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  • richardmitnick 11:33 am on October 15, 2018 Permalink | Reply
    Tags: , AO-Adaptive Optics, Caltech, , , University of California   

    From Keck Observatory: “W. M. Keck Observatory Awarded NSF Grant To Develop Next-Generation Adaptive Optics System” 

    Keck Observatory, Maunakea, Hawaii, USA.4,207 m (13,802 ft) above sea level, with Subaru and IRTF (NASA Infrared Telescope Facility). Vadim Kurland


    From Keck Observatory

    1
    Adaptive optics (AO) measures and then corrects the atmospheric turbulence using a deformable mirror that changes shape 1,000 times per second. Initially, AO relied on the light of a star that was both bright and close to the target celestial object. But there are only enough bright stars to allow AO correction in about one percent of the sky. In response, astronomers developed Laser Guide Star Adaptive Optics using a special-purpose laser to excite sodium atoms that sit in an atmospheric layer 60 miles above Earth. Exciting the atoms in the sodium layers creates an artificial “star” for measuring atmospheric distortions, which allows the AO to produce sharp images of celestial objects positioned nearly anywhere in the sky. CREDIT: W. M. Keck Observatory/Andrew Richard Hara.

    Nearly two decades after pioneering the technology on large telescopes, W. M. Keck Observatory is once again pushing the boundaries in the field of adaptive optics (AO) after receiving a powerful boost of support.

    The National Science Foundation (NSF) has awarded the Observatory funding through their Mid-Scale Innovations Program to build a next-generation AO system on the Keck I telescope. Called Keck All-Sky Precision Adaptive Optics (KAPA), this futuristic technology will deliver significantly sharper images of the universe over nearly 100 percent of the night sky.

    “This is an exciting leap forward in our quest to overcome the blurring effects of the Earth’s atmosphere,” said Principal Investigator Peter Wizinowich, chief of technical development at Keck Observatory. “Having worked toward this project for over a decade, I am pleased to see this funding come to fruition, thanks to the NSF and also to our community’s commitment to maintaining Keck Observatory’s leadership in the cutting-edge science enabled by adaptive optics.”

    KAPA is designed to investigate some of modern astronomy’s greatest mysteries, including the following KAPA key science projects:

    1.Constrain theories of dark matter, dark energy, and cosmology using gravitational lensing of distant galaxies and quasars – Project Lead Tommaso Treu, UCLA Professor of Physics and Astronomy
    2.Test General Relativity and understanding supermassive black hole interactions in the extreme environment of the Galactic Center – Project Leads Andrea Ghez, UCLA Professor of Physics and Astronomy and director of the UCLA Galactic Center Group, and Mark Morris, UCLA Professor of Physics and Astronomy and member of the UCLA Galactic Center Group
    3.Study the evolution of galaxies’ metal-content and dynamics over cosmic time using rare, highly magnified galaxies – Project Leads Shelley Wright, UC San Diego Assistant Professor of Physics, and Claire Max, director of the University of California Observatories
    4.Find and study newly formed planets around nearby young stars via direct imaging and spectroscopy – Project Leads Michael Liu, Astronomer at University of Hawaii Institute of Astronomy, and Dimitri Mawet, Caltech Associate Professor of Astronomy

    The KAPA leadership team also includes UC Berkeley Assistant Professor Jessica Lu as Project Scientist and Keck Observatory Senior Engineer Jason Chin as Project Manager.

    In keeping with Keck Observatory’s guiding principle of sharing important new knowledge, all scientific data will be publicly released to ensure the U.S. community is provided with a valuable scientific legacy.

    “This revolutionary system will significantly expand Keck Observatory’s scientific reach,” said Co-Principal Investigator Andrea Ghez, director of the UCLA Galactic Center Group.

    Andrea Ghez, UCLA Galactic Center Group

    SO-2 Image UCLA Galactic Center Groupe via S. Sakai and Andrea Ghez at Keck Observatory


    “KAPA will also serve as an intellectual springboard for the coming generation of extremely large telescopes. We are developing KAPA in partnership with the Thirty Meter Telescope, Giant Magellan Telescope, and European Extremely Large Telescope (ELT) so they can be well-prepared when the time comes to build their own AO instrumentation.”

    TMT-Thirty Meter Telescope, proposed and now approved for Mauna Kea, Hawaii, USA4,207 m (13,802 ft) above sea level

    Giant Magellan Telescope, to be at the Carnegie Institution for Science’s Las Campanas Observatory, to be built some 115 km (71 mi) north-northeast of La Serena, Chile, over 2,500 m (8,200 ft) high

    ESO/E-ELT,to be on top of Cerro Armazones in the Atacama Desert of northern Chile. located at the summit of the mountain at an altitude of 3,060 metres (10,040 ft).

    Next-generation technology like KAPA will require next-generation expertise. As such, the KAPA team is also placing a priority on the broader impact goals of education and workforce development.

    Young scientists and engineers will be recruited to help develop KAPA and the KAPA science programs. The project will engage:

    four Hawaii college student interns from the Akamai Workforce Initiative program
    four graduate and post-doctoral students from the Keck Visiting Scholars Program
    four KAPA post-doctoral scholars

    All students and young researchers will receive mentoring and hands-on work experience. The KAPA team will also launch a new summer school focused on astronomy technology and instrumentation for about 25 undergraduate and graduate students every summer over the course of the five-year project.

    “We need more people trained in instrumentation, in particular women and other groups underrepresented in the field,” said Lisa Hunter, director of the Institute for Scientist & Engineer Educators at UC Santa Cruz and a member of the KAPA team. “This project will launch an innovative new effort to build a more diverse instrumentation workforce.”

    “We are excited by this opportunity to keep Keck Observatory at the forefront of high angular resolution science and to continue to advance the state-of-the-art in adaptive optics,” said Hilton Lewis, director of Keck Observatory. “Sharing our knowledge with the next generation of scientists and engineers is very important to us, for it is they who will continue the vital work of utilizing and continuing to develop the most scientifically-productive AO system in the world.”

    AO is a technique used to correct the distortion of astronomical images caused by the turbulence in the Earth’s atmosphere. This is done using lasers to create an artificial star anywhere in the sky, fast sensors to measure the atmospheric blurring, and a deformable mirror to correct for it – all done about 1000 times per second. The goal is to study the finest detail possible by largely removing the blurring effect of the atmosphere. It allows ground-based telescopes to match and even exceed the performance of space-based telescopes at much more modest costs.

    To further improve the clarity of these images, the KAPA project will upgrade the current system by replacing key components: the Keck I laser, the computer that calculates the real-time corrections, and the camera that measures the atmospheric turbulence. The laser beam will be divided into three laser guide stars to fully sample the atmosphere above the telescope using a technique called laser tomography.

    The project also includes upgrades to a near-infrared tip-tilt sensor to improve sky coverage and a technique called point spread function reconstruction that will optimize the value of the science data obtained with the accompanying science instrument (an integral field spectrograph and imager called OSIRIS).

    The KAPA project launched in September and is expected to be completed in 2023.

