So, up until about a month ago, I was the longtime member of a forum on the internet here, that was more or less a 'conspiracy' site. In January, this site that I had been a member of since around 2010 or so, had just gone through an 'upgrade' that left many members a bit bewildered and upset at these changes, I was among them. While I didn't do anything outright savage to earn a permanent banishment from this forum, I do admit, that I was rocking the boat. A longtime 'friend' that I and a few other longtime members had made had been made a 'moderator' of the forum and though he's a dunkard and that was kind of his redeeming quality as a friend, he beset upon us longtime members as dogs and threatened us (myself and some other friends) because we were vocal about certain changes and certain new ways of doing things. This moderator had suspended my account multiple times for small infractions, "insurrection" I believe was the word he had used. But since my last suspension, I had been pretty 'good', I hadn't been rockin' the boat as it were. But one day went to log in and found myself with a permanent ban.
This forum was a great home for me as i posted a lot of great articles there, as I had done on Facebook for sometime and long, long before Facebook had my own websites, one of which was 'Zero's World Order' and it was where I had posted also a lot of great articles.
Seeing that I no longer have a venue to post those articles and I had more or less began this Blog 'There's No Way Back From Here' to house such articles... Let it begin ( I still will make the same kind of posts that I have been over the last several months as well).....
Enjoy!
Humans Thrived In South Africa Through The Toba Super-Volcanic Eruption About 74,000 Years Ago
The glass shards at Pinnacle Point were carried nearly 9000 km from the source in Indonesia. Credit: Erich Fisher.
(phys.org) - - Imagine a year in Africa that summer never arrives. The sky takes on a gray hue during the day and glows red at night. Flowers do not bloom. Trees die in the winter. Large mammals like antelope become thin, starve and provide little fat to the predators (carnivores and human hunters) that depend on them. Then, this same disheartening cycle repeats itself, year after year. This is a picture of life on earth after the eruption of the super-volcano, Mount Toba in Indonesia, about 74,000 years ago. In a paper published this week in Nature, scientists show that early modern humans on the coast of South Africa thrived through this event.
An eruption a hundred times smaller than Mount Toba - that of Mount Tambora, also in Indonesia, in 1815 - is thought to have been responsible for a year without summer in 1816. The impact on the human population was dire - crop failures in Eurasia and North America, famine and mass migrations. The effect of Mount Toba, a super-volcano that dwarfs even the massive Yellowstone eruptions of the deeper past, would have had a much larger, and longer-felt, impact on people around the globe.
The scale of the ash-fall alone attests to the magnitude of the environmental disaster. Huge quantities of aerosols injected high into the atmosphere would have severely diminished sunlight - with estimates ranging from a 25 to 90 percent reduction in light. Under these conditions, plant die-off is predictable, and there is evidence of significant drying, wildfires and plant community change in East Africa just after the Toba eruption.
If Mount Tambora created such devastation over a full year - and Tambora was a hiccup compared to Toba - we can imagine a worldwide catastrophe with the Toba eruption, an event lasting several years and pushing life to the brink of extinctions.
In Indonesia, the source of the destruction would have been evident to terrified witnesses - just before they died. However, as a family of hunter-gatherers in Africa 74,000 years ago, you would have had no clue as to the reason for the sudden and devastating change in the weather. Famine sets in and the very young and old die. Your social groups are devastated, and your society is on the brink of collapse.
The effect of the Toba eruption would have certainly impacted some ecosystems more than others, possibly creating areas - called refugia - in which some human groups did better than others throughout the event. Whether or not your group lived in such a refuge would have largely depended on the type of resources available. Coastal resources, like shellfish, are highly nutritious and less susceptible to the eruption than the plants and animals of inland areas.
When the column of fire, smoke and debris blasted out the top of Mount Toba, it spewed rock, gas and tiny microscopic pieces (cryptotephra) of glass that, under a microscope, have a characteristic hook shape produced when the glass fractures across a bubble. Pumped into the atmosphere, these invisible fragments spread across the world.
Panagiotis (Takis) Karkanas, director of the Malcolm H. Wiener Laboratory for Archaeological Science, American School of Classical Studies, Greece, saw a single shard of this explosion under a microscope in a slice of archaeological sediment encased in resin.
"It was one shard particle out of millions of other mineral particles that I was investigating. But it was there, and it couldn't be anything else," says Karkanas.
The shard came from an archaeological site in a rockshelter called Pinnacle Point 5-6, on the south coast of South Africa near the town of Mossel Bay. The sediments dated to about 74,000 years ago.
The photo shows a volcanic glass shard erupted 74,000 years ago from the Toba volcano in Indonesia found at an archaeological site nearly 9000 km away at Vleesbaai, South Africa. Credit: Racheal Johnsen.
"Takis and I had discussed the potential of finding the Toba shards in the sediments of our archaeological site, and with his eagle eye, he found one," explains Curtis W. Marean, project director of the Pinnacle Point excavations. Marean is the associate director of the Institute of Human Origins at Arizona State University and honorary professor at the Centre for Coastal Palaeoscience at Nelson Mandela University, South Africa.
