среда, 25 декабря 2019 г.

Плащ невидимка новые технологии

Представляет собой материал, который способен сделать объект совершенно невидимым, сгибая вокруг него световые волны. При этом необходимо отметить, что он способен сокрыть не только визуальную копию, но и инфракрасную и тепловую, которые заметны в приборах ночного видения, тепловизорах. Кроме того, он удаляет тени от объекта.
Плащ невидимка новые технологии Invisible Cloak revealed

По словам директора корпорации, в целях соблюдения безопасности, он не может открыть подробности того, каким именно образом происходит изгиб света. Он также отметил, что материал был продемонстрирован двум группам американских и двум командам канадских военных, а также Федеральному подразделению реагирования на чрезвычайные происшествия. Таким образом, они могут подтвердить, что существование необычного материала – это не миф и не манипуляции с фото и видео. 

Плащ невидимка новые технологии Invisible Cloak revealed
Военные убедились в том, что материал очень недорогой и легкий по весу, и что для его эффективности не требуется никаких дополнительных приспособлений в виде аккумуляторов, камеры, зеркал или фар. Кроме того, и канадские, и американские военные подтвердили, что он эффективен также против тепловой и инфракрасной техники, которая используется в военных целях.
Плащ невидимка новые технологии

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Invisible Cloak revealed

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Spitzer studies a stellar playground with a long history

This image from NASA's Spitzer Space Telescope shows the Perseus Molecular Cloud, a massive collection of gas and dust that stretches over 500 light-years across. Home to an abundance of young stars, it has drawn the attention of astronomers for decades.

Spitzer studies a stellar playground with a long history
A collection of gas and dust over 500 light-years across, the Perseus Molecular Cloud hosts
an abundance of young stars. It was imaged here by the NASA's Spitzer Space Telescope
[Credit: NASA/JPL-Caltech]
Spitzer's Multiband Imaging Photometer (MIPS) instrument took this image during Spitzer's "cold mission," which ran from the spacecraft's launch in 2003 until 2009, when the space telescope exhausted its supply of liquid helium coolant. (This marked the beginning of Spitzer's "warm mission.") Infrared light can't be seen by the human eye, but warm objects, from human bodies to interstellar dust clouds, emit infrared light.

Infrared radiation from warm dust generates much of the glow seen here from the Perseus Molecular Cloud. Clusters of stars, such as the bright spot near the left side of the image, generate even more infrared light and illuminate the surrounding clouds like the Sun lighting up a cloudy sky at sunset. Much of the dust seen here emits little to no visible light (in fact, the dust blocks visible light) and is therefore revealed most clearly with infrared observatories like Spitzer.

On the right side of the image is a bright clump of young stars known as NGC 1333, which Spitzer has observed multiple times. It is located about 1,000 light-years from Earth. That sounds far, but it is close compared to the size of our galaxy, which is about 100,000 light-years across. NGC 1333's proximity and strong infrared emissions made it visible to astronomers using some of the earliest infrared instruments.

In fact, some of its stars were first observed in the mid-1980s with the Infrared Astronomical Survey (IRAS), a joint mission between NASA, the United Kingdom and the Netherlands. The first infrared satellite telescope, it observed the sky in infrared wavelengths blocked by Earth's atmosphere, providing the first-ever view of the universe in those wavelengths.

Spitzer studies a stellar playground with a long history
This image from NASA'S Spitzer Space Telescope shows the location and apparent size of the Perseus Molecular Cloud
in the night sky. Located on the edge of the Perseus Constellation, the collection of gas and dust is about
1,000 light-years from Earth and about 500 light-years wide [Credit: NASA/JPL-Caltech]
More than 1,200 peer-reviewed research papers have been written about NGC 1333, and it has been studied in other wavelengths of light, including by the Hubble Space Telescope, which detects mostly visible light, and the Chandra X-Ray Observatory.

Many young stars in the cluster are sending massive outflows of material—the same material that forms the star—into space. As the material is ejected, it is heated up and smashes into the surrounding interstellar medium. These factors cause the jets to radiate brightly, and they can be seen in close-up studies of the region. This has provided astronomers with a clear glimpse of how stars go from a sometimes-turbulent adolescence into calmer adulthood.

