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  • richardmitnick 11:19 am on February 5, 2021 Permalink | Reply
    Tags: "Has life existed beyond Earth? Purdue professor going to great lengths to find out", Briony Horgan, Mars reseach, , NASA plans to send a return mission in the next decade to retrieve the samples., One of the best things about a Mars mission like this is that it's a great opportunity for students to get involved., Perseverance will spend its time taking photographs; video; and pulverizing rock by shooting lasers., Perseverance will spend its time using microscopes to search for organic molecules; drilling; analyzing; and doing a variety of science chores., , Purdue scientist plays a critical role in 2020 NASA Mars rover mission., Purdue University, Searching for signs of past life on the red planet., The attention will be on a 7-foot robotic arm on the exterior of the rover; at the end of the arm is a lawn-mower-sized cluster of instruments., The first Mars rover-the diminutive microwave-sized Sojourner-landed on the Fourth of July in 1997., The scientists are looking for signs of past life by looking for biosignatures which are clues that life once existed there., This will all produce enormous volumes of data that will take the scientists years to analyze.   

    From Purdue University: “Has life existed beyond Earth? Purdue professor going to great lengths to find out” Briony Horgan 

    From Purdue University

    1
    Briony Horgan, associate professor of Earth, Atmospheric, and Planetary Sciences at Purdue University, is working to determine whether we are alone in the universe or if life once existed on other planets such as Mars. Credit: John Underwood/Purdue University.

    2
    Briony Horgan, associate professor of earth, atmospheric, and planetary sciences at Purdue University, is working to determine whether we are alone in the universe, or if life once existed on other planets such as Mars. Credit: John Underwood/Purdue University.

    July 22, 2020 [Just now in social media.I have not done much on Perseverance, so I seized on this article because it tells such a complete story.]

    Steve Tally
    steve@purdue.edu

    Purdue scientist plays a critical role in 2020 NASA Mars rover mission.

    When the NASA Mars rover Perseverance launches in the next few weeks, it will travel to Jezero Crater, which preserves evidence of a time when rivers flowed on Mars.

    Perseverence

    NASA Perseverance Mars Rover.

    The mission will take the next leap in space science by searching for signs of past life on the red planet. Not the Martians of comic-book science fiction, but instead ancient microbes may have lived in Mars’ rivers, lakes and swamps billions of years ago.

    This scientifically important landing site within Jezero Crater was selected by NASA following a presentation by Briony Horgan, Purdue University associate professor of planetary science, who is a member of the Perseverance science team. Horgan led a study of the mineralogy of the site, which produced one of the major results that contributed to its selection. She was also on the team that designed the camera that will be the scientific eyes for Perseverance.

    2
    The Mars rover Perseverance will arrive at the red planet in February 2021. Purdue planetary scientist Briony Horgan was part of the science team that selected the landing site in Jezero Crater, just north of the planet’s equator. Credit: Corrine Rojas/NASA Ames/USGS/JPL/.

    The Mission

    The primary mission of the Perseverance rover is to look for signs of past life on Mars. Horgan and her colleagues approach the work like forensic detectives, looking for clues and literally microscopic bits of evidence.

    If there had been life on the Red Planet, it would have left behind chemical clues that the scientists hope can still be found in the rock.

    “The goal of this mission is to look for signs of ancient life on Mars and then also collect samples for future return to Earth, Horgan says. “It’s possibly the only chance we’ll ever have to get to do both of those things, especially the sample return. It’s really hard to do, and it’s expensive.

    “We know we might only have this one chance to do this, and it was tough to select the site. If we had to choose just one spot on Earth to gather all the data about the entire history of the planet — well, where would you go? But we think Jezero Crater is the best location to search for evidence that life existed on Mars, if it ever did. And what we find will help us learn more about whether or not we are alone in the universe.”

    Perseverance will spend its time taking photographs, video, pulverizing rock by shooting lasers (so that scientists can determine the chemical composition), using microscopes to search for organic molecules, drilling, analyzing and doing a variety of science chores. This will produce enormous volumes of data that will take the scientists years to analyze.

    NASA plans to send a return mission in the next decade to retrieve the samples, which will be stored in Perseverance.

    “Bringing samples back from Mars would be amazing,” Horgan says. “It would not only be a feat of engineering to retrieve the samples and return them, but it would be the first time we would have samples brought back to Earth from another planet. That would be quite historic.”

    4
    The Mars rover Perseverance is an SUV-sized feat of engineering that is both an advanced spacecraft and a mobile scientific laboratory. Purdue planetary scientist Briony Horgan was part of a team that designed some of the scientific instruments, including the stereo Mastcam-Z camera. Credit: NASA/JPL-Caltech.

    The Rover

    The first Mars rover, the diminutive, microwave-sized Sojourner, landed on the Fourth of July in 1997.

    NASA Mars Sojourner 1996-1997.

    The American public found the rover fascinating —possibly even adorable — and Hot Wheels soon began producing a popular toy model of the craft.

    The car-sized Perseverance, NASA’s fifth Mars rover, more than makes up in scientific capability for what it lacks in toy-like cuteness. It is the largest, heaviest rover, and contains a futuristic suite of technologies. It has lasers to vaporize rock (so that scientists can view the light wavelengths produced to understand the chemical composition), autonomous driving capabilities so that it can move above the speed of a crawl to the next research site, drills to collect pencil-sized samples, an internal robotic system to collect and store the samples, a test system for creating breathable oxygen from Mars’ atmosphere. And, as the late Steve Jobs might say, one more thing: a helicopter-like drone, which will attempt to fly in an atmosphere that is 100 times thinner than that of Earth.

    But for the science team, the attention will be on a 7-foot robotic arm on the exterior of the rover; at the end of the arm is a lawn-mower-sized cluster of instruments.

    “This robotic arm is really the workhorse,” Horgan says. “We can place it with millimeter precision, which is incredible. And out on the arm are these amazing microscopes that we can use to map minerals and organic materials at very fine scale.”

    Atop the mast of the rover is a special dual-lens camera, Mastcam-Z, that Horgan has a special affinity to because she is part of the team that designed it and will help to operate the camera on Mars.

    The camera has a zoom capability strong enough that it could be used to view a house fly at the far end of a soccer field. The camera can record images in color, in 3D, and in video. It is precise enough that the scientists can use it for compositional analysis of the surrounding terrain.

    “We can actually do some really simple spectroscopy looking at the wavelength dependence of sunlight reflected off of rocks to help identify their mineral fingerprints,” Horgan says.

    5
    The landing site for the Mars rover Perseverance is shown with the oval circle on the edge of Jezero Crater. The landing site is at the edge of what is thought to be an ancient river delta. In this image, green is higher elevation and blue is lower elevation. Purdue University planetary scientist Briony Horgan was a member of the team of scientists that identified and selected the landing site. Credit: NASA/JPL-Caltech.

    The Landing Site

    Perseverance is expected to land in a specific location north of the Martian equator in a 28-mile-wide crater named Jezero, a site selected by a scientific team. The site is attractive because it’s thought that the crater once contained a lake about the size of Lake Tahoe.

    “If you look at the site, you can see evidence of a big river channel leading into the crater, creating a delta where it entered a lake, and a second big river channel leading out of the crater,” Horgan says. “This landing site is exciting because we have really clear evidence that this ancient lake existed, that it had persistent liquid water for a long enough time to create this ancient delta, and that there was enough water flow to overflow out the other side to create the outflow channel. This suggests that the lake was a long-lived and stable environment that could have been inhabited by ancient microbial life.”

