News from www.caltech.eduhttps://www.caltech.edu/about/news2024-02-20T17:21:35.741172+00:00The Office of Strategic Communicationswww@caltech.eduCopyright © 2024 California Institute of TechnologyCaltech Professors Win 2024 Sloan Fellowships2024-02-20T17:21:35.741172+00:002024-02-20T17:21:35.531604+00:00Whitney Clavinwclavin@caltech.eduhttps://www.caltech.edu/about/news/caltech-professors-win-2024-sloan-fellowships<p data-block-key="sjv42">Four Caltech faculty members have been awarded the prestigious Sloan Research Fellowship for 2024: Katie Bouman, assistant professor of computing and mathematical sciences, electrical engineering and astronomy; Lee McCuller, assistant professor of physics; Vikram Ravi, assistant professor of astronomy; and Antoine Song, assistant professor of mathematics.</p><p data-block-key="99nha">The fellowships honor exceptional U.S. and Canadian researchers "whose creativity, innovation, and research accomplishments make them stand out as the next generation of leaders," according to the <a href="https://sloan.org/">Alfred P. Sloan Foundation</a>, which has been granting the awards annually since 1955. The Caltech professors are among 126 early-career scientists who have been selected to receive the fellowships, which come with $75,000 over two years to advance research projects.</p><p data-block-key="4l2id"><a href="/about/news/seeing-farther-and-deeper-interview-katie-bouman">Katie Bouman</a> is a computational imaging scientist whose methods combine ideas from signal processing, computer vision, machine learning, and physics to bring out hidden signals in scientific and technical data. She is a key member of the <a href="https://eventhorizontelescope.org/">Event Horizon Telescope</a> project, which made history in 2019 by unveiling the first image of a black hole, in this case, a supermassive black hole lying at the heart of the M87 galaxy. Using data acquired by a global network of radio telescopes, Bouman and her teammates developed a computational approach that transformed the black hole data into an image. Since then, her team has helped produce an <a href="/about/news/caltech-researchers-help-generate-first-image-of-black-hole-at-the-center-of-our-galaxy">image of the supermassive black hole at the heart of our Milky Way Galaxy</a>, called Sagittarius A*, as well as a new <a href="/about/news/new-data-same-great-appearance-for-m87">image of the M87 black hole made with enhanced data</a>. Bouman is also developing next-generation computational cameras for other imaging problems in astronomy, medicine, and seismology, where traditional cameras will not work.</p><p data-block-key="899b3"><a href="/about/news/at-the-edge-of-physics">Lee McCuller</a> is an expert at creating technologies that make the most precise measurements in the world. These quantum measurements are at the heart of the <a href="https://www.ligo.caltech.edu/">Laser Interferometer Gravitational-wave Observatory</a>(LIGO), which has been detecting gravitational waves from colliding black holes and neutron stars since it first detected ripples in space-time in 2015. McCuller helped lead the development of essential technology at LIGO based on a concept called quantum squeezing. This method helps reduce unwanted noise in LIGO's detectors—noise that bubbles up from the quantum realm—to make the facilities even more sensitive to gravitational waves. Recently, Lee and his LIGO collaborators <a href="/about/news/ligo-surpasses-the-quantum-limit">took the technology one step further</a> to make quantum squeezing work across the range of gravitational frequencies detected by LIGO. The research helped surpass limits imposed by quantum physics and made LIGO even more powerful.</p><p data-block-key="1kqt6"><a href="/about/news/build-it-and-they-will-come-fast-radio-bursts">Vikram Ravi</a> is an astronomer specializing in energetic dynamic events, such as fast radio bursts, or FRBs, which are powerful eruptions of radio waves that <a href="/about/news/fast-radio-burst-pinpointed-distant-galaxy">originate primarily from remote galaxies</a> and whose cause remains unknown. Ravi co-led the development of the Deep Synoptic Array-110, an array of radio dishes at Caltech's Owens Valley Radio Observatory, which has now identified and pinpointed over 60 FRBs to their galaxies of origin. Ravi plans to use this growing sample—a significant fraction of the fewer than 90 FRBs so far associated with galaxies—to better understand <a href="/about/news/cosmic-burst-probes-milky-ways-halo">how matter is distributed within and in between galaxies</a>. He is also embarking on a new program to identify tidal disruption events, or TDEs, which occur when a star wanders too close to a black hole and is devoured. Ravi and his colleagues will use data from the <a href="https://ztf.ipac.caltech.edu/">Zwicky Transient Facility</a> (ZTF) at Caltech's Palomar Observatory to search for more obscure TDEs, and help piece together the puzzles of how often these events occur as well as why they do not look the same when viewed at different wavelengths of light.</p><p data-block-key="5fteo"><a href="/about/news/Geometry_of_Minimal_Surfaces">Antoine Song</a> specializes in differential geometry, the study of shapes using analysis and differential equations. His goal is to better understand minimal surfaces, geometrical shapes that minimize total surface area and total energy; for instance, a circular wire frame dipped in soapy water leads to a film with a minimal optimal shape. For his PhD thesis, Song showed that there are infinitely many minimal surfaces in any three-dimensional space. Recently, Song and his colleague Conghan Dong, a graduate student at Stony Brook University, helped prove an aspect of Albert Einstein's general theory of relativity, showing that "a sequence of curved spaces with smaller and smaller amounts of mass will eventually converge to a flat space with zero curvature," according to <a href="https://www.quantamagazine.org/a-century-later-new-math-smooths-out-general-relativity-20231130/">Quanta Magazine</a>.</p><p data-block-key="12ql6">Read more about the Sloan Research Fellowships at its <a href="https://sloan.org/fellowships/">website</a>.</p>New Caltech-led Mission Will Study Ultraviolet Sky, Stars, Stellar Explosions2024-02-13T23:43:00+00:002024-02-14T20:49:33.417115+00:00Whitney Clavinwclavin@caltech.eduhttps://www.caltech.edu/about/news/new-caltech-led-mission-will-study-ultraviolet-sky-stars-stellar-explosions<p data-block-key="js6x7">As NASA explores the unknown in air and space, a new mission to survey ultraviolet light across the sky will provide the agency with more insight into how galaxies and stars evolve. The space telescope, called <a href="https://www.uvex.caltech.edu/">UVEX</a> (Ultraviolet Explorer), is targeted to launch in 2030 as NASA's next Astrophysics Medium-Class Explorer mission. The mission is led by Caltech's <a href="https://pma.caltech.edu/people/fiona-a-harrison">Fiona Harrison</a>, the Harold A. Rosen Professor of Physics and the Kent and Joyce Kresa Leadership Chair of the Division of Physics, Mathematics and Astronomy.</p><p data-block-key="6be28">"I feel privileged to lead the amazing team that will execute the UVEX mission and its exciting scientific program," says Harrison, who is also the principal investigator of NASA's <a href="https://www.nustar.caltech.edu/">NuSTAR</a> (Nuclear Spectroscopic Telescope Array) mission. "UVEX is a true Explorer mission that will answer questions we can pose today and open vast discovery space for the future."</p><p data-block-key="6ro9v">In addition to conducting a highly sensitive all-sky survey, UVEX will be able to quickly point toward sources of ultraviolet light in the universe. This will enable it to capture the explosions that follow bursts of gravitational waves caused by merging neutron stars, such as the <a href="https://www.caltech.edu/about/news/caltech-led-teams-strike-cosmic-gold-80074">dramatic event known as GW170817</a>, first detected by <a href="https://www.ligo.caltech.edu">LIGO</a> (the Laser Interferometer Gravitational-wave Observatory) in August 2017. The UVEX telescope also will carry an ultraviolet spectrograph to study stellar explosions and massive stars.</p><p data-block-key="500rc">"NASA's UVEX will help us better understand the nature of both nearby and distant galaxies, as well as follow up on dynamic events in our changing universe," said Nicola Fox, associate administrator for NASA's Science Mission Directorate "This mission will bring key capabilities in near-and far-ultraviolet light to our fleet of space telescopes, delivering a wealth of survey data that will open new avenues in exploring the secrets of the cosmos."</p><p data-block-key="rcef"></p><p data-block-key="8m5ag"></p><p data-block-key="3fotb">Other Caltech team members include: Shri Kulkarni, Mansi Kasliwal, Kareem El-Badry, Christopher Martin, Sterl Phinney, Harry Teplitz, Matthew Graham, and project scientist Brian Grefenstette. Additional team members are listed on the <a href="https://www.uvex.caltech.edu/page/team">project's website</a>. The Jet Propulsion Laboratory, managed by Caltech for NASA, will provide key detector and UV-coating technologies at the heart of the UVEX focal plane. Caltech's <a href="https://www.ipac.caltech.edu">IPAC</a>, a premier data center for astrophysics and planetary science, will develop the science analysis pipeline and provide community data access and archiving. The mission is managed by UC Berkeley's Space Science Laboratory. The spacecraft will be built by Northrop Grumman.</p><p data-block-key="ens34">Read the <a href="https://www.nasa.gov/news-release/new-nasa-mission-will-study-ultraviolet-sky-stars-stellar-explosions/">full story from NASA</a>.</p>75 Years Later, Palomar Observatory Still Shaping Astronomy2024-01-26T19:12:00+00:002024-02-02T19:56:11.240886+00:00Whitney Clavinwclavin@caltech.eduhttps://www.caltech.edu/about/news/75-years-later-palomar-observatory-still-shaping-astronomy<p data-block-key="qh7sr">"It's on the money," said Paul Nied, one of three telescope operators for the 200-inch Hale Telescope at Caltech's <a href="https://sites.astro.caltech.edu/palomar/homepage.html">Palomar Observatory</a> near San Diego. Nied was sitting in a large black chair at the helm of the controls for the massive telescope, which is nestled on Palomar Mountain. He had just directed the telescope to point at a star on the sky while astronomer Zach Vanderbosch watched nearby as the target moved into view on a screen in front of him.</p><p data-block-key="beuog">"The atmosphere is pretty turbulent right now," Vanderbosch said as he peered at the screen from the chilly control room, a wool hat on his head. "The star we are observing is very far south. At lower elevations, you have to look through more atmosphere, which smears out the stars from small pinpoints of light to large fuzzy blobs."</p><p data-block-key="4k78a">Vanderbosch, a Caltech postdoctoral scholar in the research group of <a href="https://pma.caltech.edu/people/thomas-a-tom-prince">Tom Prince</a>, the Ira S. Bowen Professor of Physics, Emeritus, was working through the night to observe a handful of dead stars called white dwarfs that he believes are circled by the pulverized remains of planets. He had observed some of the same objects the night before and was hoping to compare the two datasets to better understand the nature of the suspected planetary debris.</p><p data-block-key="74h2m">The telescope quietly tracked Vanderbosch's white dwarfs as they slid across the sky. Every time Nied guided the telescope to a new target, the giant machine made a whining noise and the rotating dome rumbled.</p><p data-block-key="fv455">The Hale Telescope, known affectionately by many during its development as the Big Eye, is celebrating is 75th "first-light" anniversary this month. On January 26, 1949, renowned astronomer Edwin Hubble took the telescope's first picture, a celebratory moment in astronomy known as first light. The image, which shows a billowing nebula dotted with stars, marked the start of what was to be the world's largest effective optical telescope for the next 44 years, until the W. M. Keck Observatory opened on Maunakea in Hawaiʻi in 1993. (The Russian Large Altazimuth Telescope, which is larger than Palomar, opened in 1975 but never operated at its theoretical limits).</p><p data-block-key="18f85">Back in Palomar's early days, the astronomers studied the dark skies from an elevated platform known as the prime focus cage, which could be as high as 78 feet above the observing floor. This is where light from the 200-inch mirror is focused. A lift would carry the scientists up the side of the dome to the cage, where they could peer into an eye piece to help find their target of interest. <a href="https://pma.caltech.edu/people/shrinivas-r-shri-kulkarni">Shri Kulkarni</a>, the George Ellery Hale Professor of Astronomy and Planetary Science, and the director of Palomar Observatory from 2006–18, remembers what it was like in the cage.