Marean showed the shard image to Eugene Smith, a volcanologist with the University of Nevada at Las Vegas, and Smith confirmed it was a volcanic shard.
"The Pinnacle Point study brought me back to the study of glass shards from my master's thesis 40 years earlier," says Smith.
Early in the study, the team brought in expert cryptotephra scientist Christine Lane who trained graduate student Amber Ciravolo in the needed techniques. Racheal Johnsen later joined Ciravalo as lab manager and developed new techniques.
From scratch, with National Science Foundation support, they developed the Cryptotephra Laboratory for Archaeological and Geological Research, which is now involved in projects not only in Africa, but in Italy, Nevada and Utah.
Encased in that shard of volcanic glass is a distinct chemical signature, a fingerprint that scientists can use to trace to the killer eruption. In their paper in Nature, the team describes finding these shards in two archaeological sites in coastal South Africa, tracing those shards to Toba through chemical fingerprinting and documenting a continuous human occupation across the volcanic event.
"Many previous studies have tried to test the hypothesis that Toba devastated human populations," Marean notes. "But they have failed because they have been unable to present definitive evidence linking a human occupation to the exact moment of the event."
Most studies have looked at whether or not Toba caused environmental change. It did, but such studies lack the archaeological data needed to show how Toba affected humans.
The Pinnacle Point team has been at the forefront of development and application of highly advanced archaeological techniques. They measure everything on site to millimetric accuracy with a "total station," a laser-measurement device integrated to handheld computers for precise and error-free recording.
Naomi Cleghorn with the University of Texas at Arlington, recorded the Pinnacle Point samples as they were removed.
The research team has been excavating caves at Pinnacle Point, South Africa, for nearly 20 years. Glass shards from Mount Toba were discovered at the PP5-6 location. Credit: Erich Fisher.
Cleghorn explains, "We collected a long column of samples - digging out a small amount of sediment from the wall of our previous excavation. Each time we collected a sample, we shot its position with the total station."
The sample locations from the total station and thousands of other points representing stone artifacts, bone, and other cultural remains of the ancient inhabitants were used to build digital models of the site.
"These models tell us a lot about how people lived at the site and how their activities changed through time," say Erich Fisher, associate research scientist with the Institute of Human Origins, who built the detailed photorealistic 3D models from the data. "What we found was that during and after the time of the Toba eruption people lived at the site continuously, and there was no evidence that it impacted their daily lives."
In addition to understanding how Toba affected humans in this region, the study has other important implications for archaeological dating techniques. Archaeological dates at these age ranges are imprecise - 10 percent (or 1000s of years) error is typical. Toba ash-fall, however, was a very quick event that has been precisely dated. The time of shard deposition was likely about two weeks in duration - instantaneous in geological terms.
"We found the shards at two sites," explains Marean. "The Pinnacle Point rockshelter (where people lived, ate, worked and slept) and an open air site about 10 kilometers away called Vleesbaai. This latter site is where a group of people, possibly members of the same group as those at Pinnacle Point, sat in a small circle and made stone tools. Finding the shards at both sites allows us to link these two records at almost the same moment in time."
Not only that, but the shard location allows the scientists to provide an independent test of the age of the site estimated by other techniques. People lived at the Pinnacle Point 5-6 site from 90,000 to 50,000 years ago. Zenobia Jacobs with the University of Wollongong, Australia, used optically stimulated luminescence (OSL) to date 90 samples and develop a model of the age of all the layers. OSL dates the last time individual sand grains were exposed to light.
"There has been some debate over the accuracy of OSL dating, but Jacobs' age model dated the layers where we found the Toba shards to about 74,000 years ago - right on the money," says Marean. This lends very strong support to Jacobs' cutting-edge approach to OSL dating, which she has applied to sites across southern Africa and the world.
"OSL dating is the workhorse method for construction of timelines for a large part of our own history. Testing whether the clock ticks at the correct rate is important. So getting this degree of confirmation is pleasing," says Jacobs.
In the 1990s, scientists began arguing that this eruption of Mount Toba, the most powerful in the last two million years, caused a long-lived volcanic winter that may have devastated the ecosystems of the world and caused widespread population crashes, perhaps even a near-extinction event in our own lineage, a so-called bottleneck.
This study shows that along the food-rich coastline of southern Africa, people thrived through this mega-eruption, perhaps because of the uniquely rich food regime on this coastline. Now other research teams can take the new and advanced methods developed in this study and apply them to their sites elsewhere in Africa so researchers can see if this was the only population that made it through these devastating times.
