From “Science Alert (AU)” : “A New Satellite Is One of The Brightest Objects in The Sky And It’s a Big Problem”

From “Science Alert (AU)”

11.30.22
David Nield

BlueWalker 3 satellite trail Trails in the night sky left by BlueWalker 3. (R. Sparks/KPNO/NOIRLab/IAU/SKAO/NSF/AURA)

BlueWalker 3. Credit: EarthSky.

We’re putting more and more satellites into orbit, and along with all the welcome technological and scientific advances that brings, there are also potential problems.

Intended to be the start of an orbiting communications network that can be accessed by standard smartphones, the recently launched prototype BlueWalker 3 satellite is now one of the brightest objects in the night sky.

For experts and enthusiasts who peer out into space, that’s a major issue. While astronomers have a few telescopes high above, many of our observations on the Universe are logged from Earth’s surface.

All but the brightest stars can now be outshone by the satellite’s glare, according to the International Astronomical Union Center for the Protection of the Dark and Quiet Sky from Satellite Constellation Interference (IAU CPS).

“BlueWalker 3 is a big shift in the constellation satellite issue and should give us all reason to pause,” says Piero Benvenuti, the Director of the IAU CPS.

“It’s like exactly what astronomers don’t want,” astronomer Meredith Rawls, from the University of Washington-Seattle, told Science. “It’ll show up as a super bright streak in images and potentially saturate camera detectors at observatories.”

BlueWalker 3 is certainly an impressive bit of hardware. Its 693-square-foot (64-square-meter) antenna array is the largest commercial array in low Earth orbit, capable of reflecting much more light than the SpaceX Starlink satellites, for example.

The intention of parent company AST SpaceMobile is to get more than 100 satellites up in the sky by the end of 2024, many potentially even bigger than BlueWalker 3. That’s a significant worry for scientists.

There’s another concern too: BlueWalker 3 is built to act as a cell phone tower in space, which means it uses terrestrial radio frequencies that might interfere with radio telescopes – telescopes that are currently built well away from areas with mobile phone coverage.

“Frequencies allocated to cell phones are already challenging to observe even in radio quiet zones we have created for our facilities,” says Philip Diamond, Director-General at the Square Kilometer Array Observatory, headquartered in the UK.

“New satellites such as BlueWalker 3 have the potential to worsen this situation and compromise our ability to do science if not properly mitigated.”

Representatives from the IAU CPS and its partners are also keen to acknowledge the potential for satellites to improve worldwide communications, but they want more discussions to happen over the “equitable and sustainable use of space”.

The US Federal Communications Commission (FCC) is responsible for regulating communications networks both within the US and internationally. It has announced plans to open an office dedicated to space, but in the meantime conversations between the IAU CPS and AST SpaceMobile have already started.

“We’re eager to use the newest technologies and strategies to mitigate possible impacts to astronomy,” an AST SpaceMobile spokesperson told New Scientist.

“We are actively working with industry experts on the latest innovations, including next-generation anti-reflective materials.”

See the full article here .

Comments are invited and will be appreciated, especially if the reader finds any errors which I can correct. Use “Reply”.

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From “Science Alert (AU)” : “Two Black Holes Met by Chance And It Created Something Never Seen Before”

From “Science Alert (AU)”

11.24.22
Michelle Starr

A numerical simulation of the curvature of space-time during the merger that produced GW190521. (AG Bernuzzi/University of Jena)

SXS – Simulating eXtreme Spacetimes Black Holes merging

The ripples in space-time generated by colliding black holes have taught us a lot about these enigmatic objects.

Gravitational waves. Credit: W.Benger-Zib. MPG Institute for Gravitational Physics (DE)

These gravitational waves encode information about black holes: their masses, the shape of their inward spiral towards each other, their spins, and their orientations.

From this, scientists ascertained that most of the collisions we’ve seen have been between black holes in binary systems. The two black holes started as a binary of massive stars that turned into black holes together, then spiraled in and merged.

Of the 90 or so mergers detected so far, however, one stands out as very peculiar. Detected in May 2019, GW19052 emitted space-time ripples like no other.

“Its morphology and explosion-like structure are very different from previous observations,” says astrophysicist Rossella Gamba of the University of Jena in Germany.

She adds, “GW190521 was initially analyzed as the merger of two rapidly rotating heavy black holes approaching each other along almost circular orbits, but its special features led us to propose other possible interpretations.”

Caltech /MIT Advanced aLigo

In particular, the short, sharp duration of the gravitational wave signal was challenging to explain.

Gravitational waves are generated by the actual merger of two black holes, like ripples from a rock dropped into a pond. But they’re also generated by the binary inspiral, and the intense gravitational interaction sends out weaker ripples as two black holes move inexorably closer.

Artist’s by now iconic conception of two merging black holes similar to those detected by LIGO. Credit: Aurore Simonnet /Caltech MIT Advanced aLIGO/Sonoma State University.

Gravitational waves from the first detection of a neutron star – black hole merger (GW200105)

“The shape and brevity – less than a tenth of a second – of the signal associated with the event lead us to hypothesize an instantaneous merger between two black holes, which occurred in the absence of a spiraling phase,” explains astronomer Alessandro Nagar of The National Institution for Nuclear Physics in Italy.

There’s more than one way to end up with a pair of black holes gravitationally interacting.

The first is that the two were together for a long time, perhaps even from the formation of baby stars from the same piece of molecular cloud in space.

The other is when two objects moving through space pass each other closely enough to get snagged gravitationally in what is known as a dynamical encounter.

This is what Gamba and her colleagues thought might have happened with GW190521, so they designed simulations to test their hypothesis. They smashed together pairs of black holes, tweaking parameters such as trajectory, spin, and mass, to try to reproduce the weird gravitational wave signal detected in 2019.

Their results suggest that the two black holes did not start out in a binary but were caught in each other’s gravitational web, tumbling past each other twice on a wild, eccentric loop before slamming together to form one larger black hole. And neither of the black holes in this scenario was spinning.

“By developing precise models using a combination of state-of-the-art analytical methods and numerical simulations, we found that a highly eccentric merger in this case explains the observation better than any other hypothesis previously put forward,” says astronomer Matteo Breschi of the University of Jena.

