Monday, 31 October 2022

Science News: Behavior of star clusters challenge Newton's laws of gravity

Behavior of star clusters challenge Newton's laws of gravity

Data from open star clusters seems to fit better with an alternate theory of gravity.


 By JERUSALEM POST STAFF, OCTOBER 30, 2022

The Pleiades, an open cluster consisting of approximately 3,000 stars at a distance of 400 light-years (120 parsecs) from Earth. (photo credit: NASA, ESA, AURA/Caltech, Palomar Observatory)

Certain star clusters do not seem to be following current understandings of Isaac Newton's laws of gravity, according to new research published on Wednesday.


The study, published in the Monthly Notices of the Royal Astronomical Society, analyzed open star clusters which are formed when thousands of stars are born in a short time period in a huge gas cloud.

As the stars are born, they blow away the remnants of the gas cloud, causing the cluster to expand and create a loose formation of dozens to thousands of stars held together by weak gravitational forces.

As the clusters dissolve, the stars accumulate on two "tidal tails:" one pulled behind the cluster and the other pushed forward.

"According to Newton's laws of gravity, it's a matter of chance in which of the tails a lost star ends up," explains Dr. Jan Pflamm-Altenburg of the Helmholtz Institute of Radiation and Nuclear Physics at the University of Bonn. "So both tails should contain about the same number of stars. However, in our work we were able to prove for the first time that this is not true: In the clusters we studied, the front tail always contains significantly more stars nearby to the cluster than the rear tail."

                                     Isaac Newton 521 (credit: Wikimedia Commons)

New methods helped scientists find the crack in the theory

Dr. Tereza Jerabkova, a co-author of the paper, explained that it is very difficult to determine which stars belong to which tail.

"To do this, you have to look at the velocity, direction of motion and age of each of these objects," said Jerabkova, who managed to develop a method to accurately count the stars for the first time using data from the European Space Agency's Gaia mission.

The perks of a modified theory

When the researchers looked at the data, they found that it did not fit Newton's law of gravity and instead fit better with an alternate theory called Modified Newtonian Dynamics (MOND).

"Put simply, according to MOND, stars can leave a cluster through two different doors," explained Prof. Dr. Pavel Kroupa of the Helmholtz Institute of Radiation and Nuclear Physics. "One leads to the rear tidal tail, the other to the front. However, the first is much narrower than the second - so it’s less likely that a star will leave the cluster through it. Newton's theory of gravity, on the other hand, predicts that both doors should be the same width."

The researchers simulated the stellar distribution expected according to the MOND theory and found that it lined up well with what they observed in the data from the Gaia mission.

Dr. Ingo Thies, who played a key role in the simulations, explained that the researchers needed to rely on relatively simple computational methods in the study since currently there are no mathematical tools for more detailed analyses of the MOND theory.

The simulations also coincided with the Gaia data in terms of how long the star clusters typically survive, which is much shorter than would be expected according to Newton's laws.

"This explains a mystery that has been known for a long time," said Kroupa. "Namely, star clusters in nearby galaxies seem to be disappearing faster than they should."

The MOND theory is controversial as modifications to Newton's laws of gravity would have far-reaching consequences for other areas of physics as well, although they would solve many problems facing cosmology.

The team from the University of Bonn is now working on new mathematical methods to create even more accurate simulations.

The Charles University in Prague, the European Southern Observatory (ESO) in Garching, the Observatoire astronomique de Strasbourg, the European Space Research and Technology Centre (ESA ESTEC) in Nordwijk, the Institute for Advanced Studies in Basic Sciences (IASBS) in Zanjan (Iran), the University of Science and Technology of China, the Universidad de La Laguna in Tenerife, and the University of Cambridge also took part in the study. 


Newton's Law of Gravity explained: fizzics.org



Neander-Troll says: I don't know anything about gravity but when a Coconut fell on my head it cracked open (the coconut not my hard head) & it led me to cover its contents in chocolate & thus the Bounty Bar was born! (Shameless plug for the Coconut Whisperer blog)



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The Green Revolution – Were We Lied To?

By THE ALLIANCE OF BIOVERSITY INTERNATIONAL   AND
THE INT. CENTER FOR TROPICAL AGRICULTURE OCT. 31, 2022


The collection of research and technology transfer programs known as the “Green Revolution,” sometimes known as the “Third Agricultural Revolution,” took place between 1950 and the late 1960s and significantly enhanced agricultural productivity in many regions of the globe.

A founding narrative of the Green Revolution was discovered to be false.

In a recent analysis, a researcher at the Alliance of Bioversity International and CIAT revealed that one of the founding narratives of the Green Revolution, a movement to modernize agriculture through technology that began more than 50 years ago, was untrue.

The Green Revolution is frequently credited for tripling the production of staple crops while only requiring 30% additional cultivated land in the second half of the 20th century. This accomplishment was largely made possible by the use of technology, such as the breeding of higher-yielding plant varieties and the use of pesticides and fertilizers.

Policy thinkers paved the way for the Green Revolution, and Nobel Prize-winning economist Ted Schultz described the tale of Maya Kaqchikel farmers cultivating onions and other crops in the delta of a tiny river and the surrounding hills in Panajachel, Guatemala, in his 1964 book, Transforming Traditional Agriculture. He supported his worldwide vision of technology-centered agricultural growth with this narrative of a technologically-stagnant rural village completely integrated into a market economy. This village served as a well-established example of a much larger trend in global agriculture for Schultz.

