Tag Archives: experiment

Monkey Experiment Reveals a Brain Switch That Could Be Useful For Space Travel : ScienceAlert

For humans to ever venture out among the stars, we will have to solve some hefty logistical problems.

Not the least of these is the travel time involved. Space is so large, and human technology so limited, that the time it would take to travel to another star presents a significant barrier.

The Voyager 1 probe, for instance, would take 73,000 years to reach Proxima Centauri, the nearest star to the Sun, at its current speed.

Voyager launched more than 40 years ago, and more recent spacecraft might be expected to travel faster; even so, the journey would still take thousands of years with our current technology.

One potential solution would be generation ships, which would see multiple generations of space travelers live and die before reaching the final destination. Another would be artificial hibernation, if it could be successfully implemented.

This is what scientists from the Shenzhen Institute of Advanced Technology (SIAT) of the Chinese Academy of Sciences have started to investigate; not in humans, but in monkeys, by chemically triggering a state of hypothermia.

“Here, we show that activating a subpopulation of preoptic area (POA) neurons by a chemogenetic strategy reliably induces hypothermia in anesthetized and freely moving macaques,” the researchers write in their paper.

“Altogether, our findings demonstrate the central regulation of body temperature in primates and pave the way for future application in clinical practice.”

Hibernation and its slightly less comatose state, torpor, are physiological states that allow animals to withstand adverse conditions, like extreme cold and low oxygen.

The body temperature lowers, and metabolism slows to a crawl, keeping the body in a bare-bones ‘maintenance mode’ – the bare minimum to stay alive while preventing atrophy.

This can be found across several animals, including warm-blooded mammals, but very few primates. Neuroscientists Wang Hong and Dai Ji of SIAT wanted to see if they could artificially induce a state of hypometabolism, or even hibernation, in primates by chemically manipulating neurons in the hypothalamus responsible for sleep and thermoregulation processes – the preoptic neurons.

The research was performed on three young male crab-eating monkeys (Macaca fascicularis). In both anesthetized and non-anesthetized states, the researchers applied drugs designed to activate specific modified receptors in the brain, known as Designer Receptors Exclusively Activated by Designer Drugs, or DREADDs.

Then, the scientists studied the results using functional magnetic resonance imaging, behavioral changes, and physiological and biochemical changes.

An illustration showing the role preoptic neurons play in hypothermia. (SIAT)

“To investigate the brain-wide network as a consequence of preoptic area (POA) activation, we performed fMRI scans and identified multiple regions involved in thermoregulation and interoception,” Dai says.

“This is the first fMRI study to investigate the brain-wide functional connections revealed by chemogenetic activation.”

The researchers found that a synthetic drug called Clozapine N-oxide (CNO) reliably induced hypothermia in both the anesthetized and awake states in the macaques.

However, in anesthetized monkeys, the CNO-induced hypothermia resulted in a drop in core body temperature, preventing external heating. The researchers say that this demonstrates the critical role POA neurons play in primate thermoregulation.

The researchers recorded behavioral changes in the awake monkeys and compared them to those of mice with induced hypothermia. Typically, mice decrease activity, and their heart rate lowers in an attempt to conserve heat.

The monkeys, by contrast, showed an increased heart rate and activity level and, in addition, started shivering. This suggests that thermoregulation in primates is more complex than in mice; hibernation in humans (if it can be done at all) will need to take this into account.

“This work provides the first successful demonstration of hypothermia in a primate based on targeted neuronal manipulation,” Wang says.

“With the growing passion for human spaceflight, this hypothermic monkey model is a milestone on the long path toward artificial hibernation.”

The research has been published in The Innovation.

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A Powerful Recoil Effect Magnified NASA’s Asteroid Deflection Experiment

Composite image of the Didymos-Dimorphos system taken on November 30, showing its new ejecta tail.

Scientists continue to pore over the results of NASA’s stunningly successful DART test to deflect a harmless asteroid. As the latest findings suggest, the recoil created by the blast of debris spewing out from Dimorphos after impact was significant, further boosting the spacecraft’s influence on the asteroid.