    _______________________________________________________
    ABOUT ADAPTIVE OPTICS

    W. M. Keck Observatory is a distinguished leader in the field of adaptive optics (AO), a breakthrough technology that removes the distortions caused by the turbulence in the Earth’s atmosphere. Keck Observatory pioneered the astronomical use of both natural guide star (NGS) and laser guide star adaptive optics (LGS AO) on large telescopes and current systems now deliver images three to four times sharper than the Hubble Space Telescope. Keck AO has imaged the four massive planets orbiting the star HR8799, measured the mass of the giant black hole at the center of our Milky Way Galaxy, discovered new supernovae in distant galaxies, and identified the specific stars that were their progenitors. Support for this technology was generously provided by the Bob and Renee Parsons Foundation, Change Happens Foundation, Gordon and Betty Moore Foundation, Heising-Simons Foundation, Mt. Cuba Astronomical Foundation, NASA, NSF, and W. M. Keck Foundation.

    See the full article here .


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    Mission
    To advance the frontiers of astronomy and share our discoveries with the world.

    The W. M. Keck Observatory operates the largest, most scientifically productive telescopes on Earth. The two, 10-meter optical/infrared telescopes on the summit of Mauna Kea on the Island of Hawaii feature a suite of advanced instruments including imagers, multi-object spectrographs, high-resolution spectrographs, integral-field spectrometer and world-leading laser guide star adaptive optics systems. Keck Observatory is a private 501(c) 3 non-profit organization and a scientific partnership of the California Institute of Technology, the University of California and NASA.

    Today Keck Observatory is supported by both public funding sources and private philanthropy. As a 501(c)3, the organization is managed by the California Association for Research in Astronomy (CARA), whose Board of Directors includes representatives from the California Institute of Technology and the University of California, with liaisons to the board from NASA and the Keck Foundation.


    Keck UCal

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  • richardmitnick 1:02 pm on October 14, 2018 Permalink | Reply
    Tags: Caltech, , , The World's Fastest Camera Can 'Freeze Time' Show Beams of Light in Slow Motion, University of Quebec   

    From Science Alert: “The World’s Fastest Camera Can ‘Freeze Time’, Show Beams of Light in Slow Motion” 

    ScienceAlert

    From Science Alert

    14 OCT 2018
    JON CHRISTIAN

    1
    (Adobe Stock)

    When you push the button on a laser pointer, its entire beam seems to appear instantaneously. In reality, though, the photons shoot out like water from a hose, just at a speed too fast to see.

    Too fast for the human eye to see, anyways.

    Researchers at Caltech and the University of Quebec have invented what is now the world’s fastest camera, and it takes a mind-boggling 10 trillion shots per second —enough to record footage of a pulse of light as it travels through space.

    The extraordinary camera, which the researchers describe in a paper published Monday in the journal Light: Science & Applications, builds on a technology called compressed ultrafast photography (CUP).

    2
    Figure 1. The trillion-frame-per-second compressed ultrafast photography system. INRS

    CUP can lock down an impressive 100 billion frames per second, but by simultaneously recording a static image and performing some tricky math, the researchers were able to reconstruct 10 trillion frames.

    They call the new technique T-CUP, and while they don’t say what the “T” stands for, our money is on “trillion.”

    Ludicrous Speed

    The camera more than doubles the speed record set in 2015 by a camera that took 4.4 trillion shots per second. Its inventors hope it’ll be useful in biomedical and materials research.

    But they’ve already turned their attention to smashing their newly set record.

    “It’s an achievement in itself,” said lead author Jinyang Liang in a press release, “but we already see possibilities for increasing the speed to up to one quadrillion frames per second!”

    See the full article here .


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  • richardmitnick 2:26 pm on October 11, 2018 Permalink | Reply
    Tags: , , , Caltech, , , , iPTF=intermediate Palomar Transient Factory, Massive star’s unusual death heralds the birth of compact neutron star binary,   

    From Carnegie Institution for Science: “Massive star’s unusual death heralds the birth of compact neutron star binary” 

    Carnegie Institution for Science
    From Carnegie Institution for Science

    October 11, 2018

    1

    Carnegie’s Anthony Piro was part of a Caltech-led team of astronomers who observed the peculiar death of a massive star that exploded in a surprisingly faint and rapidly fading supernova, possibly creating a compact neutron star binary system. Piro’s theoretical work provided crucial context for the discovery. Their findings are published by Science.

    Observations made by the Caltech team—including lead author Kishalay De and project principal investigator Mansi Kasliwal (herself a former-Carnegie postdoc)—suggest that the dying star had an unseen companion, which gravitationally siphoned away most of the star’s mass before it exploded as a supernova. The explosion is believed to have resulted in a neutron star binary, suggesting that, for the first time, scientists have witnessed the birth of a binary system like the one first observed to collide by Piro and a team of Carnegie and UC Santa Cruz astronomers in August 2017.

    A supernova occurs when a massive star—at least eight times the mass of the Sun—exhausts its nuclear fuel, causing the core to collapse and then rebound outward in a powerful explosion. After the star’s outer layers have been blasted away, all that remains is a dense neutron star—an exotic star about the size of a city but containing more mass than the Sun.

    Usually, a lot of material—many times the mass of the Sun—is observed to be blasted away in a supernova. However, the event that Kasliwal and her colleagues observed, dubbed iPTF 14gqr, ejected matter only one fifth of the Sun’s mass.

    “We saw this massive star’s core collapse, but we saw remarkably little mass ejected,” Kasliwal says. “We call this an ultra-stripped envelope supernova and it has long been predicted that they exist. This is the first time we have convincingly seen core collapse of a massive star that is so devoid of matter.”

    Piro’s theoretical modeling guided the interpretation of these observations. This allowed the observers to infer the presence of dense material surrounding the explosion.

    “Discoveries like this demonstrate why it has been so important to build a theoretical astrophysics group at Carnegie,” Piro said. “By combining observations and theory together, we can learn so much more about these amazing events.”

    The fact that the star exploded at all implies that it must have previously had a lot of material, or its core would never have grown large enough to collapse. But where was the missing mass hiding? The researchers inferred that the mass must have been stolen by a compact companion star, such as a white dwarf, neutron star, or black hole.

    The neutron star that was left behind from the supernova must have then been born into orbit with this compact companion. Because this new neutron star and its companion are so close together, they will eventually merge in a collision. In fact, the merger of two neutron stars was first observed in August 2017 by Piro and a team of Carnegie and UC Santa Cruz astronomers, and such events are thought to produce the heavy elements in our universe, such as gold, platinum, and uranium.

    The event was first seen at Palomar Observatory as part of the intermediate Palomar Transient Factory (iPTF), a nightly survey of the sky to look for transient, or short-lived, cosmic events like supernovae.

    Caltech Palomar Observatory, located in San Diego County, California, US, at 1,712 m (5,617 ft)

    Caltech Palomar Intermediate Palomar Transient Factory telescope at the Samuel Oschin Telescope at Palomar Observatory,located in San Diego County, California, United States

    Because the iPTF survey keeps such a close eye on the sky, iPTF 14gqr was observed in the very first hours after it had exploded. As the earth rotated and the Palomar telescope moved out of range, astronomers around the world collaborated to monitor iPTF 14gqr, continuously observing its evolution with a number of telescopes that today form the Global Relay of Observatories Watching Transients Happen (GROWTH) network of observatories.