According to a recent analysis, the Green Revolution narrative was based on a misinterpretation of a case study in Guatemala. 
Credit: Alliance of Bioversity and CIAT / Manon Koningstein

This story, Jacob van Etten, Principal Scientist and Director of the Digital Inclusion research program at the Alliance of Bioversity International and CIAT, said, became the narrative basis of the Green Revolution, along with the population growth and food security aspects from Norman Borlaug, who also helped to develop the dwarf strain of wheat that dramatically increased crop yields.

Van Etten said that by revisiting the history and context of the 1930s, it became clear that Schultz had “got the story wrong” and that new narratives about the Green Revolution should reserve a much more important place for institutional change in agricultural development.

In his paper, Revisiting the adequacy of the economic policy narrative underpinning the Green Revolution, published in the journal Agriculture and Human Values, van Etten showed that Schultz deliberately tried to hide that the village’s Mayan farmers were not challenged in technological terms and were able to reach relatively high economic returns.

“I hadn’t expected this… What I thought I would find would be that the story only represents one kind of experience in agriculture, but actually, it’s not even about this village, it’s a story about Schultz’s version of the village that influenced the world,” van Etten said, “and it’s a wrong story.”

The researcher explained that Schultz presented a distorted narrative that painted a picture of a population held back by a lack of access to modern varieties and fertilizers.

“What limited farms in that village wasn’t technology, it was access to land, to markets, to credit,” van Etten said, adding that Schultz’s parable ignored ethnic tensions dominating market exchange, the main barrier for agricultural development.

Lessons for the Future of Agricultural Research

In the paper, van Etten explained that Schultz told his own story rather than the narrative-as-lived of the farmers he portrayed and as a result, the Panajachel story neglected the institutional and ethnic reasons behind the farmers’ struggles harnessing technological change.

The reason why it matters, van Etten said, is that these founding myths continue to influence how researchers and the general public perceive the Green Revolution.

“It helps to look back at history and look at the Green Revolution as a broad process of change that was not only about crop seeds and fertilizers,” he said, adding that for example, historian Kapil Subramanian found in a 2015 study that the Green Revolution’s impact on productivity in India did not only rely on improved varieties.

There were also major infrastructural investments in rural electricity to power irrigation pumps, as well as strong government management of markets for inputs, credit and food grains.

According to van Etten, agricultural development is not just about technology but about a mix of things, in which markets and other institutions play the most important part.

“Our founding myth might be wrong, but if it gained influence, it was because of human choices,” van Etten said, “These choices become enshrined in the way we run research organizations, but we can take a new course in defining the goals of where we should go next.”

In addition, van Etten said that much of the work of CGIAR is already correcting old technology-centric thinking.

“We take a critical look at the delivery of new technologies, gender, and inequality aspects, and look beyond technologies to policies and institutions,” van Etten said, “Being aware of our own history helps to remove blinkers.”

Another lesson was that in Panajachel, far from stagnation, there was a traditional knowledge base that was innovative in its own way.

“A lot of innovation was happening… The local varieties are not just the result of 10,000 years of slow work and in Panajachel, farmers got seeds from all over the place and tried them on their farms,” van Etten said.

As agricultural research moves into a new phase, van Etten said, it’s important to give farmers and their communities more agency to mix new technological solutions with their local knowledge.

“Agricultural research can tap into local inventiveness and amplify it and Schultz was wrong in painting farmers as helpless and stagnant,” van Etten said.

“But Shultz was right in claiming that agricultural research is a good public investment and it can further accelerate farmer innovation, as we need all hands on deck to deal with current challenges, such as climate change.”


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Just like humans, more intelligent jays have greater self-control

OCTOBER 31, 2022, by U. of Cambridge

One of the worst performers, 'Homer', could only wait a maximum of 20 seconds for a better snack.
 Credit: Alex Schnell

A study has found that Eurasian jays can pass a version of the 'marshmallow test'—and those with the greatest self-control also score the highest on intelligence tests.

This is the first evidence of a link between self-control and intelligence in birds.

Self-control—the ability to resist temptation in favor of a better but delayed reward—is a vital skill that underpins effective decision-making and future planning.

Jays are members of the corvid family, often nicknamed the 'feathered apes' because they rival non-human primates in their cognitive abilities. Corvids hide, or 'cache', their food to save it for later. In other words, they need to delay immediate gratification to plan for future meals. The researchers think this may have driven the evolution of self-control in these birds.

Self-control has been previously shown to be linked to intelligence in humans, chimpanzees and—in an earlier study by these researchers—in cuttlefish. The greater the intelligence, the greater the self-control.

The new results show that the link between intelligence and self-control exists across distantly related animal groups, suggesting it has evolved independently several times.

Of all the corvids, jays in particular are vulnerable to having their caches stolen by other birds. Self-control also enables them to wait for the right moment to hide their food without being seen or heard.

The results are published today in the journal Philosophical Transactions of the Royal Society B.

To test the self-control of ten Eurasian jays, Garrulus glandarius, researchers designed an experiment inspired by the 1972 Stanford Marshmallow test—in which children were offered a choice between one marshmallow immediately, or two if they waited for a period of time.

Instead of marshmallows, the jays were presented with mealworms, bread and cheese. Mealworms are a common favorite; bread and cheese come second but individuals vary in their preference for one over the other.

Top of the class was 'JayLo', who ignored a piece of cheese and waited five and a half minutes for a mealworm. 
Credit: Alex Schnell

The birds had to choose between bread or cheese—available immediately, and mealworm that they could see but could only get to after a delay, when a Perspex screen was raised. Could they delay immediate gratification and wait for their favorite food?

A range of delay times was tested, from five seconds to five and a half minutes, before the mealworm was made available if the bird had resisted the temptation to eat the bread or cheese.