An Evolving Mystery

Other clusters of stars seen below NGC 1333 in this image have posed a fascinating mystery for astronomers: They appear to contain stellar infants, adolescents and adults. Such a closely packed mixture of ages is extremely odd, according to Luisa Rebull, an astrophysicist at NASA's Infrared Science Archive at Caltech-IPAC who has studied NGC 1333 and some of the clusters below it. Although many stellar siblings may form together in tight clusters, stars are always moving, and as they grow older they tend to move farther and farther apart.

Finding such a closely packed mixture of apparent ages doesn't fit with current ideas about how stars evolve. "This region is telling astronomers that there's something we don't understand about star formation," said Rebull. The puzzle presented by this region is one thing that keeps astronomers coming back to it. "It's one of my favorite regions to study," she added.

Since IRAS's early observations, the region has come into clearer focus, a process that is common in astronomy, said Rebull. New instruments bring more sensitivity and new techniques, and the story becomes clearer with each new generation of observatories. On Jan. 30, 2020, NASA will decommission the Spitzer Space Telescope, but its legacy has paved the way for upcoming observatories, including the James Webb Space Telescope, which will also observe infrared light.

The Spitzer-MIPS data used for this image is at the infrared wavelength of 24 microns. Small gaps along the edges of this image not observed by Spitzer were filled in using 22-micron data from NASA's Wide-Field Infrared Survey Explorer (WISE).

Author: Calla Cofield | Source: NASA [December 20, 2019]

* This article was originally published here

Asteroid collisions trigger cascading formation of subfamilies, study concludes

Billions of years ago, asteroid collisions resulted in the ejection of fragments hundreds of kilometers across and sharing similar orbits. The resulting groups are known as asteroid families.

Asteroid collisions trigger cascading formation of subfamilies, study concludes
Researchers at Sao Paulo State University identify groups of asteroids created
by rotational fission inside collisional families [Credit: Safwan Aljbaae]
Other asteroid groups formed as a result of rotational fission, which happens when a rapidly spinning body reaches critical rotation speed and splits into relatively small fragments only a few kilometers across.

Scientists have always thought about fission clusters as entirely distinct from collisional families. Now, however, a study conducted by researchers affiliated with Sao Paulo State University (UNESP) at Guaratingueta, under the aegis of a project supported by Sao Paulo Research Foundation—FAPESP, has shown that fission clusters may originate from collisional families in some cases.

Researchers at the National Space Research Institute (INPE) and the Federal University of Sao Paulo (UNIFESP) in Brazil, as well as the University of Cote d'Azur in France, also took part in the study, which is published in the journal Nature Astronomy.

"These discoveries change our understanding of how asteroid families are formed," Valerio Carruba, a professor at UNESP and principal investigator for the project, told Agencia FAPESP.

"It was always believed that asteroid families resulted from collisions, and that the fragments could evolve via gravitational or non-gravitational mechanisms, remaining roughly the same size. Now we've observed that a collision isn't a one-off event but may trigger the subsequent formation of a cascade of other groups," Carruba said.

The researchers set out to identify possible fission clusters inside asteroid families created by collision, selecting four young asteroid families formed less than 5 million years ago: Jones, Kazuya, 2001 GB11, and Lorre.

Using asteroid family recognition methods based on time-reversal simulation, machine learning clustering algorithms, and high-quality astrometric data (on orbital position and motion) obtained from observations of Solar System objects by Gaia, the European Space Agency (ESA) telescope and astrometry mission, they identified several subclusters inside these four extremely young collisional families.

Their analysis confirmed three secondary or tertiary fission clusters in the Jones family (6.7% of the total population), two in the 2001 GB11 family (6.3%), and two in the Lorre family (27.3%).

They defined secondary clusters as subsets of the larger family created by the primary collision and including the parent body, while tertiary groups are subsets of the primary family created by subsequent collisions and not including the parent body.

