Jewel beetle’s bright colored shell serves as camouflage from predators

Science - Posted On:2020-01-23 11:15:01 Source: arstechnica

Artist and naturalist Abbott Handerson Thayer became known as the "father of camouflage" with the publication in 1909 of a book on coloration in animals. He was particularly fascinated by the phenomenon of iridescence: many species exhibit bright, metallic jewel tones that shift hues depending on viewing angle. While iridescence is often viewed as a means of sexual selection—think the magnificent peacock, shimmering his feathers to attract a willing peahen—Thayer suggested that in some species, it was also an effective means of camouflage.

Thayer endured a fair bit of mockery for his ideas, most notably from Theodore Roosevelt, a big game hunter who thought Thayer had grossly overstated his case. Indeed, there has been very little empirical support for Thayer's hypothesis in the ensuing century. But researchers from the University of Bristol have now uncovered the first solid evidence for this in the jewel beetle, according to a new paper in Current Biology.

What makes iridescence in nature so unusual is the fact that the color we see doesn't come from actual pigment molecules, but from the precise lattice-like structure of the wings (or abalone shells, or peacock feathers, or opals, for that matter). That structure forces each light wave passing through to interfere with itself, so it can propagate only in certain directions and at certain frequencies. In essence, the structure acts like naturally occurring diffraction gratings. Physicists call these structures photonic crystals, an example of so-called "photonic band gap materials," meaning they block out certain frequencies of light and let through others.

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Huawei Postpones Its Developers Conference Over Deadly Coronavirus

science - Posted On:2020-01-23 10:44:56 Source: slashdot

Huawei has postponed its upcoming HDC.Cloud developer conference as Chinese authorities try to control the spread of the deadly coronavirus detected in the southeastern city of Wuhan. From a report: The controversial company's event was going to take place in Shenzhen -- which lies more than 700 miles south of Wuhan -- Feb. 11-12, but it's been rescheduled to March 27-28. "Based on the prevention and control of the pneumonia epidemic situation of the new coronavirus infection, we attach great importance to the health and safety of all the participants," Huawei said in its announcement. It also asked staff to avoid traveling to Wuhan and limit contact with animals, Reuters reported, and said it set up an outbreak prevention and control team in the city. Read more of this story at Slashdot.

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No one hurt in Firefly “anomaly” as company tests its Alpha first stage

Science - Posted On:2020-01-23 09:29:56 Source: arstechnica

On Wednesday evening, at Firefly Aerospace's test site about an hour north of Austin in Central Texas, some sort of anomaly occurred. The Burnet County Sheriff's Office reported that the incident took place at 6:24pm CT (00:24 UTC, Thursday), and that officers had called for evacuations of residences within one mile of the test site.

Earlier in the evening, in a subsequently deleted tweet, the company stated that it was loading liquid oxygen onto the rocket and about to attempt a qualification hot fire test of the first stage of its Alpha booster. This rocket is powered by four Reaver engines and has a reported capacity of 1 metric ton to low-Earth orbit. Firefly has been working toward the inaugural launch of the rocket, from Vandenberg Air Force Base, in April.

Later Wednesday night, the company issued a statement about the test, noting that no one had been hurt.

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Firefly experiences a “test anomaly” as it works toward first launch

Science - Posted On:2020-01-23 09:14:56 Source: arstechnica

On Wednesday evening, at Firefly Aerospace's test site about an hour north of Austin in Central Texas, some sort of anomaly occurred. The Burnet County Sheriff's Office reported that the incident took place at 6:24pm CT (00:24 UTC, Thursday), and that officers had called for evacuations of residences within one mile of the test site.

Earlier in the evening, in a subsequently deleted tweet, the company stated that it was loading liquid oxygen onto the rocket and about to attempt a qualification hot fire test of the first stage of its Alpha booster. This rocket is powered by four Reaver engines and has a reported capacity of 1 metric ton to low-Earth orbit. Firefly has been working toward the inaugural launch of the rocket, from Vandenberg Air Force Base, in April.

Later Wednesday night, the company issued a statement about the test, noting that no one had been hurt.