</p><p data-block-key="2j8ml">"It was cold, and, in the winter, you would wear a heated suit," says Kulkarni, who led the development of several instruments for Palomar telescopes. "You go all over the sky, and sometimes you are lying down or leaning forward."</p><p data-block-key="fdc64">Instrument Specialist Keith Matthews (BS '62), who has also built many instruments for the Palomar Observatory, says he had a good parka and snowmobile boots for observing nights and could easily stay up in the cage for 12 hours. "The mirror is big enough that you could see stars at the level of the prime focus over the edge of the cage. They look like they are floating there in the air," he says.</p><p data-block-key="5ehsq">Today, many of the telescope control systems are automated, and astronomers often observe from the comfort of either their homes or a conference room at Caltech while communicating via Zoom with telescope operators on site. Andy Boden, the deputy director of Palomar, refers to observing from home as "pajama observing," and says that about 40 percent of researchers now make a trip to Palomar Mountain to observe in person, down from about 50 to 60 percent before the COVID-19 pandemic.</p><p data-block-key="b0c5i">Some astronomers like Vanderbosch say they still like to observe in person. A trip to Palomar includes a stay at the astronomers' dorm, a simple white building nicknamed the Monastery tucked among a forest of fir trees. Vanderbosch, who likes to hike in the area, says he finds it rewarding to stay up all night in the control room with the operators, noting that his addiction to coffee started on these observing nights.</p><p data-block-key="fjod0"></p><embed alt="Photos of Palomar staff members: Greg Van Idsinga, Carolyn Heffner, Diana Roderick, Kathleen Koviak, and Paul Nied." embedtype="image" format="MiddleAlignLarge" id="10335"/><p data-block-key="3u87"></p><p data-block-key="c97ml">Professor of Astronomy <a href="https://pma.caltech.edu/people/mansi-m-kasliwal">Mansi Kasliwal</a> (MS '07, PhD '11), who was a graduate student under Kulkarni and has also developed instruments for Palomar, still likes to make her way to the 5,600-foot mountaintop when she can. She loves the food served by on-site chefs at the Monastery. "They make me Indian food and spoil me," she says. Kasliwal adds that Palomar is the "best playground for new ideas in astronomy. Even as a grad student, you can do innovative work there."</p><p data-block-key="on6l">Now, 75 years after its first light, Palomar is still going strong. "They built an extremely good telescope," says Nied, who, along with a staff of more than 20 Caltech employees, spends his nights not only taking care of the 200-inch telescope but also several others at the site. One of these, the Samuel Oschin Telescope, a workhorse also known as the 48-inch, recently celebrated its own 75th anniversary (its first light occurred in September 1948).</p><p data-block-key="ctrmm">A vital part of Palomar's continuing success is its evolving array of instruments such as the wildly successful <a href="https://www.ztf.caltech.edu/">Zwicky Transient Facility</a> (ZTF), a robotic camera currently attached to the 48-inch. ZTF's discoveries include the "<a href="/about/news/green-comet-viewing-event">green comet</a>," <a href="/about/news/first-asteroid-found-inside-orbit-venus">the first asteroid known to reside inside the orbit of Venus</a>, <a href="/about/news/star-eats-planet-brightens-dramatically">the first glimpse of a star eating a planet</a>, and more than 10,000 supernovae candidates.</p><p data-block-key="bdm7q">"They are doing things routinely now that were completely out of reach before," says Robert Brucato, who served as the assistant director of the observatory from 1982–2003 . "We have robotic telescopes like ZTF, and we can handle much more data than before due to processing with computers and machine learning. Palomar is continually renewed with new instrumentation."</p><p data-block-key="apogs"><b>The Big Eye</b></p><p data-block-key="9nejk">Before Palomar Observatory was built, the world's largest telescope was the 100-inch Hooker Telescope perched above Pasadena at the Mount Wilson Observatory. The 100-inch, along with its sister telescope, the 60-inch, are owned by the Carnegie Institution for Science. Both telescopes were developed by Caltech co-founder George Ellery Hale, widely considered to be one of the greatest telescope builders of all time.</p><p data-block-key="clvhb">"Hale was a one-man show who had a hunger to make things happen," said Kulkarni in a <a href="/about/news/celebrating-caltechs-founder-and-builder-large-telescopes-82669#:~:text=When%20George%20Ellery%20Hale%20climbed,bigger%20window%20to%20the%20cosmos.">Caltech news story about Hale</a>. "The telescopes he built are just magnificent."</p><p data-block-key="1187b"></p><embed alt="George Ellery Hale" embedtype="image" format="LeftAlignMedium" id="10336"/><p data-block-key="frhll"></p><p data-block-key="5gblu">Using Mount Wilson's 100-inch telescope, Hubble discovered our Milky Way galaxy is not alone but adrift in a sea of other galaxies. Hubble also discovered that galaxies are flying away from us, indicating the expansion of space itself, a finding that provided the first hints of the explosive Big Bang that produced our universe.</p><p data-block-key="72qn6">These discoveries led to burning questions about the birth and fate of our cosmos—questions that could not be answered without a much larger telescope. Hale took up the fight, traveling by train back and forth to the East Coast, to discuss the telescope project with influential philanthropists. In 1928, he persuaded the Rockefeller Foundation to provide $6 million to fund the 200-inch observatory's construction. At that time, Los Angeles and its city lights had begun to spread, and Mount Wilson was no longer the ideal place from which to peer into dark skies. Ultimately, Palomar Mountain northeast of San Diego was chosen as the observatory's site, but it would be another 20 years—a decade after Hale's death—before the observatory finally opened.</p><p data-block-key="au3v1">The sheer size of the Hale Telescope, a 530-ton structure containing a 200-inch, first-of-its-kind Pyrex mirror, led to engineering challenges that took years to overcome. The creation, or casting, and polishing of the great mirror was plagued by one problem after another. During one crucial stage in casting the mirror, which took place at Corning Glass Works in New York, a heavy storm hit the area, resulting in floods and power outages. Corning employees and firefighters worked through the night to restore power and save the mirror.</p><p data-block-key="bdtk4">The design and construction of the huge Hale telescope tube and mounting also presented a challenge. The steel structure is so big that the Westinghouse Corporation, which made battleship components for the U.S. Navy, was hired to produce it.</p><p data-block-key="4kvvn">As the Big Eye slowly came together, the whole world seemed to root for the project. During the mirror-making process at Corning, onlookers watched and cheered from a platform in the building as searing-hot molten glass was poured ladle by ladle into the mirror cast. When the mirror <a href="https://www.youtube.com/watch?v=kim-fO9448U&list=PLTWQbEZMrCz1CSiPsyVxA5udz14SgTz8d&index=21">made its way across the country via train</a> in 1936, thousands of people came out to gaze at the odd-shaped cargo and cheer.</p><p data-block-key="9o1t5">"The great telescope, an achievement of American science and technology in the midst of the most terrible depression anyone could remember, had become a part of the American consciousness, a symbol of pride and achievement," wrote Ronald Florence in <i>The Perfect Machine</i>, a history of the building of Palomar.</p><p data-block-key="67ia9">"Anybody alive during that time knew about the Big Eye," Brucato adds.</p><p data-block-key="fkcse">The grinding and polishing of the delicate mirror took place in Caltech's Optical Shop (known later as the <a href="https://magazine.caltech.edu/post/synchrotron-building">Synchrotron building</a>) over a period of more than 11 years. The tedious process required fastidiously clean conditions. The workers wore immaculate white uniforms, and the floors were washed daily. At times, the walls were coated with cedar oil to make them sticky enough to catch stray grains. A speck of dust under a polishing tool could make a scratch that would lead to major setbacks. During World War II, work on the mirror was largely paused as the Optical Shop was turned over to war-related research. By 1947, the mirror was finally ready to be driven up Palomar Mountain.</p><p data-block-key="59khp"></p><embed alt="The 200-inch pictured in Caltech's Optical Shop." embedtype="image" format="RightAlignMedium" id="10337"/><p data-block-key="eq24"></p><p data-block-key="4jhrj">In June 1948, about 1,000 people gathered below the grand machine for its dedication ceremony. Several months later, the telescope saw first light, and it has not stopped operating since.</p><p data-block-key="15hlp">"In a quiet moment at Palomar, I stop and pinch myself because I feel so incredibly lucky to be there," Boden says. "I am from a generation that grew up reading about Palomar as this icon. The first time I walked on the catwalk that circles the dome, I knew I was hooked."</p><p data-block-key="ffmdq"><b>Breaking Open the Cosmos</b></p><p data-block-key="51bbh">Some of the most significant discoveries from the 200-inch telescope involve studies of distant objects. The giant eye allowed astronomers to see farther back into space than ever before—and farther back in time, since light from those distant objects can take billions of years to reach us. In 1963, Caltech astronomer Maarten Schmidt stunned the world with the discovery of the first-known quasar, an extremely luminous source of light that we know is generated by an actively feeding black hole.</p><p data-block-key="c60dt">"Many people didn't believe it and thought these objects must be in our Milky Way galaxy," said Richard Ellis, a former Caltech professor and director of the Palomar Observatory from 2000–05, in an <a href="/about/news/caltech-mourns-the-passing-of-maarten-schmidt-1929-2022">obituary for Schmidt</a>. "His discovery created this excitement that the 200-inch could look back at the evolution of our universe."</p><p data-block-key="5udju">Building on the findings of Hubble and astronomer Walter Baade of Carnegie Institution, Allan Sandage (PhD '53) of Carnegie Institution used the 200-inch to study the size and expansion rate of the universe. In 1958, Sandage measured a value for the expansion rate, also known as Hubble's parameter, of 75 kilometers per second per megaparsec, which is not far from its modern value of 71 kilometers per second per megaparsec (one megaparsec equals 3.26 million light-years). He also studied the large-scale structure of the universe, declaring that it is essentially similar in all directions. "Sandage's work at Palomar made observational cosmology a real science," Boden says.</p><p data-block-key="24gdk">Data from the 200-inch was also used to help show <a href="https://www.youtube.com/watch?v=o08mTfdBSf4&list=PLTWQbEZMrCz3JoFh4rneKTkgKmf652J1N&index=3">how elements are synthesized by stars</a>, a landmark finding from the 1950s known as B<sup>2</sup>FH after its authors: Margaret Burbidge, Geoffrey Burbidge, and William Fowler (PhD '36) of Caltech, along with Fred Hoyle of the University of Cambridge. The finding was based in large part on observations made by Caltech's Jesse Greenstein, an authority on the evolution and composition of stars, who <a href="/about/news/caltech-astronomer-jesse-greenstein-dies-was-early-investigator-quasars-white-dwarfs-629">spent more than 1,000 nights</a> observing at Palomar.</p><p data-block-key="eomdu">"A major portion of the Infrared Army's arc also took place at Palomar," Boden says, referring to <a href="/about/news/celebrating-50-years-infrared-astronomy-48629">pioneers in infrared astronomy</a> who, among other achievements, created new instruments for Palomar Observatory that captured previously unseen wavelengths of infrared light. The pioneers include <a href="/about/news/remembering-gerry-neugebauer-43976">Gerry Neugebauer</a> (PhD '60), director of Palomar from 1980–94; Tom Soifer (BS '68), the Harold Brown Professor of Physics, Emeritus; and Keith Matthews. The Big Eye also enabled pioneering submillimeter observations led by Caltech's <a href="/about/news/caltech-mourns-the-passing-of-thomas-g-phillips">Tom Phillips</a>. Neugebauer's graduate student Andrea Ghez (PhD '92), a Nobel laureate now at UCLA, used Palomar for her Caltech PhD thesis, which showed that most young stars in dense star-forming clouds form in pairs.