“The probability of error is 1:4,300!”

This scenario, the team says, is more likely in a densely populated region of space, such as a star cluster, where such gravitational interactions are more likely.

This tracks with previous discoveries about GW190521. One of the black holes in the merger was measured at around 85 times the mass of the Sun.

According to our current models, black holes over 65 solar masses can’t form from a single star; the only way we know a black hole of that mass can form is through mergers between two lower-mass objects.

The work of Gamba and her colleagues found that the masses of the two black holes in the collision sit at around 81 and 52 solar masses; that’s slightly lower than previous estimates, but one of the black holes is still outside the single star core collapse formation pathway.

It’s still unclear if our models need tweaking, but hierarchical mergers – whereby larger structures form through the continuous merging of smaller objects – are more likely in a cluster environment with a large population of dense objects.

Dynamic encounters between black holes are considered pretty rare, and the gravitational wave data collected by LIGO and Virgo to date would seem to support this. However, rare doesn’t mean impossible, and the new work suggests that GW190521 may be the first we’ve detected.

And a first means that there could be more in the years ahead. The gravitational wave observatories are currently being upgraded and maintained but will come online again in March 2023 for a new observing run. This time, LIGO’s two detectors in the US and the Virgo detector in Italy will be joined by KAGRA in Japan for even more observing power.

___________________________________________________________________
LIGO-VIRGO-KAGRA-GEO 600-LIGO-India-ESA/NASA LISA

Caltech /MIT Advanced aLigo.

Caltech/MIT Advanced aLigo detector installation Livingston, LA. installation.

Caltech/MIT Advanced aLigo Hanford, WA. installation.

VIRGO Gravitational Wave interferometer installation, near Pisa (IT).

KAGRA Large-scale Cryogenic Gravitational Wave Telescope Project installation (JP).

GEO600 Gravitational wave detector installation, situated 20 kilometers south of Hannover close to Sarstedt near the village Ruthe. (DE)

LIGO-India installation in the Hingoli district in western India (IN).

Gravity is talking. Lisa will listen. Dialogos of Eide.

The European Space Agency [La Agencia Espacial Europea] [Agence spatiale européenne][Europäische Weltraumorganisation](EU)National Aeronautics and Space Administration eLISA space based, the future of gravitational wave research, due to launch in 2037.

___________________________________________________________________

LIGO Virgo Kagra Masses in the Stellar Graveyard. Credit: Frank Elavsky and Aaron Geller at Northwestern University.

___________________________________________________________________
More detections like GW190521 would be amazing.

The research has been published in Nature Astronomy.

See the full article here .

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Comments are invited and will be appreciated, especially if the reader finds any errors which I can correct.

From “Science Alert (AU)” : “It’s Official – Scientists Confirm a New Expanded Scale of Measurement”

From “Science Alert (AU)”

11.21.22
Daniel Lawler, Agence France-Presse

(Pobytov/Getty Images)

Say hello to ronnagrams and quettameters: International scientists gathered in France voted on Friday for new metric prefixes to express the world’s largest and smallest measurements, prompted by an ever-growing amount of data.

It marks the first time in more than three decades that new prefixes have been added to the International System of Units (SI), the agreed global standard for the metric system.

Joining the ranks of well-known prefixes like kilo and milli are ronna and quetta for the largest numbers – and ronto and quecto for the smallest.

The change was voted on by scientists and government representatives from across the world attending the 27th General Conference on Weights and Measures, which governs the SI and meets roughly every four years at Versailles Palace, west of Paris.

The UK’s National Physical Laboratory, which led the push for the new prefixes, confirmed that the resolution had passed in a statement.

The prefixes make it easier to express large amounts – for example, always referring to a kilometer as 1,000 meters or a millimeter as one thousandth of a meter would quickly become cumbersome.

Since the SI was established in 1960, scientific need has led to a growing number of prefixes. The last time was in 1991, when chemists wanting to express vast molecular quantities spurred the addition of zetta and yotta.

A yottameter is a one followed by 24 zeroes.

But even the mighty yotta is not enough to handle the world’s voracious appetite for data, according to Richard Brown, the head of metrology at the UK’s National Physical Laboratory.

“In terms of expressing data in yottabytes, which is the highest prefix currently, we’re very close to the limit,” Brown told Agence France-Presse.

“At the bottom end, it makes sense to have a symmetrical expansion, which is useful for quantum science, particle physics – when you’re measuring really, really small things.”

New weight of the world

The new prefixes can simplify how we talk about some pretty big objects.

“If we think about mass, instead of distance, the Earth weighs approximately six ronnagrams,” which is a six followed by 27 zeroes, Brown said.

” Jupiter, that’s about two quettagrams,” he added – a two followed by 30 zeroes.

Brown said he had the idea for the update when he saw media reports using unsanctioned prefixes for data storage such as brontobytes and hellabytes. Google in particular has been using hella for bytes since 2010.

“Those were terms that were unofficially in circulation, so it was clear that the SI had to do something,” he said.

However metric prefixes need to be shortened to just their first letter – and B and H were already taken, ruling out bronto and hella.

“The only letters that were not used for other units or other symbols were R and Q,” Brown said.

Convention dictates that the larger prefixes end in an A, and the smaller ones in an O.

And “the middle of the words are very, very loosely based on the Greek and Latin for 9 and 10,” Brown said.

The new prefixes should “future proof the system” and satisfy the world’s need for higher numbers – at least for the next 20 to 25 years, he added.

See the full article here .

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From “Science Alert (AU)” : “The Mysterious Origins of The Great Barrier Reef May Finally Be Explained”

From “Science Alert (AU)”

11.15.22
Carly Cassella

The Great Barrier Reef

(zstockphotos/Getty Images)

Australia’s Great Barrier Reef might never have come to be were it not for the formation of a vast island based mostly on sand.

K’gari, also known as Fraser Island, has the honor of being the world’s largest sand island, covering around 640 square miles (nearly 1,700 square kilometers) just off the southeastern coast of Queensland.

Along with the nearby Cooloola Sand Mass, the mass of forested dunes and beaches forms an unofficial base to the vast reef that sits to its north.