    GROWTH map

    3
    The three panels represent moments before, when and after the faint supernova iPTF14gqr, visible in the middle panel, appeared in the outskirts of a spiral galaxy located 920 million light years away from us. The massive star that died in the supernova left behind a neutron star in a very tight binary system. These dense stellar remnants will ultimately spiral into each other and merge in a spectacular explosion, giving off gravitational and electromagnetic waves. Image credit: SDSS/Caltech/Keck

    SDSS Telescope at Apache Point Observatory, near Sunspot NM, USA, Altitude 2,788 meters (9,147 ft)


    Keck Observatory, Maunakea, Hawaii, USA.4,207 m (13,802 ft), above sea level, showing also NASA’s IRTF and NAOJ Subaru

    See the full article here .


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    Carnegie Institution of Washington Bldg

    Andrew Carnegie established a unique organization dedicated to scientific discovery “to encourage, in the broadest and most liberal manner, investigation, research, and discovery and the application of knowledge to the improvement of mankind…” The philosophy was and is to devote the institution’s resources to “exceptional” individuals so that they can explore the most intriguing scientific questions in an atmosphere of complete freedom. Carnegie and his trustees realized that flexibility and freedom were essential to the institution’s success and that tradition is the foundation of the institution today as it supports research in the Earth, space, and life sciences.

    6.5 meter Magellan Telescopes located at Carnegie’s Las Campanas Observatory, Chile.
    6.5 meter Magellan Telescopes located at Carnegie’s Las Campanas Observatory, Chile

     
  • richardmitnick 3:16 pm on October 4, 2018 Permalink | Reply
    Tags: "Directed evolution has transformed how we make proteins and how we think about new protein catalysts" says Jacqueline K. Barton Caltech's John G. Kirkwood and Arthur A. Noyes Professor of Chemistry a, "I am absolutely floored. I have to wrap my head around this. It's not something I was expecting.", 2018 Nobel Prize in Chemistry for "the directed evolution of enzymes", Caltech, Directed evolution pioneered by Arnold in the early 1990s, Frances Arnold Wins 2018 Nobel Prize in Chemistry,   

    From Caltech: Women in STEM-“Frances Arnold Wins 2018 Nobel Prize in Chemistry” 

    Caltech Logo

    From Caltech

    10/03/2018

    Whitney Clavin
    (626) 395-1856
    wclavin@caltech.edu

    1
    Frances Arnold. Credit: Caltech.

    Frances H. Arnold, the Linus Pauling Professor of Chemical Engineering, Bioengineering and Biochemistry, has won the 2018 Nobel Prize in Chemistry for “the directed evolution of enzymes,” according to the award citation. Directed evolution, pioneered by Arnold in the early 1990s, is a bioengineering method for creating new and better enzymes in the laboratory using the principles of evolution. Today, the method is used in hundreds of laboratories and companies that make everything from laundry detergents to biofuels to medicines. Enzymes created with the technique have replaced toxic chemicals in many industrial processes.

    Arnold shares the prize with George P. Smith of the University of Missouri in Columbia, who developed a “phage display” method for evolving proteins, and Sir Gregory P. Winter of the MRC Laboratory of Molecular Biology in Cambridge, United Kingdom, who used phage display for evolving antibodies. One half of the prize, which comes with an award of 9 million Swedish krona (about $1 million), goes to Arnold, with the other half shared by Smith and Winter.

    Arnold received the call at a hotel in Dallas, Texas, at around 4 a.m. local time; she was scheduled to give a lecture today at UT Southwestern, but had to reschedule to fly back to California. She says she was in a “deep, deep sleep” when awakened by the call. “I am absolutely floored. I have to wrap my head around this. It’s not something I was expecting.”

    “Frances’s work on directed evolution is a beautiful example of an enterprise that has both deep scientific significance and enormous practical consequences,” says David A. Tirrell, Caltech’s provost, the Carl and Shirley Larson Provostial Chair, and the Ross McCollum-William H. Corcoran Professor of Chemistry and Chemical Engineering. “Through decades of commitment to exploring a powerful idea, Frances has transformed the fields of protein chemistry, catalysis, and biotechnology. She has changed the way we think about things and the way we do things.”

    “Directed evolution has transformed how we make proteins and how we think about new protein catalysts,” says Jacqueline K. Barton, Caltech’s John G. Kirkwood and Arthur A. Noyes Professor of Chemistry and the Norman Davidson Leadership Chair of the Division of Chemistry and Chemical Engineering. “Through this work, she has broadened the repertoire of nature’s catalysts.”

    “Life—the biological world—is the greatest chemist, and evolution is her design process,” says Arnold. “I may not be the best chemist but I do appreciate evolution.”

    Arnold was born on July 25, 1956, in Pittsburgh, Pennsylvania. She received her undergraduate degree in mechanical and aerospace engineering from Princeton University in 1979 and her graduate degree in chemical engineering from UC Berkeley in 1985. She arrived at Caltech as a visiting associate in 1986 and was named assistant professor in 1987, associate professor in 1992, and professor in 1996. In 2000, she was named the Dick and Barbara Dickinson Professor of Chemical Engineering, Bioengineering and Biochemistry; she became the Linus Pauling Professor in 2017. She became the director of the Donna and Benjamin M. Rosen Bioengineering Center at Caltech in 2013.

    Directed evolution works in the same way that breeders mate cats or dogs to bring out desired traits. To perform the method, scientists begin by inducing mutations to the DNA, or gene, that encodes a particular enzyme (a molecule that catalyzes, or facilitates, chemical reactions). An array of thousands of mutated enzymes is produced and then tested for a desired trait. The top-performing enzymes are selected and the process is repeated to further enhance the enzymes’ performances. For instance, in 2009, Arnold and her team engineered enzymes that break down cellulose, the main component of plant cell walls, creating better catalysts for turning agricultural wastes into fuels and chemicals.

    A number of additional enzymes produced through directed evolution are now used for a host of products, including biofuels, agricultural chemicals, paper products, and pharmaceuticals. For example, the method led to a better way to produce a drug for treating type 2 diabetes.

    More recently, Arnold and her colleagues used directed evolution to persuade bacteria to make chemicals not found in nature, including molecules containing silicon-carbon or boron-carbon bonds, or bicyclobutanes, which contain energy-packed carbon rings. By using bacteria, researchers can potentially make these chemical compounds in “greener” ways that are more economical and produce less toxic waste.

    “My entire career I have been concerned about the damage we are doing to the planet and each other,” said Arnold when she won the 2016 Millennium Technology Prize, granted by the Technology Academy Finland. “Science and technology can play a major role in mitigating our negative influences on the environment. Changing behavior is even more important. However, I feel that change is easier when there are good, economically viable alternatives to harmful habits.”

    Arnold was the first woman to receive the 2011 Charles Stark Draper Prize from the National Academy of Engineering (NAE). She is among the small number of individuals, and the first woman, elected to all three branches of the National Academies: the NAE (2000), the National Academy of Medicine (2004; it was then called the Institute of Medicine), and the National Academy of Sciences (NAS; 2008). She received the 2011 National Medal of Technology and Innovation and was inducted into the National Inventors Hall of Fame in 2014. She has won numerous other awards, including the 2017 Sackler Prize in Convergence Research from the NAS and the Society of Women Engineers’ 2017 Achievement Award.

    She is a member of the American Academy of Arts and Sciences and the American Philosophical Society, and is a fellow of the American Association for the Advancement of Science and the Royal Academy of Engineering.