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Scientists Discover 'Why Stress Turns Hair White'

science - Posted On:2020-01-23 08:14:56 Source: slashdot

An anonymous reader quotes a report from the BBC: Scientists say they may have discovered why stress makes hair turn white, and a potential way of stopping it happening without reaching for the dye. Researchers behind the study, published in Nature, from the Universities of Sao Paulo and Harvard, believed the effects were linked to melanocyte stem cells, which produce melanin and are responsible for hair and skin color. And while carrying out in experiments on mice, they stumbled across evidence this was the case. Pain in mice triggered the release of adrenaline and cortisol, making their hearts beat faster and blood pressure rise, affecting the nervous system and causing acute stress. This process then sped up the depletion of stem cells that produced melanin in hair follicles. In another experiment, the researchers found they could block the changes by giving the mice an anti-hypertensive, which treats high blood pressure. And by comparing the genes of mice in pain with other mice, they could identify the protein involved in causing damage to stem cells from stress. When this protein -- cyclin-dependent kinase (CDK) -- was suppressed, the treatment also prevented a change in the color of their fur. This leaves the door open for scientists to help delay the onset of grey hair by targeting CDK with a drug. Read more of this story at Slashdot.

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Google Scientists Unveil the Biggest, Most Detailed Map of the Fly Brain Yet

science - Posted On:2020-01-22 22:44:58 Source: slashdot

An anonymous reader shares a summary from Howard Hughes Medical Institute: In a darkened room in Ashburn, Virginia, rows of scientists sit at computer screens displaying vivid 3-D shapes. With a click of a mouse, they spin each shape to examine it from all sides. The scientists are working inside a concrete building at the Howard Hughes Medical Institute's Janelia Research Campus, just off a street called Helix Drive. But their minds are somewhere else entirely -- inside the brain of a fly. Each shape on the scientists' screens represents part of a fruit fly neuron. These researchers and others at Janelia are tackling a goal that once seemed out of reach: outlining each of the fly brain's roughly 100,000 neurons and pinpointing the millions of places they connect. Such a wiring diagram, or connectome, reveals the complete circuitry of different brain areas and how they're linked. The work could help unlock networks involved in memory formation, for example, or neural pathways that underlie movements. Gerry Rubin, vice president of HHMI and executive director of Janelia, has championed this project for more than a decade. It's a necessary step in understanding how the brain works, he says. When the project began, Rubin estimated that with available methods, tracing the connections between every fly neuron by hand would take 250 people working for two decades -- what he refers to as "a 5,000 person-year problem." Now, a stream of advances in imaging technology and deep-learning algorithms have yanked the dream of a fly connectome out of the clouds and into the realm of probability. High-powered customized microscopes, a team of dedicated neural proofreaders and data analysts, and a partnership with Google have sped up the process by orders of magnitude. Today, a team of Janelia researchers reports hitting a critical milestone: they've traced the path of every neuron in a portion of the female fruit fly brain they've dubbed the "hemibrain." The map encompasses 25,000 neurons -- roughly a third of the fly brain, by volume -- but its impact is outsized. It includes regions of keen interest to scientists -- those that control functions like learning, memory, smell, and navigation. With more than 20 million neural connections pinpointed so far, it's the biggest and most detailed map of the fly brain ever completed. The scientists have published a pre-print paper describing their work, and have made the data they collected available to view and download. Read more of this story at Slashdot.

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Ancient African skeletons hint at a “ghost lineage” of humans

Science - Posted On:2020-01-22 18:44:59 Source: arstechnica

Understanding humanity's shared history means understanding what happened in Africa. But figuring out what happened in Africa has been a difficult task. Not every area is well represented in the fossil history, and most African environments aren't conducive to the preservation of ancient DNA. DNA sequencing of modern African populations lags behind other regions, in part because DNA sequencing hardware is more common elsewhere. Finally, as in many other areas, massive migrations within the continent have helped scramble the genetic legacy of the past.

Now, researchers are describing a new window into our collective past: DNA from ancient skeletons found in a rock shelter in West Africa. The skeletons come from a location and time that are both near the origin of the Bantu expansion that spread West African peoples across the entirety of Africa but have little in common with Bantu-speaking populations. Yet, at the same time, they provide hints of what might have happened very early in humanity's history, including the existence of a lineage of archaic humans we've not yet identified.