All the birds in the experiment managed to wait for the worm, but some could wait much longer than others. Top of the class was 'JayLo', who ignored a piece of cheese and waited five and a half minutes for a mealworm. The worst performers, 'Dolci' and 'Homer', could only wait a maximum of 20 seconds.

"It's just mind-boggling that some jays can wait so long for their favorite food. In multiple trials, I sat there watching JayLo ignore a piece of cheese for over five minutes—I was getting bored, but she was just patiently waiting for the worm," said Dr. Alex Schnell at the University of Cambridge's Department of Psychology, first author of the report.

The jays looked away from the bread or cheese when it was presented to them, as if to distract themselves from temptation. Similar behavior has been seen in chimpanzees and children.

The researchers also presented the jays with five cognitive tasks that are commonly used to measure general intelligence. The birds that performed better in these tasks also managed to wait longer for the mealworm reward. This suggests that self-control is linked with intelligence in jays.

"The birds' performance varied across individuals—some did really well in all the tasks and others were mediocre. What was most interesting was that if a bird was good at one of the tasks, it was good at all of them—which suggests that a general intelligence factor underlies their performance," said Schnell.

The jays also adjusted their self-control behavior according to the circumstances: in another experiment where the worm was visible but always out of reach, the jays always ate the immediately available bread or cheese. And the length of time they were willing to wait for the worm fell if it was pitted against their second most preferred food as the immediate treat, compared to their third. This flexibility shows that jays only delay gratification when it is warranted.

Research by other scientists has found that children taking the Stanford marshmallow test vary greatly in their self-control, and this ability is linked to their general intelligence. Children that can resist temptation for longer also get higher scores in a range of academic tasks.


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Scientists Warn of a Rare Third-Year La Nina – Risk of Intense Cold Surges in Eurasia

By INSTITUTE OF ATMOSPHERIC PHYSICS, 
CHINESE ACADEMY OF SCIENCES OCTOBER 30, 2022

Arctic sea smoke near Qingdao, China on January 7th, 2021 when cold surge hit northern China. A result of frigid air passing over relatively warm water, the phenomenon is rare, even in the Arctic. 
Credit: Shaoqing Wang

El Niño–Southern Oscillation (ENSO) is an irregular periodic variation in winds and sea surface temperatures over the tropical eastern Pacific Ocean that affects the climate of much of the tropics and subtropics. This natural phenomenon is important to study because of the socioeconomic impacts it can have on critically important global issues such as food security, agricultural production, human health, and water resources, to name but a few.

ENSO rarely maintains for long in either its cold phase (La Niña) or warm phase (El Niño). Historically, it has a strong preference to peak during boreal winter and rapidly decay in spring (known as “phase-locking”), with quasi-periodic oscillations of 2–7 years. However, since the turn of the current century, three instances of so-called “double dip” La Niña events have occurred, in 2007–09, 2010–12, and 2020–22.

This succession of double-dip La Niña events is intriguing enough in itself; but now, based on updated data from several organizations issued in April 2022, it seems that the current event is likely to continue through the boreal summer and fall of 2022, suggesting a strong possibility of a third-year La Niña lasting from 2020-23.

“This would be the first third-year La Niña since the 1998–2001 event, which was the only such event observed since 1980,” explains Dr. Xianghui Fang from Fudan University, China.

By examining the status of the atmosphere–ocean system over the tropical Pacific in March 2022, Fang and his collaborator, Prof. Fei Zheng, from the Institute of Atmospheric Physics, Chinese Academy of Sciences, found that the equatorial central to eastern Pacific was still maintaining colder conditions than normal, and the southeasterly winds over the equatorial Pacific were appreciable.

The team analyzed the possible contributions of four physical factors related to the thermocline (the boundary between warmer ocean water at the surface and cooler water below) and surface winds in this potential third-year La Niña. Historically, the atmospheric variables in spring 2022 indicate the easterly and southerly winds will reach their largest amplitude since 1980, which supports the emergence of a third-year La Niña.

The team further discusses the possible global climate impacts of this impending third-year La Niña event in a News & Views article published in Advances in Atmospheric Sciences. Specifically, they examine the only two other similar events in history, in 1973–1976 and 1998–2001, and, based on the similarities and differences, conclude that there is much uncertainty in predicting the climatic effects of the current event, both in terms of summer precipitation and winter temperature.

“Nonetheless, we should be aware of the risk of intense cold surges in Eurasia, which could also produce more cold extremes either in eastern or northeastern China,” Fang warns.

Reference: “Will the Historic Southeasterly Wind over the Equatorial Pacific in March 2022 Trigger a Third-year La Niña Event?” by Xianghui Fang, Fei Zheng, Kexin Li, Zeng-Zhen Hu, Hongli Ren, Jie Wu, Xingrong Chen, Weiren Lan, Yuan Yuan, Licheng Feng, Qifa Cai and Jiang Zhu, 26 July 2022, Advances in Atmospheric Sciences.
DOI: 10.1007/s00376-022-2147-6


Basics of El Niño–Southern Oscillation (ENSO)

Though ENSO is a single climate phenomenon, it has three states, or phases, it can be in. The two opposite phases, “El Niño” and “La Niña,” require certain changes in both the ocean and the atmosphere because ENSO is a coupled climate phenomenon. 
“Neutral” is in the middle of the continuum.

El Niño: A warming of the ocean surface, or above-average sea surface temperatures (SST), in the central and eastern tropical Pacific Ocean. Over Indonesia, rainfall tends to become reduced while rainfall increases over the tropical Pacific Ocean. The low-level surface winds, which normally blow from east to west along the equator (“easterly winds”), instead weaken or, in some cases, start blowing in the other direction (from west to east or “westerly winds”).