    The rover will attempt to land at the edge of the crater near the delta so it can explore both landscapes. The target site is known as the “landing ellipse.”

    “The landing ellipse for Mars 2020 is about 7-by-9 kilometers [4.4 by 5.6 miles], which is actually very small. If you think back to even 17 years ago, when we sent two rovers, Spirit and Opportunity, to Mars, their landing ellipse was about 100 kilometers long for each of them. So, we’ve gotten really good at pinpointing our landing,” she says.

    6
    Scientists looking for signs of past life on Mars are focusing on an area rich in minerals called carbonates (the green color in this image), which on Earth are known for preserving fossilized life. Credit: NASA/JPL-Caltech/MSSS/JHU-APL/Purdue/USGS.

    The Science

    For this Mars mission, the scientists are looking for signs of past life by looking for biosignatures, which are clues that life once existed there. Biosignatures can vary from something as small as specific isotopes or chemicals produced by living things, such as cholesterol, to something much larger, such as microscopic fossils.

    “A dinosaur bone is an example of a biosignature that we find in ancient rocks on Earth,” Horgan says. “I would love to find evidence that dinosaurs once roamed Mars, but instead we are going to be looking for biosignatures of bacteria-sized microbes.”

    This is where the stored samples on Perseverance come into play. The plan is for a separate mission, to be done in partnership with the European Space Agency, to return to Mars and retrieve the samples.

    “Once the samples are back on Earth, we can use much more powerful tools, such as scanning electron microscopes, to confirm whether these biosignatures were created by microbes,” she says.

    “As part of our work to evaluate Jezero during site selection, I led a team to study the mineralogy of the lake deposits. And we came up with some really cool results [Icarus].”

    Horgan and her colleagues discovered evidence of carbonates around the edge of the former lake, in what Horgan describes as a “bathtub ring.” The ring of carbonates occurs right where ancient shorelines and beaches for the lake are predicted, so the team proposed that they formed on the edge of the lake.

    On Earth, carbonates are known for two things. One, they indicate that the site where they are found once contained water. Second, they form sediments that are usually rich in fossils.

    “This is really exciting because that’s exactly the kind of place you would go to look for microbial biosignatures from a lake on Earth. When those minerals precipitate out of water, they can trap anything, including microbes and organic materials,” she says. “So, we’ve been doing a lot of work on the team to try to plan how we’re going to explore this site.”

    The Launch

    2020 will be the summer of Mars launches, with rockets blasting off from the United States, China, and a United Arab Emirates rocket, which launched from Japan.

    The rover will launch on top of a two-stage Atlas rocket sometime during the launch window, which extends from July 30 to Aug. 15. It is expected to arrive at Mars in February 2021.

    Horgan had planned to attend the launch of Perseverance, but because of the dramatically increasing number of cases of COVID-19, the launch viewing has been canceled, so she will watch it from West Lafayette.

    “Several years ago, I was able to watch the Mars Science Laboratory launch. It was one of the best moments of my life because it’s the result of so many years of scientific and engineering effort, and the launch is just the best feeling. It’s incredible,” she says.

    Horgan contrasts the thrill of the launch with the anxiety of the landing.

    “The landing is always so stressful because you’re basically sending your prized rover, which you’ve spent so many hours thinking about and working on, in a giant fireball to slam into the surface of a planet,” she says. “The fireball forms because the rover enters Mars’ atmosphere at 13,000 mph, generating a huge envelope of plasma around the rover. You can’t get radio signals through the plasma fireball. It takes seven minutes for the rover to go down to the surface from when it enters the atmosphere.

    “But it also takes seven minutes for the radio signal to get back to Earth. So, by the time we receive the signal that the rover has hit the atmosphere, either it is actually on the surface of the planet doing well, or it has crashed into the surface. You just don’t know, so we’ll be anxiously waiting to get that first signal back from the rover to know that it landed safely. That’s why we call it the seven minutes of terror.”

    The Future

    “One of the best things about a Mars mission like this is that it’s a great opportunity for students to get involved. I have a couple of graduate students who are helping with landing site analysis on the team and will help operate the rover on Mars,” Horgan says. “We’re planning to have undergrads back at Purdue also working on rover data processing and analysis.

    Sometimes the work with students includes field work at sites on Earth that may resemble terrain on Mars, which scientists call an analog environment. For example, in September 2019 Horgan, Ph.D. student Bradley Garczynski, and a research team traveled eight hours from Istanbul, Turkey, to a deep lake, Lake Salda. The lake has carbonates and fossilized microbes in the form of stromatolites, exactly of the type that the Mars scientists hope to find on Jezero Crater.

    “This is how we train the future of planetary science. We bring them onto the mission, and years from now they can become mission leaders,” Horgan says.

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Purdue University is a public research university in West Lafayette, Indiana, and the flagship campus of the Purdue University system. The university was founded in 1869 after Lafayette businessman John Purdue donated land and money to establish a college of science, technology, and agriculture in his name. The first classes were held on September 16, 1874, with six instructors and 39 students.

    The main campus in West Lafayette offers more than 200 majors for undergraduates, over 69 masters and doctoral programs, and professional degrees in pharmacy and veterinary medicine. In addition, Purdue has 18 intercollegiate sports teams and more than 900 student organizations. Purdue is a member of the Big Ten Conference and enrolls the second largest student body of any university in Indiana, as well as the fourth largest foreign student population of any university in the United States.

     
  • richardmitnick 12:14 pm on November 21, 2020 Permalink | Reply
    Tags: "One-step multicomponent reaction with interpretable machine learning innovation to develop chemical library for drug discovery", , , Developing new and fast reactions is essential for chemical library design in drug discovery., Machine learning has been used widely in the chemical sciences for drug design and other processes., Purdue University   

    From Purdue University: “One-step multicomponent reaction with interpretable machine learning innovation to develop chemical library for drug discovery” 

    From Purdue University

    November 17, 2020

    Writer:
    Chris Adam
    cladam@prf.org

    Source:
    Gaurav Chopra
    gchopra@purdue.edu

    1
    Purdue University scientists are using machine learning models to create new options for drug discovery pipelines. (Image provided.)

    Machine learning has been used widely in the chemical sciences for drug design and other processes.

    The models that are prospectively tested for new reaction outcomes and used to enhance human understanding to interpret chemical reactivity decisions made by such models are extremely limited.

    Purdue University innovators have introduced chemical reactivity flowcharts to help chemists interpret reaction outcomes using statistically robust machine learning models trained on a small number of reactions. The work is published in Organic Letters.

    “Developing new and fast reactions is essential for chemical library design in drug discovery,” said Gaurav Chopra, an assistant professor of analytical and physical chemistry in Purdue’s College of Science. “We have developed a new, fast and one-pot multicomponent reaction (MCR) of N-sulfonylimines that was used as a representative case for generating training data for machine learning models, predicting reaction outcomes and testing new reactions in a blind prospective manner.

    “We expect this work to pave the way in changing the current paradigm by developing accurate, human understandable machine learning models to interpret reaction outcomes that will augment the creativity and efficiency of human chemists to discover new chemical reactions and enhance organic and process chemistry pipelines.”

    Chopra said the Purdue team’s human-interpretable machine learning approach, introduced as chemical reactivity flowcharts, can be extended to explore the reactivity of any MCR or any chemical reaction. It does not need large-scale robotics since these methods can be used by the chemists while doing reaction screening in their laboratories.