</p><p data-block-key="24q12"><b>Triaging the Stars</b></p><p data-block-key="8mt0i">The success of the 200-inch also rests on the shoulders of its smaller sister telescope, the 48-inch. Built at the same time as the 200-inch, with urging from astronomers Fritz Zwicky of Caltech and Walter Baade, the 48-inch telescope has a much wider field of view than the 200-inch. Astronomers recognized in the 1940s that such a telescope could scan the skies in search of the most interesting objects, which the 200-inch could then study in more detail. Zwicky used the 48-inch (and an 18-inch prototype) to discover more than 120 supernovae, holding the record for the most supernova discoveries by a single astronomer until 2009.</p><p data-block-key="19oir">"This idea—surveying the sky with dedicated smaller telescopes and following up the interesting objects with a large telescope—is still very effective today," said George Djorgovski, professor of astronomy and data science at Caltech, in a <a href="/about/news/palomars-samuel-oschin-telescope-turns-70-83757">story about the 70th anniversary of the 48-inch</a>. "The 48-inch really pioneered the modern sky surveys." (Palomar's 60-inch telescope, which opened in 1970, would later join in this hierarchical scheme to follow up on discoveries made by the 48-inch.)</p><p data-block-key="c867b">In its more than 75 years of operations, the 48-inch has run several sky surveys. The first, now called the Palomar Observatory Sky Survey, or POSS I, took place from 1949–58 and was funded by Caltech and the National Geographic Society. The second, POSS II, took place from 1985–2000 and was funded in part by Eastman Kodak.</p><p data-block-key="9ns4p">Jean Mueller, who worked as a telescope operator at Palomar for nearly 30 years, exposed thousands of photographic plates for the POSS II survey. In her spare time, Mueller would scan the plates for stars that appeared in and around galaxies and mark the galaxy with a red felt pen. She would then compare that galaxy to an earlier epoch to see if a star had newly appeared. If it had, she would carefully measure the position of the star, and then an astronomer would confirm her discovery on the 200-inch. This meticulous work enabled Mueller to discover more than 100 supernovae in addition to more than two dozen comets and asteroids.</p><p data-block-key="enarh">"All these photographic sky surveys have been digitized, which extends their scientific utility for decades, and makes the data freely available to anyone in the world," Djorgovski says.</p><p data-block-key="df6kt">After the POSS II survey, modern digital cameras were installed on the 48-inch, and several additional surveys followed. Other discoveries from the 48-inch include that of the <a href="/about/news/dwarf-planet-formerly-known-xena-has-officially-been-named-eris-iau-announces-1187">dwarf planet Eris</a> by <a href="https://www.gps.caltech.edu/people/michael-e-mike-brown">Mike Brown</a>, Caltech's Richard and Barbara Rosenberg Professor of Planetary Astronomy, in 2005. Eris's size—it is slightly heftier than Pluto—resulted in the former planet's infamous demotion.</p><p data-block-key="e26bn">Today, the 48-inch is home to ZTF, a robotic camera that, like its predecessors, scans the skies, but at a much faster rate. The ZTF camera scans the entire accessible sky every two nights, which means it can find bursting, exploding, and other transient objects in near real time.</p><p data-block-key="92rh3"></p><embed alt="The Zwicky Transient Facility (ZTF) instrument at the 48-inch Samuel Oschin Telescope at Palomar Observatory." embedtype="image" format="RightAlignMedium" id="10342"/><p data-block-key="8o9s0"></p><p data-block-key="4oimk">"You take an image and then come back the next night and compare the two images. The things that change pop out," Kulkarni says, who developed ZTF and its predecessor, the Palomar Transient Factory (PTF). "The sheer volume of data means we need machine-learning algorithms to find the objects and classify them. The ultimate goal is to automate the discovery. But you can't complete the discovery process without ancillary telescopes to pursue the newfound objects, including the 60-inch, the 200-inch, and Keck."</p><p data-block-key="6lqf6">Kasliwal adds that ZTF has had a huge impact on astronomy. "Astronomers have already written nearly 1,000 papers involving ZTF data in just the five years that it's been in operation."</p><p data-block-key="ar0h4"><b>Keeping an Aging Observatory Relevant</b></p><p data-block-key="dqsam">Another factor that contributed to Palomar's longevity was the modernization of its control systems. Boden says Neugebauer put a lot of effort into updating the telescope's electrical infrastructure and control systems in the 1980s and early 90s, keeping it at the top of its game. Perhaps what best keeps Palomar "young," however, is the ever-changing suite of innovative instruments at its heart. Currently, eight instruments are regularly shifted in and out of the 200-inch telescope to fit astronomers' observing schedules. In addition, the 200-inch serves as the receiving end of NASA's Deep Space Optical Communications experiment, which recently <a href="https://www.jpl.nasa.gov/news/nasas-tech-demo-streams-first-video-from-deep-space-via-laser">transmitted a cat video via lasers</a> down to the telescope, demonstrating a new way to beam high-bandwidth data from space.</p><p data-block-key="4tatp">One tried-and-true instrument in use since the 1980s, the Double Spectrograph, will soon be replaced with the state-of-the-art <a href="https://sites.astro.caltech.edu/palomar/observer/newsletter/palomarobserver7.html#:~:text=The%20Next%20Generation%20Palomar%20Spectrograph,-By%20Roger%20Smith&text=COO%20and%20NAOC%2FNIAOT%20are,DBSP%2C%20commissioned%20in%201982).">Next Generation Palomar Spectrograph</a>. These instruments are used to spread light apart into its different wavelengths and reveal clues about the composition and other characteristics of cosmic objects.</p><p data-block-key="f2orh">"The new instrument will have modern, much faster optics and a high level of automation. What we could do in one hour will take 15–20 minutes," says <a href="https://pma.caltech.edu/people/jonas-zmuidzinas">Jonas Zmuidzinas</a>, the Merle Kingsley Professor of Physics at Caltech and director of Palomar Observatory from 2018–23.</p><p data-block-key="6ruid">Other mini domes housing new kinds of instruments also reside at the Palomar site, including the infrared sky surveys called <a href="/about/news/opening-dynamic-infrared-sky-84061">Palomar Gattini-IR and WINTER</a> (Wide-field INfrared Transient ExploreR), <a href="/about/news/opening-dynamic-infrared-sky-84061">developed by Kasliwal and her students</a>. Like ZTF, both telescopes are designed to look for cosmic fireworks and other rapidly changing objects. However, they will do so using infrared wavelengths, allowing them to sleuth out objects, such as dusty supernovae, hidden in optical light.</p><p data-block-key="avgu7"></p><embed alt="The WINTER telescope at Palomar Observatory, with the 200-inch Hale Telescope dome behind it." embedtype="image" format="LeftAlignMedium" id="10339"/><p data-block-key="9fq7s"></p><p data-block-key="fnqpc">"Palomar is unique in hosting experimental instruments like these that are shaping real-time, or transient, astronomy," Kasliwal says.</p><p data-block-key="fg6qv"><a href="https://pma.caltech.edu/people/christopher-martin">Christopher Martin</a>, the current director of the observatory and the Edward C. Stone Professor of Physics, says that the observatory remains a platform for trying risky new ideas both for science observations and creating instruments. "It's also a place for educating instrument builders," he says, noting that he and his students built the state-of-the-art Cosmic Web Imager for Palomar, a predecessor to the <a href="/about/news/cosmic-web-lights-up-in-the-darkness-of-space">Keck Cosmic Web Imager</a> (KCWI) now at Keck.</p><p data-block-key="b8q5m">Using the Double Spectrograph, Zach Vanderbosch searched for metal pollution around his target white dwarfs—the presence of heavy metals is a sign of pulverized planets—while a camera called CHIMERA (Caltech HIgh-speed Multi-color camERA) developed by professor of astronomy <a href="https://pma.caltech.edu/people/gregg-w-hallinan">Gregg Hallinan</a> helped characterize suspected clumps of debris circling the white dwarfs. When stars like our Sun die and evolve into white dwarfs, the orbits of planets become jostled. Nearby planets that creep too close to their stars could be become shredded by the gravitational forces of a white dwarf, leaving a circling cloud of debris.</p><p data-block-key="8c7g4"></p><embed alt="Zach Vanderbosch observing in the 200-inch dome." embedtype="image" format="MiddleAlignMedium" id="10347"/><p data-block-key="l0ff"></p><p data-block-key="3m5pv">Vanderbosch is not yet sure if this phenomenon occurred around the stars he is studying but says it is "more fun to tackle projects that are less guaranteed. There's a higher risk and reward." Although clouds and atmospheric turbulence threatened to derail his latest observ run, "In the end, the data are pretty good," he says.</p><p data-block-key="6k171">One final and very important reason for Palomar's endurance is the telescope itself, a marvel of engineering that still runs smoothly 75 years later.</p><p data-block-key="46qnt">"To this day, I cannot believe how well they built that telescope," Jean Mueller says. "Sure, things go wrong, but the telescope always weathers it."</p>New Data, Same Great Appearance for M87*2024-01-22T20:11:00+00:002024-01-22T22:02:52.705391+00:00Emily Velascoevelasco@caltech.eduhttps://www.caltech.edu/about/news/new-data-same-great-appearance-for-m87<p data-block-key="6rn4g">Nearly five years ago, a globe-spanning team of astronomers gave the world its first-ever glimpse of a black hole. Now the team has validated both their original findings and our understanding of black holes with <a href="https://eventhorizontelescope.org/M87-one-year-later-proof-of-a-persistent-black-hole-shadow">a new image of the supermassive black hole M87*</a>. This supermassive black hole, 6.5 billion times the mass of our Sun, resides at the center of the Messier 87 (M87) galaxy in the Virgo galaxy cluster, located 55 million light-years from Earth.</p><p data-block-key="9nclk">The new image, like the old one, was captured by the Event Horizon Telescope (EHT), an array of radio telescopes stretching across the planet. These new data, however, were gathered a year later, in 2018, and benefitted from enhancements in the telescope array, notably with the inclusion of a telescope in Greenland.</p><p data-block-key="2fdu3">EHT's original image of M87* was important not just because it represented the first time humans had imaged a black hole, but also because the object looked the way it was <i>supposed</i> to look. Notably, the image showed what is known as a black-hole shadow—a dark region at the center of a glowing disk of hot matter circling the black hole. A black-hole shadow isn't a shadow in the same sense as the one you cast when you walk outside on a sunny day. Instead, the dark region is created by the black hole's immense gravitational field, which is so strong that light cannot escape it. Since no light leaves a black hole, it appears dark.</p><p data-block-key="bf8nl">Additionally, that strong gravity bends light that passes near the black hole without falling into it, effectively acting like a lens. This is known as gravitational lensing, and it creates a ring of light that can be seen no matter which angle the black hole is viewed from. These effects were both predicted from Albert Einstein's theory of general relativity. Because M87*'s image shows these effects, it is strong evidence that general relativity and our understanding of the physics of black holes is correct.</p><p data-block-key="8hg9m">This new M87* image was produced with key contributions from an imaging team at Caltech, including Professor <a href="https://www.cms.caltech.edu/people/klbouman">Katherine (Katie) L. Bouman</a>, assistant professor of computing and mathematical sciences, electrical engineering, and astronomy; former Caltech PhD student Nitika Yadlapalli Yurk (PhD '23); and current Caltech postdoctoral research associate in computing and mathematical sciences Aviad Levis.