La Niña: A cooling of the ocean surface, or below-average sea surface temperatures (SST), in the central and eastern tropical Pacific Ocean. Over Indonesia, rainfall tends to increase while rainfall decreases over the central tropical Pacific Ocean. The normal easterly winds along the equator become even stronger.

Neutral: Neither El Niño or La Niña. Often tropical Pacific SSTs are generally close to average. However, there are some instances when the ocean can look like it is in an El Niño or La Niña state, but the atmosphere is not playing along (or vice versa).


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Sunday, 30 October 2022

New dates suggest Oceania's megafauna lived until 25,000 years ago, implying coexistence with people for 40,000 years

OCTOBER 21, 2022, by M. Westaway, The Conversation

Credit: Wikimedia, CC BY-SA

For most of Australia's human past sea levels were lower than they are today. Australia's mainland was connected to Papua New Guinea and Tasmania as part of a larger landmass called "Sahul".

During the Ice Ages Sahul was home to a unique range of megafauna, which included giant marsupials, birds and reptiles. The extinction of megafauna in Sahul remains one of the most contested debates in Australian science.

Now, our new paper published in Archaeology in Oceania provides compelling evidence megafauna may have coexisted with people in the region longer than previously thought—and as recently as about 25,000 years ago.

Our research extends the likely period of overlap between megafauna and people to about 40,000 years. It brings new evidence against the theory that people in Sahul drove the megafauna extinction.

An enduring scientific debate

Like other regions during the ice ages (a period known as the Pleistocene) Sahul contained the enigmatic megafauna. The term "megafauna" as it's used in Australia is generally applied to ancient animals that weighed more than about 45kg.

There is disagreement on how Sahul's megafauna went extinct. Since 1831—when eminent anatomist Sir Richard Owen received megafauna fossils from Wellington Cave in New South Wales, and a decade later from the Darling Downs in Queensland—there has been speculation about how Sahul's megafauna went extinct.

Owen argued humans were responsible. Others, such as Prussian scientist Ludwig Leichhardt, favored environmental change as the cause, proposing megafauna extinction in the Darling Downs occurred as a result of the draining of swamps due to tectonic uplift.

Today the debate continues along similar lines. Some researchers argue Aboriginal people were responsible for driving all megafauna extinct by 42,000 years ago.

Decades of work in Sahul

The most direct approach to understanding what happened to the megafauna involves excavating sites containing their remains, and applying a range of techniques to understand how these sites (and their surroundings) have changed through time. Revisiting old sites with new techniques helps us gather as much data as possible.

The most significant research into understanding megafauna extinction in northernmost Sahul was conducted in the 1970s by archaeologist Mary-Jane Mountain at the Nombe rockshelter in the Papuan Highlands.

Mountain's careful excavation of a site known to have been inhabited by people in the late Pleistocene also uncovered megafauna fossils.

While the fossils themselves couldn't be dated, the dating of charcoal samples, non-megafauna animal bones and snail shells from adjacent deposits revealed megafauna existed in the area as recently as 19,000 years ago.

However, a paper published in 2001 argued archaeological sites weren't ideal for testing megafauna extinctions as they lacked near-complete animal fossils that had been moved by people.

Nombe was removed from the list, along with the original dates for megafauna surviving as recently as 19,000 to 25,000 years ago.

The Nombe rockshelter excavation in the 1970s provided some of the most significant estimates for when Sahul’s megafauna went extinct. 
Credit: Barry Shaw, Author provided

In 2016, another important paper was published reassessing these dates. This research used a more modern carbon-dating approach called accelerated mass spectrometry (AMS) dating.

This method can date much smaller charcoal particles, and once more led researchers to dates that supported the original estimates revealed through Mountain's work.

Redating Nombe

For our new paper, we decided to further test these estimates using uranium-series (U-series) dating of megafauna fossils. The U-series dating technique has been refined over several decades. It allowed us to directly date megafauna fossils from the Papuan Highlands for the first time.

Our research suggests the fossils date to between 22,000 and 27,000 years ago—which is very close to Mountain's original estimates and the more recent accelerated mass spectrometry dates.

The U-series dating provides minimum age estimates, which means the fossils could be older. But since our estimates are supported by previous accelerated mass spectrometry dating, collectively the data provide a compelling case for the existence of megafauna in Sahul as recently as 25,000 years ago.

This contradicts the persisting theory these animals were extinct by 42,000 years ago.

Our research also extends the period of overlap between megafauna and people. If the earliest dates for people in Sahul go back 65,000 years, this implies some 40,000 years of overlap.

Adding to this, recent work at the Willandra Lakes in NSW and the Seton Rockshelter at Kangaroo Island also estimates Sahul's megafauna were alive some 30,000 years ago.

Was there another ancient human?

Some argued the arrival of people to Sahul drove significant environmental change, to the point that megafauna could no longer survive.

But our analysis of pollen at Nombe reveals high-altitude forests (called montane forests) persisted from at least 26,000 years ago to the end of the Pleistocene 10,000 years ago. The archaeological evidence shows people weren't that active in the area during this time—which suggests it's unlikely they drove the megafauna extinction.

Rather, we raise the possibility megafauna may have coexisted with hominins (a group including us, Homo sapiens, and our close ancestors) for much longer than previously thought.

Geneticists have found the mysterious ancient humans called Denisovans were likely present in the Papuan Highlands before Homo sapiens arrived. So they may have been familiar with megafauna further back than 65,000 years ago.

But this idea needs to be further investigated. We don't have Denisovan fossils from Papua New Guinea. We only have genetic data in modern Highland populations to study.

More field work will help us understand not only how megafauna went extinct across Sahul, but how they interacted with their surroundings, and how their collapse may have shaped today's environments.