    “We provide the first report of a framework to combine fast synthetic chemistry experiments and quantum chemical calculations for understanding reaction mechanism and human-interpretable statistically robust machine learning models to identify chemical patterns for predicting and experimentally testing heterogeneous reactivity of N-sulfonylimines,” Chopra said.

    2
    Purdue University innovators have introduced chemical reactivity flowcharts to help chemists interpret reaction outcomes using statistically robust machine learning models trained on a small number of reactions. (Stock photo.)

    This work aligns with other innovations and research from Chopra’s labs, whose team members work with the Purdue Research Foundation Office of Technology Commercialization to patent numerous technologies. To find out more information about their patented inventions, contact otcip@prf.org.

    “The unprecedented use of a machine learning model in generating chemical reactivity flowcharts helped us to understand the reactivity of traditionally used different N-sulfonylimines in MCRs,” said Krupal Jethava, a postdoctoral fellow in Chopra’s laboratory, who co-authored the work. “We believe that working hand-to-hand with organic and computational chemists will open up a new avenue for solving complex chemical reactivity problems for other reactions in the future.”

    Chopra said the Purdue researchers hope their work will pave the way to become one of many examples that will showcase the power of machine learning for new synthetic methodology development for drug design and beyond in the future.

    “In this work, we strived to ensure that our machine learning model can be easily understood by chemists not well versed in this field,” said Jonathan Fine, a former Purdue graduate student, who co-authored the work. “We believe that these models have the ability not only be used to predict reactions but also be used to better understand when a given reaction will occur. To demonstrate this, we used our model to guide additional substrates to test whether a reaction will occur.”

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Purdue University is a public research university in West Lafayette, Indiana, and the flagship campus of the Purdue University system. The university was founded in 1869 after Lafayette businessman John Purdue donated land and money to establish a college of science, technology, and agriculture in his name. The first classes were held on September 16, 1874, with six instructors and 39 students.

    The main campus in West Lafayette offers more than 200 majors for undergraduates, over 69 masters and doctoral programs, and professional degrees in pharmacy and veterinary medicine. In addition, Purdue has 18 intercollegiate sports teams and more than 900 student organizations. Purdue is a member of the Big Ten Conference and enrolls the second largest student body of any university in Indiana, as well as the fourth largest foreign student population of any university in the United States.

     
  • richardmitnick 4:05 pm on September 4, 2020 Permalink | Reply
    Tags: "New evidence that the quantum world is even stranger than we thought", Anyons display this behavior only as collective crowds of electrons where many electrons behave as one under very extreme and specific conditions., Anyons maintain a "memory" of their interactions with other quasiparticles by inducing quantum mechanical phase changes., Anyons respond as if they have a fractional charge and even more interestingly create a nontrivial phase change as they braid around one another., , Experimental evidence of quasiparticles called anyons has been found by a team of scientists at Purdue University., In the case of our anyons the phase generated by braiding was 2π/3., , Purdue University, , Quasiparticles called "anyons", They are more robust in their properties than other quantum particles. This characteristic is said to be topological.   

    From Purdue University: “New evidence that the quantum world is even stranger than we thought” 

    From Purdue University

    September 4, 2020

    Writer, Media contact:
    Steve Tally
    steve@purdue.edu

    Sources:
    Michael Manfra
    mmanfra@purdue.edu

    James Nakamura
    jnakamur@purdue.edu

    1
    Experimental evidence of quasiparticles called anyons has been found by a team of scientists at Purdue University. Electrical interference in the experiment created a pattern which the researchers called a “pyjama plot”; jumps in the interference pattern were the signature of the presence of anyons. (Purdue University image/James Nakamura.)

    New experimental evidence of a collective behavior of electrons to form “quasiparticles” called “anyons” has been reported by a team of scientists at Purdue University.

    Anyons have characteristics not seen in other subatomic particles, including exhibiting fractional charge and fractional statistics that maintain a “memory” of their interactions with other quasiparticles by inducing quantum mechanical phase changes.

    Postdoctoral research associate James Nakamura, with assistance from research group members Shuang Liang and Geoffrey Gardner, made the discovery while working in the laboratory of professor Michael Manfra. Manfra is a Distinguished Professor of Physics and Astronomy, Purdue’s Bill and Dee O’Brien Chair Professor of Physics and Astronomy, professor of electrical and computer engineering, and professor of materials engineering. Although this work might eventually turn out to be relevant to the development of a quantum computer, for now, Manfra said, it is to be considered an important step in understanding the physics of quasiparticles.

    A research paper on the discovery was published in this week’s Nature Physics.

    Nobel Prize-winning theoretical physicist Frank Wilczek, professor of physics at MIT, gave these quasiparticles the tongue-in-cheek name “anyon” due to their strange behavior because unlike other types of particles, they can adopt “any” quantum phase when their positions are exchanged.

    2
    Scientists at Purdue have announced new experimental evidence of a collective behavior of electrons to form “quasiparticles” called “anyons.” The team was able to demonstrate this behavior by routing the electrons through a specific maze-like etched nanostructure in a nanoscale device called an interferometer. (Purdue University image/James Nakamura.)

    Before the growing evidence of anyons in 2020, physicists had categorized particles in the known world into two groups: fermions and bosons. Electrons are an example of fermions, and photons, which make up light and radio waves, are bosons. One characteristic difference between fermions and bosons is how the particles act when they are looped, or braided, around each other. Fermions respond in one straightforward way, and bosons in another expected and straightforward way.

    Anyons respond as if they have a fractional charge, and even more interestingly, create a nontrivial phase change as they braid around one another. This can give the anyons a type of “memory” of their interaction.

    “Anyons only exist as collective excitations of electrons under special circumstances,” Manfra said. “But they do have these demonstrably cool properties including fractional charge and fractional statistics. It is funny, because you think, ‘How can they have less charge than the elementary charge of an electron?’ But they do.”

    Manfra said that when bosons or fermions are exchanged, they generate a phase factor of either plus one or minus one, respectively.

    “In the case of our anyons the phase generated by braiding was 2π/3,” he said. “That’s different than what’s been seen in nature before.”

    Anyons display this behavior only as collective crowds of electrons, where many electrons behave as one under very extreme and specific conditions, so they are not thought to be found isolated in nature, Nakamura said.

    “Normally in the world of physics, we think about fundamental particles, such as protons and electrons, and all of the things that make up the periodic table,” he said. “But we study the existence of quasiparticles, which emerge from a sea of electrons that are placed in certain extreme conditions.”

    Because this behavior depends on the number of times the particles are braided, or looped, around each other, they are more robust in their properties than other quantum particles. This characteristic is said to be topological [WolframMathWorld] because it depends on the geometry of the system and may eventually lead to much more sophisticated anyon structures that could be used to build stable, topological quantum computers.

    The team was able to demonstrate this behavior by routing the electrons through a specific maze-like etched nanostructure made of gallium arsenide and aluminum gallium arsenide. This device, called an interferometer, confined the electrons to move in a two-dimensional path. The device was cooled to within one-hundredth of a degree from absolute zero (10 millikelvin), and subjected to a powerful 9-Tesla magnetic field. The electrical resistance of the interferometer generated an interference pattern which the researchers called a “pyjama plot.” Jumps in the interference pattern were the signature of the presence of anyons.

    “It is definitely one of the more complex and complicated things to be done in experimental physics,” Chetan Nayak, theoretical physicist at the University of California, Santa Barbara told Science News.