If this terrestrial ‘launching pad’ had never formed, researchers think the masses of sand carried northwards along the coast by ocean currents would have landed right where the reef now sits.

Quartz-rich sands have a way of smothering carbonate-rich sediments, which are necessary for coral development.

Without K’gari in the way to guide sediment off the continental shelf and into the deep, conditions would not have suited the formation of the world’s largest coral reef, experts argue.

The Great Barrier Reef has a confusing origin story. It only formed half a million years ago, long after conditions were appropriate for the growth of coral.

K’gari might be the lost puzzle piece researchers have been searching for. Analysis and dating of sand from the many dunes on the 123 kilometer (76 mile) long island suggest the land mass formed between 1.2 and 0.7 million years ago, just a few hundred thousand years before the Great Barrier Reef came to be.

The island’s presence probably deflected northward currents, researchers explain, providing the southern and central parts of the great barrier reef the reprieve they needed to start growing thousands of kilometers of coral.

The coast of Queensland, Australia, showing sediment dispersal before the formation of K’gari and Cooloola (left) and after (right). (Ellerton et al., Nature Geoscience, 2022)

K’gari and Cooloola themselves arose from the accumulation of sand and sediment from the south.

Amid periods of ice formation and fluctuating sea levels, researchers suspect sediment around the world ‘suddenly’ became exposed. In successive periods of ice melt and rising oceans, that sediment then got caught up in the currents.

Along the east coast of Australia this probably meant a long northward treadmill of soil and sand tracing the continental shelf.

A slope off the southern coast of Queensland, however, makes the perfect place for sediment to accumulate, and this is right where K’gari and Cooloola are found.

Just south of the sand masses, coral reefs are conspicuously missing.

If researchers are right, that’s probably because the northward currents here are too strong. K’gari and Cooloola break up the long distance dispersal, stopping quartz-rich sands from smothering developing reefs.

“Before Fraser Island developed, northward longshore transport would have interfered with coral reef development in the southern and central [Great Barrier Reef],” researchers write.

Sediment records from the southern Great Barrier Reef support this idea. About 700,000 years ago, there appears to have been an uptick in carbonate content in sediment in this region.

Research on reefs further north is now needed as well, but at least two-thirds of the Great Barrier Reef seems to owe its existence to a wall of sand to the south.

“The development of Fraser Island dramatically reduced sediment supply to the continental shelf north of the island,” the authors argue.

“This facilitated widespread coral reef formation in the southern and central Great Barrier Reef and was a necessary precondition for its development.”

The study was published in Nature Geoscience.
See the science paper for detailed material with images.

See the full article here .

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From The Natural History Museum-London (UK) Via “Science Alert (AU)” : “Scientists Say These Mysterious Rocks Are The Oldest Evidence of Life on Earth”

From The Natural History Museum-London (UK)

Via

“Science Alert (AU)”

11.14.22
Michelle Starr

A stromatolite sample from the Dresser Formation. (James St. John/Flickr, CC BY 2.0)

Tracking down the oldest traces of life on Earth isn’t easy. Smoosh a bunch of microbes between layers of rock and let them ripen for billions of years; what you end up with is going to resemble rock more than an ancient life form.

It takes a real eye to then distinguish one from the other, and even then debates are rarely settled.

Take a set of 3.48 billion-year-old rock formations from Western Australia for example. Speculated to be the fossilized remains of microbial metropolises known as stromatolites, ruling out the possibility they are purely geological is easier said than done.

Now a new analysis by an international team of researchers provides strong evidence that these formations really are biological in origin, and not the result of non-living processes.

“If an archaeologist discovered the foundations of a ruined city, they would nonetheless know it was built by people because it would bear all the hallmarks of being built by people – doorways and roads and bricks,” explains paleontologist Keyron Hickman-Lewis of the Natural History Museum in the UK.

“In very much the same way, there are numerous structural elements integral to stromatolites that allow us to identify their processes of formation and decode their origins. We can almost be archaeologists in deep time.”

Stromatolites dating back billions of years are found scattered around the world. They consist of laminated, or finely layered, rock that could be produced either by mineralized layers of microbial matting or by non-living chemical reactions between the rock and its environment.

The job of the paleontologist is to try to work out which is which – not always easy, as seen in 3.7 billion-year-old stromatolite-like layers in Greenland, which were first declared the world’s oldest fossils and then found to be just plain old rocks.

But the identification of the oldest fossils on this marvelous, 4.54 billion–year-old blue marble of ours isn’t just an exercise in breaking records. It’s of deep interest to all of us when, and where, life first developed on Earth – the ancient origins of humanity, and all the life that thrives today.

Currently, the 3.43 billion-year-old stromatolites from another site in Western Australia, the Strelley Pool formation, are the oldest widely accepted traces of life on Earth. Now Hickman-Lewis and his colleagues have subjected 3.48 billion-year-old stromatolites from the Western Australian Dresser Formation to new and rigorous study.

They used multiple techniques to examine the two- and three-dimensional microstructures present in the Dresser stromatolites, including optical microscopy, Raman spectroscopy, scanning electron microscopy, laser ablation inductively coupled plasma-mass spectrometry (ICP-MS), and laboratory and synchrotron computed tomography.

None of these tests revealed microfossils or organic materials, but they did show structures and characteristics consistent with a biological origin.

Dresser Formation stromatolite sample showing clear lamination and dome structures. (Hickman-Lewis et al., Geology [below], 2022)

Once upon a time, the team concluded, the stromatolites were photosynthetic microbial mats thriving on the floor of a shallow marine lagoon. As sediment settled on the mats the microbes pushed upwards, away from the sediment and towards the sunlight to form dome structures resembling the cups in an egg carton. These shapes were what were preserved in the fossil formation.

The team also observed pillar-like “palisade” formations, consistent with patterns in rock known to be created by the growth of microbes. Like the dome structures, these were probably the result of organisms moving towards sunlight, the researchers claimed. Small voids in the rock are consistent with degassing or desiccation of decaying organic material.

Taken together, these clues constitute strong evidence in favor of the biological origin of these ancient layers of rock, making them the oldest evidence of life on Earth – which has implications for the search for life elsewhere.