NASA’s fridge-sized spacecraft smashed into the 535-foot-long (163-meter) Dimorphos on September 26, shortening its orbit around its larger partner, Didymos, by a whopping 33 minutes. That equates to several dozen feet, demonstrating the feasibility of using kinetic impactors as a means to deflect threatening asteroids.

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A stunning side-effect of the test were the gigantic and complex plumes that emanated from the asteroid after impact. The Didymos-Dimorphos system, located 7 million miles (11 million kilometers) from Earth, even sprouted a long tail in the wake of the experiment. DART, short for Double Asteroid Redirection Test, had a profound impact on Dimorphos, kicking up a surprising amount of debris, or “ejecta,” in the parlance of planetary scientists.

Dimorphos, as we learned, is a rubble pile asteroid, as opposed to it being a dense, tightly packed rocky body. This undoubtedly contributed to the excessive amount of ejected debris, but scientists weren’t entirely sure how much debris the asteroid shed as a result of the impact. Preliminary findings presented on Thursday at the American Geophysical Union’s Fall Meeting in Chicago are casting new light on this and other aspects of the DART mission.

Not only did DART kick up tons of ejecta, it also triggered a recoil effect that further served to nudge the asteroid in the desired direction, as Andy Rivkin, DART investigation team lead, explained at the meeting. “We got a lot of bang for the buck,” he told BBC News.

Indeed, had Dimorphos been a more compact body, the same level of recoil likely wouldn’t have happened. “If you blast material off the target then you have a recoil force,” explained DART mission scientist Andy Cheng from the Johns Hopkins University Applied Physics Lab, who also spoke at the meeting. The resulting recoil is analogous to letting go of a balloon; as the air rushes out, it pushes the balloon in the opposite direction. In the case of Dimorphos, the stream of ejecta served as the air coming out of the balloon, which likewise pushed the asteroid in the opposite direction.

Planetary scientists are starting to get a sense as to how much debris got displaced. DART, traveling at 14,000 miles per hour (22,500 km/hour), struck with enough force to spill over 2 million pounds of material into the void. That’s enough to fill around six or seven rail cars, NASA said in a statement. That estimate might actually be on the low side, and the true figure could possibly be 10 times higher, Rivkin said at the meeting.

The scientists assigned DART’s momentum factor, known as “beta,” a value of 3.6, meaning that the momentum transferred into Dimorphos was 3.6 times greater than an impact event that produced no ejecta plume. “The result of that recoil force is that you put more momentum into the target, and you end up with a bigger deflection,” Cheng told reporters. “If you’re trying to save the Earth, this makes a big difference.”

That’s a good point, as those values will dictate the parameters for an actual mission to deflect a legitimately dangerous asteroid. Cheng and his colleagues will now use these results to infer the beta values of other asteroids, a task that will require a deeper understanding of an object’s density, composition, porosity, and other parameters. The scientists are also hoping to figure out the degree to which DART’s initial hit moved the asteroid and how much of its movement happened on account of the recoil.

The speakers also produced another figure—the length of the tail, or ejecta plume, that formed in the wake of the impact. According to Rivkin, Dimorophos sprouted a tail measuring 18,600 miles (30,000 km) long.

“Impacting the asteroid was just the start,” Tom Statler, the program scientist for DART and a presenter at the meeting, said in the statement. “Now we use the observations to study what these bodies are made of and how they were formed—as well as how to defend our planet should there ever be an asteroid headed our way.”

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A Powerful Recoil Effect Magnified NASA’s Asteroid Deflection Experiment

Composite image of the Didymos-Dimorphos system taken on November 30, showing its new ejecta tail.
Image: Magdalena Ridge Observatory/NM Tech

Scientists continue to pore over the results of NASA’s stunningly successful DART test to deflect a harmless asteroid. As the latest findings suggest, the recoil created by the blast of debris spewing out from Dimorphos after impact was significant, further boosting the spacecraft’s influence on the asteroid.