    Nakamura said the facilities at Purdue created the environment for this discovery to happen.

    “We have the technology to grow the gallium arsenide semiconductor that’s needed to realize our electron system. We have the nanofabrication facilities in the Birck Nanotechnology Center to make the interferometer, the device we used in our experiments. In the physics department, we have the ability to measure ultra-low temperatures and to create strong magnetic fields.” he said. “So, we have all of the necessary components that allowed us to make this discovery all here at Purdue. That’s a great thing about doing research here and why we’ve been able to make this progress.”

    Manfra said the next step in the quasiparticle frontier will involve building more complicated interferometers.

    “In the new interferometers we will have the ability to control the location and number of quasiparticles in the chamber,” he said. “Then we will be able to change the number of quasiparticles inside the interferometer on demand and change the interference pattern as we choose.”

    This research was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under award number DE-SC0020138.

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Purdue University is a public research university in West Lafayette, Indiana, and the flagship campus of the Purdue University system. The university was founded in 1869 after Lafayette businessman John Purdue donated land and money to establish a college of science, technology, and agriculture in his name. The first classes were held on September 16, 1874, with six instructors and 39 students.

    The main campus in West Lafayette offers more than 200 majors for undergraduates, over 69 masters and doctoral programs, and professional degrees in pharmacy and veterinary medicine. In addition, Purdue has 18 intercollegiate sports teams and more than 900 student organizations. Purdue is a member of the Big Ten Conference and enrolls the second largest student body of any university in Indiana, as well as the fourth largest foreign student population of any university in the United States.

     
  • richardmitnick 12:30 pm on May 15, 2020 Permalink | Reply
    Tags: "Artificial intelligence is energy-hungry. New hardware could curb its appetite", , , , , Purdue University,   

    From Purdue University: “Artificial intelligence is energy-hungry. New hardware could curb its appetite” 

    From Purdue University

    May 7, 2020
    Kayla Wiles,
    wiles5@purdue.edu

    Shriram Ramanathan
    shriram@purdue.edu

    Hai-Tian Zhang
    HTZhang@purdue.edu

    1
    Researchers have developed new hardware for artificial intelligence. (Purdue University image/Qi Wang)

    Just to solve a puzzle or play a game, artificial intelligence can require software running on thousands of computers. That could be the energy that three nuclear plants produce in one hour.

    A team of engineers has created hardware that can learn skills using a type of AI that currently runs on software platforms. Sharing intelligence features between hardware and software would offset the energy needed for using AI in more advanced applications such as self-driving cars or discovering drugs.

    “Software is taking on most of the challenges in AI. If you could incorporate intelligence into the circuit components in addition to what is happening in software, you could do things that simply cannot be done today,” said Shriram Ramanathan, a professor of materials engineering at Purdue University.

    AI hardware development is still in early research stages. Researchers have demonstrated AI in pieces of potential hardware, but haven’t yet addressed AI’s large energy demand.

    As AI penetrates more of daily life, a heavy reliance on software with massive energy needs is not sustainable, Ramanathan said. If hardware and software could share intelligence features, an area of silicon might be able to achieve more with a given input of energy.

    Ramanathan’s team is the first to demonstrate artificial “tree-like” memory in a piece of potential hardware at room temperature. Researchers in the past have only been able to observe this kind of memory in hardware at temperatures that are too low for electronic devices.

    The results of this study are published in the journal Nature Communications.

    The hardware that Ramanathan’s team developed is made of a so-called quantum material. These materials are known for having properties that cannot be explained by classical physics.

    Ramanathan’s lab has been working to better understand these materials and how they might be used to solve problems in electronics.

    Software uses tree-like memory to organize information into various “branches,” making that information easier to retrieve when learning new skills or tasks.

    The strategy is inspired by how the human brain categorizes information and makes decisions.

    “Humans memorize things in a tree structure of categories. We memorize ‘apple’ under the category of ‘fruit’ and ‘elephant’ under the category of ‘animal,’ for example,” said Hai-Tian Zhang, a Lillian Gilbreth postdoctoral fellow in Purdue’s College of Engineering. “Mimicking these features in hardware is potentially interesting for brain-inspired computing.”

    The team introduced a proton to a quantum material called neodymium nickel oxide. They discovered that applying an electric pulse to the material moves around the proton. Each new position of the proton creates a different resistance state, which creates an information storage site called a memory state. Multiple electric pulses create a branch made up of memory states.

    “We can build up many thousands of memory states in the material by taking advantage of quantum mechanical effects. The material stays the same. We are simply shuffling around protons,” Ramanathan said.

    Through simulations of the properties discovered in this material, the team showed that the material is capable of learning the numbers 0 through 9. The ability to learn numbers is a baseline test of artificial intelligence.

    The demonstration of these trees at room temperature in a material is a step toward showing that hardware could offload tasks from software.

    “This discovery opens up new frontiers for AI that have been largely ignored because implementing this kind of intelligence into electronic hardware didn’t exist,” Ramanathan said.

    The material might also help create a way for humans to more naturally communicate with AI.

    “Protons also are natural information transporters in human beings. A device enabled by proton transport may be a key component for eventually achieving direct communication with organisms, such as through a brain implant,” Zhang said.

    Researchers at the University of California, San Diego, studied the quantum material test strips. The team used synchrotron facilities at the U.S. Department of Energy’s Brookhaven and Argonne National Laboratories to demonstrate that an electric pulse can move protons within neodymium nickel oxide. Other collaborating institutions are the University of Illinois, the University of Louisville and the University of Iowa.

    BNL NSLS-II

    ANL Advanced Photon Source

    The work was supported by the Lillian Gilbreth Fellowship from Purdue University’s College of Engineering, the Air Force Office of Scientific Research, and the U.S. Department of Energy.

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Purdue University is a public research university in West Lafayette, Indiana, and the flagship campus of the Purdue University system. The university was founded in 1869 after Lafayette businessman John Purdue donated land and money to establish a college of science, technology, and agriculture in his name. The first classes were held on September 16, 1874, with six instructors and 39 students.

    The main campus in West Lafayette offers more than 200 majors for undergraduates, over 69 masters and doctoral programs, and professional degrees in pharmacy and veterinary medicine. In addition, Purdue has 18 intercollegiate sports teams and more than 900 student organizations. Purdue is a member of the Big Ten Conference and enrolls the second largest student body of any university in Indiana, as well as the fourth largest foreign student population of any university in the United States.

     
  • richardmitnick 10:04 am on May 9, 2020 Permalink | Reply
    Tags: "New imaging technology allows visualization of nanoscale structures inside whole cells and tissues", , , , , , Purdue University   

    From Purdue University: “New imaging technology allows visualization of nanoscale structures inside whole cells and tissues” 

    From Purdue University

    1
    This image shows a 3D super-resolution reconstruction of dendrites in primary visual cortex. (Image provided)

    Since Robert Hooke’s first description of a cell in Micrographia 350 years ago, microscopy has played an important role in understanding the rules of life.

    However, the smallest resolvable feature, the resolution, is restricted by the wave nature of light. This century-old barrier has restricted understanding of cellular functions, interactions and dynamics, particularly at the sub-micron to nanometer scale.

    Super-resolution fluorescence microscopy overcomes this fundamental limit, offering up to tenfold improvement in resolution, and allows scientists to visualize the inner workings of cells and biomolecules at unprecedented spatial resolution.

