLR670 that's really a restored SX-70 accompanied by a gizmo that plugs into the flash port to allow for manual settings. And Open SX-70 is a project to smarten up the SX-70 by replacing its 1970s circuit board with a tiny Arduino computer.
Other things I learned from the article:

• "Each film pack contained its own battery, so the camera would never run out of juice at an inopportune moment."
• Kodak was forced out of the instant photography market in 1986 by a Polaroid patent infringement suit in which Polaroid won $925 million in damages.
• Edwin Land's "final gambit to revolutionize photography" was 1977's wildly unpopular Polavision instant home movies.
• There's a 1974 ad for the cameras narrated by Laurence Olivier.

An anonymous reader quotes a report from Bloomberg: California, which aims to have a carbon-free power grid within 25 years, got a short glimpse of that possibility earlier this month. The state's main grid ran on more than 97% renewable energy at 3:39 p.m. on Sunday April 3, breaking a previous record of 96.4% that was set just a week earlier, the California Independent System Operator said Thursday in a statement. While these all-time highs are for a brief time, they solidly demonstrate the advances being made to reliably achieve California's clean energy goals," said California ISO CEO Elliot Mainzer said in the statement.

Power production from the sun and wind typically peak in the spring, due to mild temperatures and the angle of the sun allowing for an extended period of strong solar production, the grid operator said. While hitting the new renewable record is remarkable, the state has found itself scrambling for power supplies during the past two summers as it has added more intermittent sources and retired natural-gas plants for environmental reasons. California has set a target to have a zero-carbon power system by 2045.

NASA's Hubble Space Telescope has confirmed the largest icy comet nucleus ever seen by scientists. NPR reports: The nucleus of comet C/2014 UN271 (Bernardinelli-Bernstein) is about 80 miles in diameter, which is larger than the state of Rhode Island, NASA says. The comet's nucleus is about 50 times larger than that of most comets, and its mass is estimated to be a gigantic 500 trillion tons.

Comet C/2014 UN271 was discovered by astronomers Pedro Bernardinelli and Gary Bernstein using archival images from the Cerro Tololo Inter-American Observatory in Chile. The comet has been observed since 2010, when it was 3 billion miles away from the sun, and has been studied since then. NASA says there was a challenge in measuring the comet's nucleus because it was too far away for the Hubble telescope to determine its size. Instead, scientists had to make a computer model that was adjusted to fit the images of the comet's bright light that they got from the telescope's data.

Despite traveling at 22,000 mph, the massive comet is still coming from the edge of the solar system. But NASA assures us that it will never get closer than 1 billion miles away from the sun -- and even then, that won't be until 2031. The previous record-holder for largest comet nucleus was discovered in 2002. Comet C/2002 VQ94 was approximately 60 miles across.

An anonymous reader quotes a report from MIT News: Engineers at MIT and the National Renewable Energy Laboratory (NREL) have designed a heat engine with no moving parts. Their new demonstrations show that it converts heat to electricity with over 40 percent efficiency -- a performance better than that of traditional steam turbines. The heat engine is a thermophotovoltaic (TPV) cell, similar to a solar panel's photovoltaic cells, that passively captures high-energy photons from a white-hot heat source and converts them into electricity. The team's design can generate electricity from a heat source of between 1,900 to 2,400 degrees Celsius, or up to about 4,300 degrees Fahrenheit.

The researchers plan to incorporate the TPV cell into a grid-scale thermal battery. The system would absorb excess energy from renewable sources such as the sun and store that energy in heavily insulated banks of hot graphite. When the energy is needed, such as on overcast days, TPV cells would convert the heat into electricity, and dispatch the energy to a power grid. With the new TPV cell, the team has now successfully demonstrated the main parts of the system in separate, small-scale experiments. They are working to integrate the parts to demonstrate a fully operational system. From there, they hope to scale up the system to replace fossil-fuel-driven power plants and enable a fully decarbonized power grid, supplied entirely by renewable energy. The researchers published their findings in the journal Nature.