The skeletons come from a site called Shum Laka, which is located in a grassland area of Cameroon. For those not up on their African geography, Cameroon is located at the angle where West Africa meets Southern Africa. This is also the region where the Bantu people put together a collection of agricultural and metallurgical technologies that allowed them to sweep across the rest of the continent, leaving their linguistic and genetic mark on many other populations.

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The Mount Vesuvius eruption was so hot, one man’s brain turned to glass.

Science - Posted On:2020-01-22 17:29:59 Source: arstechnica

When Mount Vesuvius erupted in 79 CE, the heat was so extreme in some places that it vaporized body fluids and exploded the skulls of several inhabitants unable to flee in time. Now, archaeologists have determined that the heat also fused brain tissue into glass in one victim. The discovery is described in a new short paper in the New England Journal of Medicine.

The eruption released thermal energy roughly equivalent to 100,000 times the atomic bombs dropped on Hiroshima and Nagasaki at the end of World War II, spewing molten rock, pumice, and hot ash over the the cities of Pompeii and Herculaneum in particular. Pliny the Younger wrote of "broad sheets of flame" and a rain of ash in a letter to the historian Tacitus (the letter is the sole surviving eyewitness account of the disaster). 

The vast majority of the victims died of asphyxiation, choking to death on the thick clouds of noxious gas and ash. But a 2001 study in Nature estimated a temperature of 300° Celsius (572° Fahrenheit) for the pyroclastic surge that destroyed Pompeii, sufficient to kill inhabitants in fractions of a second. Back in 2018, we reported on the conclusion of University of Naples archaeologist Pierpaolo Petrone (one of the co-authors of the 2001 Nature paper) that inhabitants of Herculaneum may have suffered a similar fate.

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Extreme heat from Vesuvius eruption turned one victim’s brain to glass

Science - Posted On:2020-01-22 17:15:00 Source: arstechnica

When Mount Vesuvius erupted in 79 CE, the heat was so extreme in some places that it vaporized body fluids and exploded the skulls of several inhabitants unable to flee in time. Now, archaeologists have determined that the heat also fused brain tissue into glass in one victim. The discovery is described in a new short paper in the New England Journal of Medicine.

The eruption released thermal energy roughly equivalent to 100,000 times the atomic bombs dropped on Hiroshima and Nagasaki at the end of World War II, spewing molten rock, pumice, and hot ash over the the cities of Pompeii and Herculaneum in particular. Pliny the Younger wrote of "broad sheets of flame" and a rain of ash in a letter to the historian Tacitus (the letter is the sole surviving eyewitness account of the disaster). 

The vast majority of the victims died of asphyxiation, choking to death on the thick clouds of noxious gas and ash. But a 2001 study in Nature estimated a temperature of 300° Celsius (572° Fahrenheit) for the pyroclastic surge that destroyed Pompeii, sufficient to kill inhabitants in fractions of a second. Back in 2018, we reported on the conclusion of University of Naples archaeologist Pierpaolo Petrone (one of the co-authors of the 2001 Nature paper) that inhabitants of Herculaneum may have suffered a similar fate.

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IBM's Debating AI Just Got a Lot Closer To Being a Useful Tool

science - Posted On:2020-01-22 15:59:59 Source: slashdot

We make decisions by weighing pros and cons. Artificial intelligence has the potential to help us with that by sifting through ever-increasing mounds of data. But to be truly useful, it needs to reason more like a human. An artificial intelligence technique known as argument mining could help. From a report: IBM has just taken a big step in that direction. The company's Project Debater team has spent several years developing an AI that can build arguments. Last year IBM demonstrated its work-in-progress technology in a live debate against a world-champion human debater, the equivalent of Watson's Jeopardy! showdown. Such stunts are fun, and it provided a proof of concept. Now IBM is turning its toy into a genuinely useful tool. The version of Project Debater used in the live debates included the seeds of the latest system, such as the capability to search hundreds of millions of new articles. But in the months since, the team has extensively tweaked the neural networks it uses, improving the quality of the evidence the system can unearth. One important addition is BERT, a neural network Google built for natural-language processing, which can answer queries. The work will be presented at the Association for the Advancement of Artificial Intelligence conference in New York next month. To train their AI, lead researcher Noam Slonim and his colleagues at IBM Research in Haifa, Israel, drew on 400 million documents taken from the LexisNexis database of newspaper and journal articles. This gave them some 10 billion sentences, a natural-language corpus around 50 times larger than Wikipedia. They paired this vast evidence pool with claims about several hundred different topics, such as "Blood donation should be mandatory" or "We should abandon Valentine's Day." They then asked crowd workers on the Figure Eight platform to label sentences according to whether or not they provided evidence for or against particular claims. The labeled data was fed to a supervised learning algorithm. Read more of this story at Slashdot.