</p><p data-block-key="f4r33"></p><embed alt="Bouman" embedtype="image" format="RightAlignSmall" id="6734"/><p data-block-key="bblou"></p><p data-block-key="fii8q">Bouman is a coordinator of the EHT Imaging Working Group and was a postdoctoral fellow at the Harvard Smithsonian Center for Astrophysics and co-lead of the EHT imaging team when the original image was published in 2019. In that role, she helped develop the algorithms that assembled the trove of data collected by the EHT's multiple radio telescopes into a single, cohesive image. Since joining the Caltech faculty, Bouman, who is also a Rosenberg Scholar and Heritage Medical Research Institute Investigator, has continued her work with EHT. She also co-led the <a href="/about/news/caltech-researchers-help-generate-first-image-of-black-hole-at-the-center-of-our-galaxy">imaging of the Milky Way's supermassive black hole</a> published in 2022.<br/></p><embed alt="A portrait of Nitika Yadlapalli Yurk. She stands before an outdoor wall, wearing a blazer and smiling." embedtype="image" format="LeftAlignSmall" id="10330"/><p data-block-key="fatpq"></p><p data-block-key="5m84g">Yurk joined the EHT Collaboration in 2020 and played an active role in the imaging team for the latest M87* image. Her main contributions included developing synthetic datasets to be used in the training and validation of the imaging algorithms. Yurk also wrote software that was used in the exploration of image candidates. She was recently recognized by the EHT for her efforts with a PhD Thesis Award for the advances she brought to the imaging and validation of the most recent M87* image. She is currently a NASA Postdoctoral Program fellow at JPL, which Caltech manages for NASA.</p><p data-block-key="e2to6">Imaging an object like M87* with the EHT is very different than imaging a planet like Saturn with a conventional telescope. Instead of seeing light, the EHT observes the radio waves emitted by objects and must computationally combine the information to form a picture.</p><p data-block-key="4b63m">"The raw data that comes out of these telescopes are basically just voltage values," Yurk says. "I like to describe radio telescopes as the world's most sensitive volt meters, and they collect voltages really accurately from different parts of the sky."</p><p data-block-key="7d8q4">Turning those voltage values into an image is tricky, Bouman says, because the information the researchers are working with is incomplete, and there is nothing to compare the image against since no one has seen M87* with their own eyes.</p><p data-block-key="6a2h">"We don't want to plug in our expectations of what the black hole should look like when we're computationally forming the image," Bouman says. "Otherwise, it might lead us to an image that we expect rather than one that captures reality."</p><p data-block-key="6dv39">To avoid that problem, the researchers test their image processing algorithms with what is known as synthetic data, a suite of simulated images with simple geometric shapes. Those data are run through the algorithms to produce an image. If the output image is true to the input image, they know the algorithm is working correctly and would be able to accurately see surprising structures around the black hole.</p><p data-block-key="5momq">Bouman says that process, which was co-led by Yurk, involved exploring hundreds of thousands of parameters to gauge the effectiveness of the algorithms in reconstructing different image structures. The team found that with the addition of the Greenland telescope to the EHT, the methods more robustly recovered features in the images.</p><p data-block-key="10pd0">The process produced an image of M87* that is only slightly different than the first. The most obvious difference is that the brightest portion of the glowing ring surrounding M87* has shifted about 30 degrees counterclockwise. According to the EHT, that movement is likely the result of the turbulent flow of matter around a black hole. Importantly, the ring has remained the same size, which was also predicted by general relativity.</p><p data-block-key="3v6vm">Bouman adds that the team's ability to produce another image of M87* with new data that agrees so closely with the previous image is exciting.</p><p data-block-key="2a90q">"I think that people are going to ask, 'Why is this important? You already showed a picture of M87*.' Other groups have reproduced the M87* picture with data that were taken in 2017. But it's a totally different thing to have a new dataset taken a different year and to come to the same conclusions. Reproducibility with independent data is a big deal, too."</p>Tilted Orbits2024-01-10T20:19:00+00:002024-01-10T22:02:19.698976+00:00Whitney Clavinwclavin@caltech.eduhttps://www.caltech.edu/about/news/tilted-orbits<p data-block-key="l4wha">Within the family of celestial orbs in the universe, brown dwarfs are somewhat like misfits. They are less massive and cooler than stars but are 10 to 80 times more massive than Jupiter. Brown dwarfs are sometimes called "failed stars," because they lack the mass to ignite nuclear fusion and shine with starlight.</p><p data-block-key="c82eb"></p><p data-block-key="bkst6">One mystery that surrounds these oddballs is how they formed: Some theories propose that they form like stars do, out of collapsing clouds of material, while others suggest they form like planets, taking shape within rotating dusty disks that circle young stars. It is also possible, scientists propose, that brown dwarfs may form both like stars and planets.</p><p data-block-key="85m5c"></p><p data-block-key="118ld">Steven Giacalone, a National Science Foundation (NSF) Postdoctoral Scholar Fellowship Trainee in Astronomy at Caltech, and his colleagues are addressing the mystery by studying the orbital tilts of brown dwarfs that circle very closely around companion stars. Brown dwarfs, as well as some other exoplanets, can have orbits that are tilted to varying degrees relative to the rotational direction of their host stars. If a brown dwarf has an orbital tilt, then it is out of whack with its partner star: the brown dwarf will loop above and below a plane that aligns with the star's equator. This is unlike the planets in our own solar system that orbit in a plane that aligns with the Sun's rotational direction.</p><p data-block-key="c527q"></p><p data-block-key="3k7pr">Using the <a href="https://www.caltech.edu/about/news/keck-observatorys-newest-planet-hunter-puts-its-eye-on-the-sky">Keck Planet Finder</a> (KPF), a new planet-hunting instrument at the W. M. Keck Observatory in Hawaiʻi, Giacalone and his colleagues wanted to assess whether a brown dwarf named GPX-1b has an orbital tilt. They say that a tilt would indicate that the object probably formed like a star and not like a planet.</p><p data-block-key="28aes"></p><p data-block-key="cg4ja">"For a brown dwarf to have made its way into a tilted close-in orbit, it would have had to have been knocked around by a larger planetary body or captured by the star as the brown dwarf passed by," explains Giacalone, who works in the group of <a href="https://pma.caltech.edu/people/andrew-w-howard">Andrew Howard</a>, a professor of astronomy at Caltech and the principal investigator of KPF. "That would mean it started out like a star."</p><p data-block-key="7quh6"></p><p data-block-key="5280r">On the other hand, if the brown dwarf has an orbit aligned with the equatorial plane of its central star, then "it most likely migrated inward similar to planets via interactions with the disk in which it formed," Giacalone says.</p><p data-block-key="5f014"></p><p data-block-key="cui5u">The results revealed GPX-1b is not tilted in its orbit, but that it circles in a plane that aligns with the host star's equator.</p><p data-block-key="dbces"></p><p data-block-key="4eg5j">"This is only one data point, and preliminary, but it suggests that the brown dwarf migrated close to its companion star in a similar manner to planets," says Giacalone, who presented the results at the 243rd meeting of the American Astronomical Society (AAS) in New Orleans on January 10, 2024. "Theory has predicted that brown dwarfs should be able to form like planets, but observational evidence is only just beginning to be gathered to support that idea."</p><p data-block-key="c7v99"></p><p data-block-key="4bar4">The result contrasts with what is known about brown dwarfs with wide separations from their companion stars. "The wide-separation brown dwarfs are known to have high orbital tilts and do not form in a disk, but rather, like stars," Giacalone says. "The short-separation ones like GPX-1b, on the other hand, probably do form in the disk if they have low orbital tilts, meaning they form like planets. In other words, we think brown dwarfs can form either like stars or planets."</p><p data-block-key="4gcoj"></p><p data-block-key="b9rn0">KPF, a high-precision spectrograph, was able to determine the orbital inclination of the object by watching it pass in front of, or transit, its star. The <a href="https://ui.adsabs.harvard.edu/abs/2021MNRAS.505.4956B/abstract">brown dwarf was discovered</a> by NASA's TESS (Transiting Exoplanet Survey Satellite) mission and the Galactic Plane eXoplanet Survey (GPX) in 2021. It is one of a small number of brown dwarfs known to pass in front of, or transit, its host star.</p><p data-block-key="ba2p9"></p><p data-block-key="ac3ua">The researchers hope to use KPF to study the orbital inclinations of more brown dwarfs in the future. "We have demonstrated the power of KPF for studying these systems," Giacalone says. "Because close-in brown dwarfs are so rare, they are mostly found around relatively faint and distant stars. That means we need large telescopes like Keck and advanced instruments like KPF to study them accurately."</p>Prepping for Data From the Nancy Grace Roman Space Telescope2023-12-19T23:19:00+00:002023-12-20T00:02:02.006281+00:00Whitney Clavinwclavin@caltech.eduhttps://www.caltech.edu/about/news/data_from_roman_space_telescope<p data-block-key="7idkv"></p><p data-block-key="dst6j">As part of a plan to prepare for the quantity and range of data that will be coming in from the <a href="https://roman.gsfc.nasa.gov/">Nancy Grace Roman Space Telescope</a>, currently scheduled to launch by May 2027, NASA has granted funding to five project infrastructure teams (PITs), which will write software, run simulations, and plot out optimal uses of the telescope's data stream.</p><p data-block-key="6o7em">Three of these PITs, each of which has received five-year, multimillion-dollar grants for their work, are based in Pasadena and affiliated with Caltech faculty and staff. Mansi Kasliwal (MS '07, PhD '11), Caltech professor of astronomy, heads up the RAPID (Roman Alerts Promptly from Image Differencing) team; Yun Wang, senior scientist with Caltech's IPAC, is in charge of infrastructure for the galaxy redshift survey; and Olivier Doré, principal scientist at JPL, which Caltech manages for NASA, leads the weak-lensing team with Dida Markovic, the deputy principal investigator, who also works at JPL.</p><p data-block-key="e4v4k">The Roman Space Telescope project began in 2010 under the name Wide-Field InfraRed Space Telescope (WFIRST), promising to provide the same image precision obtained by the Hubble Space Telescope but with a field of vision at least 100 times larger, making it possible to survey the sky that much faster. The mission's observations of galaxies and supernovas will tell us much about the history and expansion of the cosmos. With another technology demonstration instrument on board, the coronagraph, exoplanets in other star systems can be imaged. WFIRST was named the top priority for astrophysics in the 2010 Astronomy and Astrophysics Decadal Survey, a list of research goals undertaken every decade by the National Research Council of the National Academy of Sciences since the 1960s.</p><p data-block-key="7dkjd">In 2020, WFIRST was renamed in honor of Nancy Grace Roman, who served as NASA's Chief of Astronomy and Solar Physics from 1961 to 1979 and lobbied relentlessly for the construction of the Hubble Space Telescope. "The Roman mission was conceived quite a while ago," Kasliwal explains, "but so much has changed since then. "We now have actually seen light, or electromagnetic radiation, from powerful cosmic events associated with gravitational waves."</p><p data-block-key="cupmo">These new findings have opened avenues for those who, like Kasliwal, Wang, and Doré, are intent on making the best possible use of Roman's infrared observing run. "The Roman hardware is already built and being tested," Wang says, "but the observing plan and software are still under development, so we can help to optimize it."</p><p data-block-key="92smq">Kasliwal's PIT team is responsible for the creation of an alert system—RAPID—that tells astronomers where they might find interesting new phenomena to observe. RAPID achieves its goal through a process known as image differencing. "We take an image again and again of the same piece of the sky. Then we compare the images to see what has changed," Kasliwal says. "We're looking for fireworks, cosmic fireworks … anything that explodes, anything that is changing before our eyes. This is called time-domain astronomy. Time-domain astronomy is undergoing a revolution because we have so many very sensitive telescopes now that are capable of understanding the dynamic universe."