Summer on Neptune seems to be cooling down. Observations dating back to 2003 show that the temperature in the planet's southern hemisphere has been dropping, despite the fact that these measurements were taken in the early part of its long summer. New Scientist reports: Michael Roman at the University of Leicester, UK, and his colleagues examined data from several of the world's biggest telescopes to figure out how the temperature of Neptune has changed since the first relatively detailed measurements were made in 2003. "Because we are observing Neptune in this southern summer, we basically expect temperatures to be getting slowly warmer in time," says Roman. "But what we saw was that they dropped by about 8C" over the course of 15 years, he says. The observations also revealed a surprise near the planet's south pole. Between 2018 and 2020, an area there warmed by about 11C, an unexpectedly rapid change given that it takes Neptune more than 165 Earth years to complete a circuit around the sun. "A season on Neptune is over 40 years long, so we'd expect these changes to be a lot more gradual," says Roman.

sciencehabit shares a report from Science.org: How do you bottle renewable energy for when the Sun doesn't shine and the wind won't blow? That's one of the most vexing questions standing in the way of a greener electrical grid. Massive battery banks are one answer. But they're expensive and best at storing energy for a few hours, not for days long stretches of cloudy weather or calm. Another strategy is to use surplus energy to heat a large mass of material to ultrahigh temperatures, then tap the energy as needed. This week, researchers report a major improvement in a key part of that scheme: a device for turning the stored heat back into electricity.

A team at the Massachusetts Institute of Technology (MIT) and the National Renewable Energy Laboratory achieved a nearly 30% jump in the efficiency of a thermophotovoltaic (TPV), a semiconductor structure that converts photons emitted from a heat source to electricity, just as a solar cell transforms sunlight into power. "This is very exciting stuff," says Andrej Lenert, a materials engineer at the University of Michigan, Ann Arbor. "This is the first time [TPVs have] gotten into really promising efficiency ranges, which is ultimately what matters for a lot of applications." Together with related advances, he and others say, the new work gives a major boost to efforts to roll out thermal batteries on a large scale, as cheap backup for renewable power systems. The idea is to feed surplus wind or solar electricity to a heating element, which boosts the temperature of a liquid metal bath or a graphite block to several thousand degrees. The heat can be turned back into electricity by making steam that drives a turbine, but there are trade-offs. High temperatures raise the conversion efficiency, but turbine materials begin to break down at about 1500C. TPVs offer an alternative: Funnel the stored heat to a metal film or filament, setting it aglow like the tungsten wire in an incandescent light bulb, then use TPVs to absorb the emitted light and turn it to electricity.

For the new device, Asegun Henry, an MIT mechanical engineer, tinkered with both the emitter and the TPV itself. Previous TPV setups heated the emitters to about 1400C, which maximized their brightness in the wavelength range for which TPVs were optimized. Henry aimed to push the temperature 1000C higher, where tungsten emits more photons at higher energies, which could improve the energy conversion. But that meant reworking the TPVs as well. With researchers at the National Renewable Energy Laboratory, Henry's team laid down more than two dozen thin layers of different semiconductors to create two separate cells stacked one on top of another. The top cell absorbs mostly visible and ultraviolet photons, whereas the lower cell absorbs mostly infrared. A thin gold sheet under the bottom cell reflects low-energy photons the TPVs couldn't harvest. The tungsten reabsorbs that energy, preventing it from being lost. The result, the group reports today in Nature, is a TPV tandem that converts 41.1% of the energy emitted from a 2400C tungsten filament to electricity.

An anonymous reader quotes a report from Ars Technica: The mysterious Antikythera mechanism -- an ancient device believed to have been used for tracking the heavens -- has fascinated scientists and the public alike since it was first recovered from a shipwreck over a century ago. Much progress has been made in recent years to reconstruct the surviving fragments and learn more about how the mechanism might have been used. And now, members of a team of Greek researchers believe they have pinpointed the start date for the Antikythera mechanism, according to a preprint posted to the physics arXiv repository. Knowing that "day zero" is critical to ensuring the accuracy of the device.

"Any measuring system, from a thermometer to the Antikythera mechanism, needs a calibration in order to [perform] its calculations correctly," co-author Aristeidis Voulgaris of the Thessaloniki Directorate of Culture and Tourism in Greece told New Scientist. "Of course it wouldn't have been perfect -- it's not a digital computer, it's gears -- but it would have been very good at predicting solar and lunar eclipses." [...] In 1951, a British science historian named Derek J. de Solla Price began investigating the theoretical workings of the device. Based on X-ray and gamma ray photographs of the fragments, Price and physicist Charalambos Karakalos published a 70-page paper in 1959 in the Transactions of the American Philosophical Society. Based on those images, they hypothesized that the mechanism had been used to calculate the motions of stars and planets -- making it the first known analog computer. [...]

Voulgaris and his co-authors based their new analysis on a 223-month cycle called a Saros, represented by a spiral inset on the back of the device. The cycle covers the time it takes for the Sun, Moon, and Earth to return to their same positions and includes associated solar and lunar eclipses. Given our current knowledge about how the device likely functioned, as well as the inscriptions, the team believed the start date would coincide with an annular solar eclipse. [...] "The eclipse predictions on the [device's back] contain enough astronomical information to demonstrate conclusively that the 18-year series of lunar and solar eclipse predictions started in 204 BCE," Alexander Jones of New York University told New Scientist, adding that there have been four independent calculations of this. "The reason such a dating is possible is because the Saros period is not a highly accurate equation of lunar and solar periodicities, so every time you push forward by 223 lunar months the quality of the prediction degrades."