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One immune cell type appears to attack any type of cancer

Science - Posted On:2020-01-22 14:15:00 Source: arstechnica

While cancerous cells look a lot like normal human cells, they're still different enough that the immune system regularly attacks them. Obviously, this attack sometimes bogs down, allowing cancer to thrive and spread. Figuring out how to get the immune system back on track has been a major focus of research, and success in the area has been honored with a Nobel Prize.

Despite these successes, many patients aren't helped by the newer immune-focused therapies, raising questions of what else we still need to figure out to help cancer patients. A new paper highlights something we may have missed: a class of immune cells that appears to be primed specifically to attack cancer. But the finding raises questions about what it is on cancer cells that the immune cells are recognizing and why they fail to keep cancer in check.

The start of this work was pretty simple: a large international team of researchers grew a mix of immune cells called "T cells" in the presence of cancerous cells and looked for cells that grew rapidly. This rapid growth is typically a sign that the immune cells have been activated by something they recognize—in this case, the cancer. They identified one particular lineage of T cells that grew well and named it MC.7.G5, confirming yet again that most scientists don't belong in the creative industries.

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The math of brewing a better espresso

Science - Posted On:2020-01-22 11:15:00 Source: arstechnica

Skilled baristas know that achieving the perfect complex flavor profile for a delectable shot of espresso is as much art as science. Get it wrong, and the resulting espresso can taste too bitter or sourly acidic rather than being a perfect mix of each. Now an international team of scientists has devised a mathematical model for brewing the perfect cup, over and over, while minimizing waste, outlined in a new paper in the journal Matter.

"A good espresso beverage can be made in a multitude of ways," said co-author Christopher Hendon, a computational chemist at the University of Oregon. "The point of this paper was to give people a map for making an espresso beverage that they like and then be able to make it 100 times in a row."

There's actually an official industry standard for brewing espresso, courtesy of the Specialty Coffee Association, which sets out strict guidelines for its final volume (25-35mL, or roughly one ounce) and preparation. The water must be heated to 92-95° C (197-203° F) and forced (at a specific pressure) through a bed of 7-9 grams (about a quarter of an ounce) of finely ground coffee over the course of 20-30 seconds. But most coffee shops don't follow this closely, typically using more coffee, while the brewing machines allow baristas to configure water pressure, temperature, and other key variables to their liking. The result of all those variations in technique is a great deal of variability in quality and taste.

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China's 500-Meter FAST Radio Telescope Is Now Operational

science - Posted On:2020-01-22 05:14:57 Source: slashdot

China's Five-hundred meter Aperture Spherical Telescope (FAST) -- the world's largest and most sensitive radio telescope -- is now operational. The telescope was completed in 2016 -- 20 years after it was first proposed -- but has been undergoing testing and commissioning since then. Phys.Org reports: FAST's nickname is Tianyan, which means "Eye of the Sky" or "Eye of Heaven." It's built in a natural depression in Guizhou, Southwest China. Among other things, its scientific goals are to study pulsars. FAST has already discovered two of those, in August 2017. FAST's name is not exactly accurate. Though it does have a 500 meter diameter, only 300 meters of it is used at any one time. The telescope is active and can change so that one 300 meter segment is focused on the receiver. According to Xinhua, all the technical indicators from FAST are meeting or exceeding planned levels. FAST is a powerful radio telescope, and scientists think it will make some major discoveries, especially in its first couple of years. FAST will also perform two sky surveys, which will take about five years. It'll take another 10 years just to analyze all that data. Still, there's room for flexibility in the telescope's operational schedule to pursue any surprises that come up. The surveys will take up about half of the telescope's observing time, leaving room for objectives like searching for exoplanets with magnetic fields, which are probably crucial for life. Read more of this story at Slashdot.