    Such resolving capability is impeded, however, when observing inside whole-cell or tissue specimens, such as the ones often analyzed during the studies of the cancer or the brain. Light signals, emitted from molecules inside a specimen, travel through different parts of cell or tissue structures at different speeds and result in aberrations, which will deteriorate the image.

    Now, Purdue University researchers have developed a new technology to overcome this challenge.

    “Our technology allows us to measure wavefront distortions induced by the specimen, either a cell or a tissue, directly from the signals generated by single molecules – tiny light sources attached to the cellular structures of interest,” said Fang Huang, an assistant professor of biomedical engineering in Purdue’s College of Engineering. “By knowing the distortion induced, we can pinpoint the positions of individual molecules at high precision and accuracy. We obtain thousands to millions of coordinates of individual molecules within a cell or tissue volume and use these coordinates to reveal the nanoscale architectures of specimen constituents.”

    The Purdue team’s technology is recently published in Nature Methods. A video showing an animated 3D super-resolution is available at https://youtu.be/c9j621vUFBM. This tool from Purdue researchers allows visualization of nanoscale structures inside whole cells and tissues. It could allow for better understanding for diseases affecting the brain and regenerative therapies.

    “During three-dimensional super-resolution imaging, we record thousands to millions of emission patterns of single fluorescent molecules,” said Fan Xu, a postdoctoral associate in Huang’s lab and a co-first author of the publication. “These emission patterns can be regarded as random observations at various axial positions sampled from the underlying 3D point-spread function describing the shapes of these emission patterns at different depths, which we aim to retrieve. Our technology uses two steps: assignment and update, to iteratively retrieve the wavefront distortion and the 3D responses from the recorded single molecule dataset containing emission patterns of molecules at arbitrary locations.”

    The Purdue technology allows finding the positions of biomolecules with a precision down to a few nanometers inside whole cells and tissues and therefore, resolving cellular and tissue architectures with high resolution and fidelity.

    “This advancement expands the routine applicability of super-resolution microscopy from selected cellular targets near coverslips to intra- and extra-cellular targets deep inside tissues,” said Donghan Ma, a postdoctoral researcher in Huang’s lab and a co-first author of the publication. “This newfound capacity of visualization could allow for better understanding for neurodegenerative diseases such as Alzheimer’s, and many other diseases affecting the brain and various parts inside the body.”

    The National Institutes of Health provided major support for the research.

    Other members of the research team include Gary Landreth, a professor from Indiana University’s School of Medicine; Sarah Calve, an associate professor of biomedical engineering in Purdue’s College of Engineering (currently an associate professor of mechanical engineering at the University of Colorado Boulder); Peng Yin, a professor from Harvard Medical School; and Alexander Chubykin, an assistant professor of biological sciences at Purdue. The complete list of authors can be found in Nature Methods.

    “This technical advancement is startling and will fundamentally change the precision with which we evaluate the pathological features of Alzheimer’s disease,” Landreth said. “We are able to see smaller and smaller objects and their interactions with each other, which helps reveal structure complexities we have not appreciated before.”

    Calve said the technology is a step forward in regenerative therapies to help promote repair within the body.

    “This development is critical for understanding tissue biology and being able to visualize structural changes,” Calve said.

    Chubykin, whose lab focuses on autism and diseases affecting the brain, said the high-resolution imaging technology provides a new method for understanding impairments in the brain.

    “This is a tremendous breakthrough in terms of functional and structural analyses,” Chubykin said. “We can see a much more detailed view of the brain and even mark specific neurons with genetic tools for further study.”

    The team worked with the Purdue Research Foundation Office of Technology Commercialization to patent the technology. The office recently moved into the Convergence Center for Innovation and Collaboration in Discovery Park District, adjacent to the Purdue campus.

    The inventors are looking for partners to commercialize their technology. For more information on licensing this innovation, contact Dipak Narula of OTC at dnarula@prf.org.

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Purdue University is a public research university in West Lafayette, Indiana, and the flagship campus of the Purdue University system. The university was founded in 1869 after Lafayette businessman John Purdue donated land and money to establish a college of science, technology, and agriculture in his name. The first classes were held on September 16, 1874, with six instructors and 39 students.

    The main campus in West Lafayette offers more than 200 majors for undergraduates, over 69 masters and doctoral programs, and professional degrees in pharmacy and veterinary medicine. In addition, Purdue has 18 intercollegiate sports teams and more than 900 student organizations. Purdue is a member of the Big Ten Conference and enrolls the second largest student body of any university in Indiana, as well as the fourth largest foreign student population of any university in the United States.

     
  • richardmitnick 10:25 am on February 24, 2020 Permalink | Reply
    Tags: "Helix of an Elusive Rare Earth Metal Could Help Push Moore's Law to The Next Level", , , , Purdue University, Rare earth metal Tellurium, , , The tellurium helix slip neatly inside a nanotube of boron nitride.,   

    From Purdue University via Science Alert: “Helix of an Elusive Rare Earth Metal Could Help Push Moore’s Law to The Next Level” 

    From Purdue University

    via

    ScienceAlert

    Science Alert

    23 FEB 2020
    MIKE MCRAE

    1
    Tellurium helix (Qin et al., Nature Electronics, 2020)

    To cram ever more computing power into your pocket, engineers need to come up with increasingly ingenious ways to add transistors to an already crowded space.

    Unfortunately there’s a limit to how small you can make a wire. But a twisted form of rare earth metal just might have what it takes to push the boundaries a little further.

    A team of researchers funded by the US Army have discovered a way to turn twisted nanowires of one of the rarest of rare earth metals, tellurium, into a material with just the right properties that make it an ideal transistor at just a couple of nanometres across.

    “This tellurium material is really unique,” says Peide Ye, an electrical engineer from Purdue University.

    “It builds a functional transistor with the potential to be the smallest in the world.”

    Transistors are the work horse of anything that computes information, using tiny changes in charge to prevent or allow larger currents to flow.

    Typically made of semiconducting materials, they can be thought of as traffic intersections for electrons. A small voltage change in one place opens the gate for current to flow, serving as both a switch and an amplifier.

    Combinations of open and closed switches are the physical units representing the binary language underpinning logic in computer operations. As such, the more you have in one spot, the more operations you can run.

    Ever since the first chunky transistor was prototyped a little more than 70 years ago, a variety of methods and novel materials have led to regular downsizing of the transistor.

    In fact the shrinking was so regular that co-founder of the computer giant Intel, George Moore, famously noted in 1965 that it would follow a trend of transistors doubling in density every two years.

    Today, that trend has slowed considerably. For one thing, more transistors in one spot means more heat building up.

    But there are also only so many ways you can shave atoms from a material and still have it function as a transistor. Which is where tellurium comes in.

    Though not exactly a common element in Earth’s crust, it’s a semi-metal in high demand, finding a place in a variety of alloys to improve hardness and help it resist corrosion.

    It also has properties of a semiconductor; carrying a current under some circumstances and acting as a resistor under others.

    Curious about its characteristics on a nanoscale, engineers grew single-dimensional chains of the element and took a close look at them under an electron microscope. Surprisingly, the super-thin ‘wire’ wasn’t exactly a neat line of atoms.

    “Silicon atoms look straight, but these tellurium atoms are like a snake. This is a very original kind of structure,” says Ye.

    On closer inspection they worked out that the chain was made of pairs of tellurium atoms bonded strongly together, and then stacking into a crystal form pulled into a helix by weaker van der Waal forces.