The authors of the published study note that detectable fission clusters in secondary and tertiary groups never account for more than 5% of the total population in asteroid families older than 100 million years.

"This is probably linked to the mechanism whereby primary asteroid families are formed," Carruba said.

According to Carruba, when asteroid families are formed they include streams of fragments that spin at high speed owing to the collision, or owing to non-gravitational effects such as YORP (the Yarkovsky-O'Keefe-Radzievskii-Paddack effect), a thermal torque due associated with solar radiation.

The fragments eventually cluster into fission groups that are visible only for a time. "After 5 to 10 million years they break up and can no longer be detected by the methods available to us," he explained. "Many fission clusters formed in the past are no longer detectable."

He added that there are no estimates of the rotation period (the time taken to rotate once) of the asteroids in many collision families. "Obtaining rotational data would help us find out which asteroids may be members of fission clusters," he said.

Author: Elton Alisson | Source: FAPESP [December 20, 2019]

* This article was originally published here

New study identifies last known occurrence of Homo erectus

Scientists have identified the last known occurrence of Homo erectus--in Central Java, Indonesia between 117,000 and 108,000 years ago. An ancient ancestor of modern humans that lived in the Pleistocene era, Homo erectus first appeared approximately 2 million years ago.

New study identifies last known occurrence of Homo erectus
These skull caps belonged to the last known members of the Homo erectus species, found in Central Java,
Indonesia [Credit: Russell L. Ciochon & Kiran Patel, University of Iowa]
An international team of researchers including the University of Alberta's John-Paul Zonneveld applied modern dating technology to a group of fossils originally found in the 1930s. The fossils include 12 skull caps and 2 lower leg bones found in a bone bed 20 metres above the Solo River at Ngandong, Central Java, Indonesia.

"Uncertainty of the age of the Ngandong Homo erectus beds has prevented us from accurately assessing the relationship of these early humans to other human species," said Zonneveld, professor in the University of Alberta's Department of Earth and Atmospheric Sciences. "It is also intriguing that these dates indicate that Homo erectus overlapped temporally with one or more other human species."

The fossils are part of a mass death event that occurred as a result of a change in climate. Approximately 130,000 years ago, Indonesia's climate shifted from dry grasslands to tropical rainforest, and the Homo erectus species could not adapt. It is here that they went extinct. According to the study, the bone bed was formed when the remains were washed into the river and deposited downstream.

"This was an exciting project to be involved in. I was honored to be able to contribute to analyses of the fauna associated with Homo erectus at Ngandong," added Zonneveld.

The research paper was published in Nature.

Source: University Of Alberta [December 19, 2019]

* This article was originally published here

Ardestie Iron Age Earth House, Angus, Scotland, 22.12.19.

Ardestie Iron Age Earth House, Angus, Scotland, 22.12.19.

* This article was originally published here

Amazon forest regrowth much slower than previously thought

The regrowth of Amazonian forests following deforestation can happen much slower than previously thought, a new study shows.

Amazon forest regrowth much slower than previously thought
Secondary forests are increasingly fragmented, and isolated from remaining primary forests
[Credit: Marizilda Cruppe/Rede Amazonia Sustentavel]
The findings could have significant impacts for climate change predictions as the ability of secondary forests to soak up carbon from the atmosphere may have been over-estimated.

The study, which monitored forest regrowth over two decades, shows that climate change, and the wider loss of forests, could be hampering regrowth in the Amazon.

By taking large amounts of carbon from the atmosphere, forests regrowing after clear-felling—commonly called secondary forests—have been thought an important tool in combatting human-caused climate change.

However, the study by a group of Brazilian and British researchers shows that even after 60 years of regrowth, the studied secondary forests held only 40% of the carbon in forests that had not been disturbed by humans. If current trends continue, it will take well over a century for the forests to fully recover, meaning their ability to help fight climate change may have been vastly overestimated.

Amazon forest regrowth much slower than previously thought
Scientist collecting leaves in a secondary forest in Brazil
[Credit: Fernando Elias/Rede Amazonia Sustentavel]
The study, published in the journal Ecology, also shows that secondary forests take less carbon from the atmosphere during droughts. Yet, climate change is increasing the number of drought-years in the Amazon.