NASA’s fridge-sized spacecraft smashed into the 535-foot-long (163-meter) Dimorphos on September 26, shortening its orbit around its larger partner, Didymos, by a whopping 33 minutes. That equates to several dozen feet, demonstrating the feasibility of using kinetic impactors as a means to deflect threatening asteroids.

A stunning side-effect of the test were the gigantic and complex plumes that emanated from the asteroid after impact. The Didymos-Dimorphos system, located 7 million miles (11 million kilometers) from Earth, even sprouted a long tail in the wake of the experiment. DART, short for Double Asteroid Redirection Test, had a profound impact on Dimorphos, kicking up a surprising amount of debris, or “ejecta,” in the parlance of planetary scientists.

Animated image showing changes to the Didymos-Dimorphos system in the first month following DART’s impact.
Gif: University of Canterbury Ōtehīwai Mt. John Observatory/UCNZ

Dimorphos, as we learned, is a rubble pile asteroid, as opposed to it being a dense, tightly packed rocky body. This undoubtedly contributed to the excessive amount of ejected debris, but scientists weren’t entirely sure how much debris the asteroid shed as a result of the impact. Preliminary findings presented on Thursday at the American Geophysical Union’s Fall Meeting in Chicago are casting new light on this and other aspects of the DART mission.

Not only did DART kick up tons of ejecta, it also triggered a recoil effect that further served to nudge the asteroid in the desired direction, as Andy Rivkin, DART investigation team lead, explained at the meeting. “We got a lot of bang for the buck,” he told BBC News.

Indeed, had Dimorphos been a more compact body, the same level of recoil likely wouldn’t have happened. “If you blast material off the target then you have a recoil force,” explained DART mission scientist Andy Cheng from the Johns Hopkins University Applied Physics Lab, who also spoke at the meeting. The resulting recoil is analogous to letting go of a balloon; as the air rushes out, it pushes the balloon in the opposite direction. In the case of Dimorphos, the stream of ejecta served as the air coming out of the balloon, which likewise pushed the asteroid in the opposite direction.

Planetary scientists are starting to get a sense as to how much debris got displaced. DART, traveling at 14,000 miles per hour (22,500 km/hour), struck with enough force to spill over 2 million pounds of material into the void. That’s enough to fill around six or seven rail cars, NASA said in a statement. That estimate might actually be on the low side, and the true figure could possibly be 10 times higher, Rivkin said at the meeting.

The scientists assigned DART’s momentum factor, known as “beta,” a value of 3.6, meaning that the momentum transferred into Dimorphos was 3.6 times greater than an impact event that produced no ejecta plume. “The result of that recoil force is that you put more momentum into the target, and you end up with a bigger deflection,” Cheng told reporters. “If you’re trying to save the Earth, this makes a big difference.”

That’s a good point, as those values will dictate the parameters for an actual mission to deflect a legitimately dangerous asteroid. Cheng and his colleagues will now use these results to infer the beta values of other asteroids, a task that will require a deeper understanding of an object’s density, composition, porosity, and other parameters. The scientists are also hoping to figure out the degree to which DART’s initial hit moved the asteroid and how much of its movement happened on account of the recoil.

The speakers also produced another figure—the length of the tail, or ejecta plume, that formed in the wake of the impact. According to Rivkin, Dimorophos sprouted a tail measuring 18,600 miles (30,000 km) long.

“Impacting the asteroid was just the start,” Tom Statler, the program scientist for DART and a presenter at the meeting, said in the statement. “Now we use the observations to study what these bodies are made of and how they were formed—as well as how to defend our planet should there ever be an asteroid headed our way.”

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4-day work week experiment deemed a success, with higher productivity and lower stress levels

Could a five-day work-week soon become a thing of the past?

The results of a six-month experiment with the participation of dozens of companies are now in: A four-day work week may actually be better for business.