Read more at: https://phys.org/news/2018-03-humans-south-africa-toba-super-volcanic.html#jCp
Arrested Development: Hubble Finds Relic Galaxy Close To Home
[Upper right] --This is a Hubble Space Telescope image of galaxy NGC 1277. The galaxy is unique in that it is considered a relic of what galaxies were like in the early universe. The galaxy is composed exclusively of aging stars that were born 10 billion years ago. But unlike other galaxies in the local universe, it has not undergone any further star formation. Astronomers nickname such galaxies as "red and dead," because the stars are aging and there aren't any successive generations of younger stars. The telltale sign of the galaxy's "arrested development" lies in the ancient globular clusters that swarm around it. The reddish clusters are the strongest evidence that the galaxy went out of the star-making business long ago. Otherwise, there would be a lot of blue globular star clusters, which are largely absent. The lack of blue clusters suggests that NGC 1277 never grew further by gobbling up surrounding galaxies. [Background image] -- The galaxy lives near the center of the Perseus cluster of over 1,000 galaxies, located 240 million light-years away from Earth. NGC 1277 is moving so fast through the cluster, at 2 million miles per hour, that it cannot merge with other galaxies to collect stars or pull in gas to fuel star formation. In addition, near the galaxy cluster center, intergalactic gas is so hot it cannot cool to condense and form stars. Credit: NASA, ESA, M. Beasley (Instituto de Astrofísica de Canarias), and P. Kehusmaa
(Phys.org) - - Astronomers have put NASA's Hubble Space Telescope on an Indiana Jones-type quest to uncover an ancient "relic galaxy" in our own cosmic backyard.
The very rare and odd assemblage of stars has remained essentially unchanged for the past 10 billion years. This wayward stellar island provides valuable new insights into the origin and evolution of galaxies billions of years ago.
The galaxy, NGC 1277, started its life with a bang long ago, ferociously churning out stars 1,000 times faster than seen in our own Milky Way today. But it abruptly went quiescent as the baby boomer stars aged and grew ever redder.
The findings are being published online in the March 12 issue of the science journal Nature.
Though Hubble has seen such "red and dead" galaxies in the early universe, one has never been conclusively found nearby. Where the early galaxies are so distant, they are just red dots in Hubble deep-sky images. NGC 1277 offers a unique opportunity to see one up close and personal. "We can explore such original galaxies in full detail and probe the conditions of the early universe," said Ignacio Trujillo, of the Instituto de Astrofisica de Canarias at the University of La Laguna, Spain.
The researchers learned that the relic galaxy has twice as many stars as our Milky Way, but physically it is as small as one quarter the size of our galaxy. Essentially, NGC 1277 is in a state of "arrested development." Perhaps like all galaxies it started out as a compact object but failed to accrete more material to grow in size to form a magnificent pinwheel-shaped galaxy.
Approximately one in 1,000 massive galaxies is expected to be a relic (or oddball) galaxy, like NGC 1277, researchers say. They were not surprised to find it, but simply consider that it was in the right place at the right time to evolve - or rather not evolve - the way it did.
The telltale sign of the galaxy's state lies in the ancient globular clusters of stars that swarm around it. Massive galaxies tend to have both metal-poor (appearing blue) and metal-rich (appearing red) globular clusters. The red clusters are believed to form as the galaxy forms, while the blue clusters are later brought in as smaller satellites are swallowed by the central galaxy. However, NGC 1277 is almost entirely lacking in blue globular clusters. "I've been studying globular clusters in galaxies for a long time, and this is the first time I've ever seen this," said Michael Beasley, also of the Instituto de Astrofisica de Canarias.
The red clusters are the strongest evidence that the galaxy went out of the star-making business long ago. However, the lack of blue clusters suggests that NGC 1277 never grew further by gobbling up surrounding galaxies.
By contrast, our Milky Way contains approximately 180 blue and red globular clusters. This is due partly to the fact that our Milky Way continues cannibalizing galaxies that swing too close by in our Local Group of a few dozen small galaxies.
It's a markedly different environment for NGC 1277. The galaxy lives near the center of the Perseus cluster of over 1,000 galaxies, located 240 million light-years away. But NGC 1277 is moving so fast through the cluster, at 2 million miles per hour, that it cannot merge with other galaxies to collect stars or pull in gas to fuel star formation. In addition, near the galaxy cluster center, intergalactic gas is so hot it cannot cool to condense and form stars.
The team started looking for "arrested development" galaxies in the Sloan Digital Sky Survey and found 50 candidate massive compact galaxies. Using a similar technique, but out of a different sample, NGC 1277 was identified as unique in that it has a central black hole that is much more massive than it should be for a galaxy of that size. This reinforces the scenario that the supermassive black hole and dense hub of the galaxy grew simultaneously, but the galaxy's stellar population stopped growing and expanding because it was starved of outside material.
"I didn't believe the ancient galaxy hypothesis initially, but finally I was surprised because it's not that common to find what you predict in astronomy," Beasley added. "Typically, the universe always comes up with more surprises that you can think about."
The team has 10 other candidate galaxies to look at with varying degrees of "arrested development."