When the Dresser Formation was a shallow lagoon, the Jezero crater on Mars was likely a very similar environment. So it’s possible that life was emerging on Mars at the same time, a Martian period known as the Noachian. Identifying fossilized life of a similar age and environment here on Earth could help us identify such fossils on Mars, if the Perseverance rover finds any.

“Occurring within the stratigraphically lowermost sedimentary horizons of the Dresser Formation, these stromatolites are the oldest direct evidence for life on Earth,” the researchers write in their paper.

“Their paleodepositional setting, polyextremophilic biology, and taphonomy make them ideal analog biosignatures for Mars, reflecting the type of morphological fossils one might expect to encounter in altered Noachian carbonates.”

The research has been published in Geology.

See the full article here .

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From “Science Alert (AU)” : “Last 8 Years Hottest on Record as Climate Breakdown Dramatically Accelerates”

From “Science Alert (AU)”

11.7.22
Marlowe Hood | Agence France-Presse

Each of the last eight years, if projections for 2022 hold, will be hotter than any year prior to 2015, the United Nations (UN) said Sunday, detailing a dramatic increase in the rate of global warming.

Climate Change. Credit: Columbia University – State of the Planet.

Sea level rise, glacier melt, torrential rains, heat waves – and the deadly disasters they cause – have all accelerated, the World Meteorological Organization (WMO) said in a report as the COP27 UN Climate Summit opened in Sharm el-Sheikh, Egypt.

“As COP27 gets underway, our planet is sending a distress signal,” said UN chief Antonio Guterres, describing the report as “a chronicle of climate chaos”.

Earth has warmed more than 1.1 degrees Celsius since the late 19th century, with roughly half of that increase occurring in the past 30 years, the report shows.

Nearly 200 nations gathered in Egypt have set their sights on holding the rise in temperatures to 1.5 Celsius (2.7 degrees Fahrenheit), a goal some scientists believe is now beyond reach.

This year is on track to be the fifth or sixth warmest ever recorded despite the impact since 2020 of La Nina – a periodic and naturally occurring phenomenon in the Pacific that cools the atmosphere.

“The greater the warming, the worse the impacts,” said WMO head Petteri Taalas.

Surface water in the ocean – which soaks up more than 90 percent of accumulated heat from human carbon emissions – hit record high temperatures in 2021, warming especially fast during the past 20 years.

Marine heat waves were also on the rise, with devastating consequences for coral reefs and the half-billion people who depend on them for food and livelihoods.

Overall, 55 percent of the ocean surface experienced at least one marine heatwave in 2022, the report said.

Driven by melting ice sheets and glaciers, the pace of sea level rise has doubled in the past 30 years, threatening tens of millions in low-lying coastal areas.

“The messages in this report could barely be bleaker,” said Mike Meredith, science leader at the British Antarctic Survey.

“All over our planet, records are being shattered as different parts of the climate system begin to break down.”

Records shattered

​Greenhouse gases accounting for more than 95 percent of warming are all at record levels, with methane showing the largest one-year jump ever recorded, the WMO’s annual State of the Global Climate found.

The increase in methane emissions has been traced to leaks in natural gas production and a rise in beef consumption.

In 2022, a cascade of extreme weather exacerbated by climate change devastated communities across the globe.

A two-month heatwave in South Asia in March and April bearing the unmistakable fingerprint of man-made warming was followed by floods in Pakistan that left a third of the country under water. At least 1,700 people died, and 8 million were displaced.

In East Africa, rainfall has been below average in four consecutive wet seasons, the longest in 40 years, with 2022 set to deepen the drought.

China saw the longest and most intense heatwave on record and the second-driest summer.

Falling water levels disrupted or threatened commercial river traffic along China’s Yangtze, the Mississippi in the US and several major inland waterways in Europe, which also suffered repeated bouts of sweltering heat.

Poorer nations least responsible for climate change but most vulnerable to its dire impacts suffered the most.

“But even well-prepared societies this year have been ravaged by extremes -– as seen by the protracted heatwaves and drought in large parts of Europe and southern China,” Taalas said.

In the European Alps, glacier melt records have been shattered in 2022, with average thickness losses of between 3 and over 4 meters (between 9.8 and over 13 feet), the most ever recorded.

Switzerland has lost more than a third of its glacier volume since 2001.

“If there was ever a year to swamp, shred, and burn off the blinkers of global climate inaction then 2022 should be it,” said Dave Reay, head of the University of Edinburgh’s Climate Change Institute.

“The world now has a monumental job of damage limitation.”

See the full article here .

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From The University of Queensland (AU) Via “Science Alert (AU)” : “Tree Rings Chronicle a Mysterious Cosmic Storm That Strikes Every Thousand Years”

From The University of Queensland (AU)

Via

“Science Alert (AU)”

10.26.22
Michelle Starr

(The University of Queensland)

The history of Earth’s bombardment with cosmic radiation is written in the trees.

Specifically, when radiation slams into Earth’s atmosphere, it can alter any nitrogen atoms it slams into to produce a form of carbon, which is in turn absorbed by plants. Linking spikes in this carbon isotope with the growth rings in trees can give us a reliable record of radiation storms going back thousands of years.

This record shows us that the most colossal of these events, known as “Miyake events” (after the scientist who discovered them), occur around once every thousand years. However, we don’t know what causes them – and new research suggests that our leading theory, involving giant solar flares, could be off the table.

Without an easy way to predict these potentially devastating events, we’re left with a serious problem.

“We need to know more, because if one of these happened today, it would destroy technology including satellites, internet cables, long-distance power lines and transformers,” says astrophysicist Benjamin Pope of the University of Queensland in Australia.

“The effect on global infrastructure would be unimaginable.”

The history of Earth’s encounters with storms of cosmic radiation is there to decipher if you know how to look. The main clue is a radioactive isotope of carbon called carbon-14, often referred to as radiocarbon. Compared to other naturally occurring isotopes of carbon on Earth, radiocarbon is relatively scarce. It forms only in the upper atmosphere, when cosmic rays collide with nitrogen atoms, triggering a nuclear reaction that creates radiocarbon.