    Building any kind of electronics from a crinkly nanowire is just asking for trouble, so to give the material some structure the researchers went on the hunt for something to encapsulate it in.

    The solution, they found, was a nanotube of boron nitride. Not only did the tellurium helix slip neatly inside, the tube acted as an insulator, ticking all the boxes that would make it suit life as a transistor.

    Most importantly, the whole semiconducting wire was a mere 2 nanometres across, putting it in the same league as the 1 nanometre record set a few years ago.

    Time will tell if the team can squeeze it down further with fewer chains, or even if it will function as expected in a circuit.

    If it works as hoped, it could contribute to the next generation of miniaturised electronics, potentially halving the size of current cutting edge microchips.

    “Next, the researchers will optimise the device to further improve its performance, and demonstrate a highly efficient functional electronic circuit using these tiny transistors, potentially through collaboration with ARL researchers,” says Joe Qiu, program manager for the Army Research Office.

    Even if the concept pans out, there’s a variety of other challenges for shrinking technology to overcome before we’ll find it in our pockets.

    While tellurium isn’t currently considered to be a scarce resource, in spite of its relative rarity, it could be in high demand in future electronics such as solar cells.

    This research was published in Nature Electronics.

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Purdue University is a public research university in West Lafayette, Indiana, and the flagship campus of the Purdue University system. The university was founded in 1869 after Lafayette businessman John Purdue donated land and money to establish a college of science, technology, and agriculture in his name. The first classes were held on September 16, 1874, with six instructors and 39 students.

    The main campus in West Lafayette offers more than 200 majors for undergraduates, over 69 masters and doctoral programs, and professional degrees in pharmacy and veterinary medicine. In addition, Purdue has 18 intercollegiate sports teams and more than 900 student organizations. Purdue is a member of the Big Ten Conference and enrolls the second largest student body of any university in Indiana, as well as the fourth largest foreign student population of any university in the United States.

     
  • richardmitnick 8:45 am on December 18, 2019 Permalink | Reply
    Tags: "This New Type of 'Quantum Camouflage' Can Hide Heat Signatures From Infrared Vision", , , Purdue University, , , Thermal radiation   

    From Purdue University via Science Alert: “This New Type of ‘Quantum Camouflage’ Can Hide Heat Signatures From Infrared Vision” 

    via

    ScienceAlert

    Science Alert

    18 DEC 2019
    PETER DOCKRILL

    1
    (Erin Easterling/Purdue University)

    A unique material that appears to decouple an object’s temperature from the amount of thermal radiation it produces could provide a new way of hiding from infrared cameras (not to mention bloodthirsty aliens equipped with infrared vision).

    Thermal radiation is emitted by basically everything with a temperature above absolute zero, and the hotter things get, generally speaking, the brighter they glow in wavelengths of light.

    However, a new discovery presents a surprising exception to these enduring principles of physics, thanks to the strange properties of a quantum material called samarium nickel oxide.

    In new research, scientists found that samarium nickel oxide bucks the thermal trend exhibited by nearly all solid matter, in that it doesn’t necessarily glow brighter just because it’s heated up.

    “Typically, when you heat or cool a material, the electrical resistance changes slowly,” explains materials engineer Shriram Ramanathan from Purdue University.

    “But for samarium nickel oxide, resistance changes in an unconventional manner from an insulating to a conducting state, which keeps its thermal light emission properties nearly the same for a certain temperature range.”

    Since infrared cameras work on the principle of detecting thermal radiation, a material like this that can mask an object’s heat signature could go some way to camouflaging the object, effectively making it invisible in terms of heat.

    The new study hasn’t gotten us quite there yet, but the researchers say that what they’re learning about samarium nickel oxide could get us to that point one day, in addition to figuring out other ways of manipulating thermal signatures to increase object visibility too, not just reduce it.

    “We demonstrate a coating that emits the same amount of thermal radiation irrespective of temperature, within a temperature range of about 30°C,” the team writes in new paper [PNAS].

    “This is the first time that temperature-independent thermal radiation has been demonstrated, and has substantial implications for infrared camouflage, privacy shielding, and radiative heat transfer.”

    In experiments, the researchers heated a number of sample materials to temperatures between 100 to 140°C, and measured their thermal radiation in long-wave infrared.

    Wafers composed of sapphire, fused silica, and a carbon nanotube forest all showed significant differences in their thermal emissions as they were heated to higher temperatures, but wafers coated with a film of the samarium nickel oxide material basically remained unchanged regardless of the increase in heat.

    2
    (Shahsafi et al., PNAS, 2019)

    In the image above the samarium nickel oxide tests are marked as ZDTE, short for zero-differential thermal emitters (ZDTE): materials that can break down the conventional one-to-one mapping between an object’s temperature and its thermally emitted power.

    As the image shows, samarium nickel oxide largely succeeds as a ZDTE in that limited temperature range. Note that the little bright flecks in the ZDTE rows show portions of the sapphire wafer not coated in the quantum material, as a means of illustrating the thermal emission contrast between the treated and non-treated wafer.

    There’s a lot more work to be done before we can realistically exploit this to stealthily sneak undetected past infrared cameras, but as the research team points out, the possibilities are massive.

    “The ability to decouple temperature and thermal radiation with our simple design enables new approaches to conceal heat signatures over large areas, for example for wearable personal privacy technologies, and also has implications for thermal management in space,” the authors write [PNAS].

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Purdue University is a public research university in West Lafayette, Indiana, and the flagship campus of the Purdue University system. The university was founded in 1869 after Lafayette businessman John Purdue donated land and money to establish a college of science, technology, and agriculture in his name. The first classes were held on September 16, 1874, with six instructors and 39 students.

    The main campus in West Lafayette offers more than 200 majors for undergraduates, over 69 masters and doctoral programs, and professional degrees in pharmacy and veterinary medicine. In addition, Purdue has 18 intercollegiate sports teams and more than 900 student organizations. Purdue is a member of the Big Ten Conference and enrolls the second largest student body of any university in Indiana, as well as the fourth largest foreign student population of any university in the United States.

     
  • richardmitnick 1:09 pm on February 4, 2019 Permalink | Reply
    Tags: A lot of fascinating phenomena occur when you collide two condensates, , , , Mini quantum fluid collider, New quantum system could help design better spintronics, , Purdue University, Using this system researchers can literally turn spin-orbit coupling on and off   

    From Purdue University: “New quantum system could help design better spintronics” 

    From Purdue University

    January 29, 2019

    Kayla Zacharias
    765-494-9318
    kzachar@purdue.edu

    1
    Purdue University researchers used lasers to trap and cool atoms down to nearly absolute zero, at which point they become a quantum fluid known as Bose-Einstein condensate, and collided condensates with opposite spins. (Purdue University photo/Purdue Quantum Center)

    Researchers have created a new testing ground for quantum systems in which they can literally turn certain particle interactions on and off, potentially paving the way for advances in spintronics.

    Spin transport electronics have the potential to revolutionize electronic devices as we know them, especially when it comes to computing. While standard electronics use an electron’s charge to encode information, spintronic devices rely on another intrinsic property of the electron: its spin.

    Spintronics could be faster and more reliable than conventional electronics, as these devices use less power. However, the field is young and there are many questions researchers need to solve to improve their control of spin information. One of the most complex questions plaguing the field is how the signal carried by particles with spin, known as spin current, decays over time.