The upcoming NASA James Webb Space Telescope (scheduled for launch in 2019) will allow astronomers to measure the motions of the globular clusters in NGC 1277. This will provide the first opportunity to measure how much dark matter the primordial galaxy contains.
Read more at: https://phys.org/news/2018-03-hubble-relic-galaxy-home.html#jCp
Riding The (Quantum Magnetic) Wave—Next-Generation Electronics One Leap Closer To Reality
V(TCNE)x thin film with an inverse spin Hall effect detector. Credit: Joel Miller
(phys.org) - - In 1991, University of Utah chemist Joel Miller developed the first magnet with carbon-based, or organic, components that was stable at room temperature. It was a great advance in magnetics, and he's been exploring the applications ever since.
Twenty-five years later, physicists Christoph Boehme and Valy Vardeny demonstrated a method to convert quantum waves into electrical current. They too, knew they'd discovered something important, but didn't know its application.
Now those technologies have come together and could be the first step towards a new generation of faster, more efficient and more flexible electronics.
Working together, Miller, Boehme, Vardeny and their colleagues have shown that an organic-based magnet can carry waves of quantum mechanical magnetization, called magnons, and convert those waves to electrical signals. It's a breakthrough for the field of magnonics (electronic systems that use magnons instead of electrons) because magnons had previously been sent through inorganic materials that are more difficult to handle.
"Going to these organic materials, we have an opportunity to push magnonics into an area that is more controllable than inorganic materials," Miller says. Their results are published today in Nature Materials.
How magnonics works
Before proceeding, let's talk about what a magnon is and how it can be used in electronics. Current electronics use electrons to carry information along wires. Magnons can also conduct information through materials, but instead of being composed of electrons, magnons are waves composed of a quantum property called spin.
Imagine a football stadium, packed full of enthusiastic fans holding up their arms to cheer on their team. Let's say that the direction in which their arms point is their spin orientation. If every fan holds their arms straight up in the air simultaneously, then everyone's spin orientation is the same and they've made, in essence, a magnet.
Now the crowd starts "The Wave," except instead of standing and sitting, one aisle of fans tilts their arms to the right. The next aisle picks up on this change in spin and passes it along to the next row. Before long, this magnet has a spin-based wave coursing around the stadium.
The quantum version of the spin-based wave is a magnon.
"Now you have a way to broadcast information in a material," says physics professor and paper co-author Boehme. "You can think about magnonics like electronics. You have circuitry and when you manage to build digital logic out of this, you can also build computers."
Well, not yet. Although magnons have been known to science for decades, only recently has their potential for building electronics been realized.
Currently, most magnonics researchers are using yttrium iron garnet (YIG) as their wave carrier material. It's expensive and difficult to produce, especially as a thin film or wire. Boehme says he once considered incorporating YIG into one of his instruments and had to give up because the material proved so problematic to handle that particular application.
The researchers from left to right: Joel Miller, Royce Davidson, Hans Malissa, Haoliang Liu and Christoph Boehme. Credit: Eric V. Campbell
Assembling The Team
Boehme and Vardeny, distinguished professor of physics, also study the field of alternatives to electronics called spintronics, of which magnonics is a subfield. In 2016 they showed how to straightforwardly observe the "inverse spin Hall effect," a way to convert spin waves into electrical current.
They began working together with Miller through a National Science Foundation-funded Materials Research Science and Engineering Center (MRSEC) at the University of Utah. In 1991, Miller had produced the first magnetic material using organic, or carbon-based, components. The three decided to test Miller's organic magnet to see if it could be used as an alternative to YIG in magnonics materials. They tested for electron spin resonance (ESR), a measure of how long magnons would last in the material. The narrower the ESR line, the longer-lived the magnons.
The line was very narrow indeed, Vardeny says. "It's a record narrow line."
But working with the organic-based magnet, known as vanadium tetracyanoethylene or V(TCNE)x, still presented some challenges. The material is highly sensitive to oxygen, akin to rare-earth magnets. "If it's freshly made, it'll likely catch fire," Miller says. "It'll lose its magnetism." The team needed to handle the thin films of V(TCNE)x under low-oxygen conditions.
Conducting experiments required a concert of activity, with members of the research team each at their right place at the right time to carry on the next phase of the experiment.
"Count the number of authors on the paper," Boehme says. (There are 14.) "Every time we carried out an experiment, everyone had to stand there and be ready on time to participate in this process." It began with one of Miller's students arriving at 4 a.m. to prepare a precursor material and continued for two to three days continuously as research teams passed the baton of material and data.
Not every experimental run was successful. Early on, the team learned that the copper connector they were using to convert magnons into electricity using the inverse spin Hall effect was reacting with the V(TCNE)x and thus wouldn't work. A switch to platinum contacts in the next run was successful.
Promising Results
In the end, the team reported that they were able to generate stable magnons in organic magnets and convert those spin waves into electrical signals—a major stepping stone. The stability of the magnons in the V(TCNE)x was as good as that in YIG.