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Coronavirus from China has made its way to the United States

Science - Posted On:2020-01-21 17:30:00 Source: arstechnica

On Tuesday afternoon, the US Centers for Disease Control announced that the coronavirus that's been spreading within China had made it to the United States. A patient in Washington state is the first confirmed case in the US, although indications are that the disease has already spread to other countries in Asia.

A single patient in Washington had been traveling in Wuhan, the area of China hardest hit by the newly described virus, before returning to the US last week. Shortly after their return, the patient was hospitalized with pneumonia-like symptoms. The hospital staff, based on the travel history and symptoms, suspected that the new virus, called 2019-nCoV, might be at fault, and sent samples in to the CDC for testing. Those tests confirmed the virus' identity.

While the initial cases were confined to people who had been in contact with live animals at a seafood market, suggesting that it should be possible to contain the virus. But since then, the news has gotten worse. In addition to spreading to other countries—Thailand and Japan had confirmed cases prior to the US—the virus is now confirmed to be spreading through human contact, which has helped increase the number of cases and enabled its spread to other cities within China. There have also been a number of reported fatalities, although these remain a small percentage of the confirmed infections.

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First US case of new coronavirus reported

Science - Posted On:2020-01-21 17:15:00 Source: arstechnica

On Tuesday afternoon, the US Centers for Disease Control announced that the coronavirus that's been spreading within China had made it to the United States. A patient in Washington state is the first confirmed case in the US, although indications are that the disease has already spread to other countries in Asia.

A single patient in Washington had been traveling in Wuhan, the area of China hardest hit by the newly described virus, before returning to the US last week. Shortly after their return, the patient was hospitalized with pneumonia-like symptoms. The hospital staff, based on the travel history and symptoms, suspected that the new virus, called 2019-nCoV, might be at fault, and sent samples in to the CDC for testing. Those tests confirmed the virus' identity.

While the initial cases were confined to people who had been in contact with live animals at a seafood market, suggesting that it should be possible to contain the virus. But since then, the news has gotten worse. In addition to spreading to other countries—Thailand and Japan had confirmed cases prior to the US—the virus is now confirmed to be spreading through human contact, which has helped increase the number of cases and enabled its spread to other cities within China. There have also been a number of reported fatalities, although these remain a small percentage of the confirmed infections.

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First Case of New Coronavirus Detected In US

science - Posted On:2020-01-21 16:30:00 Source: slashdot

The first case of an infection with a new coronavirus has been discovered in the United States. NPR reports: A man from Washington state returned home after a trip to Wuhan, China, on Jan. 15, sought medical attention on Jan. 19 and now is in isolation at Providence Regional Medical Center in Everett, Wash. State health officials say his condition is quite good and even referred to him as "healthy." But testing from the Centers for Disease Control and Prevention on the 20th confirm that he is infected with the Wuhan coronavirus. The man arrived back in the U.S. prior to the implementation of screening at three domestic airports on Friday. As of yesterday, over 200 cases of the virus have been reported in China. Read more of this story at Slashdot.

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Why isn’t California using more prescribed burns to reduce fire risk?

Science - Posted On:2020-01-21 13:15:01 Source: arstechnica

Whenever wildfires rip through an area, splashing nightmarish scenes across the evening news, people who live elsewhere seem to have a lot of suggestions. Why don’t they log the forest so there’s less to burn? Why don’t they get millions of goats to graze the brush? Why live in such a dangerous spot? But as with most things, there are usually complications when you look closer.

A new study led by Stanford’s Rebecca Miller analyzes one option for limiting fires in California: prescribed burns. The researchers interviewed experts in state government, federal agencies, non profits, and academia to find out what barriers are preventing greater use of prescribed burns.

Prescribed burns utilize low-intensity fires during favorable weather to safely remove some of the fuel that has accumulated on the ground—fuel present partly as a result of our past practice of putting out wildfires as aggressively as possible. It’s often combined with mechanical thinning of brush and trees that serve as “ladders” for fires to climb into treetops, with the resulting brush piles burned later. The researchers say that about 20 percent of the state—20 million acres—could benefit from prescribed burns to reduce the wildfire hazard. But California is not currently on pace to complete that monumental task any time soon.