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The Surreal Mystery of Namibia's 'Fairy Circles' May Finally Be Solved

NATURE: 30 October 2022, By R. MCLENDON

Fairy circles in Namibia.
 (Stephan Getzin)

Sprawling across a remote swath of the Namib Desert, rugged grasses eke out a living from the region's meager rainfall.

The growth of so much grass in such a harsh environment is impressive, but also mysterious. The grassland is dotted by millions of strange circles, each devoid of grass or other vegetation, that together form an eerie polka-dot pattern of "fairy circles" across the landscape.

Located 80 to 140 kilometers (50 to 87 miles) inland from Namibia's coast, this zone of circular gaps in the grassland is visible from miles around, the study's authors note, and exhibits "an extraordinary degree of spatial ordering."

The NamibRand Nature Reserve, one of the fairy-circle regions studied in Namibia. 
(Stephan Getzin)

A typical fairy circle measures anywhere from 2 to 10 meters across, separated from the rest by a distance of up to 10 meters.

Scientists have made steady progress on demystifying Namibia's fairy circles, with leading theories falling into two main camps.

One theory contends the circles are caused by termites feasting on roots, while the other suggests the grasses self-organize to maximize water availability.

Studies have lent credence to each theory, and some research has indicated both termites and self-organization may be behind the fairy circles. But that explanation became trickier after similar circles were reported in Australia in 2016, without a clear link to termites.

Recent research has pointed more firmly toward self-organization, in which the grasses form fairy circles to make the most of scant rainfall, but without necessarily ruling out termites.

In 2020, research led by Stephan Getzin, from the Department of Ecosystem Modeling at the University of Goettingen in Germany, added further support to the water-scarcity scenario, which Getzin and his colleagues described as an example of a Turing pattern.

In their latest study, Getzin and a team of researchers returned to Namibia in hopes of finding even more compelling evidence, investigating fairy circles in 10 regions across the Namib Desert.

Rainfall is rare and irregular in this area. Grasses do sometimes appear within the fairy circles right after it rains, but they typically die soon after, the researchers note, while grass between the circles survives.

Getzin and his colleagues tracked sporadic rains in the 10 regions, examining the grasses, their roots and shoots, and any potential root damage wrought by termites.

They studied the circumstances around dying grass after rainfall, and set up soil-moisture sensors in and around fairy circles to record data at half-hour intervals, beginning in the dry season of 2020 and continuing until the end of 2022's rainy season.

Ten days after rainfall, the interior of the fairy circles had very little new growth, the study found, and what new grass had sprouted was already dying. Twenty days after rainfall, any grass inside the circles was dead, while surrounding grass was "green and soft."

Roots from dead grass inside the circles were as long – or even longer than – roots from outside the circles, suggesting the plants were investing heavily in root growth to search for water. The researchers did not find evidence of termites feeding on the roots, they report.

"The sudden absence of grass for most areas within the circles cannot be explained by the activity of termites because there was no biomass for these insects to feed on," Getzin says. "But more importantly, we can show that the termites are not responsible because the grasses die immediately after rainfall without any sign of creatures feeding on the root."

The soil sensors revealed a slow decline in soil moisture both inside and outside the circles after an initial rainfall, the researchers report, when grasses weren't well-established yet.

Once the surrounding grasses were robust, however, soil moisture vanished quickly everywhere — including inside the fairy circles, despite the lack of grass there to take up the water.


"Under the strong heat in the Namib, the grasses are permanently transpiring and losing water. Hence, they create soil-moisture vacuums around their roots and water is drawn toward them," Getzin says.

"Our results strongly agree with those of researchers who have shown that water in soil diffuses quickly and horizontally in these sands even over distances greater than seven meters."

This is an incredible example of "ecohydrological feedback," the researchers write, in which the barren circles essentially become reservoirs that help sustain grasses at the edges.

This research could also have implications elsewhere, Getzin points out, as this kind of self-organization seems to buffer plants against rising aridity – a problem that's already worsening in some places due to climate change.

"By forming strongly patterned landscapes of evenly spaced fairy circles, the grasses act as ecosystem engineers and benefit directly from the water resource provided by the vegetation gaps," Getzin says.

"In fact, we know related self-organized vegetation structures from various other harsh drylands in the world, and in all those cases the plants have no other chance to survive except by growing exactly in such geometrical formations."

The study was published in Perspectives in Plant Ecology, Evolution and Systematics.


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Paranormal or Psychology? The 'Spooky' Science Behind Ouija Boards

HUMANS: 30 October 2022, By M. KENNY, THE CONVERSATION

Ellen Denuto/Photodisc/Getty Images

Despite being around for more than 100 years, Ouija boards (a wooden board covered with the letters of the alphabet, the numbers 0-9, and the words "yes", "no" and "goodbye") continue to be a popular activity – especially around Halloween.

To work, all participants must place their hands on the wooden pointer (or planchette) and ask any present "spirits" to answer their questions by moving the planchette around the board to spell out their response.

While some see it as a harmless parlor game, others swear by the board's ability to communicate with those who have passed to the "other side".

But though science suggests that ghosts aren't behind the board's mysterious movements, the explanation for how they do work isn't as straightforward as you might expect.

The history of the Ouija board is a long and varied one. It may first be partially traced back to the Fox Sisters, popular mediums in the 19th century who pioneered the spiritualism movement.

One of their most frequently used methods for communicating with so-called spirits involved saying the alphabet aloud and listening for a knock in response. This allowed them to spell out words and messages, supposedly from the dead.

This method captured the public's imagination but was quickly frustrating. People wanted to be able to communicate with spirits as quickly as they were able to communicate with people using new technologies, such as the telegraph. So when the Ouija board was finally developed in 1890, it was an instant success.