Workers reported lower levels of stress and fatigue and company revenue was often higher compared to the prior year.

The experiment involved 33 companies and more than 900 employees.

In fact, out of the 33 companies, 27 completed a survey after the experiment and none of those said they were planning to go back to the five-day work week.

A separate six-month trial is currently underway in the United Kingdom, with 70 companies and more than 3,000 workers participating. Results are due in February.



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‘Liver King’ Admits Steroid Use, Calls Persona ‘Experiment’ – Rolling Stone

Brian Johnson, better known as the organ-devouring masculinity influencer “Liver King,” has admitted to steroid use in a somber video shared on his YouTube and Instagram accounts.

“I fully own that I fucked up,” he said in the six-minute confession. “I am as sorry as a man can be.”

The pained statement comes in response to a video from another bodybuilder, Derek of the online fitness brand “More Plates More Dates,” that purported to show emails in which Johnson described his steroid regimen — a suite of injections costing some $11,000 per month. Since launching the Liver King persona in August of 2021, Johnson had given several interviews during which he categorically denied using performance-enhancing drugs to achieve his muscular physique. He’d also brushed aside accusations of steroid use from podcast kingpin Joe Rogan.

But in just three days, the hour-long “More Plates More Dates” exposé garnered 3 million views, with many in the fitness community saying it confirmed their suspicions about Johnson.

“I’m here now to set the record straight,” Johnson says in his new video, then sighs heavily. “Yes, I’ve done steroids, and yes, I’m on steroids, monitored and managed by a trained hormone clinician. Liver King, the public figure, was an experiment to spread the message.” He went on to mention the social ills of suicide, depression and anxiety, adding: “Our young men are hurting the most.” He said that when he talks about low self-esteem, he’s talking about himself.

Johnson explained that he was already wealthy, and his supplements business a success, before he adopted the guise of the Liver King for social media. The persona drew a following of 1.7 million Instagram followers in just a year, with Johnson selling his products while advocating a caveman lifestyle featuring extreme exercise and a “natural” raw diet of animal livers, hearts, and testicles. Johnson claimed he never expected Liver King to become a viral sensation — contradicting an alleged email included in the “More Plates More Dates” video where he appeared to lay out a plan for gaining a million social media followers in a matter of months. He has yet to confirm or deny the authenticity of that message, or any other private correspondence now circulating.

Johnson also pledged to talk about steroid use “openly” in the future, “because I believe that there’s a time and a place for pharmacological intervention,” if overseen by a physician. He once more denied, however, that he’s had ab implants or other plastic surgery.

On YouTube, reactions were mostly negative, with commenters criticizing Johnson for invoking others’ mental health struggles as the reason for his pattern of lying. Some called the video “damage control” or insincere, with many saying he was only sorry he got caught.

Johnson found more support on his Instagram page. “No bullshit, no excuses,” wrote a fan. “Earned respect with me from this post. Much love!” Another remarked, “It takes a lot to admit it when you’ve made a mistake, and honestly, I’m glad you came clean. You’re a really inspiring guy, and definitely someone to look up to in the fitness world.”

Redditors were far less impressed. “The image of him confessing to using steroids is hilarious, like a child with a face covered in blueberry pie confessing to eating a pie,” observed one. “Thinking of all the dudes that legit ate testicles trying to be this guy,” quipped someone else.

As Johnson himself noted, he isn’t a competitive athlete, so it’s not as if he’ll be disciplined or suspended by a sports organization. Nor is the admission that he lied about PEDs likely to diminish his online fame or audience, both of which were built on spectacle from the start. So, although Johnson referred to Liver King in the past tense, expect him to live on, hyping both “ancestral” tenets and the miraculous effects of human growth hormone. Oh, and the importance of never, ever wearing a shirt.