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Starliner’s thruster performance receiving close scrutiny from NASA

Science - Posted On:2020-01-21 11:15:00 Source: arstechnica

Nearly one month ago, Boeing completed the first orbital test flight of its Starliner spacecraft with a near-perfect landing at White Sands Space Harbor in New Mexico.

The mission had to be cut short due to a well-publicized timing error that delayed the spacecraft's service module from performing an orbital insertion burn. This caused the thrusters on board the service module, which provides power to Starliner during most of its mission, to fire longer than expected. As a result, the spacecraft did not have enough fuel to complete a rendezvous with the International Space Station, a key component of the test flight in advance of crewed missions.

Since providing some initial information during a post-flight news conference, NASA and Boeing have gone mostly quiet about the investigation into the timing error. Two weeks ago, the space agency said it had initiated two investigations. One would find the root cause of the "mission elapsed timer anomaly" over the course of about two months, and the second will determine whether another uncrewed test flight of Starliner is required before astronauts fly on the vehicle.

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New twist on marshmallow test: Kids depend on each other for self control

Science - Posted On:2020-01-21 09:29:56 Source: arstechnica

In the 1970s, the late psychologist Walter Mischel explored the importance of the ability to delay gratification as a child to one's future success in life, via the famous Stanford "marshmallow experiment." Now a team of German researchers has adapted the classic experimental setup with German and Kenyan schoolchildren and found that kids are more likely to delay gratification when they depend on each other. They described their findings in a recent paper in Psychological Science.

As we previously reported, Mischel's landmark behavioral study involved 600 kids between the ages of four and six, all culled from Stanford University's Bing Nursery School. He would give each child a marshmallow and give them the option of eating it immediately if they chose. But if they could wait 15 minutes, they would get a second marshmallow as a reward. Then Mischel would leave the room, and a hidden video camera would tape what happened next.

Some kids just ate the marshmallow right away. Others found a handy distraction: covering their eyes, kicking the desk, or poking at the marshmallow with their fingers. Some smelled it, licked it, or took tiny nibbles around the edges. Roughly one-third of the kids held out long enough to earn a second marshmallow. Several years later, Mischel noticed a strong correlation between the success of some of those kids later in life (better grades, higher self-confidence) and their ability to delay gratification in nursery school. Mischel's follow-up study confirmed the correlation.

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New Research Provides Evidence of Strong Early Magnetic Field Around Earth

science - Posted On:2020-01-21 02:14:58 Source: slashdot

New research from the University of Rochester provides evidence that the magnetic field that first formed around Earth was even stronger than scientists previously believed. The research, published in the journal PNAS, will help scientists draw conclusions about the sustainability of Earth's magnetic shield and whether or not there are other planets in the solar system with the conditions necessary to harbor life. Phys.Org reports: Using new paleomagnetic, electron microscope, geochemical, and paleointensity data, the researchers dated and analyzed zircon crystals -- the oldest known terrestrial materials -- collected from sites in Australia. The zircons, which are about two-tenths of a millimeter, contain even smaller magnetic particles that lock in the magnetization of the earth at the time the zircons were formed. Previous research by [John Tarduno, Professor of Earth and Environmental Sciences and Dean of Research for Arts, Sciences, and Engineering at Rochester] found that Earth's magnetic field is at least 4.2 billion years old and has existed for nearly as long as the planet. Earth's inner core, on the other hand, is a relatively recent addition: it formed only about 565 million years ago, according to research published by Tarduno and his colleagues earlier this year. While the researchers initially believed Earth's early magnetic field had a weak intensity, the new zircon data suggests a stronger field. But, because the inner core had not yet formed, the strong field that originally developed 4 billion years ago must have been powered by a different mechanism. "We think that mechanism is chemical precipitation of magnesium oxide within Earth," Tarduno says. The magnesium oxide was likely dissolved by extreme heat related to the giant impact that formed Earth's moon. As the inside of Earth cooled, magnesium oxide could precipitate out, driving convection and the geodynamo. The researchers believe inner Earth eventually exhausted the magnesium oxide source to the point that the magnetic field almost completely collapsed 565 million years ago. But the formation of the inner core provided a new source to power the geodynamo and the planetary magnetic shield Earth has today. Read more of this story at Slashdot.

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