But despite its early popularity, the Ouija board fell out of favor at the start of the 20th century. This was largely due to many famous mediums who used the device being publicly debunked.

Even the Society for Psychical Research moved away from spirit communication, towards other paranormal phenomena such as extra-sensory perception (the ability to send and receive information with your mind) and haunted houses.

However, interest in spiritualism and Ouija boards more generally was rapidly revived after the second world war – and continues to this day.

Ouija boards at work

But do Ouija boards work? It depends on who you ask. For those who believe in the ability to communicate with spirits, the answer would be yes. But given there's no conclusive evidence spirits exist, the answer from skeptics and scientists alike would be a firm no.

And yet we often hear stories from so-called "non-believers" who say that they have felt the planchette move over the board, spelling out words and telling them things no one else around the table could know.

So, if it isn't ghostly messages from the other side, what is it?

One possible answer is the ideomotor effect. The term ideomotor stems from ideo (an idea) and motor (muscular activity), suggesting our movements can be driven by our thoughts.

The ideomotor effect refers to movements people make that they're unaware of – referred to as a subconscious movement. So when using a Ouija board, for example, a person may subconsciously move the planchette, spelling out things only they could know.

Those around them may also contribute their own subconscious movement, which can also explain why the planchette appears to move independently.

This effect may explain a variety of other paranormal phenomena as well – including automatic writing and dowsing (a type of pseudoscience which uses a y-shaped twig or metal rods to find the location of buried objects, such as water or oil).

Another explanation, which is also linked to the ideomotor effect, is related to our sense of agency. Sense of agency refers to our subjective ability to control actions that will have an influence on external events. So for example, if you decide to lift a table up, it will cause it to move.

Experiments with Ouija boards have demonstrated that our sense of agency can be manipulated, leading us to think that an invisible third party is moving the planchette.

This is thought to be due to issues our brain faces around predicting the consequences of outcomes. When our predictions match the outcome (for example, you lift the table and the table moves), we feel that we are responsible for the action.

But if we feel the actual outcome doesn't match up with how we expected things to turn out, then our sense of agency decreases – and it's possible that, in the context of a seance, we may instead attribute this movement as coming from an external source.

A third factor to consider is emotional contagion. We know that shocking, highly emotional events can lead to witnesses nearby "catching" those emotions. This was thought to be a prevalent factor in the witch trials of Salem and Europe.

So when using a Ouija board with other people, the excitement of the highly charged environment may make it easier for us to start to empathize with those around us. This may see us pick up on their fear and anxiety, making it more likely for us to think the planchette is moving on its own.

It's possible then to see that a combination of factors – the ideomotor effect, a manipulated sense of agency, and emotional contagion – can all combine to convince people that the planchette is moving and spirits are speaking to them.

But given how difficult it is to replicate the social setting in which most people use Ouija boards in a lab, we can't say with complete certainty that these factors alone explain what actually happens when we place our fingers on the planchette and call to the spirits to share their knowledge.

As some experts note, the public's desire to communicate with the dead tends to become more popular following times of social and political upheaval.

Given the present social, economic, and political climate – including the COVID-19 pandemic, the ongoing war in Ukraine, and the cost-of-living crisis – it's entirely possible that we will see a return to the seance rooms of the Victorian era. Or at the very least, on TikTok.

Megan Kenny, Senior Lecturer in Psychology, Sheffield Hallam University


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Saturday, 29 October 2022

Syria digs up 'rare' Roman mosaic in former rebel stronghold

OCTOBER 12, 2022, by Albert Aji

People look at a large mosaic that dates back to Roman era in the town of Rastan, Syria, Wednesday, Oct. 12, 2022. Syrian officials said it is the most important archaeological discovery since the conflict began 11 years ago. 
Credit: AP Photo/Omar Sanadiki

Journalists were shown the mosaic in the central town of Rastan near Homs, Syria's third largest city.

The mosaic, at 120 square meters (around 1300 square feet), was found in an old building that Syria's General Directorate of Antiquities and Museums had been excavating. Lebanese and Syrian businessmen from the neighboring country's Nabu Museum bought the property that dates back to the 4th century and donated it to the Syrian state. Each panel was filled with square-shaped, small colorful stones measuring about half an inch on each side.

Dr. Humam Saad, the associate director of excavation and archaeological research at the directorate, said among the scenes the mosaic shows is a rare portrayal of Ancient Amazon warriors in Roman mythology.

"What is in front of us is a discovery that is rare on a global scale," Saad told The Associated Press, adding that the images are "rich in details," and includes scenes from the Trojan War between the Greeks and Trojans.

In Ancient Greek and Roman mythology, demigod hero Hercules slayed Hippolyta, queen of the Amazons, in one of his 12 labors.

People look at a large mosaic that dates back to Roman era in the town of Rastan, Syria, Wednesday, Oct. 12, 2022. Syrian officials said it is the most important archaeological discovery since the conflict began 11 years ago. 
Credit: AP Photo/Omar Sanadiki

The mosaic also portrays Neptune, Ancient Roman god of the sea, and 40 of his mistresses.

"We can't identify the type of the building, whether it's a public bathhouse or something else, because we have not finished excavating yet," Saad told the AP.

Sulaf Fawakherji, a famous actress in Syria and a member of the Nabu Museum's board of trustees said she hopes they could purchase other buildings in Rastan, which she says is filled with heritage sites and artifacts waiting to be discovered.

"There are other buildings, and it's clear that the mosaic extends far wider," Fawkherji told the AP. "Rastan historically is an important city, and it could possibly be very important heritage city for tourism."