The researchers are hopeful that this advance leads to more progress towards magnonics replacing electronics, since magnonic systems could be smaller and faster than current systems with less heat loss and much less energy required. Conventional electronics operate on a scale of volts, Boehme says. Magnons operate on a scale of millivolts, containing around 1,000 times less energy.
The team next hopes to work toward magnonic circuits using V(TCNE)x, and also test other materials. "There are many organic-based magnets," Boehme says. "There's no reason to believe that if you randomly pick one, it's necessarily the best."
It's yet to be seen, though, what the promise of magnonics might bring beyond faster, smaller and more efficient electronics. "We can't anticipate," Miller says, "what we can't anticipate."
Read more at: https://phys.org/news/2018-03-quantum-magnetic-wavenext-generation-electronics-closer.html#jCp
This forum was a great home for me as i posted a lot of great articles there, as I had done on Facebook for sometime and long, long before Facebook had my own websites, one of which was 'Zero's World Order' and it was where I had posted also a lot of great articles.
Seeing that I no longer have a venue to post those articles and I had more or less began this Blog 'There's No Way Back From Here' to house such articles... Let it begin ( I still will make the same kind of posts that I have been over the last several months as well).....
Enjoy!
Humans Thrived In South Africa Through The Toba Super-Volcanic Eruption About 74,000 Years Ago
(phys.org) - - Imagine a year in Africa that summer never arrives. The sky takes on a gray hue during the day and glows red at night. Flowers do not bloom. Trees die in the winter. Large mammals like antelope become thin, starve and provide little fat to the predators (carnivores and human hunters) that depend on them. Then, this same disheartening cycle repeats itself, year after year. This is a picture of life on earth after the eruption of the super-volcano, Mount Toba in Indonesia, about 74,000 years ago. In a paper published this week in Nature, scientists show that early modern humans on the coast of South Africa thrived through this event.
An eruption a hundred times smaller than Mount Toba - that of Mount Tambora, also in Indonesia, in 1815 - is thought to have been responsible for a year without summer in 1816. The impact on the human population was dire - crop failures in Eurasia and North America, famine and mass migrations. The effect of Mount Toba, a super-volcano that dwarfs even the massive Yellowstone eruptions of the deeper past, would have had a much larger, and longer-felt, impact on people around the globe.
The scale of the ash-fall alone attests to the magnitude of the environmental disaster. Huge quantities of aerosols injected high into the atmosphere would have severely diminished sunlight - with estimates ranging from a 25 to 90 percent reduction in light. Under these conditions, plant die-off is predictable, and there is evidence of significant drying, wildfires and plant community change in East Africa just after the Toba eruption.
If Mount Tambora created such devastation over a full year - and Tambora was a hiccup compared to Toba - we can imagine a worldwide catastrophe with the Toba eruption, an event lasting several years and pushing life to the brink of extinctions.
In Indonesia, the source of the destruction would have been evident to terrified witnesses - just before they died. However, as a family of hunter-gatherers in Africa 74,000 years ago, you would have had no clue as to the reason for the sudden and devastating change in the weather. Famine sets in and the very young and old die. Your social groups are devastated, and your society is on the brink of collapse.
The effect of the Toba eruption would have certainly impacted some ecosystems more than others, possibly creating areas - called refugia - in which some human groups did better than others throughout the event. Whether or not your group lived in such a refuge would have largely depended on the type of resources available. Coastal resources, like shellfish, are highly nutritious and less susceptible to the eruption than the plants and animals of inland areas.
When the column of fire, smoke and debris blasted out the top of Mount Toba, it spewed rock, gas and tiny microscopic pieces (cryptotephra) of glass that, under a microscope, have a characteristic hook shape produced when the glass fractures across a bubble. Pumped into the atmosphere, these invisible fragments spread across the world.
Panagiotis (Takis) Karkanas, director of the Malcolm H. Wiener Laboratory for Archaeological Science, American School of Classical Studies, Greece, saw a single shard of this explosion under a microscope in a slice of archaeological sediment encased in resin.
"It was one shard particle out of millions of other mineral particles that I was investigating. But it was there, and it couldn't be anything else," says Karkanas.
The shard came from an archaeological site in a rockshelter called Pinnacle Point 5-6, on the south coast of South Africa near the town of Mossel Bay. The sediments dated to about 74,000 years ago.
"Takis and I had discussed the potential of finding the Toba shards in the sediments of our archaeological site, and with his eagle eye, he found one," explains Curtis W. Marean, project director of the Pinnacle Point excavations. Marean is the associate director of the Institute of Human Origins at Arizona State University and honorary professor at the Centre for Coastal Palaeoscience at Nelson Mandela University, South Africa.
Marean showed the shard image to Eugene Smith, a volcanologist with the University of Nevada at Las Vegas, and Smith confirmed it was a volcanic shard.
"The Pinnacle Point study brought me back to the study of glass shards from my master's thesis 40 years earlier," says Smith.