    “The signal we need to make spintronics work, and to study these things, can decay. Just like we want good cell phone service to make a call, we want this signal to be strong,” said Chuan-Hsun Li, a graduate student in electrical and computer engineering at Purdue University. “When spin current decays, we lose the signal.”

    In the real world, electrons don’t exist independently of everything around them and behave exactly how we expect them to. They interact with other particles and among different properties within themselves. The interaction between a particle’s spin (an intrinsic property) and momentum (an extrinsic property) is known as spin-orbit coupling.

    According to a new paper in Nature Communications, spin-orbit coupling and interactions with other particles can dramatically enhance spin current decay in a quantum fluid called Bose-Einstein condensate (BEC).

    “People want to manipulate spin formation so we can use it to encode information, and one way to do this is to use physical mechanisms like spin-orbit coupling,” Li said. “However, this can lead to some drawbacks, such as the loss of spin information.”

    The experiment was done in the lab of Yong Chen, a professor of physics and astronomy, and electrical and computer engineering at Purdue, where his team created something like a mini particle collider for BECs. Using lasers, Rubidium-87 atoms within a vacuum chamber were trapped and cooled nearly to absolute zero. (Physics junkies may recall that laser cooling technologies won the Nobel Prize in physics in 1997. Laser trapping won the Prize in 2018.)

    At this point, the atoms become a BEC: the coldest and most mysterious of the five states of matter. As atoms get colder, they start to display wave-like properties. In this quantum state, they have an identity crisis; they overlap with one another and stop behaving like individuals. Although BEC isn’t technically a gas, this might be the easiest way to picture it – physicists casually refer to it as quantum fluid or quantum gas.

    Inside the mini quantum fluid collider, Chen’s team sent two BECs with opposite spins smashing into one another. Like two clouds of gas would, they partially penetrate each other, delivering a spin current.

    “A lot of fascinating phenomena occur when you collide two condensates. Originally, they’re superfluid, but when they collide, part of the friction can turn them to thermal gas,” Chen said. “Because we can control every parameter, this is a really efficient system to study these kinds of collisions.”

    Using this system, researchers can literally turn spin-orbit coupling on and off, which allows them to isolate its effect on spin current decay. This can’t be done with electrons in solid-state materials, which is part of what makes this system so powerful, Chen said.

    So-called quantum gas is the cleanest system man can make. There’s no disorder, which makes it possible to create a pure spin current and study its properties. Chen hopes to keep using this experimental testing ground and their bosonic spin current to further explore many fundamental questions in spin transport and quantum dynamics.

    “One important challenge for spintronics and other related quantum technologies is to reduce decay so we can propagate spin information over longer distances, for longer times,” he said. “With this new knowledge of the role of spin-orbit coupling, this may help people gain new insights to reduce spin decay and potentially also design better spintronic devices.”

    This research was supported by Purdue University, the Purdue Research Foundation, the National Science Foundation, the U.S. Department of Energy, Department of Defense and Hong Kong Research Council.

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Purdue University is a public research university in West Lafayette, Indiana, and the flagship campus of the Purdue University system. The university was founded in 1869 after Lafayette businessman John Purdue donated land and money to establish a college of science, technology, and agriculture in his name. The first classes were held on September 16, 1874, with six instructors and 39 students.

    The main campus in West Lafayette offers more than 200 majors for undergraduates, over 69 masters and doctoral programs, and professional degrees in pharmacy and veterinary medicine. In addition, Purdue has 18 intercollegiate sports teams and more than 900 student organizations. Purdue is a member of the Big Ten Conference and enrolls the second largest student body of any university in Indiana, as well as the fourth largest foreign student population of any university in the United States.

     
  • richardmitnick 1:28 pm on September 12, 2018 Permalink | Reply
    Tags: , Astronomers witness birth of new star from stellar explosion, , , , , Purdue University   

    From Purdue University via Astrobiology Magazine: “Astronomers witness birth of new star from stellar explosion” 

    1

    Purdue University

    Astrobiology Magazine

    From Astrobiology Magazine

    Sep 12, 2018

    1
    Unlike most stellar explosions that fade away, supernova SN 2012au continues to shine today thanks to a powerful new pulsar. Credit: NASA, ESA, and J. DePasquale (STScI)

    The explosions of stars, known as supernovae, can be so bright they outshine their host galaxies. They take months or years to fade away, and sometimes, the gaseous remains of the explosion slam into hydrogen-rich gas and temporarily get bright again – but could they remain luminous without any outside interference?

    That’s what Dan Milisavljevic, an assistant professor of physics and astronomy at Purdue University, believes he saw six years after “SN 2012au” exploded.

    “We haven’t seen an explosion of this type, at such a late timescale, remain visible unless it had some kind of interaction with hydrogen gas left behind by the star prior to explosion,” he said. “But there’s no spectral spike of hydrogen in the data – something else was energizing this thing.”

    As large stars explode, their interiors collapse down to a point at which all their particles become neutrons. If the resulting neutron star has a magnetic field and rotates fast enough, it may develop into a pulsar wind nebula.

    This is most likely what happened to SN 2012au, according to findings published in The Astrophysical Journal Letters.

    “We know that supernova explosions produce these types of rapidly rotating neutron stars, but we never saw direct evidence of it at this unique time frame,” Milisavljevic said. “This a key moment when the pulsar wind nebula is bright enough to act like a lightbulb illuminating the explosion’s outer ejecta.”

    SN 2012au was already known to be extraordinary – and weird – in many ways. Although the explosion wasn’t bright enough to be termed a “superluminous” supernova, it was extremely energetic and long-lasting, and dimmed in a similarly slow light curve.

    Milisavljevic predicts that if researchers continue to monitor the sites of extremely bright supernovae, they might see similar transformations.

    “If there truly is a pulsar or magnetar wind nebula at the center of the exploded star, it could push from the inside out and even accelerate the gas,” he said. “If we return to some of these events a few years later and take careful measurements, we might observe the oxygen-rich gas racing away from the explosion even faster.”

    Superluminous supernovae are a hot topic in transient astronomy. They’re potential sources of gravitational waves and black holes, and astronomers think they might be related to other kinds of explosions, like gamma ray bursts and fast radio bursts. Researchers want to understand the fundamental physics behind them, but they’re difficult to observe because they’re relatively rare and happen so far from Earth.

    Only the next generation of telescopes, which astronomers have dubbed “Extremely Large Telescopes,” will have the ability to observe these events in such detail.

    “This is a fundamental process in the universe. We wouldn’t be here unless this was happening,” Milisavljevic said. “Many of the elements essential to life come from supernova explosions – calcium in our bones, oxygen we breathe, iron in our blood – I think it’s crucial for us, as citizens of the universe, to understand this process.”

    For Purdue University
    Kayla Zacharias,
    765-494-9318
    kzachar@purdue.edu

    Source:
    Dan Milisavljevic
    765-494-3042
    dmilisav@purdue.edu

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

     
  • richardmitnick 5:07 pm on September 28, 2017 Permalink | Reply
    Tags: "New ’building material’ points toward quantum computers, , Ettore Majorana's Majorana particle, Explains Fabrizio Nichele: “We are now able to design the nano wire on a laptop – and include the details we go for, , , , Purdue University, The quantum computer is by no means just around the corner   

    From Niels Bohr Institute: “New ’building material’ points toward quantum computers” 

    Niels Bohr Institute bloc

    Niels Bohr Institute

    28 September 2017
    Fabrizio Nichele
    fnichele@nbi.ku.dk

    A Danish-American research team has shown that it is possible to produce ‘Majorana particles’ in a new ‘building material’. The research, led by scientists from Niels Bohr institute, University of Copenhagen, paves the road for new types of experiments – and at the same time represents an important contribution to the construction of the information circuits of tomorrow.