</p><p data-block-key="3p20s">Working with the <a href="https://www.ztf.caltech.edu/">Zwicky Transient Facility</a> and <a href="https://sites.astro.caltech.edu/~mansi/gattini/">Palomar Gattini IR</a>, optical and near-infrared telescopes at Caltech's Palomar Observatory, which survey the entire night sky, has given Kasliwal the experience she needs to design the RAPID system for the Roman Telescope. "As the Roman data arrive, we will continuously be doing image differencing. When we see something that's changed, we'll issue an alert,'" Kasliwal explains. "We have a lot of practice in doing this at Palomar. We take an image, compare it to previous images, and then send out an alert seven minutes later, so astronomers all over the world know exactly where in the sky something interesting is happening."</p><p data-block-key="f1n68">To get RAPID up to speed before the Roman Telescope's launch, Kasliwal says she is expanding a team of scientists and software professionals to "deliver a data pipeline that will be reliable and robust, a service to the community." At this point, RAPID has a core team of six staff scientists housed at IPAC and in the Cahill Center for Astronomy and Astrophysics on the Caltech campus. Each member brings their own expertise in machine learning, alert pipelines, supernovae, stars, asteroids, and so on. "Right now, we are working with simulations," Kasliwal says. "We inject scenarios into these simulations, such as the appearance of a tidal disruption flare—that's when a star gets really close to massive black hole and gets ripped up—to learn what Roman's data stream might look like."</p><p data-block-key="bhmco">The Roman Telescope will also be able to share tasks with NASA's James Webb Space Telescope, another infrared observatory that has been orbiting the sun since December 2021. "Roman will be the discovery engine," Kasliwal says, "and then the James Webb Space Telescope can do spectroscopic follow up and detailed characterization. This will allow us to learn what elements a particular neutron star merger, for example, is composed of."</p><p data-block-key="2oppa">One primary question the Roman mission is poised to answer is how quickly the expansion of the universe is accelerating.</p><p data-block-key="as0rk">To better understand the big bang that birthed our universe, imagine a fireworks show with an enormous explosion filling the sky, the sort that is known as a coconut shell. It begins with a dramatic explosion of sparks from a pinpoint center. These sparks flare out swiftly and evenly in all directions from the center before they gradually slow down and die out. This is not what is happening in our universe. Its expansion is getting faster rather than slowing down.</p><p data-block-key="clkca">"This is contrary to our expectations," Wang says, "because if matter is all there is in the universe, the expansion of the universe should be decelerating today. Its acceleration requires the existence of something other than matter: perhaps a form of energy. We call it dark energy because it's not visible to us. We don't know if this is truly an unknown component of energy, or if we need to modify our theory of gravity (i.e., Albert Einstein's theory of general relativity) to account for these observations. It's a huge mystery, one of the most exciting and challenging problems in cosmology and physics today."</p><p data-block-key="f1aab">There are three ways of measuring the acceleration of the universe's expansion, and the Roman Telescope will utilize all of them. The first is by looking at Type Ia supernovas, as has been done before. Because these supernovas all have roughly the same level of luminosity, they have been described as "cosmological standard candles." When closer to us, they shine brighter. When farther away—which is also back in time, since we are looking at light that travels to us from billions of years ago—they appear dimmer.</p><p data-block-key="bsac9">The second way is through a phenomenon called weak gravitational lensing, the slight bending of light from galaxies due to the gravity from matter lying between us and the galaxies. The measurement of the resultant subtle changes in the shapes of galaxies probes the distribution of cosmic matter as well as the activity of dark energy. Doré's team will concentrate on this effort.</p><p data-block-key="9ulsl">"Gravitational lensing allows us to conduct a complete census of matter. With the Roman Telescope, we will conduct such a census over a very large swath of the universe, which will teach us so much more about the universe," Doré says. "By creating these teams, NASA recognizes it will take the richness and diversity of a very broad scientific community to make the most of this unprecedented observatory."</p><p data-block-key="bfoan">Wang's team will build the infrastructure for the third way of measuring the acceleration of the expanding universe, a galaxy redshift survey. This survey enables astronomers to visualize the three-dimensional distribution of galaxies in the universe, probing the cosmic expansion history as well as the growth history of large-scale structure in the universe, both of which are sensitive to dark energy. (The term redshift refers to the distance of galaxies; the farther a galaxy, the more it will shift, or stretch, light into redder wavelengths due to the expansion of the universe.) The Roman galaxy redshift survey PIT consists of 11 participating institutions led by Caltech. The team includes leaders from all the current and planned galaxy redshift surveys from ground-based facilities, as well as the European Space Agency's Euclid mission.</p><p data-block-key="duuh9">"The Roman Telescope will observe galaxies that are very far away," Wang explains. "These are ideal tracers of the large-scale structure of the universe. The Roman Telescope uses these galaxy tracers over a very wide redshift range—that is, closer and farther away—which translates into a very wide range in the history of the cosmos. With this information, we can almost read off the expansion rate of the universe at various distances from us. But by having additional data sets using Type Ia supernovas and weak gravitational lensing, we can cross-check our results. That's why I'm confident that within 10 years we should be able to find some real answers to our questions about what causes the accelerated expansion of the universe."</p><p data-block-key="ba8k5">Wang says she was drawn to the excitement and romance of astronomy and continues to delight in it. "I was born a romantic," Wang says. "When I was a baby, my dad would recite ancient Chinese poetry to calm me down. Then when I was growing up, I recited poetry to myself while looking at the night sky. I grew up in a rural area. It was very dark, so the sky was spectacular. Later, when I was attending Tsinghua University, I went to a colloquium on cosmology. I was astounded and thought, 'Wow, you mean you can actually study the whole universe using science?' After that, I was obsessed with becoming a cosmologist."</p><p data-block-key="2pjpc">Kasliwal learned about infrared astronomy when she was an undergraduate at Cornell University majoring in engineering physics. "I was always interested in astronomy, but I had no idea what it meant to be an astronomer," Kasliwal says. "It just sounded like a crazy dream at that point. But then I got a job in the lab of Jim Houck, who built the infrared spectrometer on the Spitzer Space Telescope, a NASA infrared space telescope that operated for more than 15 years. I got to see Houck's team collect data and be so excited learning something new every single day about the universe. That's what really piqued my interest in astronomy. The universe keeps you on your toes. There's never a dull moment."</p><p data-block-key="alvc8">Meanwhile, Wang says she is "not afraid to think big." She adds: "I just think about what matters, what's important, what are the key questions that should be asked. The reward will hopefully be the discoveries. There will be discoveries one way or the other!"</p>Telescope Dismantled and Heading to New Mission in Chile2023-12-19T17:01:00+00:002023-12-19T17:05:47.527047+00:00Whitney Clavinwclavin@caltech.eduhttps://www.caltech.edu/about/news/telescope-dismantled-and-heading-to-new-mission-in-chile<p data-block-key="t4phi">At nearly 14,000 feet, Maunakea is the tallest mountain in Hawaiʻi, and the second tallest on any island on Earth. Clouds often settle below the mountain's barren, dark-brown summit, making the site one of the best for astronomy in the world.</p><p data-block-key="dcu8d">At the summit, one can find several of the world's finest telescopes, including the <a href="https://www.keckobservatory.org/">W. M. Keck Observatory</a>, a partnership between Caltech and the University of California. Situated below Keck's twin telescopes is an area dubbed Submillimeter Valley, where the silver geodesic dome of the <a href="http://cso.caltech.edu/">Caltech Submillimeter Observatory</a>(CSO) has resided since the observatory's inception in 1985, along with two other facilities that observe the cosmos using similar wavelengths of light.</p><p data-block-key="bvrgc">This past summer, astronomers, engineers, and technicians dismantled CSO's telescope, including its 10.4-meter primary mirror, or reflector, which is made of 84 hexagonal aluminum honeycomb panels and weighs 10,000 pounds. They carefully reverse engineered the mirror frame, or truss, separating it into eight pieces and then loaded these and other telescope components into shipping containers that wound down the mountain on trucks.</p><p data-block-key="a1fi9"></p><p data-block-key="f208b"></p><p data-block-key="9gt1u">Ultimately, astronomers plan to ship the telescope to the Atacama Desert in Chile, where it will be reassembled and renamed the Leighton Chajnantor Telescope. The name honors both the inventor of the telescope, the late Caltech professor <a href="/about/news/renowned-physicist-robert-b-leighton-dies-160">Robert B. Leighton</a> (BS '41, MS '44, PhD '47), and the planned site for the observatory on the high Chajnantor Plateau.</p><p data-block-key="6e07s">"The submillimeter light we want to observe from the cosmos can be absorbed by water vapor in the air, and the air is even drier at Chajnantor, so being there will enhance our observations," says <a href="https://pma.caltech.edu/people/sunil-golwala">Sunil Golwala</a>, director of CSO since 2013 and a professor of physics at Caltech.</p><p data-block-key="2n5mm">With its rebirth in Chile, the observatory will focus in part on the fast-growing field of time-domain astronomy. It will observe, in real time, a wide range of stellar eruptions and explosions, for which millimeter-submillimeter observations are in their early days. The facility will also expand on its original work, observing objects near and far, from planetary and stellar nurseries in our own galaxies to the most distant galaxies that date back to the universe's first billion years.</p><h4 data-block-key="21ars">Piece by Piece</h4><p data-block-key="8m6q3">Caltech announced that <a href="/about/news/caltech-submillimeter-observatory-hawaii-be-decommissioned-1531">CSO would be decommissioned</a> in 2009. In 2015, Caltech suspended CSO operations and initiated the decommissioning process, which is outlined by the State of Hawai‘i's <a href="https://hilo.hawaii.edu/maunakea/stewardship/documents/management/comprehensive-plan/CMP_DecommissioningPlan_2010.pdf">2010 Decommissioning Plan for Maunakea Observatories</a>. The physical decommissioning began in 2022 and is being done in accordance with the Conservation District Use Permit issued by the State of Hawaii Department of Land and Natural Resources<b>.</b></p><p data-block-key="chaqp">The first step in dismantling CSO's mirror was to remove the 84 panels that make up the mirror surface. Screws attaching the panels to the truss were removed one by one, and the panels were lifted off using a crane. The truss itself was then lifted off the base of the telescope in one piece by a large crane and placed down on the ground, where it was then further dismantled into eight pieces. The crane extracted the heavy base of the telescope in seven pieces.</p><p data-block-key="aqm64">"A large crane was needed because of the weight of the individual pieces, up to 10,000 to 20,000 pounds, and because the crane had to reach into the dome to get at the telescope," Golwala says.</p><p data-block-key="6adv6">The mirror panels, truss, and other telescope parts have been carefully packed into standard shipping containers and are stored at the Kawaihae Harbor on the west coast of Hawai‘i island awaiting shipment to Chile in 2024.