First author Fernando Elias from the Federal University of Para explained: "The region we studied in the Amazon has seen an increase in temperature of 0.1 C per decade, and tree growth was lower during periods of drought. With predictions of more drought in the future, we must be cautious about the ability of secondary forests to mitigate climate change. Our results underline the need for international agreements that minimise the impacts of climate change."

Beyond helping fight climate change, secondary forests can also provide important habitat for threatened species. However, the researchers found that biodiversity levels in the secondary forests were only 56% of those seen local undisturbed forests, with no increase in species diversity during the 20 years of monitoring.

Many nations have made large reforestation pledges in recent years, and Brazil committed to restoring 12 million ha of forest under the Paris climate agreement. Taken together, these results suggest that these large forest restoration pledges need to accompanied by firmer action against deforestation of primary forests, and careful consideration about where and how to reforest.

Amazon forest regrowth much slower than previously thought
A subplot within the secondary forest showing the very open canopy and small stature
of the forest after 50 years [Credit: Fernando Elias/Rede Amazonia Sustentavel]
The research was undertaken in the Braganca, Brazil, the oldest deforestation frontier region in the Amazon that has lost almost all of its original forest cover.

Biologist Joice Ferreira, a researcher at the Brazilian Agricultural Research Corporation, said: "Our study shows that in heavily deforested areas, forest recovery needs additional support and investment to overcome the lack of seed sources and seed-dispersing animals. This is different from other areas we have studied where historic deforestation is much lower and secondary forests recover much faster without any human intervention."

Jos Barlow, Professor of Conservation Science at Lancaster University in the United Kingdom, points out the need for more long-term studies. He said: "Secondary forests are increasingly widespread in the Amazon, and their climate change mitigation potential makes them of global importance. More long-term studies like ours are needed to better understand secondary forest resilience and to target restoration to the areas that will do most to combat climate change and preserve biodiversity."

Source: Lancaster University [December 19, 2019]

* This article was originally published here

2019 December 25 An Annular Solar Eclipse over New Mexico Image...

2019 December 25

An Annular Solar Eclipse over New Mexico
Image Credit & Copyright: Colleen Pinski

Explanation: What is this person doing? In 2012 an annular eclipse of the Sun was visible over a narrow path that crossed the northern Pacific Ocean and several western US states. In an annular solar eclipse, the Moon is too far from the Earth to block out the entire Sun, leaving the Sun peeking out over the Moon’s disk in a ring of fire. To capture this unusual solar event, an industrious photographer drove from Arizona to New Mexico to find just the right vista. After setting up and just as the eclipsed Sun was setting over a ridge about 0.5 kilometers away, a person unknowingly walked right into the shot. Although grateful for the unexpected human element, the photographer never learned the identity of the silhouetted interloper. It appears likely, though, that the person is holding a circular device that would enable them to get their own view of the eclipse. The shot was taken at sunset on 2012 May 20 at 7:36 pm local time from a park near Albuquerque, New Mexico, USA. Tomorrow another annular solar eclipse will become visible, this time along a thin path starting in Saudi Arabia and going through southern India, Singapore, and Guam. However, almost all of Asia with a clear sky will be able to see, tomorrow, at the least, a partial solar eclipse.

∞ Source: apod.nasa.gov/apod/ap191225.html

* This article was originally published here

How genetics and social games drive evolution of mating systems in mammals

Traditional explanations for why some animals are monogamous and others are promiscuous or polygamous have focused on how the distribution and defensibility of resources (such as food, nest sites, or mates) determine whether, for example, one male can attract and defend multiple females.

How genetics and social games drive evolution of mating systems in mammals
A thirteen-lined ground squirrel (Ictidomys tridecemlineatus) at the Pawnee National Grassland in northeastern
Colorado. Species in the squirrel family are likely to have two or three alternative mating strategies
(polygynous, monogamous, and sneaker) [Credit: Alexis Chaine]
A new model for the evolution of mating systems focuses instead on social interactions driven by genetically determined behaviors, and how competition among different behavioral strategies plays out, regardless of external factors such as defensible resources. In this model, social interactions can drive evolutionary transitions from one mating system to another, and can even drive a population to split into two separate species with different mating systems.