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This Egg Drop Experiment Goes All the Way to Space

Many of us tackled the egg drop experiment in science class at some point in our childhood. But this former NASA engineer took it to a whole other level. The stratosphere, to be specific. And just like you’d expect a former NASA engineer to, Mark Rober and his team constantly designed and redesigned a rig that would take an egg to space and drop it back to Earth. They had some help from other Jet Propulsion Lab alumni. And even a parachute made out of the same material used on Mars rovers. And just like the best NASA projects, years of trials, failures, and scrubbed launches are necessary steps to this successful project.

After starting the project three years ago, the video above thankfully ends in triumph. And it has over 17 million views in the few days since it was posted! Both the egg in the rocket and the redundant backup egg Rober insisted on including land back on Earth fully intact. Though the rig cut them loose at 100,000 feet (which is “only” about 19 miles up) rather than technically in space (which is about three times that high). The only thing missing is someone breaking the egg at the end to prove it was a regular egg. We’re sure they didn’t hard boil it in advance. But they do mention the addition of a warming device to keep the egg from freezing on the way up.

Rober jokes about creating the world’s largest mattress and executing the world’s tallest egg drop. Even if those aren’t actual records he’s chasing, he already holds two Guinness World Records. One for highest elephant’s toothpaste fountain and the other for most dominoes set up and toppled in one hour. The Mark Rober YouTube channel has those and other fun but unnecessary feats of engineering, including the increasingly complex mazes he sets up for backyard squirrels and wildly convoluted glitterbomb traps for package thieves.

Melissa is Nerdist’s science & technology staff writer. She also moderates “science of” panels at conventions and co-hosts Star Warsologies, a podcast about science and Star Wars. Follow her on Twitter @melissatruth.



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China space station will run high-energy beam experiment: chief scientist – South China Morning Post

  1. China space station will run high-energy beam experiment: chief scientist South China Morning Post
  2. China Could Set Up ‘Moon Base’ By 2028; Lunar Station Likely To Be Powered By Nuclear Energy – Chief Designer EurAsian Times
  3. China to use space station to test space-based solar power SpaceNews
  4. China to build solar power plant in space ‘by 2028’ – and send energy back to Earth with ‘laser beam’… The Sun
  5. Basic structure for Intl Lunar Research Station to be built by 2028: China lunar exploration chief designer Global Times
  6. View Full Coverage on Google News

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Astonishing Experiment Shows Bumble Bees “Play” With Objects

First-ever study shows that bumble bees ‘play’. The experiment, in which bumble bees rolled wooden balls, was the first time that object play behavior has been shown in an insect.

Bumble bees play, according to new research published in the journal Animal Behaviour.  It is the first time that object play behavior has been shown in an insect, adding to mounting evidence that bees may experience positive ‘feelings’.

Numerous experiments were set up by a team of researchers, who were led by scientists from Queen Mary University of London, to test their hypothesis. They showed that bumble bees went out of their way to roll wooden balls repeatedly despite there being no apparent incentive for doing so.

According to the findings, younger bees rolled more balls than older bees. These results mirrored the human behavior of young children and other juvenile mammals and birds being the most playful. Additionally, male bees rolled the balls for longer than their female counterparts.

Forty-five bumble bees were followed in the study as they went through an arena. They were given the option of walking through an unobstructed path to reach a feeding area or deviating from this path into the areas with wooden balls. Individual bees rolled balls between 1 and, impressively, 117 times over the experiment. The repeated behavior suggested that ball-rolling was rewarding.

This was further supported by another experiment where a different set of 42 bees was given access to two colored chambers. One chamber always contained movable balls, while the other one did not have any objects. When tested later and given a choice between the two chambers, neither containing balls at the time, bees showed a preference for the color of the chamber previously associated with the wooden balls. The set-up of the experiments removed any notion that the bees were moving the balls for any greater purpose other than play. Rolling balls did not contribute to survival strategies, such as gaining food, clearing clutter, or mating and was done under stress-free conditions.