Because cosmic rays are constantly colliding with our atmosphere, we have a constant but very small supply of the stuff raining down on the surface. Some of it gets caught up in tree rings. Since trees add a new growth ring every year, the radiocarbon deposition can be traced back through time, giving a record of radiation activity over tens of millennia.

A large spike in radiocarbon found in trees around the world means an uptick in cosmic radiation. There are several mechanisms that can cause this, and solar flares are a big one. But there are some other possible sources of radiation storms that haven’t been conclusively ruled out. Nor have solar flares been conclusively ruled in.

Because interpreting tree ring data necessitates a comprehensive understanding of the global carbon cycle, a team of researchers led by mathematician Qingyuan Zhang of the University of Queensland set about reconstructing the global carbon cycle, based on every scrap of tree ring radiocarbon data they could get their hands on.

“When radiation strikes the atmosphere it produces radioactive carbon-14, which filters through the air, oceans, plants, and animals, and produces an annual record of radiation in tree rings,” Zhang explains.

“We modeled the global carbon cycle to reconstruct the process over a 10,000-year period, to gain insight into the scale and nature of the Miyake events.”

The results of this modeling gave the team an extremely detailed picture of a number of radiation events – enough to conclude that the timing and profile is inconsistent with solar flares. The spikes in radiocarbon do not correlate with sunspot activity, which is itself linked with flare activity. Some spikes persisted across multiple years.

And there was inconsistency in the radiocarbon profiles between regions for the same event. For one major event, recorded in 774 CE, some trees in some parts of the world showed sharp, sudden rises in radiocarbon for one year, while others showed a slower spike across two to three years.

“Rather than a single instantaneous explosion or flare, what we may be looking at is a kind of astrophysical ‘storm’ or outburst,” Zhang says.

The researchers don’t know, at this point, what might be causing those outbursts, but there are a number of candidates. One of those is supernova events, the radiation from which can blast across space. A supernova possibly did take place in 774 CE, and scientists have made links between radiocarbon spikes and other possible supernova events, but we have known supernovae with no radiocarbon spikes, and spikes with no linked supernovae.

Other potential causes include solar superflares, but a flare powerful enough to produce the 774 CE radiocarbon spike is unlikely to have erupted from our Sun. Perhaps there’s some previously unrecorded solar activity. But the fact is, there’s no simple explanation that neatly explains what causes Miyake events.

And this, according to the researchers, is a worry. The human world has changed dramatically since 774 CE; a Miyake event now could cause what the scientists call an “internet apocalypse” as infrastructure gets damaged, harm the health of air travelers, and even deplete the ozone layer.

“Based on available data, there’s roughly a one percent chance of seeing another one within the next decade,” Pope says.

“But we don’t know how to predict it or what harms it may cause. These odds are quite alarming, and lay the foundation for further research.”

The research has been published in Proceedings of the Royal Society A: Mathematical, Physical, and Engineering Sciences.

See the full article here .

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The University of Queensland (AU) is a public research university located primarily in Brisbane, the capital city of the Australian state of Queensland. Founded in 1909 by the Queensland parliament, UQ is one of the six sandstone universities, an informal designation of the oldest university in each state. The University of Queensland was ranked second nationally by the Australian Research Council in the latest research assessment and equal second in Australia based on the average of four major global university league tables. The University of Queensland is a founding member of edX, Australia’s leading Group of Eight and the international research-intensive Association of Pacific Rim Universities.

The main St Lucia campus occupies much of the riverside inner suburb of St Lucia, southwest of the Brisbane central business district. Other University of Queensland campuses and facilities are located throughout Queensland, the largest of which are the Gatton campus and the Mayne Medical School. University of Queensland’s overseas establishments include University of Queensland North America office in Washington D.C., and the University of Queensland-Ochsner Clinical School in Louisiana, United States.

The university offers associate, bachelor, master, doctoral, and higher doctorate degrees through a college, a graduate school, and six faculties. University of Queensland incorporates over one hundred research institutes and centres offering research programs, such as the Institute for Molecular Bioscience, Boeing Research and Technology Australia Centre, the Australian Institute for Bioengineering and Nanotechnology, and the University of Queensland Dow Centre for Sustainable Engineering Innovation. Recent notable research of the university include pioneering the invention of the HPV vaccine that prevents cervical cancer, developing a COVID-19 vaccine that was in human trials, and the development of high-performance superconducting MRI magnets for portable scanning of human limbs.

The University of Queensland counts two Nobel laureates (Peter C. Doherty and John Harsanyi), over a hundred Olympians winning numerous gold medals, and 117 Rhodes Scholars among its alumni and former staff. University of Queensland’s alumni also include The University of California-San Francisco,The University of Queensland (AU) Chancellor Sam Hawgood, the first female Governor-General of Australia Dame Quentin Bryce, former President of King’s College London (UK) Ed Byrne, member of United Kingdom’s Prime Minister Council for Science and Technology Max Lu, Oscar and Emmy awards winner Geoffrey Rush, triple Grammy Award winner Tim Munro, the former CEO and Chairman of Dow Chemical, and current Director of DowDuPont Andrew N. Liveris.

Research

The University of Queensland has a strong research focus in science, medicine and technology. The university’s research advancement includes pioneering the development of the cervical cancer vaccines, Gardasil and Cervarix, by University of Queensland Professor Ian Frazer. In 2009, the Australian Cancer Research Foundation reported that University of Queensland had taken the lead in numerous areas of cancer research.

In the Commonwealth Government’s Excellence in Research for Australia 2012 National Report, University of Queensland’s research is rated above world standard in more broad fields than at any other Australian university (in 22 broad fields), and more University of Queensland researchers are working in research fields that ERA has assessed as above world standard than at any other Australian university. University of Queensland research in biomedical and clinical health sciences, technology, engineering, biological sciences, chemical sciences, environmental sciences, and physical sciences was ranked above world standard (rating 5).

In 2015, University of Queensland is ranked by Nature Index as the research institution with the highest volume of research output in both interdisciplinary journals Nature and Science within the southern hemisphere, with approximately twofold more output than the global average.