The model is based on three fundamental behavioral strategies: aggression, cooperation, and deception. The conflict between competitive and cooperative social behaviors drives the evolution of the mating systems. In a paper published in American Naturalist, researchers compared the predictions generated by this model with published data on the mating behavior of 288 species of rodents.

"By and large, everything in our predictions seems to be borne out in rodents," said first author Barry Sinervo, professor of ecology and evolutionary biology at the University of California, Santa Cruz. "Our model is a universal equation of sorts for mating systems."

The evolutionary story that emerges from the study goes something like this: An ancestral population of rodents is promiscuous in its mating behavior. Genetic variation within the population results in individuals with distinctive behaviors. Some males are highly aggressive, defend large territories, and mate with as many females as they can. Others are not territorial, but sneak onto the territories of other males for surreptitious mating opportunities. And some are monogamous and defend small territories, cooperating with neighboring males at territorial boundaries.

These three types can coexist, but any imbalance in the relative advantages of different strategies can lead to the elimination of some behaviors and an evolutionary transition to a species that is, for example, entirely monogamous or entirely polygamous. The cooperative behavior of monogamous males, for example, can include paternal care for the young and the ability recognize and affiliate with other cooperative males, making them stronger in the competition with other strategies.

"They are able to find each other and form colonies, and the bigger the colonies get the stronger they are against the barbarians at the gate. Then they split off from the rest of the population as a separate monogamous species," Sinervo said.

This may sound like little more than storytelling, but in fact it emerges from a set of mathematical equations based on game theory and population genetics, and it is supported by extensive research in animal behavior and genetics.

The new paper builds on Sinervo's decades-long research on mating behaviors in California's side-blotched lizards. He showed that three throat colors correspond with different behaviors in the male lizards: blue-throated monogamous males form partnerships and cooperate to protect their territories and their mates; orange-throated males are highly aggressive and usurp territories and mates from other lizards; and yellow-throated males sneak into the territories of other males to mate.

How genetics and social games drive evolution of mating systems in mammals
A portion of the phylogenetic tree of the squirrel family (Sciuridae) illustrates how promiscuous ancestral
species (black dots) gave rise to both monogamous species (blue dots) and polygynous species (red dots).
Marmots (genus Marmota), for example, are mostly monogamous, although there are a couple of
polygynous species. Ground squirrels in the genus Spermophilus include promiscuous,
polygynous, and monogamous species [Credit: Sinervo et al., 2019]
The competition between these strategies takes the form of a rock-paper-scissors game in which orange aggressors defeat blue cooperators, which defeat yellow sneakers, which defeat orange aggressors. Thus, no single type can dominate the population, and the abundance of each rises and falls in cycles. In 2007, Sinervo and his collaborators discovered the same dynamic in the distantly related European common lizard.

"That was when I started thinking that the same thing could be happening in mammals," Sinervo said.

In the new paper, Sinervo and two of his longtime collaborators--Alexis Chaine at the National Center for Scientific Research (CNRS) in Moulis, France, and Donald Miles at CNRS and Ohio University--generalized the rock-paper-scissors system and extended it to include additional behaviors such as paternal care for offspring (linked to monogamy). They focused on male strategies to simplify the analysis. Sinervo has documented corresponding female strategies in side-blotched lizards and is currently working to incorporate female strategies into the general model.

The three male behavioral strategies represented in the model are: - Polygyny, characterized by aggression to maintain large territories overlapping with several females, but without paternal care for the offspring, as seen in polygamous mating systems where one male mates with multiple females; - Monogamy, involving lower aggression and smaller territories, with cooperation at territorial boundaries and investment in paternal care; and - Sneak, a non-territorial strategy with no paternal care, resulting in sneaking behavior in otherwise territorial systems.

Using a computer to run a mathematical model of these strategies, the researchers simulated the evolution of mating systems over 1,000 generations, varying the strength of different parameters in each simulation. At the start of the simulations, the genes that determine the different strategies were assumed to be equally abundant in the population.