Early in the study, the team brought in expert cryptotephra scientist Christine Lane who trained graduate student Amber Ciravolo in the needed techniques. Racheal Johnsen later joined Ciravalo as lab manager and developed new techniques.
From scratch, with National Science Foundation support, they developed the Cryptotephra Laboratory for Archaeological and Geological Research, which is now involved in projects not only in Africa, but in Italy, Nevada and Utah.
Encased in that shard of volcanic glass is a distinct chemical signature, a fingerprint that scientists can use to trace to the killer eruption. In their paper in Nature, the team describes finding these shards in two archaeological sites in coastal South Africa, tracing those shards to Toba through chemical fingerprinting and documenting a continuous human occupation across the volcanic event.
"Many previous studies have tried to test the hypothesis that Toba devastated human populations," Marean notes. "But they have failed because they have been unable to present definitive evidence linking a human occupation to the exact moment of the event."
Most studies have looked at whether or not Toba caused environmental change. It did, but such studies lack the archaeological data needed to show how Toba affected humans.
The Pinnacle Point team has been at the forefront of development and application of highly advanced archaeological techniques. They measure everything on site to millimetric accuracy with a "total station," a laser-measurement device integrated to handheld computers for precise and error-free recording.
Naomi Cleghorn with the University of Texas at Arlington, recorded the Pinnacle Point samples as they were removed.
Cleghorn explains, "We collected a long column of samples - digging out a small amount of sediment from the wall of our previous excavation. Each time we collected a sample, we shot its position with the total station."
The sample locations from the total station and thousands of other points representing stone artifacts, bone, and other cultural remains of the ancient inhabitants were used to build digital models of the site.
"These models tell us a lot about how people lived at the site and how their activities changed through time," say Erich Fisher, associate research scientist with the Institute of Human Origins, who built the detailed photorealistic 3D models from the data. "What we found was that during and after the time of the Toba eruption people lived at the site continuously, and there was no evidence that it impacted their daily lives."
In addition to understanding how Toba affected humans in this region, the study has other important implications for archaeological dating techniques. Archaeological dates at these age ranges are imprecise - 10 percent (or 1000s of years) error is typical. Toba ash-fall, however, was a very quick event that has been precisely dated. The time of shard deposition was likely about two weeks in duration - instantaneous in geological terms.
"We found the shards at two sites," explains Marean. "The Pinnacle Point rockshelter (where people lived, ate, worked and slept) and an open air site about 10 kilometers away called Vleesbaai. This latter site is where a group of people, possibly members of the same group as those at Pinnacle Point, sat in a small circle and made stone tools. Finding the shards at both sites allows us to link these two records at almost the same moment in time."
Not only that, but the shard location allows the scientists to provide an independent test of the age of the site estimated by other techniques. People lived at the Pinnacle Point 5-6 site from 90,000 to 50,000 years ago. Zenobia Jacobs with the University of Wollongong, Australia, used optically stimulated luminescence (OSL) to date 90 samples and develop a model of the age of all the layers. OSL dates the last time individual sand grains were exposed to light.
"There has been some debate over the accuracy of OSL dating, but Jacobs' age model dated the layers where we found the Toba shards to about 74,000 years ago - right on the money," says Marean. This lends very strong support to Jacobs' cutting-edge approach to OSL dating, which she has applied to sites across southern Africa and the world.
"OSL dating is the workhorse method for construction of timelines for a large part of our own history. Testing whether the clock ticks at the correct rate is important. So getting this degree of confirmation is pleasing," says Jacobs.
In the 1990s, scientists began arguing that this eruption of Mount Toba, the most powerful in the last two million years, caused a long-lived volcanic winter that may have devastated the ecosystems of the world and caused widespread population crashes, perhaps even a near-extinction event in our own lineage, a so-called bottleneck.
This study shows that along the food-rich coastline of southern Africa, people thrived through this mega-eruption, perhaps because of the uniquely rich food regime on this coastline. Now other research teams can take the new and advanced methods developed in this study and apply them to their sites elsewhere in Africa so researchers can see if this was the only population that made it through these devastating times.