In 2020 Clarivate named 34 UQ professors to its list of Highly Cited Researchers.

Aside from disciplinary-focused teaching and research within the academic faculties, the university maintains a number of interdisciplinary research institutes and centres at the national, state and university levels. For example, the Asia-Pacific Centre for the Responsibility to Protect, the University of Queensland Seismology Station, Heron Island Research Station and the Institute of Modern Languages.

With the support from the Queensland Government, the Australian Government and major donor The Atlantic Philanthropies, The University of Queensland dedicates basic, translational and applied research via the following research-focused institutes:

Institute for Molecular Bioscience – within the Queensland Bioscience Precinct which houses scientists from the CSIRO-Commonwealth Scientific and Industrial Research Organisation (AU) and the Community for Open Antimicrobial Drug Discovery

Translational Research Institute, which houses The University of Queensland’s Diamantina Institute, School of Medicine and the Mater Medical Research Institute
Australian Institute for Bioengineering and Nanotechnology
Institute for Social Science Research
Sustainable Mineral Institute
Global Change Institute
Queensland Alliance for Environmental Health Science
Queensland Alliance for Agriculture and Food Innovation
Queensland Brain Institute
Centre for Advanced Imaging
Boeing Research and Technology Australia Centre
UQ Dow Centre

The University of Queensland plays a key role in Brisbane Diamantina Health Partners, Queensland’s first academic health science system. This partnership currently comprises Children’s Health Queensland, Mater Health Services, Metro North Hospital and Health Service, Metro South Health, QIMR Berghofer Medical Research Institute, The Queensland University of Technology (AU), The University of Queensland and the Translational Research Institute.

International partnerships

The University of Queensland has a number of agreements in place with many of her international peers, including: Princeton University, The University of Pennsylvania, The University of California, Washington University in St. Louis, The University of Toronto (CA), McGill University (CA), The University of British Columbia (CA), Imperial College London (UK), University College London (UK), The University of Edinburgh (SCT), Balsillie School of International Affairs (CA), Sciences Po (FR), Ludwig Maximilians University of Munich [Ludwig-Maximilians-Universität München](DE), Technical University of Munich [Technische Universität München] (DE), The University of Zürich [Universität Zürich ](CH), The University of Auckland (NZ), The National University of Singapore [universiti kebangsaan singapura] (SG), Nanyang Technological University [Universiti Teknologi Nanyang](SG),Peking University [北京大学](CN), The University of Hong Kong [香港大學] (HKU) (HK), The University of Tokyo[(東京大] (JP), The National Taiwan University [國立臺灣大學](TW), and The Seoul National University [서울대학교](KR).

From “Science Alert (AU)” : “Scientists Say mysterious Object May Be a ‘Strange Star’ Made Out of Quarks”

From “Science Alert (AU)”

10.25.22
Michelle Starr

Credit: Pobytov/DigitalVision Vectors/Getty Images.

A relatively small, dense object cloaked within a cloud of its own exploded remains just a few thousand light-years away is defying our understanding of stellar physics.

By all accounts it seems to be a neutron star, though it’s an unusual one at that. At just 77 percent of the mass of the Sun, it’s the lowest mass ever measured for an object of its kind.

Previously [The Astrophysical Journal (below)], the lightest neutron star ever measured clocked in at 1.17 times the mass of the Sun.

This more recent discovery isn’t just smaller, it’s significantly lower than the minimum neutron star mass predicted by theory. This suggests either there’s some gap in our understanding of these ultradense objects… or what we’re looking at is not a neutron star at all, but a peculiar, never-before-seen object known as a ‘strange’ star.

Neutron stars are among the densest objects in the entire Universe.

Neutron Star L. Calçada/ European Southern Observatory [La Observatorio Europeo Austral] [Observatoire européen austral][Europäische Südsternwarte] (EU) (CL)

They’re what remains after a massive star between about 8 and 30 times the mass of the Sun has reached the end of its life. When the star runs out of material to fuse in its core, it goes supernova, ejecting its outer layers of material into space.

No longer supported by the outward pressure of fusion, the core collapses in on itself to form an object so dense, atomic nuclei squish together and electrons are forced to become intimate with protons long enough for them to transform into neutrons.

Most of these compact objects are around 1.4 times the mass of the Sun, though theory says they could range from something as massive as around 2.3 solar masses, down to just 1.1 solar masses. All of this packed inside a sphere just packed into a sphere just 20 kilometers (12 miles) or so across, making every teaspoonful of neutron star material weigh somewhere between 10 million and several billion tons.

Stars with higher and lower masses than neutron stars can also turn into dense objects. Heavier stars turn into black holes. Lighter stars turn into white dwarfs – less dense than neutron stars, with an upper mass limit of 1.4 solar masses, though still pretty compact. This is the eventual fate of our own Sun.

The neutron star that is the subject of this study is at the center of a supernova remnant called HESS J1731-347, which had previously been calculated to sit more than 10,000 light-years away. One of the difficulties in studying neutron stars, however, lies in poorly constrained distance measurements. Without an accurate distance, it’s hard to obtain accurate measurements of the other characteristics of a star.

Recently, a second, optically bright star was discovered lurking in HESS J1731-347. From this, using data from the Gaia mapping survey, a team of astronomers led by Victor Doroshenko of Eberhard Karls University of Tübingen in Germany were able to recalculate the distance to HESS J1731-347, and found it’s much closer than thought, at around 8,150 light-years away.

This means that previous estimates of the neutron star’s other characteristics needed to be refined, including its mass. Combined with observations of the X-ray light emitted by the neutron star (inconsistent with X-radiation from a white dwarf), Doroshenko and his colleagues were able to refine its radius to 10.4 kilometers, and its mass to an absolutely gobsmackingly low 0.77 solar masses.

This means that it might not actually be a neutron star as we know it, but a hypothetical object not yet positively identified in the wild.

“Our mass estimate makes the central compact object in HESS J1731-347 the lightest neutron star known to date, and potentially a more exotic object – that is, a ‘strange star’ candidate,” the researchers write in their paper.