The study expands on earlier work from the same Queen Mary lab that showed that bumble bees can be trained to score goals by rolling a balls to targets in exchange for a sugary food reward. During the previous experiment, the team observed that bumble bees rolled balls outside of the experiment, without getting any food reward. The new research demonstrated that the bees rolling balls repeatedly without being trained and without receiving any food for doing so — it was voluntary and spontaneous — therefore akin to play behavior as seen in other animals.

Samadi Galpayage, first author on the study and PhD student at Queen Mary University of London said: “It is certainly mind-blowing, at times amusing, to watch bumble bees show something like play. They approach and manipulate these ‘toys’ again and again. It goes to show, once more, that despite their little size and tiny brains, they are more than small robotic beings. They may actually experience some kind of positive emotional states, even if rudimentary, like other larger fluffy, or not so fluffy, animals do. This sort of finding has implications to our understanding of sentience and welfare of insects and will, hopefully, encourage us to respect and protect life on Earth ever more.”

Professor Lars Chittka, Professor of Sensory and Behavioural Ecology at Queen Mary University of London, head of the lab and author of the recent book ‘The Mind of a Bee’, said: “This research provides a strong indication that insect minds are far more sophisticated than we might imagine. There are lots of animals who play just for the purposes of enjoyment, but most examples come from young mammals and birds.

“We are producing ever-increasing amounts of evidence backing up the need to do all we can to protect insects that are a million miles from the mindless, unfeeling creatures they are traditionally believed to be.”

Reference: “Do bumble bees play?” by Hiruni Samadi Galpayage Dona, Cwyn Solvi, Amelia Kowalewska, Kaarle Mäkelä, HaDi MaBouDi and Lars Chittka, 19 October 2022, Animal Behaviour.
DOI: 10.1016/j.anbehav.2022.08.013



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Astonishing Experiment Shows Bumble Bees “Play” With Objects

First-ever study shows that bumble bees ‘play’. The experiment, in which bumble bees rolled wooden balls, was the first time that object play behavior has been shown in an insect.

Bumble bees play, according to new research published in the journal Animal Behaviour.  It is the first time that object play behavior has been shown in an insect, adding to mounting evidence that bees may experience positive ‘feelings’.

Numerous experiments were set up by a team of researchers, who were led by scientists from Queen Mary University of London, to test their hypothesis. They showed that bumble bees went out of their way to roll wooden balls repeatedly despite there being no apparent incentive for doing so.

According to the findings, younger bees rolled more balls than older bees. These results mirrored the human behavior of young children and other juvenile mammals and birds being the most playful. Additionally, male bees rolled the balls for longer than their female counterparts.

Forty-five bumble bees were followed in the study as they went through an arena. They were given the option of walking through an unobstructed path to reach a feeding area or deviating from this path into the areas with wooden balls. Individual bees rolled balls between 1 and, impressively, 117 times over the experiment. The repeated behavior suggested that ball-rolling was rewarding.

This was further supported by another experiment where a different set of 42 bees was given access to two colored chambers. One chamber always contained movable balls, while the other one did not have any objects. When tested later and given a choice between the two chambers, neither containing balls at the time, bees showed a preference for the color of the chamber previously associated with the wooden balls. The set-up of the experiments removed any notion that the bees were moving the balls for any greater purpose other than play. Rolling balls did not contribute to survival strategies, such as gaining food, clearing clutter, or mating and was done under stress-free conditions.

The study expands on earlier work from the same Queen Mary lab that showed that bumble bees can be trained to score goals by rolling a balls to targets in exchange for a sugary food reward. During the previous experiment, the team observed that bumble bees rolled balls outside of the experiment, without getting any food reward. The new research demonstrated that the bees rolling balls repeatedly without being trained and without receiving any food for doing so — it was voluntary and spontaneous — therefore akin to play behavior as seen in other animals.