"Weather predictions here on Earth are more accurate than they've ever been," writes ScienceAlert.

"Trying to predict the behavior of our wild and wacky Sun is a little more tricky." Case in point: according to official predictions, the current cycle of solar activity should be mild. But the gap between the prediction and what's actually happening is pretty significant — and it's getting wider. Sunspot counts, used as a measure for solar activity, are way higher than the predicted values calculated by the NOAA, NASA, and the International Space Environmental Service.

In fact, sunspot counts have been consistently higher than predicted levels since September 2020. This could mean that, in contrast to predictions, the Sun is in the swing of an unusually strong activity cycle.... [T]he number of sunspots for the last 18 months has been consistently higher than predictions. At time of writing, the Sun has 61 sunspots, and we're still over three years from solar maximum.
Here's what makes that even more significant. In 2020 a team of scientists (led by solar physicist Scott McIntosh of the U.S. National Center for Atmospheric Research) predicted that, based on long-term solar cycle trends, this solar cycle was likely to be stronger — and perhaps one of the strongest ever recorded.

They'd also said in 2020 that scientists "lacked a fundamental understanding" of the mechanism behind sun spot cycles, and argued that if this sun cycle proves them correct, "we will have evidence that our framework for understanding the Sun's internal magnetic machine is on the right path."

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A possible galaxy that exists some 13.5 billion light-years from Earth has broken the record for farthest astronomical object ever seen. Live Science reports: That age places this collection of stars, now dubbed HD1, between a time of total darkness -- about 14 billion years ago the universe was a blank slate devoid of any stars or galaxies -- and one of just-burgeoning lights as clumps of dust and gas were growing into their cosmic destinies. [...] The researchers discovered HD1 in data collected over 1,200 hours of observation time using the Subaru Telescope, the VISTA Telescope, the U.K. Infrared Telescope and the Spitzer Space Telescope. They were particularly looking at redshift, a phenomenon in which light waves stretch out or become redder as an object moves away from the observer. In this case, the redshift suggested HD1 was extremely distant. The researchers found that the red wavelengths were the equivalent to a galaxy located 13.5 billion light-years away.

HD1 also seems to be growing at a feverish rate -- about 100 stars each year, or at least 10 times the rate predicted for starburst galaxies that are known to produce stars at an extraordinarily high pace. These stars were also more massive, brighter (in ultraviolet wavelengths) and hotter than younger stars, the researchers found. As such, HD1 could be home to the universe's very first stars, called Population III stars; if that identity is verified, this would be the first observation of this type of star, the researchers said. There's also the possibility that HD1 is a supermassive black hole with a mass of about 100 million times that of the sun. To figure out HD1's true identity, the researchers can look for X-rays, which are emitted as material gets devoured by the gravity of a black hole. "If HD1 is a black hole, we should see X-ray emission from it. If we do not find X-rays, the emission must originate from massive stars," [one of the researchers told Live Science].

A British startup pioneering a new approach to fusion energy has successfully combined atomic nuclei, in what the UK regulator described as an important step in the decades-long effort to generate electricity from the reaction that powers the sun. From a report: Oxford-based First Light Fusion, which has been developing an approach called projectile fusion since 2011, said it had produced energy in the form of neutrons by forcing deuterium isotopes to fuse, validating years of research. While other fusion experiments have generated more power for longer, either by using "tokamak" machines or high-powered lasers, First Light says its approach, which involves firing a projectile at a target containing the fuel, could offer a faster route to commercial fusion power. "The value of this [result] is that it offers potentially a much cheaper, a much easier path to power production," said chief executive Nicholas Hawker.

To achieve fusion, First Light used a hyper-velocity gas gun to launch a projectile at a speed of 6.5km per second -- about 10 times faster than a rifle bullet -- at a tiny target designed to amplify the energy of the impact and force the deuterium fuel to fuse. The design of the target -- a clear cube, a little over a centimetre wide, enclosing two spherical fuel capsules -- is the key technology and is closely guarded by the company. "It is the ultimate espresso capsule," Hawker told the Financial Times last year. First Light, which is backed by China's Tencent, hopes to manufacture and sell the targets to future power plants -- built to its design -- which would need to vaporise one every 30 seconds to generate continual power. Further reading: So How Close Are We Now to Nuclear Fusion Energy? (August 2021).