    “Frances’s methods have been adopted by scientists and engineers around the world, and many more have been inspired by her vision and her impact on chemical science and technology,” says Tirrell. “Her extraordinary accomplishments reflect the unconventional research environment at Caltech, where scholars are encouraged to dream, to take risks, and to venture beyond the constraints of disciplinary boundaries.”

    The 2018 Nobel Prize in Chemistry is the 39th Nobel Prize awarded to Caltech faculty and alumni. Other Caltech faculty with Nobel Prizes include: Kip S. Thorne (BS ’62) and Barry C. Barish, winners of the 2017 Nobel Prize in Physics with Rainer Weiss; Robert Grubbs, winner of the 2005 Nobel Prize in Chemistry with Yves Chauvin and Richard R. Schrock; David Politzer, recipient of the 2004 Nobel Prize in Physics with David J. Gross and Frank Wilczek; Rudy Marcus, sole winner of the 1992 Nobel Prize in Chemistry; and David Baltimore, winner of the 1975 Nobel Prize in Physiology or Medicine with Renato Dulbecco and Howard M. Temin.

    See the full article here .


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    The California Institute of Technology (commonly referred to as Caltech) is a private research university located in Pasadena, California, United States. Caltech has six academic divisions with strong emphases on science and engineering. Its 124-acre (50 ha) primary campus is located approximately 11 mi (18 km) northeast of downtown Los Angeles. “The mission of the California Institute of Technology is to expand human knowledge and benefit society through research integrated with education. We investigate the most challenging, fundamental problems in science and technology in a singularly collegial, interdisciplinary atmosphere, while educating outstanding students to become creative members of society.”

    Caltech campus

     
  • richardmitnick 9:25 am on September 27, 2018 Permalink | Reply
    Tags: Caltech, Photonic bandgap, , , Superconducting Metamaterial Traps Quantum Light, Superconducting metamaterials   

    From Caltech: “Superconducting Metamaterial Traps Quantum Light” 

    Caltech Logo

    From Caltech

    09/26/2018

    Robert Perkins
    (626) 395-1862
    rperkins@caltech.edu

    1
    A superconducting metamaterial chip mounted into a microwave test package. The purplish-violet reflection in the center is an optical effect that can seen by the naked eye, and is the result of the diffaction of light by the periodic patterning of the microwave metamaterial. Credit: Oskar Painter/Caltech

    Newly developed material may be key to scaling up quantum circuits.

    Conventional computers store information in a bit, a fundamental unit of logic that can take a value of 0 or 1. Quantum computers rely on quantum bits, also known as a “qubits,” as their fundamental building blocks. Bits in traditional computers encode a single value, either a 0 or a 1. The state of a qubit, by contrast, can simultaneously have a value of both 0 and 1. This peculiar property, a consequence of the fundamental laws of quantum physics, results in the dramatic complexity in quantum systems.

    Quantum computing is a nascent and rapidly developing field that promises to use this complexity to solve problems that are difficult to tackle with conventional computers. A key challenge for quantum computing, however, is that it requires making large numbers of qubits work together—which is difficult to accomplish while avoiding interactions with the outside environment that would rob the qubits of their quantum properties.

    New research from the lab of Oskar Painter, John G Braun Professor of Applied Physics and Physics in the Division of Engineering and Applied Science, explores the use of superconducting metamaterials to overcome this challenge.

    Metamaterials are specially engineered by combining multiple component materials at a scale smaller than the wavelength of light, giving them the ability to manipulate how particles of light, or photons, behave. Metamaterials can be used to reflect, turn, or focus beams of light in nearly any desired manner. A metamaterial can also create a frequency band where the propagation of photons becomes entirely forbidden, a so-called “photonic bandgap.”

    The Caltech team used a photonic bandgap to trap microwave photons in a superconducting quantum circuit, creating a promising technology for building future quantum computers.

    “In principle, this is a scalable and flexible substrate on which to build complex circuits for interconnecting certain types of qubits,” says Painter, leader of the group that conducted the research, which was published in Nature Communications on September 12. “Not only can one play with the spatial arrangement of the connectivity between qubits, but one can also design the connectivity to occur only at certain desired frequencies.”

    Painter and his team created a quantum circuit consisting of thin films of a superconductor—a material that transmits electric current with little to no loss of energy—traced onto a silicon microchip. These superconducting patterns transport microwaves from one part of the microchip to another. What makes the system operate in a quantum regime, however, is the use of a so-called Josephson junction, which consists of an atomically thin non-conductive layer sandwiched between two superconducting electrodes. The Josephson junction creates a source of microwave photons with two distinct and isolated states, like an atom’s ground and excited electronic states, that are involved in the emission of light, or, in the language of quantum computing, a qubit.

    “Superconducting quantum circuits allow one to perform fundamental quantum electrodynamics experiments using a microwave electrical circuit that looks like it could have been yanked directly from your cell phone,” Painter says. “We believe that augmenting these circuits with superconducting metamaterials may enable future quantum computing technologies and further the study of more complex quantum systems that lie beyond our capability to model using even the most powerful classical computer simulations.”

    The paper is titled “Superconducting metamaterials for waveguide quantum electrodynamics,” The team of authors was led by Mohammad Mirhosseini, a Kavli Nanoscience Institute Postdoctoral Scholar at Caltech. Co-authors include postdoctoral scholars Andrew Keller and Alp Sipahigil of the Institute for Quantum Information and Matter (IQIM); and graduate students Eun Jong Kim, Vinicius Ferreira, and Mahmoud Kalaee. The work was performed as part of a pair of Multidisciplinary University Research Initiatives from the Air Force Office of Scientific Research (“Quantum Photonic Matter” and “Wiring Quantum Networks with Mechanical Transducers”), and in conjunction with IQIM, a National Science Foundation Physics Frontiers Center supported by the Gordon and Betty Moore Foundation.

    See the full article here .


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    Please help promote STEM in your local schools.


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    The California Institute of Technology (commonly referred to as Caltech) is a private research university located in Pasadena, California, United States. Caltech has six academic divisions with strong emphases on science and engineering. Its 124-acre (50 ha) primary campus is located approximately 11 mi (18 km) northeast of downtown Los Angeles. “The mission of the California Institute of Technology is to expand human knowledge and benefit society through research integrated with education. We investigate the most challenging, fundamental problems in science and technology in a singularly collegial, interdisciplinary atmosphere, while educating outstanding students to become creative members of society.”

    Caltech campus

     
  • richardmitnick 4:24 pm on September 20, 2018 Permalink | Reply
    Tags: Caltech, Evidence suggests that subducting slabs of the earth's crust may generate unusual features spotted near the core, Experiment used a diamond anvil cell which is essentially a tiny chamber located between two diamonds, ULVZs consist of chunks of a magnesium/iron oxide mineral called magnesiowüstite, ULVZs-ultra-low velocity zones   

    From Caltech: “Experiments using Diamond Anvils Yield New Insight into the Deep Earth” 

    Caltech Logo

    From Caltech

    09/20/2018
    Robert Perkins
    (626) 395-1862
    rperkins@caltech.edu

    1
    The diamond anvil in which samples of magnesiowüstite were placed under extreme pressure and studied. Credit: Jennifer Jackson/Caltech

    2
    Cross-section illustration shows slabs of the earth’s crust descending through the mantle and aligning magnesiowüstite in ultra-low velocity zones.

    Evidence suggests that subducting slabs of the earth’s crust may generate unusual features spotted near the core.