</p><p data-block-key="76l9m">Still remaining on the mountain is the helmet-like dome of the observatory. Its removal, paused due to winter weather, will continue in the spring of 2024.</p><p data-block-key="d4obf">Prior to the telescope disassembly, a blessing was performed to commemorate the beginning of efforts to restore the CSO site. Representatives from Caltech and the Center for Maunakea Stewardship were in attendance. Maunakea is also known as Mauna a Wākea, which refers to the first-born mountain son of the mythical creators of the Hawaiian Islands: Papahānaumoku (Earth Mother) and Wākea (Sky Father). "We seek to thank and honor Maunakea and those in its genealogy by respectfully restoring the site," Golwala says.</p><h4 data-block-key="9uvlm">New Window to the Cosmos</h4><p data-block-key="69fcm">Robert Leighton designed and led the construction of a set of seven telescopes in the 1970s and 1980s (the Raman Research Institute, in Bengaluru, India, built an eighth telescope using Leighton's design). Six of Leighton's telescopes have been used at Caltech's <a href="https://www.ovro.caltech.edu">Owens Valley Radio Observatory</a> (OVRO) near Bishop, California, for decades. "Leighton made the CSO's mirror surface more precise than the others, so it would work well at the submillimeter wavelengths accessible from Maunakea," Golwala says.</p><p data-block-key="eo3j2"></p><embed alt="Robert Leighton is pictured standing on one of the mirrors he designed while it was being first assembled and the reflecting surface cut to shape." embedtype="image" format="MiddleAlignMedium" id="10282"/><p data-block-key="1o9gn"></p><p data-block-key="3h7fr">The telescopes were made at a time when the field of submillimeter and millimeter astronomy was just beginning to take off. Submillimeter light, which has a wavelength about 10 times the width of a human hair, falls between infrared and radio on the electromagnetic spectrum. It can be used to peer into regions of the cosmos that are thick with dust, and it can carry signatures of dust and other molecules that play crucial roles in the formation of planets, stars, and galaxies.</p><p data-block-key="dcgjh">To enable the cost-effective construction of such large mirrors at these wavelengths, <a href="http://www.cso.caltech.edu/outreach/log/CSO_History/dish.htm">Leighton came up with a clever design</a> that included lightweight aluminum honeycomb panels tiled together in a hexagonal pattern and supported by a truss made of steel-tube struts and posts. Leighton wrote a computer program to figure out the dimensions of the roughly 80 different kinds of struts needed to make the desired truss shape.</p><p data-block-key="4m5db">The observatory dome itself housed the control room, laboratories, and other support systems. It was first assembled on Caltech's then-football field beginning in 1984 and was later dismantled and reassembled on Maunakea (the telescope was constructed on Maunakea for the first time). CSO achieved "first light" with a spectrum of Messier 82, a starburst galaxy, in March of 1987.</p><p data-block-key="5ve44">"When the CSO first began observations, you had to be standing right there to tune the receivers," recalls Golwala, who was a postdoc at Caltech in the early 2000s when the observatory was in full swing. "Telescopes and instruments are controlled remotely by computer now, so one no longer needs to be in the dome to use the observatory."</p><h4 data-block-key="2i6a3">Receiver Revolution</h4><p data-block-key="4o8d5">The submillimeter light receivers employed at CSO were a first-of-their-kind innovation from the <a href="/about/news/caltech-mourns-the-passing-of-thomas-g-phillips">late Caltech professor Thomas Phillips</a>, who served as director of CSO from 1986 to 2013. The devices, called superconductor-insulator-superconductor (SIS) receivers, opened a window to the previously unexplored territory of submillimeter light, reshaping astronomy. They were first used at OVRO and then further developed for CSO and other observatories. In fact, they are still in use today at the world's most productive ground-based observatory in operation, the Atacama Large Millimeter/submillimeter Array (ALMA), in Chile.</p><p data-block-key="215sa"></p><embed alt="Tom Phillips in his lab working on one of his early SIS receivers." embedtype="image" format="RightAlignMedium" id="10281"/><p data-block-key="2qdso"></p><p data-block-key="590s0">In addition to the SIS receivers, Caltech professor of physics Jamie Bock and <a href="/about/news/caltech-mourns-passing-andrew-lange-1589">late Caltech professor Andrew Lange</a> developed bolometers for CSO using JPL's Microdevices Laboratory (JPL is managed by Caltech for NASA). Bolometers are simpler in concept than SIS receivers and easier to fabricate. They detect light by measuring the heating of a microscopic light absorber using a sensitive thermometer (the word stems in part from the Greek word "bole," which can translate to ray of light).</p><p data-block-key="57bi8">CSO was one of the first observatories where spiderweb bolometers—bolometers in which the absorbing material is supported by a web etched out of silicon nitride—were demonstrated. Such bolometers were later used on Lange and Bock's BOOMERAnG balloon telescope, which showed that the universe's geometry is not curved but flat. These bolometers were also used in the successful <a href="https://www.herschel.caltech.edu/">Herschel Space Observatory</a> and <a href="https://www.ipac.caltech.edu/project/planck">Planck</a> missions.</p><p data-block-key="c9hmu">"CSO opened a window to the electromagnetic spectrum at submillimeter wavelengths, which was a new frontier to explore, so there were many discoveries made," says Jonas Zmuidzinas (BS '81), the Merle Kinglsey Professor of Physics at Caltech. "It was also a place where instrument builders could experiment with new technologies, bringing them from proof of concept to working receivers."</p><p data-block-key="2eef7">Among its many discoveries, CSO determined the role of atomic carbon in the space between stars; discovered a new phase of stellar evolution for red giant stars; made the first ground-based detection of heavy, or deuterium-based, water in a comet; identified a <a href="/about/news/astrophysicists-announce-surprising-discoveryof-extremely-rare-molecule-interstellar-space-580">rare type of ammonia in space</a> that includes three atoms of deuterium; imaged planet-forming disks around stars; and, in 2011, uncovered what was then the <a href="/about/news/caltech-led-astronomers-discover-largest-and-most-distant-reservoir-water-yet-1704">largest and farthest reservoir of water</a> in the universe: a quasar, or actively accreting supermassive black hole, surrounded by water molecules.</p><p data-block-key="1dvag">The observatory also <a href="/about/news/massive-galaxy-cluster-verifies-predictions-cosmological-theory-41506">pioneered studies of the Sunyaev–Zel'dovich effect</a>, which occurs when the light from the early universe (the cosmic microwave background) becomes skewed as it passes through massive galaxy clusters on its way to Earth. These observations are important for, among other pursuits, studying the incredibly energetic collisions that occur when clusters of galaxies merge.</p><h4 data-block-key="e2dvv">A Clever Design</h4><p data-block-key="3t6ia">One of the challenges faced by Golwala and his collaborators was to figure out how to take the aging observatory apart. "It's 40 years old, and we don't have a lot of documentation on how things were put together," he says. For advice, the team spoke with OVRO assistant director David Woody, an expert on the telescope's design and performance, who worked with Leighton when the telescopes were built.</p><p data-block-key="66oqv">"It's a rare situation," Golwala says. "Most astronomers do not get the opportunity to figure out how to take apart and rebuild a telescope. Luckily, Bob Leighton's telescope design was so clever that it has been relatively easy to figure it out. We were also lucky to find independent contractor Bill Johnson, who has experience building telescopes around the world, to lead the disassembly process."</p><p data-block-key="75n6v">Simon Radford, former CSO technical manager who serves as project manager for the move, says the possibility of overstressing and damaging the truss struts was a major concern during disassembly. "As was done during the original assembly, we floated the truss on springs so the connections between sections were almost stress free," Radford says. The struts came out with only modest effort."</p><p data-block-key="arhoe">Now that the telescope has been removed from Maunakea, general contractor Goodfellow Bros. Inc. (GBI) will remove the CSO dome and related structures, including underground plumbing, electrical and communications conduits, and other components. GBI will restore the site, grading and contouring the land and adding ash and small rocks to restore its natural appearance. The Leighton Chajnantor Telescope, CSO's next incarnation, is expected to begin operations in 2026.</p><p data-block-key="7j11d">"What was once the site of one of the world's premier submillimeter telescopes will be home to lichens and insects and be indistinguishable from the mauna around it," Golwala says. "We are grateful for the time we spent there."</p><p data-block-key="d72hp">The decommissioning effort is funded in large part by the <a href="https://www.moore.org/">Gordon and Betty Moore Foundation</a>, while the careful preparation of the telescope for shipment and reuse in Chile is funded by the <a href="https://www.hsfoundation.org/">Heising–Simons Foundation</a>. The move to Chile will be partially supported by the municipality of Shanghai through a collaboration with Shanghai Normal University. In Chile, the project's lead institution is the Universidad de Concepción.</p>2023 Year in Review2023-12-18T16:25:42.997628+00:002023-12-18T16:25:42.923047+00:00Kathy Svitilksvitil@caltech.eduhttps://www.caltech.edu/about/news/2023-year-in-review<p data-block-key="eb6ts">As we close out the year and look ahead to the next, we take this opportunity to reflect on the groundbreaking research findings that emerged from Caltech in 2023. From furthering humanity's knowledge of and response to viruses, to refining the use of autonomous technologies, to leveraging advanced instrumentation to bring greater clarity on our universe and our place within it, Caltech continues to powerfully and meaningfully shape understanding of and interaction with the world. Here are some highlights.</p><h3 data-block-key="3asd6">Shaking and Quaking Earth and Moon</h3><p data-block-key="8mhjq">New insights into earthquake physics that could improve early warning systems emerged from the use of <a href="/about/news/fiber-optic-cables-detect-and-characterize-earthquakes">existing underground fiber-optic cables</a>, while a study of earthquake swarms on the eastern side of the Sierra Nevada mountains in California led researchers to conclude that the <a href="/about/news/california-supervolcano-is-cooling-off-but-may-still-cause-quakes">Long Valley caldera</a>, the remains of a volcanic eruption occurring 760,000 years ago, is simply settling from the effects of the ancient event and not heading toward another one.</p><p data-block-key="ef4g4">Far more distant quakes—on the Moon—were examined using data from seismometers placed by Apollo astronauts on the lunar surface five decades ago. With the help of machine learning, researchers showed that the Moon shakes more often and more predictably than Earth, principally because of the extreme swings of temperature experienced by its atmosphere-less surface. Along with these "thermal" moonquakes, <a href="/about/news/the-lunar-alarm-clock-new-study-characterizes-regular-moonquakes">regular moonquakes</a> were found to occur each morning, caused by vibrations of the abandoned Apollo 17 lunar lander structure as it expands and contracts with changes in surface temperature.</p><p data-block-key="46e3h">The theory that <a href="/about/news/the-remains-of-an-ancient-planet-lie-deep-within-earth">the Moon itself is the result of a collision between Earth and another planetary body</a>—called Theia—gained support from Caltech researchers, while a modeling study suggested our solar system's inner planets and the moons of the outer planets, as well as numberless "super-Earths" scattered across the universe, may all be the result of <a href="/about/news/how-do-rocky-planets-really-form">a single mechanism of rocky planet formation</a> that takes place in a narrow band around stars or planets, where competing forces turn vapor into solids.