The results of the simulations revealed four evolutionarily stable outcomes determined by the interactions and payoffs (in terms of reproductive success) of the different behavioral strategies. Which stable outcome emerges depends on how much of an advantage each behavior provides.

One of the key factors influencing the effectiveness of a given strategy is a male's ability to recognize which behavioral group other males belong to and choose a neighborhood to settle in where his own strategy will have a competitive advantage. Cooperative, monogamous males need to recognize and affiliate with other cooperative males, whereas aggressive, polygynous males want to avoid other aggressive males and find cooperative males whose territories they can take over.

"It all depends on how good you are at finding the right neighborhood, or how good you are at cooperation and paternal care. By varying these parameters in the model, we were able to find the four different evolutionarily stable states," Sinervo said.

One stable outcome is the rock-paper-scissors dynamic documented in lizards, with the coexistence of all three male strategies. Another stable outcome is the coexistence of polygyny and sneak.

There are two stable outcomes in which only one strategy survives, either polygyny or monogamy. A mix of polygyny and monogamy is rare and unstable, eventually leading to a pure system of one or the other.

How genetics and social games drive evolution of mating systems in mammals
An alpine marmot (Marmota marmota) from Lac d'Anglas, Pyrenees, France. The alpine marmot is a
monogamous species in a largely monogamous lineage, which includes many other monogamous
 species as well as polygynous species. The evolution of monogamy is tightly associated
with paternal care for the offspring [Credit: Barry Sinervo]
Turning to the empirical data, the researchers found evidence in studies of rodent behavior and territoriality of the mating systems and behavioral strategies described in the model. There is even a type of mole rat found in southern Africa that exhibits the rock-paper-scissors combo of all three male strategies that Sinervo discovered in lizards. He noted that, whereas mutual recognition of male strategies is based on throat colors in the lizards, in mammals it is more likely to be mediated by smells. "It's there, but we don't see it. We only saw it in lizards because of their bright colors," he said.

The researchers analyzed the phylogenetic tree of rodents (representing the evolutionary relationships among rodent species) and found the same patterns they had seen in the simulations. Species at the base of the phylogenetic tree, closer to the common ancestor of all rodents, tend to be promiscuous, with multiple mating strategies. Polygyny and monogamy very rarely occur together, but they frequently appear in sister species, suggesting they diverged from an ancestral population of mixed strategies.

The model showed that evolutionary transitions in mating systems are largely driven by increases in the benefits of monogamous behaviors. In rodents, monogamy is the most common evolutionary transition from a promiscuous ancestor, and more rodents are monogamous than polygynous. In the simulations, pure polygyny is a relatively uncommon outcome. "Polygyny is readily invaded by the sneak strategy," Sinervo explained.

Paternal care for the offspring is found in all monogamous species, supporting a key assumption linking paternal care to the evolution of monogamy.

"Promiscuity is very common, and can involve two or three different strategies. But the neat thing is that cooperation and monogamy are far more common than anyone realized," Sinervo said. "The frequency of monogamy in rodents is about 26 percent, much higher than for mammals in general and similar to primates."

The model assumes that these behavioral strategies are genetically based. Evidence in support of this includes research on the role of the hormone vasopressin (and the related hormone oxytocin) in complex social behaviors in numerous species, including rodents and humans. In the monogamous prairie voles, for example, vasopressin has been linked to pair bonding, mate guarding, and paternal care. In some rodent lineages, evolutionary transitions between monogamy and polygyny have been linked to a mutation in a vasopressin receptor gene.

The effects of the genes underlying monogamous behaviors may even drive the evolution of more advanced forms of sociality. Highly social species of rodents--such as mole rats, some of which live in colonies in which only one pair reproduces--originate from monogamous lineages.

Sinervo and his coauthors are not claiming that resources and other external ecological factors have no role in the evolution of mating systems. But the genetic model gives predictions that are consistent with the rodent data and can explain cases where a species' mating system does not match its resource ecology.