Samadi Galpayage, first author on the study and PhD student at Queen Mary University of London said: “It is certainly mind-blowing, at times amusing, to watch bumble bees show something like play. They approach and manipulate these ‘toys’ again and again. It goes to show, once more, that despite their little size and tiny brains, they are more than small robotic beings. They may actually experience some kind of positive emotional states, even if rudimentary, like other larger fluffy, or not so fluffy, animals do. This sort of finding has implications to our understanding of sentience and welfare of insects and will, hopefully, encourage us to respect and protect life on Earth ever more.”

Professor Lars Chittka, Professor of Sensory and Behavioural Ecology at Queen Mary University of London, head of the lab and author of the recent book ‘The Mind of a Bee’, said: “This research provides a strong indication that insect minds are far more sophisticated than we might imagine. There are lots of animals who play just for the purposes of enjoyment, but most examples come from young mammals and birds.

“We are producing ever-increasing amounts of evidence backing up the need to do all we can to protect insects that are a million miles from the mindless, unfeeling creatures they are traditionally believed to be.”

Reference: “Do bumble bees play?” by Hiruni Samadi Galpayage Dona, Cwyn Solvi, Amelia Kowalewska, Kaarle Mäkelä, HaDi MaBouDi and Lars Chittka, 19 October 2022, Animal Behaviour.
DOI: 10.1016/j.anbehav.2022.08.013



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Mystery of Earth’s Missing Mineral Has Been Solved in a Hot New Experiment : ScienceAlert

Peering down through the layers that make up Earth – the crust, the upper mantle, the lower mantle, and the core – is no easy task. After all, it’s not as if there’s a cross-section of the planet readily available for study.

Now scientists think they have discovered a new mineral in the lower mantle, a section that makes up 55 percent of the total volume of Earth.

We already know about the layer’s three main minerals – bridgmanite, ferropericlase and davemaoite – but there could well be another. What has puzzled researchers for some time is bridgmanite and davemaoite should theoretically merge together at high temperatures, thanks to their similar crystalline arrangements (technically known as a perovskite structure).

However, previous experiments haven’t shown this to be the case.

“Why do davemaoite and bridgmanite not merge into one despite the fact that they have very similar atomic-scale structures? This question has fascinated researchers over two decades,” says geoscientist Dan (Sang-Heon) Shim from Arizona State University.

“Many attempts have been made to find conditions where these two minerals merge, yet the answer from experiments has been consistently two separate minerals. This is where we felt we needed some fresh new ideas in experiments.”

Through a series of high-pressure heating experiments in a special chamber, the researchers attempted to simulate the conditions throughout the lower mantle. Crucially, they increased temperatures very quickly, reaching around 1,650 to 1,925 degrees Celsius (3,000 to 3,500 degrees Fahrenheit) in less than a second, before rising to temperatures of around 2,800 degrees Celsius.

The small, heated samples – now at temperatures representative of the topmost layer of the lower mantle down to the deep lower mantle – were then observed through X-ray imaging to map the structure of its minerals. Unexpectedly, at temperatures approaching 2,000 degrees Celsius and above, a single perovskite mineral was shown to form, a combination of both davemaoite and bridgmanite.

This points to the deeper part of the lower mantle having a different mineralogy mix to the section higher up, because of the greater temperature and pressure. A merging of bridgmanite and davemaoite lower down would add an extra mineral to consider, and the researchers think that iron probably plays an important role.

“It has been believed that a large size difference between calcium and magnesium, the major cations of davemaoite and bridgmanite, respectively, should hinder these two minerals from merging,” says mineralogist Byeongkwan Ko from Michigan State University.

“But our study shows that they can overcome such difference in hot environments.”

Earth’s mantle was previously much hotter than it is today, which suggests that perovskite mineral merging would have been more prevalent – and therefore that the geological composition has been altered significantly over time.

These findings match up with previous research suggesting that the properties of the lower mantle change the deeper it goes. This is something that future studies will be able to analyze further – both in terms of its current state and its state in the past.

“Our finding requires revision of the deep-mantle mineralogy models and will have an impact on our understanding of the composition, structure, dynamics, and evolution of the region,” write the researchers in their published paper.

The research has been published in Nature.

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