</p><h3 data-block-key="56abi">Surveying the Cosmos and Finding Exoplanets, Two-Faced Stars, and Gravitational Waves</h3><p data-block-key="cva50">Thanks to spectral emission data obtained by the Caltech-led <a href="https://www2.keck.hawaii.edu/inst/kcwi/">Keck Cosmic Web Imager</a>, located at the W. M. Keck Observatory atop Maunakea on the island of Hawai'i, we are able to <a href="/about/news/cosmic-web-lights-up-in-the-darkness-of-space">view the cosmic web</a>, streams of gas-feeding galaxies that are faint and therefore difficult to visualize, with greater precision than ever before. Caltech teams unveiled a <a href="/about/news/star-eats-planet-brightens-dramatically">hot gas giant planet about the size of our Jupiter, located some 12,000 light years away, that is being devoured by its sun</a> (just as our Sun will consume Mercury, Venus, and probably Earth, in 5 billion years). Also discovered was a highly unusual white dwarf star that <a href="/about/news/two-faced-star-exposed">shows two very different faces to Earth-based telescopes</a> as it rotates on its axis every 15 minutes, one composed primarily of hydrogen and the other of helium.</p><p data-block-key="bsa7f">The Nanohertz Observatory for Gravitational Waves (<a href="https://nanograv.org/">NANOGrav</a>), using data from radio telescopes that monitor dead stars known as pulsars, provided Caltech astronomers with increased confidence that in addition to the supermassive events that produce gravitational waves that can be detected by <a href="https://www.ligo.caltech.edu/">LIGO</a> (the Laser Interferometer Gravitational-wave Observatory located in Hanford, Washington, and Livingston, Louisiana), there is a background hum, or <a href="/about/news/scientists-find-evidence-for-slow-rolling-sea-of-gravitational-waves">slow-rolling sea of gravitational waves</a> throughout the universe. For its part, LIGO extended its observations <a href="/about/news/ligo-surpasses-the-quantum-limit">beyond the quantum limit</a> using a technology called "squeezing" that allows quantum noise to be manipulated to improve detection and analysis of incoming gravitational waves.</p><p data-block-key="f49ve">Much closer to home, the basement of the Cahill Center for Astronomy and Astrophysics on the Caltech campus has served throughout 2023 as the site for <a href="/about/news/spherex-space-telescope-stays-cool-in-basement-at-caltech">testing the instrumentation of the SPHEREx (Spectro-Photometer for the History of the Universe, Epoch of Reionization and Ices Explorer) space telescope</a>, scheduled for launch in 2025. SPHEREx will map the entire sky at infrared wavelengths.</p><h3 data-block-key="2253g">Understanding Ourselves Through Modern Science and Ancient Documents</h3><p data-block-key="2natb">Sodium is a key nutrient for humans, but there can be a fine line between consuming too little or far too much. This year, Caltech biologists pinpointed the areas of the brain that give us an <a href="/about/news/newly-discovered-brain-circuit-controls-an-aversion-to-salty-tastes">appetite for salt</a> when we need it and the ability to tolerate high levels of salt in food and water. They also used machine learning to gain insight into the <a href="/about/news/a-theory-of-rage">unique neural mechanisms of anger</a> and our perception of <a href="/about/news/how-the-brain-creates-your-taste-in-art">beauty in art</a>.</p><p data-block-key="3pfri">Despite their promise and interrogatory power, new technologies cannot probe the behavior of people who lived centuries ago. To that end, a Caltech historian developed <a href="/about/news/ordinary-early-medieval-lives">a method to learn more about the ordinary people</a> of early medieval Europe using documents collected by ecclesiastical authorities of the time that record economic transactions, marriages, divorces, inheritances, disputes, and more.</p><h3 data-block-key="6tk4e">Improving Human Health Through AI, Wearable Sensors, and Artificial Embryos</h3><p data-block-key="9q830">In 2023, Caltech researchers continued their quest to improve modern medicine and the human condition through a variety of methods, including artificial intelligence (AI), computer models, wearable sensors, cutting-edge imaging technology, and more.</p><p data-block-key="8pvbq">Caltech researchers and colleagues presented a <a href="/about/news/ai-offers-tool-to-improve-surgeon-performance">new way to use AI to help surgeons evaluate and develop their performance</a>, while Caltech medical engineers further enhanced the capabilities of wearable sweat sensors, which can now monitor <a href="/about/news/wearable-patch-wirelessly-monitors-estrogen-in-sweat">estrogen</a> and <a href="/about/news/wearable-sweat-sensor-detects-molecular-hallmark-of-inflammation">C-reactive protein</a> (a marker for inflammation) levels, and developed a <a href="/about/news/smart-bandages-monitor-wounds-and-provide-targeted-treatment">"smart" bandage</a> that promises to improve chronic wound care by monitoring indications of inflammation or bacterial infection.</p><p data-block-key="3qgkr">An <a href="/about/news/scientists-create-embryo-like-model-that-mimics-post-implantation-stage-of-human-development">embryo-like model</a> made from stem cells that mimics the second week of human embryo development may soon offer new insights into why some pregnancies fail, where certain defects and diseases emerge, and also help scientists figure out how to develop synthetic human organs for transplant.</p><p data-block-key="bm9dk">At smaller scales, Caltech researchers investigated the mechanisms by which a particular type of bacteriophage (a tiny virus that targets bacterial cells) called <a href="/about/news/little-phage-that-could">φX174</a> escapes its bacterial host and successfully infects and destroys additional bacterial cells. This work could lead to new treatments for bacterial infections that are resistant to existing antibiotics colleagues. Researchers developed a new <a href="/about/news/microscopy-techniques-combine-to-create-more-powerful-imaging-device">molecule-imaging apparatus</a> to visualize materials at the single-molecule level, and devised a new <a href="/about/news/drug-delivery-platform-uses-sound-for-targeting">drug delivery platform</a> using ultrasound and gas vesicles that shows promise for targeting chemotherapy more directly against cancer cells.</p><p data-block-key="156m3">On the COVID-19 front, Caltech researchers developed a <a href="/about/news/at-home-rapid-covid-test-sensitivity">more sensitive at-home COVID-19 antigen test</a> with a technology that can be utilized to design tests for other pathogens, and combined the two different techniques used in current COVID-19 vaccines—mRNA technology and protein nanoparticle technology—to make a potent <a href="/about/news/new-vaccine-technology-produces-more-antibodies-against-sars-cov-2-in-mice">hybrid vaccine</a>. In other work, biologists presented new insight into the <a href="/about/news/imaging-breakthroughs-provide-insight-into-the-dynamic-architectures-of-hiv-proteins">biological processes of the human immunodeficiency virus (HIV)</a> at the atomic scale.</p><h3 data-block-key="6hs6f">Heat Waves, Air Pollution, and Solar Power from Space, Oh My!</h3><p data-block-key="1oajj">Caltech continues to investigate the drivers behind climate change and to develop alternative sources of energy. Since 2014, California state law has required cutting methane emissions, but a Caltech study found <a href="/about/news/methane-emissions-in-la-are-decreasing-more-slowly-than-previously-estimated">those emissions are decreasing in the Los Angeles area much more slowly than utility companies have estimated</a>. In other work, researchers showed that LA County's recent <a href="/about/news/low-income-areas-experience-hotter-temperatures-in-la-county">record-breaking heat waves hit low-income areas harder than more affluent ones</a>, and developed new techniques for understanding the chemistry involved in <a href="/about/news/chemists-tackle-formation-of-natural-aerosols">the naturally occurring conversion of volatile organic compounds into aerosols</a> that will allow scientists to better predict the impact of aerosols on the environment and on human health.</p><p data-block-key="8vbvc">On the green energy front, in <a href="/about/news/caltech-to-launch-space-solar-power-technology-demo-into-orbit-in-january">January 2023</a>, the Caltech Space Solar Power Project (SSPP) launched an instrument into orbit around Earth that harvests solar power and wirelessly transmits it to Earth. In the spring, this instrument, the Space Solar Power Demonstrator (SSPD) was the first to <a href="/about/news/in-a-first-caltechs-space-solar-power-demonstrator-wirelessly-transmits-power-in-space">successfully receive solar power and transmit it to Earth</a>, where it was detected by a receiver on the rooftop of the Gordon and Betty Moore Laboratory of Engineering on Caltech's campus.</p><h3 data-block-key="3irl5">Evolving Optics, Color-Changing Plastics, and Mighty Morphin' Robots</h3><p data-block-key="249hr">Caltech scientists and engineers identified, engineered, and designed a series of new devices and materials that have the potential to reshape our world, including the creation of <a href="/about/news/a-rainbow-of-force-activated-pigments">polymers that change color when stress is applied to them</a>, making the location of strain visible; metals 3D printed at the nanoscale with messy atomic arrangements that surprisingly make them three-to-five times stronger than similarly sized materials with more orderly structures; and <a href="/about/news/evolving-and-3d-printing-new-nanoscale-optical-devices">3D-printed nanoscale optical devices</a> that are so small they could direct different colors of light to individual pixels in a camera's image.</p><p data-block-key="2igj0">On a larger scale, Caltech engineers created M4, the Multi-Modal Mobility Morphobot, a <a href="/about/news/new-bioinspired-robot-flies-rolls-walks-and-more">bioinspired robot</a> that is capable of eight different types of motion (including flying, rolling, and walking) and can sense upcoming terrain and select the most effective form of locomotion.</p><h3 data-block-key="b1a39">Quantum Sound, Quantum Microscopes, Quantum Erasers, and a New Center for Quantum Research</h3><p data-block-key="74rmb">Caltech expanded its presence as a premier hub of quantum research with the summer <a href="/about/news/breaking-ground-cqpm">groundbreaking of the Dr. Allen and Charlotte Ginsburg Center for Quantum Precision Measurement</a>. The center will serve as an interdisciplinary home for precision measurement, quantum information, and the detection of gravitational waves, or ripples in space-time.</p><p data-block-key="70nr9">In other news concerning the quantum realm, a new method was revealed for <a href="/about/news/new-device-opens-door-to-storing-quantum-information-as-sound-waves">converting electrical quantum states into sound and back again</a>, allowing devices to store sound (which, like light, is both a particle and a wave) for future quantum computers. Other researchers <a href="/about/news/quantum-entanglement-of-photons-doubles-microscope-resolution">doubled the resolution of microscopes</a> through quantum entanglement, in which the respective states of two particles are linked to one another even when they are not close to one another. Entanglement is central to this year's development of "<a href="/about/news/a-new-way-to-erase-quantum-computer-errors">quantum erasers</a>" that can remove certain types of errors in quantum computers.</p><h3 data-block-key="d83j1">Slithering, Swimming, and Spinning—Animal Motion by the Numbers</h3><p data-block-key="8jsg1">Finally, as phenomena in the natural world are mapped mathematically, surprising consonances are uncovered, including the discovery that when very different animals—such as snakes, single-celled organisms, and sting rays—<a href="/about/news/what-do-a-jellyfish-a-cat-a-snake-and-an-astronaut-have-in-common-math">move by changing their shape, a single mathematical algorithm</a> can successfully describe their motion.</p>W. M. Keck Observatory Appoints Rich Matsuda as Director2023-12-14T21:40:00+00:002023-12-15T19:33:56.782914+00:00Whitney Clavinwclavin@caltech.eduhttps://www.caltech.edu/about/news/w-m-keck-observatory-appoints-rich-matsuda-as-director<p data-block-key="p1h8w">The W. M. Keck Observatory today announced the appointment of Rich Matsuda as its next director, effective January 1, 2024. </p><p data-block-key="4t278">"With the support of our Board of Directors, our Observatory has been making a pivot for the last several years, turning toward a new paradigm of mutuality with and for our community. During my tenure as director, my commitment is that our operations, our technical capabilities, and our potential for astronomical discovery will continue to be world-class, and will be even stronger because our work is rooted firmly here in Hawaiʻi, connected deeply to the community and the culture of this place," said Matsuda.