The authors also acknowledged that animal behavior can be very flexible and is not entirely determined by genetics. This is especially true in humans, whose behavior is so strongly influenced by cultural and environmental factors. In terms of mating systems, our species can be described as promiscuous, but with very high rates of monogamy. Sinervo said he sees a connection between monogamy and the deeply cooperative social behaviors that are at the core of the human condition.

"We can see analogues for human behavior in other animals, but there's really nothing else like humans," Sinervo said. "There are 'kneejerk' behavioral impulses in us that are not far from rodents, but our cultural and social complexity makes us very different from most mammals."

Source: University of California, Santa Cruz [December 19, 2019]

* This article was originally published here

Midmar Kirk Prehistoric Recumbent Stone Circle, Aberdeenshire, Scotland, 20.12.19.

Midmar Kirk Prehistoric Recumbent Stone Circle, Aberdeenshire, Scotland, 20.12.19.

* This article was originally published here

Time-to-death of Roman emperors followed distinct pattern

Roman emperors faced a high risk of violent death in their first year of rule, but the risk slowly declined over the next seven years, according to an article published in the open access journal Palgrave Communications. When statistically modelled, the length of time from the beginning of their reign until their death followed a set pattern, similar to that seen in reliability engineering, interdisciplinary research by Dr. Joseph Saleh, an Aerospace Engineer from the Georgia Institute of Technology, US suggests.

Time-to-death of Roman emperors followed distinct pattern
Credit: Shutterstock
Historical records show that of 69 rulers of the unified Roman Empire, 43 (62%) suffered violent deaths either by assassination, suicide or during combat. Historical accounts typically examine each death as a single, random event alongside individual contributing factors such as allegiances and wealth. It is not known whether there were any common, underlying patterns to how long each emperor's reign lasted before they died.

By applying statistical methods frequently used to test the reliability of components in engineering, Dr. Joseph Saleh modelled the typical length of time between the beginning of an emperor's reign and their subsequent death. The author found parallels between the seemingly random failures of components in engineering and the seemingly random deaths of emperors.

Dr. Saleh said: "In engineering, the reliability of a component or process is defined as the probability that it is still operational at a given time. The time it takes for a component or process to fail is referred to as its time-to-failure and this shows similarities to the time-to-violent-death of Roman emperors."

Dr. Saleh found that Roman emperors faced a high risk of violent death during their first year of reign, a pattern also seen when engineering components fail early, often as a result of a failure to function as intended or, in the case of an emperor, meet the demands of their role. The risk of death stabilised by the eighth year but increased again after 12 years of rule, a pattern similar to the failure of components because of fatigue, corrosion or wear-out. When data points were aligned on a graph, the failure rate of Roman emperors displayed a bathtub-like curve, a model widely seen with mechanical and electrical components.

Dr. Saleh said: "It's interesting that a seemingly random process as unconventional and perilous as the violent death of a Roman emperor—over a four-century period and across a vastly changed world—appears to have a systematic structure remarkably well captured by a statistical model widely used in engineering. Although they may appear as random events when taken singularly, these results indicate that there may have been underlying processes governing the length of each rule until death."

Data was obtained from the De Imperatoribus Romanis, a peer-reviewed online encyclopedia of Roman emperors. The author cautions that the limitations of the data should be acknowledged, as sources of ancient history are often inconsistent and the exact causes of death may differ between accounts. Further studies could explore why emperors repeatedly met a violent end and whether other historical events may be analysed in this way.

Source: Springer [December 22, 2019]

* This article was originally published here

And then came the morning mist… Eslie the Greater Recumbent Stone Circle and Cairn,...

And then came the morning mist… Eslie the Greater Recumbent Stone Circle and Cairn, Aberdeenshire, Scotland, 22.12.19.

* This article was originally published here

Ancient secret of stone circles revealed

New evidence of a massive lightning strike at the center of a hidden stone circle in the Outer Hebrides may help shed light on why these monuments were created thousands of years ago.