According to theory, a strange star looks a lot like a neutron star, but contains a larger proportion of fundamental particles called strange quarks. Quarks are fundamental subatomic particles that combine to form composite particles such as protons and neutrons. Quarks come in six different types, or flavors, called up, down, charm, strange, top, and bottom. Protons and neutrons are made of up and down quarks.

Theory suggests that, in the extremely compressed environment inside a neutron star, subatomic particles break down into their constituent quarks. Under this model, strange stars are made of matter consisting of equal proportions of up, down, and strange quarks.

Strange stars should form under masses large enough to really put the squeeze on, but since the rulebook for neutron stars goes out the window when enough quarks get involved, there’s essentially no lower limit either. Meaning we can’t rule out the possibility this neutron star is in effect a strange star.

This would be extremely cool; physicists have been searching for quark matter and strange quark matter for decades. However, while a strange star is certainly possible, the greater likelihood is that what we’re looking at is a neutron star – and that, too, is extremely cool.

“The obtained constraints on mass and radius are still fully consistent with a standard neutron star interpretation and can be used to improve astrophysical constraints on the equation of state of cold dense matter under this assumption,” the researchers write.

“Such a light neutron star, regardless of the assumed internal composition, appears to be a very intriguing object from an astrophysical perspective.”

It’s challenging to ascertain how such a light neutron star could have formed under our current models. So, whatever it is made of, the dense object at the heart of HESS J1731-347 is going to have something to teach us about the mysterious afterlives of massive stars.

The team’s research has been published in Nature Astronomy.

Previous science paper:
The Astrophysical Journal 2015
See the science paper for detailed material with images.

See the full article here .

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From “Science Alert (AU)” : “How Particle Physics Could Reduce The ‘Collateral Damage’ of Cancer Treatments”

From “Science Alert (AU)”

10.23.22
Nina Larson

Researchers at Europe’s science lab CERN, who regularly use particle physics to challenge our understanding of the universe, are also applying their craft to upend the limits to cancer treatment.

The physicists here are working with giant particle accelerators in search of ways to expand the reach of cancer radiation therapy, and take on hard-to-reach tumors that would otherwise have been fatal.

In one CERN lab, called “CLEAR”, facility coordinator Roberto Corsini stands next to a large, linear particle accelerator consisting of a 40-meter metal beam with tubes packed in aluminum foil at one end, and a vast array of measurement instruments and protruding colorful wires and cables.

The European Organization for Nuclear Research [La Organización Europea para la Investigación Nuclear][Organization européenne pour la recherche nucléaire] [Europäische Organization für Kernforschung](CH) [CERN]

The European Organization for Nuclear Research [La Organización Europea para la Investigación Nuclear][ Organization européenne pour la recherche nucléaire] [Europäische Organization für Kernforschung](CH) [CERN] “CLEAR”.

The research here, he told AFP during a recent visit, is aimed at creating very high energy beams of electrons – the negatively charged particles in the nucleus of an atom – that eventually could help to combat cancerous cells more effectively.

They are researching a “technology to accelerate electrons to the energies that are needed to treat deep-seated tumors, which is above 100 million electron volts” (MeV), Corsini explained.

The idea is to use these very high-energy electrons (VHEE) in combination with a new and promising treatment method called FLASH.

Reducing ‘collateral damage’

This method entails delivering the radiation dose in a few hundred milliseconds, instead of minutes as is the current approach.

This has been shown to have the same destructive effect on the targeted tumor but causes far less damage to the surrounding healthy tissue.

With traditional radiation therapy, “you do create some collateral damage,” said Benjamin Fisch, a CERN knowledge transfer officer.

The effect of the brief but intense FLASH treatment, he told reporters, is to “reduce the toxicity to healthy tissue while still properly damaging cancer cells.”

FLASH was first used on patients in 2018, based on currently available medical linear accelerators, linacs, that provide low-energy electron beams of around 6-10 MeV.

At such low energy though, the beams cannot penetrate deeply, meaning the highly-effective treatment has so far only been used on superficial tumors, found with skin cancer.

But the CERN physicists are now collaborating with the Lausanne University Hospital (CHUV) to build a machine for FLASH delivery that can accelerate electrons to 100 to 200 MeV, making it possible to use the method for much more hard-to-reach tumors.

‘Game-changer’

Deep-lying cancer tumors that can’t be rooted out using surgery, chemotherapy, or traditional radiation therapy are often today considered a death sentence.

“It is the ones which we don’t cure at the moment which will be the targets,” Professor Jean Bourhis, head of CHUV’s radiology department, told AFP.

“For those particular cancers, which may be one-third of the cancer cases, it could be a game-changer.”

There are particular hopes that the FLASH method, with its far less harmful impact on surrounding tissue, could make it possible to go after tumors lodged in the brain or near other vital organs.

Bourhis said it might not relegate deaths from stubborn cancer tumors to the history books, “but at least there will be a new opportunity for more cures, if it works.”

‘Compact’

One challenge is making the powerful accelerator compact enough to fit inside a hospital.

At CERN, a large gallery has been dedicated to housing the CLEAR accelerator, which requires 20 meters to push the electrons up to the required energy level – and another 20 meters to condition, measure, and deliver the beam.

But Corsini insisted that CERN had the know-how to “accelerate in a much more compact space”.

The prototype being designed with CHUV will aim to do the same job with a machine that is 10 meters overall.

This “compact” solution, Corsini said, “reduces the cost, reduces power consumption and variability, and you can easily put it into a hospital without having to build a whole building.”

Construction of the prototype is scheduled to begin next February, and patient clinical trials could begin in 2025, Bourhis said, “if everything goes smoothly”.

© Agence France-Presse

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From The Arecibo Observatory Via “Science Alert (AU)” : “This Unusual Asteroid Keeps Spinning Faster And We Don’t Know Why”

NAIC Arecibo Observatory operated by University of Central Florida, Yang Enterprises and Ana G. Méndez University [Universidad Ana G. Méndez, Recinto de Cupey] (PR) Altitude 497 m (1,631 ft), which has now collapsed.

From The Arecibo Observatory

Via

“Science Alert (AU)”

10.17.22
Michelle Starr

Some of the changes observable in Phaethon as it rotates, as seen by the Arecibo Observatory. (Taylor et al., Planetary and Space Science, 2019)

The near-Earth asteroid responsible for the spectacular annual Geminids meteor shower has been caught doing something really unexpected.