Despite Rastan's historical significance in the country, Saad says there have not been significant excavation efforts in the town prior to the country's armed conflict.

A detail of a large mosaic that dates back to Roman era is seen in the town of Rastan, Syria, Wednesday, Oct. 12, 2022. Syrian officials said it is the most important archaeological discovery since the conflict began 11 years ago. 
Credit: AP Photo/Omar Sanadiki

"Unfortunately, there were armed groups that tried to sell the mosaic at one point in 2017 and listed it on social media platforms," he said.

Syrian heritage sites have been looted and destroyed over the past decade of ongoing violent conflict.

Among the most notable incidents was the Islamic State group taking Palmyra, a UNESCO World Heritage Site that boasts 2,000-year-old towering Roman-era colonnades and priceless artifacts, and partially destroying a Roman theater. Meanwhile, Syria's cash-strapped government has slowly been rebuilding Aleppo's centuries-old bazaar after reclaiming it from armed opposition forces in 2016.

Rastan was once a major opposition stronghold and was a point of intense clashes, before the Syrian government reclaimed the city in 2018.


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Cinnamon is highly beneficial according to a new study

OCTOBER 28, 2022, by Ebony Williams

Credit: CC0 Public Domain

Cinnamon might be the oldest known spice in the world. In ancient Egypt, it was once valued more highly than gold. Cinnamon is used in nearly every holiday treat during the fall and winter, but there are plenty of benefits to using cinnamon year round.

Science has confirmed the many health benefits tied to cinnamon:

Antioxidants

Cinnamon is high in antioxidants—including polyphenols—which protect the body's tissues against oxidative stress and associated pathologies such as cancers, coronary heart disease and inflammation.

Protection against heart disease

Cinnamon has been linked to reduced blood pressure, triglycerides, cholesterol levels and blood sugar in those with metabolic diseases.

Improved insulin sensitivity

Studies suggest cinnamon might be able to reduce insulin resistance, increasing sensitivity to hormone insulin that can improve blood sugar control.

Protection from neurodegenerative diseases

Some compounds found in cinnamon have an effect on tau—a protein in the brain associated with Alzheimer's disease. In a study involving mice in 2014, cinnamon was a protectant for neurons and helped improve motor function for mice with Parkinson's disease.

Anti-inflammatory

Cinnamon is a natural anti-inflammatory that blocks the release of arachidonic acid, a fatty acid that causes inflammation. This arachidonic acid can also cause blood clotting.

While all cinnamon might look the same, there are two different kinds—Cassia and Ceylon. Both posses the helpful qualities described above; however, Cassia cinnamon contains the toxin coumarin, a compound found in some plant species that can be harmful if consumed in high quantities.

Ceylon—also known as "true cinnamon"—comes from Sri Lanka and southern India. Cassia, on the other hand, originated in southern China and is now widely grown across southern and eastern Asia. It's a darker brown-red color. Cassia is the most common cinnamon found in supermarkets and it's generally cheaper than Ceylon cinnamon.



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Manipulating light can induce psychedelic experiences—and scientists aren't quite sure why

OCTOBER 24, 2022, by M. MacKisack and R. Reeder, The Conversation

From Jan E. Purkinje’s documentation of the subjective visual phenomena he saw when he waved his hand in front of his closed eyes. 
Author provided

For millennia, people have used mind-altering techniques to achieve different states of consciousness, envision spiritual figures, connect with nature, or simply for the fun of it. Psychedelic substances, in particular, have a long and controversial history. But for just as long, people have been having these experiences without drugs too, using rhythmic techniques such as rocking, chanting or drumming.

Perhaps the most powerful technique of this kind is flickering light, called "ganzflicker." Ganzflicker effects can be achieved by turning a light on and off, or by alternating colors in a rapid, rhythmic pattern (like a strobe). This can create an instant psychedelic experience.

Ganzflicker elicits striking visual phenomena. People can see geometric shapes and illusory colors but sometimes also complex objects, such as animals and faces—all without any chemical stimulants. Sometimes ganzflicker can even lead to altered states of consciousness (such as losing a sense of time or space) and emotions (ranging from fear to euphoria).

Although its effects are little known today, ganzflicker has influenced and inspired many people through the ages, including the two of us. We are an art historian and brain scientist working together on an interactive showcase of ganzflicker techniques used in science and art. Our collaboration has culminated in the museum exhibition "Ganzflicker: art, science, and psychedelic experience," which is part of the 2022 Being Human festival.

Ganzflicker's effects were first documented in 1819 by the physiologist Jan E. Purkinje. Purkinje discovered that illusory patterns could appear if he faced the sun and waved his hand in front of his closed eyelids.

Near the end of the 19th century, an English toymaker and amateur scientist, Charles Benham, produced the first commercially available flicker device: a top with a monochrome pattern that, when spun, produced illusory colors that swirled around the disk.

Modified versions of Benham's "artificial spectrum top" were used in experiments well into the 20th century. William Grey Walter, a pioneering neurophysiologist and cybernetician, pushed flicker effects further by using electric strobe lights, synchronized with the brain's rhythms.

Fascinated by the mind-altering potential of Walter's machinery, the artist Brion Gysin, in collaboration with writer William S. Burroughs and mathematician Ian Sommerville, invented the Dreamachine (1962).

The swinging 60s of drug-free psychedelics

A Dreamachine consists of an upright cylinder with patterns cut into it and a lightbulb suspended at its center. When spun on a turntable at 78rpm, the flickering patterns (viewed through closed eyelids) can cause trance-like hallucinations.