    Nearly 1,800 miles below the earth’s surface, there are large odd structures lurking at the base of the mantle, sitting just above the core. The mantle is a thick layer of hot, mostly plastic rock that surrounds the core; atop the mantle is the thin shell of the earth’s crust. On geologic time scales, the mantle behaves like a viscous liquid, with solid elements sinking and rising through its depths.

    The aforementioned odd structures, known as ultra-low velocity zones (ULVZs), were first discovered in 1995 by Caltech’s Don Helmberger. ULVZs can be studied by measuring how they alter the seismic waves that pass through them. But observing is not necessarily understanding. Indeed, no one is really sure what these structures are.

    ULVZs are so-named because they significantly slow down the speeds of seismic waves; for example, they slow down shear waves (oscillating seismic waves capable of moving through solid bodies) by as much as 30 percent. ULVZs are several miles thick and can be hundreds of miles across. Several are scattered near the earth’s core roughly beneath the Pacific Rim. Others are clustered underneath North America, Europe, and Africa.

    “ULVZs exist so deep in the inner earth that they are impossible to study directly, which poses a significant challenge when trying to determine what exactly they are,” says Helmberger, Smits Family Professor of Geophysics, Emeritus.

    Earth scientists at Caltech now say they know not just what ULVZs are made of, but where they come from. Using experimental methods at high pressures, the researchers, led by Professor of Mineral Physics Jennifer Jackson, have found that ULVZs consist of chunks of a magnesium/iron oxide mineral called magnesiowüstite that could have precipitated out of a magma ocean that is thought to have existed at the base of the mantle millions of years ago.

    The other leading theory for ULVZs formation had suggested that they consist of melted material, some of it possibly leaking up from the core.

    Jackson and her colleagues, who reported on their work in a recent paper in the Journal of Geophysical Research: Solid Earth, found evidence supporting the magnesiowüstite theory by studying the mineral’s elastic (or seismic) anisotropy; elastic anisotropy is a variation in the speed at which seismic waves pass through a mineral depending on their direction of travel.

    One particularly unusual characteristic of the region where ULVZs exist—the core-mantle boundary (CMB)—is that it is highly heterogenous (nonuniform in character) as well as anisotropic. As a result, the speed at which seismic waves travel through the CMB varies based not only on the region that the waves are passing through but on the direction in which those waves are moving. The propagation direction, in fact, can alter the speed of the waves by a factor of three.

    “Previously, scientists explained the anisotropy as the result of seismic waves passing through a dense silicate material. What we’re suggesting is that in some regions, it is largely due to the alignment of magnesiowüstite within ULVZs,” says Jackson.

    At the pressures and temperatures experienced at the earth’s surface, magnesiowüstite exhibits little anisotropy. However, Jackson and her team found that the mineral becomes strongly anisotropic when subjected to pressures comparable to those found in the lower mantle.

    Jackson and her colleagues discovered this by placing a single crystal of magnesiowüstite in a diamond anvil cell, which is essentially a tiny chamber located between two diamonds. When the rigid diamonds are compressed against one another, the pressure inside the chamber rises. Jackson and her colleagues then bombarded the sample with x-rays. The interaction of the x-rays with the sample acts as a proxy for how seismic waves will travel through the material. At a pressure of 40 gigapascals—equivalent to the pressure at the lower mantle—magnesiowüstite was significantly more anisotropic than seismic observations of ULVZs.

    In order to create objects as large and strongly anisotropic as ULVZs, only a small amount of magnesiowüstite crystals need to be aligned in one specific direction, probably due to the application of pressure from a strong outside force. This could be explained by a subducting slab of the earth’s crust pushing its way to the CMB, Jackson says. (Subduction occurs at certain boundaries between earth’s tectonic plates, where one plate dives below another, triggering volcanism and earthquakes.)

    “Scientists are still in the process of discovering what happens to the crust when it’s subducted into the mantle,” Jackson says. “One possibility, which our research now seems to support, is that these slabs push all the way down to the core-mantle boundary and help to shape ULVZs.”

    Next, Jackson plans to explore the interaction of subducting slabs, ULVZs, and their seismic signatures. Interpreting these features will help place constraints on processes that happened early in Earth’s history, she says.

    The study is titled “Strongly Anisotropic Magnesiowüstite in Earth’s Lower Mantle.” Jackson collaborated with former Caltech postdoctoral researcher Gregory Finkelstein, now at the University of Hawai’i, who was the lead author of this study. Other colleagues include Wolfgang Sturhahn, visitor in geophysics at Caltech; as well as Ayman Said, Ahmet Alatas, Bogdan Leu, and Thomas Toellner of the Argonne National Laboratory in Illinois. This research was funded by the National Science Foundation and the W. M. Keck Institute for Space Studies.

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings
    Please help promote STEM in your local schools.


    Stem Education Coalition

    The California Institute of Technology (commonly referred to as Caltech) is a private research university located in Pasadena, California, United States. Caltech has six academic divisions with strong emphases on science and engineering. Its 124-acre (50 ha) primary campus is located approximately 11 mi (18 km) northeast of downtown Los Angeles. “The mission of the California Institute of Technology is to expand human knowledge and benefit society through research integrated with education. We investigate the most challenging, fundamental problems in science and technology in a singularly collegial, interdisciplinary atmosphere, while educating outstanding students to become creative members of society.”

    Caltech campus

     
  • richardmitnick 1:03 pm on September 5, 2018 Permalink | Reply
    Tags: , , , Caltech, , , , ,   

    From Caltech: “Superfast Jet Observed Streaming Away from Stellar Collision” 

    Caltech Logo

    From Caltech

    09/05/2018
    Elise Cutts

    1
    An artist’s impression of the jet (pictured as a ball of fire), produced in the neutron star merger first detected on August 17, 2017 by telescopes around the world, as well as LIGO, which detects gravitational waves (green ripples). Credit: James Josephides (Swinburne University of Technology, Australia)

    Using a collection of National Science Foundation radio telescopes, researchers have confirmed that a narrow jet of material was ejected at near light speeds from a neutron star collision. The collision, which was observed August 17, 2017 and occurred 130 million miles from Earth, initially produced gravitational waves that were observed by the Laser Interferometry Gravitational-wave Observatory (LIGO), alongside a flood of light in the form of gamma rays, X-rays, visible light, and radio waves. It was the first cosmic event to be observed in both gravitational waves and light waves.

    Confirmation that a superfast jet had been produced by the neutron star collision came after radio astronomers discovered that a region of radio emission created by the merger had moved in a seemingly impossible way that only a jet could explain. The radio observations were made using the Very Long Baseline Array (VLBA), the Robert C. Byrd Green Bank Telescope (GBT), and the Very Large Array (VLA). The VLA is operated by the National Radio Astronomy Observatory (NRAO), which is closely associated with the other two telescopes involved in the discovery.

    NRAO VLBA



    GBO radio telescope, Green Bank, West Virginia, USA

    NRAO/Karl V Jansky Expanded Very Large Array, on the Plains of San Agustin fifty miles west of Socorro, NM, USA, at an elevation of 6970 ft (2124 m)

    “We measured an apparent motion that is four times faster than light. That illusion, called superluminal motion, results when the jet is pointed nearly toward Earth and the material in the jet is moving close to the speed of light,” says Kunal Mooley, a Caltech postdoctoral scholar with a joint appointment at the NRAO and lead author of a new study about the jet appearing online September 5 in the journal Nature. Mooley and Assistant Professor of Astronomy Gregg Hallinan were part of an international collaboration that observed and interpreted the movement of the radio emission.