Scientists studying the shifting light of 3200 Phaethon have concluded the rocky body is spinning faster and faster on its axis, shaving off around 4 milliseconds every year. That might not seem like a lot, but asteroid spins don’t usually change at all.

Figuring out why Phaethon is behaving this way could give us new insight into a class of asteroids considered “potentially hazardous” – skimming past Earth as they orbit the Sun.

Phaethon currently poses no danger to Earth, but at 5.8 kilometers (3.6 miles) across it’s large enough to cause no small amount of pain were it to hypothetically hit. What’s more, the asteroid’s path brings it close enough that enough of a change in its 524-day orbit could cause us to rethink our concerns.

It’s also an oddball. The asteroid’s orbit dips in close to the Sun like a comet’s, for example. It also has a dusty tail, and happens to be one of just two asteroids that produce meteor showers (mostly those come from comets too).

And yet, unlike a comet, it seems to have no ice. Scientists have referred to it as a “rock comet”.

Oh, and it’s strikingly blue. Most asteroids are reddish, or gray.

Phaethon’s unusual characteristics have made it the target of a future lander mission, DESTINY+ (Demonstration and Experiment of Space Technology for INterplanetary voYage with Phaethon fLyby and dUst Science), spearheaded by the Japanese Space Agency. So scientists have been working on learning more about the strange rock, to better plan how to rendezvous with it.

Phaethon’s brightness changes as it rotates, which means that we have been able to characterize its rotational period over time, narrowing it down to 3.6 hours. But we need precise data if we’re going to land a probe on this thing, so planetary scientist Sean Marshall of Arecibo Observatory in Puerto Rico was working to refine Phaethon’s size, shape, and rotation when he noticed something screwy.

He presented his team’s findings last week at the American Astronomical Society’s 54th Annual Meeting of the Division for Planetary Sciences.

“The predictions from the shape model did not match the data,” Marshall says.

“The times when the model was brightest were clearly out of sync with the times when Phaethon was actually observed to be brightest. I realized this could be explained by Phaethon’s rotation period changing slightly at some time before the 2021 observations, perhaps from comet-like activity when it was near perihelion in December 2020.”

A closer look at the full dataset, spanning the period from 1989 to 2021, revealed that the change could be explained by a gradual, constant acceleration, losing 4 milliseconds of the rotation period a year. Year-on-year, the change doesn’t make a lot of difference, but as the decades rack up, it’s become much more prominent.

In fact, a team of researchers noticed a discrepancy in the rotational period back in 2016, when they noticed that their data was out of sync with 1989 data. At the time, the researchers didn’t have quite enough information to explain the difference. Now, that discrepancy appears to be resolved.

This makes Phaethon one of just 11 asteroids with accelerating rotations, out of the thousands of asteroids whose rotations have been characterized. It’s possible that this is the result of mass loss; outgassing in comets produces a spin-up effect, and a study last year found that Phaethon may outgas sodium.

It’s also possible that a small Yarkovsky-O’Keefe-Radzievskii-Paddack (YORP) effect may apply. This is when the heat of a star influences the spin rate of a small body, like an asteroid.

More work will need to be done to figure out what, exactly, is going on with Phaethon; but knowing that the spin rate is changing, and the rate at which it is changing, is an excellent finding in and of itself.

“This is good news for the DESTINY+ team,” Marshall says.

“A steady change means that Phaethon’s orientation at the time of the spacecraft’s flyby can be predicted accurately, so they will know which regions will be illuminated by the Sun.”

The team presented their findings at the American Astronomical Society’s 54th Annual Meeting of the Division for Planetary Sciences.

See the full article here .

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The The Arecibo Observatory was a radio telescope in the municipality of Arecibo, Puerto Rico. This observatory was operated by SRI International, USRA and UMET, under cooperative agreement with the National Science Foundation (NSF). The observatory was the sole facility of the National Astronomy and Ionosphere Center (NAIC), which refers to the observatory, and the staff that operated the telescope. From its construction in the 1960s until 2011, the observatory was managed by Cornell University.

The observatory’s 1,000-foot (305-meter) radio telescope was the largest single-aperture telescope from its completion in 1963 until July 2016 when the Five hundred meter Aperture Spherical Telescope (FAST) in China was completed.

FAST-Five-hundred-meter Aperture Spherical radio Telescope [[五百米口径球面射电望远镜] (CN), located in the Dawodang depression in Pingtang County, Guizhou Province, South China.

It was used in three major areas of research: radio astronomy, atmospheric science, and radar astronomy. Scientists who wanted to use the observatory submitted proposals that were evaluated by an independent scientific board.

The observatory’s main feature was its large radio telescope, whose main collecting dish was an inverted spherical dome 1,000 feet (305 m) in diameter with an 869-foot (265 m) radius of curvature, constructed inside a karst sinkhole. The dish’s surface was made of 38,778 perforated aluminum panels, each about 3 by 7 feet (1 by 2 m), supported by a mesh of steel cables. The ground beneath supported shade-tolerant vegetation.

Since its completion in November 1963, the Telescope had been used for radar astronomy and radio astronomy, and had been part of the Search for extraterrestrial intelligence (SETI) program. It was also used by NASA for Near-Earth object detection. Since around 2006, NSF funding support for the telescope had waned as the Foundation directed funds to newer instruments, though academics petitioned to the NSF and Congress to continue support for the telescope. Numerous hurricanes, including Hurricane Maria, had damaged parts of the telescope, straining the reduced budget.

Two cable breaks, one in August 2020 and a second in November 2020, threatened the structural integrity of the support structure for the suspended platform and damaged the dish. The NSF determined in November 2020 that it was safer to decommission the telescope rather than to try to repair it, but the telescope collapsed before a controlled demolition could be carried out. The remaining support cables from one tower failed around 7:56 a.m. local time on December 1, 2020, causing the receiver platform to fall into the dish and collapsing the telescope.

NASA led an extensive failure investigation and reported the findings, along with a technical bulletin with industry recommendations.