Ancient secret of stone circles revealed
The ancient Calanais Stones on Scotland’s Isle of Lewis were constructed
with astrological phenomena in mind [Credit: Getty]
The Calanais Virtual Reconstruction Project, a joint venture led by the University of St Andrews with the Urras nan Tursachan and the University of Bradford, with funding from Highlands and Islands Enterprise, has uncovered a potential link between ancient stone circles and the forces of nature.

While studying prehistoric Tursachan Chalanais, the main stone circle at Calanais on the Isle of Lewis, the project team surveyed nearby satellite sites to reveal evidence for lost circles buried beneath the peat.

One rarely-visited site surveyed, known as Site XI or Airigh na Beinne Bige, now consists of a single standing stone on an exposed hillside overlooking the great circle.

Geophysics revealed that not only was the stone originally part of a circle of standing stones, but also that there was a massive, star-shaped magnetic anomaly in the center—either the result of a single, large lighting strike or many smaller strikes on the same spot.

Project leader Dr. Richard Bates, of the School of Earth and Environmental Sciences at the University of St Andrews, said: "Such clear evidence for lightning strikes is extremely rare in the UK and the association with this stone circle is unlikely to be coincidental. Whether the lightning at Site XI focused on a tree or rock which is no longer there, or the monument itself attracted strikes, is uncertain. However, this remarkable evidence suggests that the forces of nature could have been intimately linked with everyday life and beliefs of the early farming communities on the island."

The researchers were also able to virtually recreate another nearby circle, with the help of the Smart History team based in the University of St Andrews School of Computer Science, which had been lost with its stones either buried or lying flat.

Known as Na Dromannan, careful scanning of the stones allowed a full 3-D model to be built allowing the passage of the sun and moon around this circle to be tracked for the first time in four millennia.

Dr. Bates added: "For the first time in over 4000 years the stones can now be seen and 'virtually' walked around. Everyone will be able to visit this remote site and get a real sense of what it was like just after it had been constructed. We have only just scratched the surface of this landscape and already we can get a feel for what might be buried out there waiting for discovery."

The team hopes to return to Lewis next year to undertake further surveys both on land, and in the waters, around the Tursachan at Calanais, where the old landscape has been flooded by rising sea levels.

Dr. Chris Gaffney, of the School of Archaeological and Forensic Sciences at the University of Bradford, said: "Evidence for such strikes within archaeological surveys is very rare and our work at Site XI demonstrates that without detailed scientific survey we would never be able to identify such events."

Dr. Tim Raub, of the School of Earth and Environmental Sciences at the University of St Andrews, added: "This evidence is rare because lighting strikes are conducted along the top 'skin' of the Earth's surface. The clarity of the strike suggests we are looking at events before the peat enveloped the site, more than 3000 years ago."

Professor Vincent Gaffney of the School Archaeological Sciences at the University of Bradford, said: "The dramatic results of survey on Lewis demonstrate that we have to understand the landscapes that surrounds these ritual monuments and the role that nature and natural events, including lightning, played in creating the rituals and beliefs of people many thousands of years ago."

Dr. Alison Sheridan, Director of Urras nan Tursachan, the Calanais based charitable trust that partnered this research, said: "This is a thrilling discovery that helps us get inside the minds of the people who built the stone circles at and around Calanais. There is much still to find out about the so-called 'satellite' circles of Neolithic Calanais and this provides an important first step. The modelling of Na Dromannan also helps us investigate whether this circle was astronomically aligned."

The findings are published in the journal Remote Sensing.

Source: University of St Andrews [December 23, 2019]

* This article was originally published here

Monkeys in my Backyard - Again: Cabo Rojo, Puerto Rico

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Channel: Frankie Lucena  

The Fish and Wildlife service has trapped and killed many of them so to see them hanging around in my backyard on Christmas Eve was a real treat. The dogs barking didn't seem to phase them at all.

Video length: 3:43
Category: Science & Technology

Loch Kinord Iron Age Hut Foundations Settlement 2, Loch Kinord, Cairngorms, 20.12.19.

Loch Kinord Iron Age Hut Foundations Settlement 2, Loch Kinord, Cairngorms, 20.12.19.

* This article was originally published here


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