Read more at: https://phys.org/news/2018-03-humans-south-africa-toba-super-volcanic.html#jCp
Arrested Development: Hubble Finds Relic Galaxy Close To Home
[Upper right] --This is a Hubble Space Telescope image of galaxy NGC 1277. The galaxy is unique in that it is considered a relic of what galaxies were like in the early universe. The galaxy is composed exclusively of aging stars that were born 10 billion years ago. But unlike other galaxies in the local universe, it has not undergone any further star formation. Astronomers nickname such galaxies as "red and dead," because the stars are aging and there aren't any successive generations of younger stars. The telltale sign of the galaxy's "arrested development" lies in the ancient globular clusters that swarm around it. The reddish clusters are the strongest evidence that the galaxy went out of the star-making business long ago. Otherwise, there would be a lot of blue globular star clusters, which are largely absent. The lack of blue clusters suggests that NGC 1277 never grew further by gobbling up surrounding galaxies. [Background image] -- The galaxy lives near the center of the Perseus cluster of over 1,000 galaxies, located 240 million light-years away from Earth. NGC 1277 is moving so fast through the cluster, at 2 million miles per hour, that it cannot merge with other galaxies to collect stars or pull in gas to fuel star formation. In addition, near the galaxy cluster center, intergalactic gas is so hot it cannot cool to condense and form stars. Credit: NASA, ESA, M. Beasley (Instituto de Astrofísica de Canarias), and P. Kehusmaa
(Phys.org) - - Astronomers have put NASA's Hubble Space Telescope on an Indiana Jones-type quest to uncover an ancient "relic galaxy" in our own cosmic backyard.
The very rare and odd assemblage of stars has remained essentially unchanged for the past 10 billion years. This wayward stellar island provides valuable new insights into the origin and evolution of galaxies billions of years ago.
The galaxy, NGC 1277, started its life with a bang long ago, ferociously churning out stars 1,000 times faster than seen in our own Milky Way today. But it abruptly went quiescent as the baby boomer stars aged and grew ever redder.
The findings are being published online in the March 12 issue of the science journal Nature.
Though Hubble has seen such "red and dead" galaxies in the early universe, one has never been conclusively found nearby. Where the early galaxies are so distant, they are just red dots in Hubble deep-sky images. NGC 1277 offers a unique opportunity to see one up close and personal. "We can explore such original galaxies in full detail and probe the conditions of the early universe," said Ignacio Trujillo, of the Instituto de Astrofisica de Canarias at the University of La Laguna, Spain.
The researchers learned that the relic galaxy has twice as many stars as our Milky Way, but physically it is as small as one quarter the size of our galaxy. Essentially, NGC 1277 is in a state of "arrested development." Perhaps like all galaxies it started out as a compact object but failed to accrete more material to grow in size to form a magnificent pinwheel-shaped galaxy.
Approximately one in 1,000 massive galaxies is expected to be a relic (or oddball) galaxy, like NGC 1277, researchers say. They were not surprised to find it, but simply consider that it was in the right place at the right time to evolve - or rather not evolve - the way it did.
The telltale sign of the galaxy's state lies in the ancient globular clusters of stars that swarm around it. Massive galaxies tend to have both metal-poor (appearing blue) and metal-rich (appearing red) globular clusters. The red clusters are believed to form as the galaxy forms, while the blue clusters are later brought in as smaller satellites are swallowed by the central galaxy. However, NGC 1277 is almost entirely lacking in blue globular clusters. "I've been studying globular clusters in galaxies for a long time, and this is the first time I've ever seen this," said Michael Beasley, also of the Instituto de Astrofisica de Canarias.
The red clusters are the strongest evidence that the galaxy went out of the star-making business long ago. However, the lack of blue clusters suggests that NGC 1277 never grew further by gobbling up surrounding galaxies.
By contrast, our Milky Way contains approximately 180 blue and red globular clusters. This is due partly to the fact that our Milky Way continues cannibalizing galaxies that swing too close by in our Local Group of a few dozen small galaxies.
It's a markedly different environment for NGC 1277. The galaxy lives near the center of the Perseus cluster of over 1,000 galaxies, located 240 million light-years away. But NGC 1277 is moving so fast through the cluster, at 2 million miles per hour, that it cannot merge with other galaxies to collect stars or pull in gas to fuel star formation. In addition, near the galaxy cluster center, intergalactic gas is so hot it cannot cool to condense and form stars.
The team started looking for "arrested development" galaxies in the Sloan Digital Sky Survey and found 50 candidate massive compact galaxies. Using a similar technique, but out of a different sample, NGC 1277 was identified as unique in that it has a central black hole that is much more massive than it should be for a galaxy of that size. This reinforces the scenario that the supermassive black hole and dense hub of the galaxy grew simultaneously, but the galaxy's stellar population stopped growing and expanding because it was starved of outside material.
"I didn't believe the ancient galaxy hypothesis initially, but finally I was surprised because it's not that common to find what you predict in astronomy," Beasley added. "Typically, the universe always comes up with more surprises that you can think about."
The team has 10 other candidate galaxies to look at with varying degrees of "arrested development."
The upcoming NASA James Webb Space Telescope (scheduled for launch in 2019) will allow astronomers to measure the motions of the globular clusters in NGC 1277. This will provide the first opportunity to measure how much dark matter the primordial galaxy contains.
Read more at: https://phys.org/news/2018-03-hubble-relic-galaxy-home.html#jCp
Riding The (Quantum Magnetic) Wave—Next-Generation Electronics One Leap Closer To Reality
(phys.org) - - In 1991, University of Utah chemist Joel Miller developed the first magnet with carbon-based, or organic, components that was stable at room temperature. It was a great advance in magnetics, and he's been exploring the applications ever since.