    1
    Fabrizio Nichele in the lab at Center for Quantum Devices. The scientists keep their samples in the transparent ‘cabinet’ – in an oxygen-free environment. Photo: Ola Jakup Joensen

    Ever since Ettore Majorana – legendary and mythical Italian physicist – back in 1937 suggested the existence of a particle that is also its own anti-particle, scientists have been searching for the ‘Majorana particle’, as it is has come to be known.

    This far the search has been to no avail

    A team of scientists from Center for Quantum Devices at Niels Bohr Institute (NBI) and from Purdue University, USA, have – however – recently contributed to the advancement of Majorana research.

    1
    The blue part of the structure – one half of a wafer – is where the scientists start building the nano wire. Photo: Ola Jakup Joensen

    Not by finding the elusive particle itself, but by figuring out how to produce a material in which electrons behave in accordance with the theoretical predictions for Majorana particles.

    The results of the research project are published in this week issue of the scientific journal Physical Review Letters.

    No charge

    An anti-particle is an elementary particle – identical to its ‘counterpart’, but with opposite electrical charge. As seen in the relationship between negatively charged electrons and positively charged positrons.

    If a particle is also its own anti-particle – which, given it does indeed exist, will be the case with a Majorana particle – it will therefore have no charge at all.

    The properties that, according to Ettore Majorana´s calculations, will characterize a Majorana particle do for a number of reasons fascinate scientists. Obviously because such properties ‘packaged’ in one particle will represent new experimental possibilities. But also because Majorana-properties are thought to be useful when scientists are e.g. attempting to construct quantum computers – i.e. the information circuits of tomorrow that will have the capacity to process data loads far, far heavier than those dealt with by our present super computers.

    3
    The nano wire is embedded in spider shaped structures. These structures are here seen through the lense of an optical microscope. The structures sit in rows, two in each row. Photo: Ola Jakup Joensen

    All over the world scientists are trying to design quantum computers.

    It’s a race – Center for Quantum Devices at NBI is one of the contestants – and assistant professor Fabrizio Nichele and professor Charles Marcus, both representing the NBI-center, have been in charge of the Danish-American research project.

    “The condensed version is that it is possible to produce a material in which electrons behave like Majorana particles, as our experiments suggest – and that it is possible to produce this material by means of techniques rather similar to those used today when manufacturing computer circuits. On top of that we have shown how this material enables us to measure properties of Majorana particles never measured before – and carry out these measurements with great precision”, explains Fabrizio Nichele.

    Laptop design

    Two ultra thin sheets – combined in a ‘sandwich’ – are at the center of the Danish-American discovery, and it all has to do with producing a material based on this ‘sandwich’.

    4
    One of the optical microscopes available to the NBI-scientists. Photo: Ola Jakup Jensen

    The bottom layer of the ‘sandwich’ is made out of indium arsenide, a semiconductor, and the top layer is made out of aluminium, a superconductor. And the ‘sandwich’ sits on top of a so called wafer, one of the building blocks used in modern computer technology.

    If you carve out a nano wire from this ‘sandwich’-layer it is possible to create a state where electrons inside the wire display Majorana-properties – and the theory behind this approach has in part been known since 2010, says Fabrizio Nichele:

    “However, until now there has been a major problem because it was necessary to ‘grow’ the nano wire in special machines in a lab – and the wire was, literally, only available in the form of minute ‘hair-like’ straws. In order to build e.g. a chip based on this material, you therefore had to assemble an almost unfathomable number of single straws – which made it really difficult and very challenging to construct circuits this way”.

    And this is exactly where the Danish-American discovery comes in very handily, explains Fabrizio Nichele: “We are now able to design the nano wire on a laptop – and include the details we go for. Further down the road production capacity will no doubt increase – which will allow us to use this technique in order to construct computers of significant size”.

    5
    Signature of a Majorana particle, shown on a screen. “The horizontal stripe in the center of the figure shows that a zero energy particle appears in a magnetic field in our devices – as expected for a Majorana particle”, explains Fabrizio Nichele.

    Faster road to Majorana

    At Center for Quantum Devices at NBI, focus is very much on the construction of a quantum computer. Still it is a long haul – the quantum computer is by no means just around the corner, says Fabrizio

    6
    One of the nanowires central to the NBI-scientist’s research. The wire is made out of aluminum. It is approx. 1/1.000 millimeter long, and 1/20.000 wide. Illustration: NBI

    Nichele: “Materials with Majorana-properties obviously have a number of relevant qualities in this context – which is why we try to investigate this field through various experiments”.

    Some of these experiments are carried out at temperatures just above absolute zero (-273,15 C), explains Fabrizio Nichele: “When you do that – which naturally requires equipment tailored for experiments of this kind – you are able to study details related to quantum properties in various materials. When it comes to constructing a quantum computer, Majorana-particles do, however, represent just one of a number of possible and promising options. This field is very complex – and when, some day, a quantum computer has indeed been constructed and is up and running, it may very well be based on some form of integration of a number of different techniques and different materials, whereof some may be based on our research”, says Fabrizio Nichele.

    7
    Fabrizio Nichele. Photo: Ola Jakup Joensen

    Scientists working with Ettore Majoranas equations for entirely other reasons than the desire to build a quantum computer, can also benefit from the Danish-American research, explains Fabrizio Nichele:

    “Our technique makes it possible to conduct experiments that have up till now not been doable – which will also facilitate the understanding of the Majorana particle itself”.

    The research project has been funded by the Danish National Research Foundation, the Villum Foundation, Deutsche Forschungsgemeinschaft (DFG) and – representing the commercial donor side – Microsoft; the latter joining the project as part of a well established cooperation with NBI.

    In addition to cooperating with colleagues from Purdue University, the NBI-researchers have also recently studied Majorana properties working together with scientists from University of California, Santa Barbara, USA. The results of this project are published in a separate article in Physical Review Letters.

    See the full article here .

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    Niels Bohr Institute Campus

    The Niels Bohr Institute (Danish: Niels Bohr Institutet) is a research institute of the University of Copenhagen. The research of the institute spans astronomy, geophysics, nanotechnology, particle physics, quantum mechanics and biophysics.

    The Institute was founded in 1921, as the Institute for Theoretical Physics of the University of Copenhagen, by the Danish theoretical physicist Niels Bohr, who had been on the staff of the University of Copenhagen since 1914, and who had been lobbying for its creation since his appointment as professor in 1916. On the 80th anniversary of Niels Bohr’s birth – October 7, 1965 – the Institute officially became The Niels Bohr Institute.[1] Much of its original funding came from the charitable foundation of the Carlsberg brewery, and later from the Rockefeller Foundation.[2]

    During the 1920s, and 1930s, the Institute was the center of the developing disciplines of atomic physics and quantum physics. Physicists from across Europe (and sometimes further abroad) often visited the Institute to confer with Bohr on new theories and discoveries. The Copenhagen interpretation of quantum mechanics is named after work done at the Institute during this time.

    On January 1, 1993 the institute was fused with the Astronomic Observatory, the Ørsted Laboratory and the Geophysical Institute. The new resulting institute retained the name Niels Bohr Institute.

     
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