    “We were lucky to be able to observe this event, because if the jet had been pointed too much farther away from Earth, the radio emission would have been too faint for us to detect,” says Hallinan.

    Superfast jets are known to give rise to intense, short-duration gamma-ray bursts or sGRBs, predicted by theorists to be associated with neutron star collisions. The observation of a jet associated with this collision is therefore an important confirmation of theoretical expectations.

    Superfast jets are known to give rise to intense, short-duration gamma-ray bursts or sGRBs, predicted by theorists to be associated with neutron star collisions. The observation of a jet associated with this collision is therefore an important confirmation of theoretical expectations.

    The aftermath of the merger is now also better understood: the jet likely interacted with surrounding debris, forming a broad “cocoon” of material that expanded outward and accounted for the majority of the radio signal observed soon after the collision. Later on, the observed radio emission came mainly from the jet.

    Read the full story from NRAO at https://public.nrao.edu/news/superfast-jet-neutron-star-merger/.

    See the full article here .
    See also https://sciencesprings.wordpress.com/2017/10/16/from-ucsc-a-uc-santa-cruz-special-report-neutron-stars-gravitational-waves-and-all-the-gold-in-the-universe/


    five-ways-keep-your-child-safe-school-shootings
    Please help promote STEM in your local schools.


    Stem Education Coalition

    The California Institute of Technology (commonly referred to as Caltech) is a private research university located in Pasadena, California, United States. Caltech has six academic divisions with strong emphases on science and engineering. Its 124-acre (50 ha) primary campus is located approximately 11 mi (18 km) northeast of downtown Los Angeles. “The mission of the California Institute of Technology is to expand human knowledge and benefit society through research integrated with education. We investigate the most challenging, fundamental problems in science and technology in a singularly collegial, interdisciplinary atmosphere, while educating outstanding students to become creative members of society.”

    Caltech campus

     
  • richardmitnick 4:33 pm on August 20, 2018 Permalink | Reply
    Tags: , Anomalies, Bosons and fermions, Branes, Caltech, , , , Murray Gell-Mann, Parity violation, , , , , , , The second superstring revolution, Theorist John Schwarz   

    From Caltech: “Long and Winding Road: A Conversation with String Theory Pioneer” John Schwarz 

    Caltech Logo

    From Caltech

    08/20/2018

    Whitney Clavin
    (626) 395-1856
    wclavin@caltech.edu

    John Schwarz discusses the history and evolution of superstring theory.

    1
    John Schwarz. Credit: Seth Hansen for Caltech

    The decades-long quest for a theory that would unify all the known forces—from the microscopic quantum realm to the macroscopic world where gravity dominates—has had many twists and turns. The current leading theory, known as superstring theory and more informally as string theory, grew out of an approach to theoretical particle physics, called S-matrix theory, which was popular in the 1960s. Caltech’s John H. Schwarz, the Harold Brown Professor of Theoretical Physics, Emeritus, began working on the problem in 1971, while a junior faculty member at Princeton University. He moved to Caltech in 1972, where he continued his research with various collaborators from other universities. Their studies in the 1970s and 1980s would dramatically shift the evolution of the theory and, in 1984, usher in what’s known as the first superstring revolution.

    Essentially, string theory postulates that our universe is made up, at its most fundamental level, of infinitesimal tiny vibrating strings and contains 10 dimensions—three for space, one for time, and six other spatial dimensions curled up in such a way that we don’t perceive them in everyday life or even with the most sensitive experimental searches to date. One of the many states of a string is thought to correspond to the particle that carries the gravitational force, the graviton, thereby linking the two pillars of fundamental physics—quantum mechanics and the general theory of relativity, which includes gravity.

    We sat down with Schwarz to discuss the history and evolution of string theory and how the theory itself might have moved past strings.

    What are the earliest origins of string theory?

    The first study often regarded as the beginning of string theory came from an Italian physicist named Gabriele Veneziano in 1968. He discovered a mathematical formula that had many of the properties that people were trying to incorporate in a fundamental theory of the strong nuclear force [a fundamental force that holds nuclei together]. This formula was kind of pulled out of the blue, and ultimately Veneziano and others realized, within a couple years, that it was actually describing a quantum theory of a string—a one-dimensional extended object.

    How did the field grow after this paper?

    In the early ’70s, there were several hundred people worldwide working on string theory. But then everything changed when quantum chromodynamics, or QCD—which was developed by Caltech’s Murray Gell-Mann [Nobel Laureate, 1969] and others—became the favored theory of the strong nuclear force. Almost everyone was convinced QCD was the right way to go and stopped working on string theory. The field shrank down to just a handful of people in the course of a year or two. I was one of the ones who remained.

    How did Gell-Mann become interested in your work?

    Gell-Mann is the one who brought me to Caltech and was very supportive of my work. He took an interest in studies I had done with a French physicist, André Neveu, when we were at Princeton. Neveu and I introduced a second string theory. The initial Veneziano version had many problems. There are two kinds of fundamental particles called bosons and fermions, and the Veneziano theory only described bosons. The one I developed with Neveu included fermions. And not only did it include fermions but it led to the discovery of a new kind of symmetry that relates bosons and fermions, which is called supersymmetry. Because of that discovery, this version of string theory is called superstring theory.

    When did the field take off again?

    A pivotal change happened after work I did with another French physicist, Joël Scherk, whom Gell-Mann and I had brought to Caltech as a visitor in 1974. During that period, we realized that many of the problems we were having with string theory could be turned into advantages if we changed the purpose. Instead of insisting on constructing a theory of the strong nuclear force, we took this beautiful theory and asked what it was good for. And it turned out it was good for gravity. Neither of us had worked on gravity. It wasn’t something we were especially interested in but we realized that this theory, which was having trouble describing the strong nuclear force, gives rise to gravity. Once we realized this, I knew what I would be doing for the rest of my career. And I believe Joël felt the same way. Unfortunately, he died six years later. He made several important discoveries during those six years, including a supergravity theory in 11 dimensions.

    Surprisingly, the community didn’t respond very much to our papers and lectures. We were generally respected and never had a problem getting our papers published, but there wasn’t much interest in the idea. We were proposing a quantum theory of gravity, but in that era physicists who worked on quantum theory weren’t interested in gravity, and physicists who worked on gravity weren’t interested in quantum theory.

    That changed after I met Michael Green [a theoretical physicist then at the University of London and now at the University of Cambridge], at the CERN cafeteria in Switzerland in the summer of 1979. Our collaboration was very successful, and Michael visited Caltech for several extended visits over the next few years. We published a number of papers during that period, which are much cited, but our most famous work was something we did in 1984, which had to do with a problem known as anomalies.

    What are anomalies in string theory?

    One of the facts of nature is that there is what’s called parity violation, which means that the fundamental laws are not invariant under mirror reflection. For example, a neutrino always spins clockwise and not counterclockwise, so it would look wrong viewed in a mirror. When you try to write down a fundamental theory with parity violation, mathematical inconsistencies often arise when you take account of quantum effects. This is referred to as the anomaly problem. It appeared that one couldn’t make a theory based on strings without encountering these anomalies, which, if that were the case, would mean strings couldn’t give a realistic theory. Green and I discovered that these anomalies cancel one another in very special situations.