Twenty-five years later, physicists Christoph Boehme and Valy Vardeny demonstrated a method to convert quantum waves into electrical current. They too, knew they'd discovered something important, but didn't know its application.
Now those technologies have come together and could be the first step towards a new generation of faster, more efficient and more flexible electronics.
Working together, Miller, Boehme, Vardeny and their colleagues have shown that an organic-based magnet can carry waves of quantum mechanical magnetization, called magnons, and convert those waves to electrical signals. It's a breakthrough for the field of magnonics (electronic systems that use magnons instead of electrons) because magnons had previously been sent through inorganic materials that are more difficult to handle.
"Going to these organic materials, we have an opportunity to push magnonics into an area that is more controllable than inorganic materials," Miller says. Their results are published today in Nature Materials.
How magnonics works
Before proceeding, let's talk about what a magnon is and how it can be used in electronics. Current electronics use electrons to carry information along wires. Magnons can also conduct information through materials, but instead of being composed of electrons, magnons are waves composed of a quantum property called spin.
Imagine a football stadium, packed full of enthusiastic fans holding up their arms to cheer on their team. Let's say that the direction in which their arms point is their spin orientation. If every fan holds their arms straight up in the air simultaneously, then everyone's spin orientation is the same and they've made, in essence, a magnet.
Now the crowd starts "The Wave," except instead of standing and sitting, one aisle of fans tilts their arms to the right. The next aisle picks up on this change in spin and passes it along to the next row. Before long, this magnet has a spin-based wave coursing around the stadium.
The quantum version of the spin-based wave is a magnon.
"Now you have a way to broadcast information in a material," says physics professor and paper co-author Boehme. "You can think about magnonics like electronics. You have circuitry and when you manage to build digital logic out of this, you can also build computers."
Well, not yet. Although magnons have been known to science for decades, only recently has their potential for building electronics been realized.
Currently, most magnonics researchers are using yttrium iron garnet (YIG) as their wave carrier material. It's expensive and difficult to produce, especially as a thin film or wire. Boehme says he once considered incorporating YIG into one of his instruments and had to give up because the material proved so problematic to handle that particular application.
Assembling The Team
Boehme and Vardeny, distinguished professor of physics, also study the field of alternatives to electronics called spintronics, of which magnonics is a subfield. In 2016 they showed how to straightforwardly observe the "inverse spin Hall effect," a way to convert spin waves into electrical current.
They began working together with Miller through a National Science Foundation-funded Materials Research Science and Engineering Center (MRSEC) at the University of Utah. In 1991, Miller had produced the first magnetic material using organic, or carbon-based, components. The three decided to test Miller's organic magnet to see if it could be used as an alternative to YIG in magnonics materials. They tested for electron spin resonance (ESR), a measure of how long magnons would last in the material. The narrower the ESR line, the longer-lived the magnons.
The line was very narrow indeed, Vardeny says. "It's a record narrow line."
But working with the organic-based magnet, known as vanadium tetracyanoethylene or V(TCNE)x, still presented some challenges. The material is highly sensitive to oxygen, akin to rare-earth magnets. "If it's freshly made, it'll likely catch fire," Miller says. "It'll lose its magnetism." The team needed to handle the thin films of V(TCNE)x under low-oxygen conditions.
Conducting experiments required a concert of activity, with members of the research team each at their right place at the right time to carry on the next phase of the experiment.
"Count the number of authors on the paper," Boehme says. (There are 14.) "Every time we carried out an experiment, everyone had to stand there and be ready on time to participate in this process." It began with one of Miller's students arriving at 4 a.m. to prepare a precursor material and continued for two to three days continuously as research teams passed the baton of material and data.
Not every experimental run was successful. Early on, the team learned that the copper connector they were using to convert magnons into electricity using the inverse spin Hall effect was reacting with the V(TCNE)x and thus wouldn't work. A switch to platinum contacts in the next run was successful.
Promising Results
In the end, the team reported that they were able to generate stable magnons in organic magnets and convert those spin waves into electrical signals—a major stepping stone. The stability of the magnons in the V(TCNE)x was as good as that in YIG.
The researchers are hopeful that this advance leads to more progress towards magnonics replacing electronics, since magnonic systems could be smaller and faster than current systems with less heat loss and much less energy required. Conventional electronics operate on a scale of volts, Boehme says. Magnons operate on a scale of millivolts, containing around 1,000 times less energy.
The team next hopes to work toward magnonic circuits using V(TCNE)x, and also test other materials. "There are many organic-based magnets," Boehme says. "There's no reason to believe that if you randomly pick one, it's necessarily the best."
It's yet to be seen, though, what the promise of magnonics might bring beyond faster, smaller and more efficient electronics. "We can't anticipate," Miller says, "what we can't anticipate."
Read more at: https://phys.org/news/2018-03-quantum-magnetic-wavenext-generation-electronics-closer.html#jCp
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