Gysin thought of the Dreamachine as a new kind of artwork—"the first art object to be seen with the eyes closed"—and a form of entertainment, which he believed could replace the television. Others saw the Dreamachine's potential to be a source of spiritual inspiration.

Burroughs thought it could be used to "storm the citadels of enlightenment." The poet Alan Ginsberg said: "It sets up optical fields as religious and mandalic as hallucinogenic drugs—it's like being able to have jeweled biblical designs and landscapes without taking chemicals."

Flicker experiments in art did not stop with the Dreamachine. Others included Tony Conrad's groundbreaking structuralist film The Flicker (1966), which was the first artwork to include the warning "may induce epileptic seizures or produce mild symptoms of shock treatment in certain persons."

The conceptual artist James Turrell's Bindu Shards (2010) was an enclosed globe that bombards the observer with strobe light. And, more recently, Collective Act created its own Dreamachine (2022) , a public planetarium-style artwork inspired by Gysin's which toured the UK.

The science of ganzflicker

Two hundred years after Jan Purkinje documented the physiological properties of ganzflicker, scientists still do not have a definitive explanation for how it works.

A recent theory proposes that visual phenomena may be the result of interactions between external flicker and the brain's natural rhythmic electrical pulses, with more intense images manifesting when the frequencies of flicker and the brain are closest.

It is also likely that a strong visual flicker influences brain states. Meaningful visions, altered conscious states and heightened emotions may be the result of imaginative suggestion, which is amplified by the trance-inducing properties of rhythmic stimulation.

What is perhaps most powerful about ganzflicker is its universality. Engineers, mathematicians, artists, historians and scientists have all been united by this modest, drug-free means of eliciting dramatic changes in consciousness. The new wave of popularity on this topic will undoubtedly lead to illuminating discoveries in the coming years.


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Friday, 28 October 2022

Ancient viral DNA in human genome guards against infections

OCTOBER 27, 2022, by K. Ramanujan, Cornell University

Credit: Pixabay/CC0 Public Domain

Viral DNA in human genomes, embedded there from ancient infections, serves as antivirals that protect human cells against certain present-day viruses, according to new research.

The paper, "Evolution and Antiviral Activity of a Human Protein of Retroviral Origin," published Oct. 28 in Science, provides proof of principle of this effect.

Previous studies have shown that fragments of ancient viral DNA—called endogenous retroviruses—in the genomes of mice, chickens, cats and sheep provide immunity against modern viruses that originate outside the body by blocking them from entering host cells. Though this study was conducted with human cells in culture in the lab, it shows that the antiviral effect of endogenous retroviruses likely also exists for humans.

The research is important because further inquiry could uncover a pool of natural antiviral proteins that lead to treatments without autoimmune side effects. The work reveals the possibility of a genome defense system that has not been characterized, but could be quite extensive.

"The results show that in the human genome, we have a reservoir of proteins that have the potential to block a broad range of viruses," said Cedric Feschotte, professor of molecular biology and genetics in the College of Agriculture and Life Sciences. John Frank, Ph.D., a former graduate student in Feschotte's lab and now a postdoctoral researcher at Yale University, is the study's first author.

Endogenous retroviruses account for about 8% of the human genome—at least four times the amount of DNA that make up the genes that code for proteins. Retroviruses introduce their RNA into a host cell, which is converted to DNA and integrated into the host's genome. The cell then follows the genetic instructions and makes more virus.

In this way, the virus hijacks the cell's transcriptional machinery to replicate itself. Typically, retroviruses infect cells that don't pass from one generation to the next, but some infect germ cells, such as an egg or sperm, which opens the door for retroviral DNA to pass from parent to offspring and eventually become permanent fixtures in the host genome.

In order for retroviruses to enter a cell, a viral envelope protein binds to a receptor on the cell's surface, much like a key into a lock. The envelope is also known as a spike protein for certain viruses, such as SARS-CoV-2.

In the study, Frank, Feschotte and colleagues used computational genomics to scan the human genome and catalog all the potential retroviral envelope protein-coding sequences that might have retained receptor binding activity. Then they ran more tests to detect which of these genes were active—that is, expressing retroviral envelope gene products in specific human cell types.

"We found clear evidence of expression," Feschotte said, "and many of them are expressed in the early embryo and in germ cells, and a subset are expressed in immune cells upon infection."

Once the researchers had identified antiviral envelope proteins expressed in different contexts, they focused on one, Suppressyn, because it was known to bind a receptor called ASCT2, the cellular entry point for a diverse group of viruses called Type D retroviruses. Suppressyn showed a high level of expression in the placenta and in very early human embryonic development.

They then ran experiments in human placental-like cells, as the placenta is a common target for viruses.

The cells were exposed to a type D retrovirus called RD114, which is known to naturally infect feline species, such as the domestic cat. While other human cell types not expressing Suppressyn could be readily infected, the placental and embryonic stem cells did not get infected. When the researchers experimentally depleted placental cells of Suppressyn, they became susceptible to RD114 infection; when Suppressyn was returned to the cells, they regained resistance.

In addition, the researchers did reverse experiments, using an embryonic kidney cell line normally susceptible to RD114. The cells became resistant when the researchers experimentally introduced Suppressyn into these cells.

The study shows how one human protein of retroviral origin blocks a cell receptor that allows viral entry and infection by a broad range of retroviruses circulating in many non-human species. In this way, Feschotte said, ancient retroviruses integrated into the human genome provide a mechanism for protecting the developing embryo against infection by related viruses.

Future work will explore the antiviral activity of other envelope-derived proteins encoded in the human genome, he said.

Co-authors include Carolyn Coyne, a virologist at Duke University's School of Medicine, and Jose Garcia-Perez, a molecular biologist at the University of Granada, Spain.


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