    When we released our results in 1984, the field exploded. That’s when Edward Witten [a theoretical physicist at the Institute for Advanced Study in Princeton], probably the most influential theoretical physicist in the world, got interested. Witten and three collaborators wrote a paper early in 1985 making a particular proposal for what to do with the six extra dimensions, the ones other than the four for space and time. That proposal looked, at the time, as if it could give a theory that is quite realistic. These developments, together with the discovery of another version of superstring theory, constituted the first superstring revolution.

    Richard Feynman was here at Caltech during that time, before he passed away in 1988. What did he think about string theory?

    After the 1984 to 1985 breakthroughs in our understanding of superstring theory, the subject no longer could be ignored. At that time it acquired some prominent critics, including Richard Feynman and Stephen Hawking. Feynman’s skepticism of superstring theory was based mostly on the concern that it could not be tested experimentally. This was a valid concern, which my collaborators and I shared. However, Feynman did want to learn more, so I spent several hours explaining the essential ideas to him. Thirty years later, it is still true that there is no smoking-gun experimental confirmation of superstring theory, though it has proved its value in other ways. The most likely possibility for experimental support in the foreseeable future would be the discovery of supersymmetry particles. So far, they have not shown up.

    What was the second superstring revolution about?

    The second superstring revolution occurred 10 years later in the mid ’90s. What happened then is that string theorists discovered what happens when particle interactions become strong. Before, we had been studying weakly interacting systems. But as you crank up the strength of the interaction, a 10th dimension of space can emerge. New objects called branes also emerge. Strings are one dimensional; branes have all sorts of dimensions ranging from zero to nine. An important class of these branes, called D-branes, was discovered by the late Joseph Polchinski [BS ’75]. Strings do have a special role, but when the system is strongly interacting, then the strings become less fundamental. It’s possible that in the future the subject will get a new name but until we understand better what the theory is, which we’re still struggling with, it’s premature to invent a new name.

    What can we say now about the future of string theory?

    It’s now over 30 years since a large community of scientists began pooling their talents, and there’s been enormous progress in those 30 years. But the more big problems we solve, the more new questions arise. So, you don’t even know the right questions to ask until you solve the previous questions. Interestingly, some of the biggest spin-offs of our efforts to find the most fundamental theory of nature are in pure mathematics.

    Do you think string theory will ultimately unify the forces of nature?

    Yes, but I don’t think we’ll have a final answer in my lifetime. The journey has been worth it, even if it did take some unusual twists and turns. I’m convinced that, in other intelligent civilizations throughout the galaxy, similar discoveries will occur, or already have occurred, in a different sequence than ours. We’ll find the same result and reach the same conclusions as other civilizations, but we’ll get there by a very different route.

    See the full article here .

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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    The California Institute of Technology (commonly referred to as Caltech) is a private research university located in Pasadena, California, United States. Caltech has six academic divisions with strong emphases on science and engineering. Its 124-acre (50 ha) primary campus is located approximately 11 mi (18 km) northeast of downtown Los Angeles. “The mission of the California Institute of Technology is to expand human knowledge and benefit society through research integrated with education. We investigate the most challenging, fundamental problems in science and technology in a singularly collegial, interdisciplinary atmosphere, while educating outstanding students to become creative members of society.”

    Caltech campus

     
  • richardmitnick 7:50 am on August 18, 2018 Permalink | Reply
    Tags: AAReST (Autonomous Assembly of a Reconfigurable Space Telescope), , , , Caltech,   

    From Caltech: “Student-Built Satellite Telescope Prepares for Space” 

    Caltech Logo

    From Caltech

    1
    Artist’s concept of AAReST
    Credit: Sergio Pellegrino/Caltech

    After nearly a decade of work, a modular reconfigurable space telescope designed by students is nearly ready to launch.

    08/16/2018

    Robert Perkins
    (626) 395-1862
    rperkins@caltech.edu

    After nine years, a student-designed-and-built satellite is being readied for launch into orbit, where it will be a test bed for a new type of space telescope that assembles itself in flight from multiple components.

    With telescopes, bigger is better: the larger their primary mirror, the more light they can capture and the better the images they can create. Currently, however, space telescopes are limited in size and must be folded up to fit inside the rockets that launch them into space. Hubble is 2.4 meters in diameter, for instance, and the James Webb Space Telescope will be 6.5 meters in diameter when it launches in 2021. To build a telescope that exceeds 10 meters, scientists and engineers will need to develop new, modular designs that can be sent to space in multiple pieces—even on multiple rockets.

    In 2008, a series of workshops at the Keck Institute of Space Studies (KISS) at Caltech inspired a low-cost mission to demonstrate the feasibility of sending a telescope to space in pieces and having it assemble itself once in orbit.

    That telescope, which came to be known as AAReST (Autonomous Assembly of a Reconfigurable Space Telescope), was designed and built in large part by students in Caltech’s Ae 105 Aerospace Engineering class, working in collaboration with the Surrey Space Centre in England and the Indian Institute of Space Science and Technology. Over the years, these students planned the mission and designed the telescope. With the spacecraft nearly complete, 2018 marks the conclusion of the AAReST project for the Ae 105 students. The AAReST satellite is scheduled to be launched on an Indian Space Research Organization (ISRO) rocket in 2019.

    Ae 105 is a yearlong class taught by JPL instructors Oscar Alvarez-Salazar, Andy Klesh, Scott Ploen, and Dan Scharf. At Caltech, aerospace engineer Sergio Pellegrino is AAReST’s campus coordinator and JPL’s John Baker is its project manager. Over the past near decade, the Ae 105 students have dealt with countless design and technical issues regarding the project. But by far the biggest challenge the class faced, Pellegrino says, was an informational one: how to pass on information from one generation of students to the next.

    “Continuity is a challenge in every project. You always have to cope with the fact that people leave because they retire or get different jobs. But in our case, the entire workforce was replaced every year,” says Pellegrino, the Joyce and Kent Kresa Professor of Aerospace and Civil Engineering and a JPL senior research scientist. “In a normal project, outgoing team members produce detailed write-ups. For us, that just wasn’t enough.”

    To cope with the turnover, Pellegrino invited many former students to stay on as mentors to the incoming Ae 105 classes. This ultimately spawned a second class, Ae 205, Advanced Space Project, to formalize the student-mentorship role. That student mentorship, coupled with the fact that the mission was actually going to space, translated into a uniquely valuable experience according to those who went through the program.

    “Having a form of practical experience to point to is very useful after university when looking for a job,” says Lee Wilson (PhD ’17), who now works on spacecraft design at Deep Space Industries in San Jose. “This project helped expose me to vibration testing and spacecraft design, assembly, and integration, and actually let me get my hands dirty.”

    Thibaud Talon, who took Ae 105 during the 2013–14 school year and remains involved in the project to this day as a graduate student, echoes Wilson’s sentiments.

    “Since the class is taught by JPL engineers, I started to make a network at JPL. I still meet, talk, and sometimes work with the professors who taught me Ae 105,” says Talon. “Also, working on an actual space mission is a great addition to my resume. As many people working in the space industry told me, such an experience is very valuable and looked at when applying for a job. Participating in such a project teaches you many concepts of designing a space mission that are hard to learn otherwise.”

    The final design that the students came up with for the AAReST spacecraft features a central core unit that contains the attitude and control system, the radio and the antennas, and two rigid mirrors. Surrounding that central unit are two smaller spacecraft containing deformable mirrors that will be co-focused with the rigid mirrors on the main spacecraft. The whole package is small, measuring just 46 x 34 x 30 centimeters. Once in orbit, the two smaller spacecraft will detach from the main one via splitting bolts and then float about 30 centimeters away from the spacecraft before reconnecting to the main body in a wider configuration via electromagnets.

    The final project for this year’s Ae 105 class was focused on testing the main spacecraft, with particular attention paid to ensuring that the recoil from the splitting bolts will not throw the side segments too far away from the main spacecraft.

    Ae 105 will no longer focus on AAReST, but there are still several details to be worked out before the spacecraft is launched, so Pellegrino will be taking a sabbatical during the 2018–19 academic year to work with the senior students on the project. Soon-Jo Chung, associate professor of aerospace and Bren Scholar and JPL research scientist, will take over Ae 105 and pick a new project for its students to tackle.

    Pellegrino says that the Caltech students working on AAReST have learned how to collaborate across continents and gained skills that will continue to serve them for years to come. In addition, he says, he’s proud to have given several generations of aerospace students the opportunity to work on a real space mission. When the mission launches in 2019, dozens of past and present Caltech students—along with their collaborators nearby and abroad—will be watching and holding their breath to see whether their hard work pays off.

    Manan Arya (PhD ’16), an Ae 105 student from 2011 who now works on large deployable spacecraft structures at JPL, says he’s looking forward to watching the launch. “Overall it’s a feeling of excitement and great joy that something that I’ve worked on will end up in space, mixed with the nervousness that all engineers must experience when they press the ‘on’ button and hope, wish, and pray that it actually turns on.”

    The AAReST mission is a collaborative effort between Caltech, the University of Surrey in England, and the Indian Institute of Space Science and Technology. The AAReST project has received funding from KISS; Caltech’s Division of Engineering and Applied Science; and the Innovation in Education Fund, which was made possible in part by the Caltech Associates.

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings
    Please help promote STEM in your local schools.


    Stem Education Coalition

    The California Institute of Technology (commonly referred to as Caltech) is a private research university located in Pasadena, California, United States. Caltech has six academic divisions with strong emphases on science and engineering. Its 124-acre (50 ha) primary campus is located approximately 11 mi (18 km) northeast of downtown Los Angeles. “The mission of the California Institute of Technology is to expand human knowledge and benefit society through research integrated with education. We investigate the most challenging, fundamental problems in science and technology in a singularly collegial, interdisciplinary atmosphere, while educating outstanding students to become creative members of society.”

    Caltech campus

     
  • richardmitnick 12:14 pm on June 2, 2018 Permalink | Reply
    Tags: , , , , Caltech, , Harry Atwater   

    From Caltech: “Building the Starshot Sail: A Q&A with Harry Atwater” 

    Caltech Logo

    From Caltech

    06/01/2018

    Robert Perkins
    (626) 395-1862
    rperkins@caltech.edu

    Breakthrough Starshot image. Credit: Breakthrough Starshot

    When manmade probes finally reach other stars, they will not be powered by rockets. Instead, they may be riding on a gossamer-thin sail that is being blasted by a giant laser beam. Harry Atwater, Howard Hughes Professor of Applied Physics and Materials Science, is a project leader of the Breakthrough Starshot Program,which seeks to make these probes a reality. In a new paper published on May 7 in Nature Materials, Atwater explores some of the major challenges the project will face in its bid to make humanity an interstellar species. We recently sat down with him to talk about the program.

    What exactly is the Breakthrough Starshot Program?

    It is a multi-disciplinary $100-million project that was announced in 2016, aimed at designing a spacecraft that can be launched to planets surrounding other stars and reach them within our lifetime. The idea is to develop spacecraft that are capable of traveling at nearly 20 percent of the speed of light.
    Why can’t that be done with conventional rockets?

    The issue with traditional rocket propulsion is that the final velocity of the rocket is limited by the final velocity of the fuel ejected from the rocket. For chemical propellants, the upper limit of the final velocity is way too low. The fastest spacecraft that has ever been launched would take tens of thousands of years to reach the nearest star, Alpha Centauri C. That is clearly impractical for any interstellar mission.

    To overcome that, we’re planning to use light itself as the fuel. In other words, we are taking advantage of the principle of conservation of momentum between light and materials. If I have a reflective object and I shine light on it, the recoiling or reflecting photons impart momentum to the object. If the object is light enough, that momentum can act as a propulsive force, and then the final velocity of that probe is limited only by the velocity of light itself.

    What is your role in the project?

    I’m an advisor to the Breakthrough Starshot Program. The program has three big technical challenges: The first is to build the so-called photon engine, the laser that’s capable of propelling the sail; the second is to design the sail itself; and the third is to design the payload, which will be a tiny spacecraft capable of taking images and spectral data and then beaming them back to the earth. My role is to help the program define pathways to making a viable lightsail that’s compatible with the other objectives of the whole program. It isn’t going to be easy: we have to make an ultra-lightweight large-scale object that is firmly and dynamically stable under propulsion.

    What other challenges are there?

    The challenges that we address in our latest paper are developing the design and materials requirements for this really extreme set of engineering conditions. We require something that has a mass of no more than a gram, but which covers an area of about 10 square meters. That means that the average thickness will be on the order of tens to hundreds of nanometers; much thinner than a human hair.

    This wafer-thin material will be subject to intense laser radiation during the propulsion phase, with an intensity of megawatts per square meter. That’s not the highest intensity that has ever been generated in a laboratory, but it’s a very high intensity to interact with an ultra-thin, gossamer-like membrane structure of the kind that we’re talking about here. So the biggest requirement is that it has to be ultra-reflective so we can impart momentum and propel the lightsail.

    Are there any materials, or families of materials, that look promising for this?

    Yes. The best materials are the ones that are dielectric, or insulating, rather than metallic materials, which transmit electrical charges. A good example of a dielectric that everyone is familiar with is glass, which is highly non-absorbing. Unfortunately, glass is a little too low in its reflectivity to be an efficient candidate for lightsail material, but nonetheless it points the way. The best materials to think about are ones that have higher reflectivity but similarly low absorption coefficients.

    How does this work fit in with your broader research goals?

    My research team is very interested in how light interacts with nanoscale materials, or materials that are sculpted or shaped at the scale of the wavelength itself. One of the things that’s fascinating is that nanostructured materials may be able to generate really optimal trade-offs between mass and reflectivity, and also help give stability to the sail. We need the sail to be passably stable, meaning that it doesn’t fall off the laser beam, so to speak.

    [My totally uneducated surmise: Don’t hold your breath.]

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings
    Please help promote STEM in your local schools.


    Stem Education Coalition

    The California Institute of Technology (commonly referred to as Caltech) is a private research university located in Pasadena, California, United States. Caltech has six academic divisions with strong emphases on science and engineering. Its 124-acre (50 ha) primary campus is located approximately 11 mi (18 km) northeast of downtown Los Angeles. “The mission of the California Institute of Technology is to expand human knowledge and benefit society through research integrated with education. We investigate the most challenging, fundamental problems in science and technology in a singularly collegial, interdisciplinary atmosphere, while educating outstanding students to become creative members of society.”

    Caltech campus

     
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