</p><p data-block-key="5qaak">The Keck Observatory Board's Search Committee, co-chaired by Director of the University of California Observatories Bruce Macintosh and by Caltech's Professor of Astronomy <a href="https://pma.caltech.edu/people/lynne-hillenbrand">Lynne Hillenbrand</a>, led the search for a director. The Keck Observatory is operated as a scientific partnership among Caltech, the University of California, and NASA.</p><p data-block-key="3ijd5">An electrical engineer by trade, Matsuda started his career at Keck Observatory helping with the construction of the Keck II telescope. He is kamaʻāina to Hawaiʻi, locally born and raised, and has served in an executive leadership role at the Observatory since 2016. Before assuming the role of interim director of the Observatory in May 2023, Matsuda served as Keck Observatory's chief of operations for five years, as well as associate director of external relations. His leadership team includes John O'Meara, deputy director and chief scientist, who will continue to serve as a close colleague and collaborator.</p><p data-block-key="4v4ln">Read the <a href="https://keckobservatory.org/new-director/">full story</a> from the Keck Observatory.</p>Caltech Science Journeys Program Returns with Physics Presentation: "Bringing Imbalance to the Universe"2023-12-08T19:38:00+00:002023-12-08T23:42:36.574119+00:00Caltech Communicationswww@caltech.eduhttps://www.caltech.edu/about/news/science-journeys-stem-arian-jadbabaie-physics<p data-block-key="en9k9">Everyone's journey into science is unique. For Arian Jadbabaie (PhD '23), it was all over the map: He was born in Iran, grew up in Connecticut, earned his bachelor's degree at Washington University in St. Louis, interned at Brookhaven National Laboratory and Lawrence Berkeley National Laboratory during a gap year, and landed in Pasadena to pursue his doctorate.</p><p data-block-key="3bvsj">Jadbabaie did his PhD work in the lab of Assistant Professor <a href="https://www.hutzlerlab.com/">Nick Hutzler</a>. Outside the lab, he was active in science outreach, seizing opportunities to share his passion for physics with the community. He collaborated with the Caltech Center for Teaching, Learning & Outreach to develop <a href="https://www.youtube.com/watch?v=T46hxSHiOoE">science demonstrations</a> and perform outreach at local <a href="/about/news/caltech-program-fosters-scientific-curiosity-pasadena-unified-students-78504">schools</a> and <a href="/about/news/city-of-stem-outreach">events</a>.</p><p data-block-key="26h8j">One of his final projects was to record a Science Journey presentation that shares the mysteries of the universe with students and science fans.</p><p data-block-key="67pgf">"When I was a young child, I was really mesmerized by spinning things; for example, a ceiling fan," Jadbabaie says in his presentation. "I actually do still work with spinning things today. They don't quite look like ceiling fans. They look like cold rotating molecules. At the end of the day, we use these cold rotating molecules to learn about very deep fundamental questions in physics related to the big bang, the origins of our universe, and how we came to be here today."</p><p data-block-key="bhgi6"></p><embed embedtype="media" url="https://youtu.be/bNrFh-Cd-rc?feature=shared"/><p data-block-key="8add9"></p><p data-block-key="couhr">Jadbabie's video premiere kicks off the 2023–24 season of Science Journeys, which will include in-person field trips that explore topics including fluid dynamics and turbulence, soil microbes and climate change, and neuroscience and decision-making.</p><h3 data-block-key="6015b"><b>About the Series</b></h3><p data-block-key="6fbqh">In Science Journeys, Caltech graduate students and postdoctoral scholars discuss a range of scientific topics that will spark students' curiosity and provide educators with supplemental resources to continue that exploration in the classroom.</p><p data-block-key="f1mfa">"I am delighted to welcome back in-person Science Journeys field trips in 2024," said Mary Herrera, the program's coordinator. "Caltech young researchers have a wealth of STEM knowledge and inspiration to share with students and lifelong learners in our community. We are ready for you—we hope you are ready for us!"</p><p data-block-key="95bas">Each field trip includes a presentation and Q&A. Programs are designed especially for middle and high school students, but everyone is welcome to attend. All events are free through the generosity of the <a href="https://events.caltech.edu/support/fob?utm_medium=web&utm_campaign=science-journeys&utm_source=caltechnews&utm_content=&utm_term=">Friends of Beckman Auditorium</a>, but registration is required.</p><p data-block-key="co3qv">Visit the <a href="https://events.caltech.edu/series/science-journeys#upcoming-science-journeys?utm_medium=web&utm_campaign=science-journeys&utm_source=caltechnews&utm_content=&utm_term=">Science Journeys website</a> to register yourself or your classroom for a future event and to watch past presentations.</p>The X-Rays That Shouldn't Be There2023-12-05T00:13:01.442573+00:002023-12-05T00:13:01.359806+00:00https://www.caltech.edu/about/news/the-x-rays-that-shouldnt-be-there<p data-block-key="dr1oj"></p><p data-block-key="ai1o1">For around 20 years, Caltech Professor of Applied Physics Paul Bellan and his group have been creating magnetically accelerated jets of plasma, an electrically conducting gas composed of ions and electrons, in a vacuum chamber big enough to hold a person. (Neon signs and lightning are everyday examples of plasma).</p><p data-block-key="cbn7e">In that vacuum chamber, wisps of gas are ionized by several thousand volts. One hundred-thousand amps then flow through the plasma, producing strong magnetic fields that mold the plasma into a jet traveling around 10 miles per second. High-speed recordings show that the jet transitions through several distinct stages in a few tens of microseconds.</p><p data-block-key="d46ml">Bellan says the plasma jet looks like an umbrella growing in length. Once the length reaches one or two feet, the jet undergoes an instability that causes it to transform into a rapidly expanding corkscrew. This rapid expansion triggers a different, faster instability that creates ripples.</p><p data-block-key="5gpah">"The ripples choke the jet's 100-kiloamp electric current, much like putting your thumb over a water hose restricts the flow and creates a pressure gradient that accelerates water," Bellan says. "Choking the jet current creates an electric field strong enough to accelerate electrons to high energy."</p><p data-block-key="59h2h">Those high-energy electrons were previously identified in the jet experiment by the X-rays they generate, and Bellan says their presence was a surprise. That's because conventional understanding says the jet plasma was too cold for electrons to be accelerated to high energy. Note that "cold" is a relative term: Although this plasma had a temperature of about 20,000 Kelvin (35,500 degrees Fahrenheit)—far hotter than anything humans normally encounter—it is nowhere near the temperature of the Sun's corona, which is over a million Kelvin (1.8 million degrees F.)</p><p data-block-key="8fg7b">"So, the question is, 'Why are we seeing X-rays?'" he says.</p><p data-block-key="957p8">Cold plasmas were thought to be incapable of generating high-energy electrons because they are too "collisional," meaning an electron cannot travel very far before colliding with another particle. It is like a driver trying to drag race through freeway gridlock. The driver might hit the accelerator but would travel only a few feet before smashing into another car. In the case of a cold plasma, an electron would accelerate only about one micron before colliding and slowing down.</p><p data-block-key="6fj8a">The Bellan group's first attempt at explaining this phenomenon was a model suggesting that some fraction of the electrons manages to avoid colliding with other particles during the first micron of travel. According to the theory, that allowed the electrons to accelerate to slightly higher velocity, and once going faster, they could travel just a little bit farther before encountering another particle with which they might collide. Some fraction of those now-faster electrons would again avoid a collision for a time, allowing them to attain an even higher speed, which would allow them to travel even farther, creating a positive feedback loop that would allow a few lucky electrons to go farther and faster, attaining high speeds and high energies.</p><p data-block-key="qb0a">But while compelling, the theory was wrong, Bellan says.</p><p data-block-key="8ab7v">"It was realized that this argument has a flaw," he says, "because electrons don't really collide in the sense of hitting something or not hitting something. They are all actually deflecting a little bit all the time. So, there's no such thing as an electron that's colliding or not colliding."</p><p data-block-key="9goc1">Yet, high-energy electrons <i>do</i> appear in the cold plasma of the jet experiment. To find out why, Bellan developed a computer code that calculated the actions of 5,000 electrons and 5,000 ions continuously deflecting off each other in an electric field. To suss out how a few electrons were managing to reach high energies, he tweaked the parameters and watched how the electrons' behavior changed.</p><p data-block-key="3ucc0">As electrons accelerate in the electric field, they pass near ions but never actually touch them. Occasionally, an electron whizzes so closely past an ion that it transfers energy to an electron attached to the ion and slows down, with the now "excited" ion radiating visible light. Because electrons only occasionally pass so closely, they usually just deflect slightly from the ion without exciting it. This occasional energy leakage occurs in most electrons, which means they never attain high energies.</p><p data-block-key="psib">When Bellan tweaked his simulation, a few high-energy electrons capable of creating X-rays appeared. "The lucky few that never come close enough to an ion to excite it never lose energy," he adds. "These electrons are continuously accelerated in the electric field and ultimately attain sufficient energy to produce the X-rays."</p><p data-block-key="3mh5b">Bellan says that if this behavior occurs in the plasma jet in his Caltech lab, it probably happens in solar flares and astrophysical situations as well. This may also explain why unexpectedly high-energy X-rays are sometimes seen during fusion-energy experiments.</p><p data-block-key="d39fb">"There's a long history of people seeing things that they thought were useful fusion," he says. "It turns out it was fusion, but it wasn't really useful. It was intense transient electric fields produced by instabilities accelerating a few particles to extremely high energy. This might be explaining what was going on. That's not what people want, but it is probably what happens."</p><p data-block-key="55kn9">The paper describing the work, "Energetic electron tail production from binary encounters of discrete electrons and ions in a sub-Dreicer electric field," appeared in the October 20 issue of <i>Physics of Plasmas</i> and was presented on November 3 at the 65th Annual Meeting of the American Physical Society Division of Plasma Physics in Denver, Colorado.</p><p data-block-key="1l9fl">Funding for the research was provided by the National Science Foundation and the Air Force Office of Scientific Research.</p>Entanglement to the Rescue2023-11-29T01:36:00+00:002023-11-29T05:03:31.988038+00:00Whitney Clavinwclavin@caltech.eduhttps://www.caltech.edu/about/news/entanglement-to-the-rescue<p data-block-key="m1l3c">In the search for new particles and forces in nature, physicists are on the hunt for behaviors within atoms and molecules that are forbidden by the tried-and-true Standard Model of particle physics. Any deviations from this model could indicate what physicists affectionately refer to as "new physics."</p><p data-block-key="eme6r">Caltech assistant professor of physics <a href="https://pma.caltech.edu/people/nicholas-r-nick-hutzler">Nick Hutzler</a> and his group are in pursuit of specific kinds of deviations that would help solve the mystery of why there is so much matter in our universe. When our universe was born about 14 billion years ago, matter and its partner, antimatter, are believed to have existed in equal measure. Typically, matter and antimatter cancel each other out, but some kind of asymmetry existed between the different types of particles to cause matter to win out over antimatter. Hutzler's group uses tabletop experiments to look for symmetry violations—the deviant particle behaviors that led to our lopsided matter-dominated universe.</p><p data-block-key="1ifus">Now, reporting in <i>Physical Review Letters</i>, the team, led by Chi Zhang, the David and Ellen Lee Postdoctoral Scholar Research Associate in Physics at Caltech, has figured out a way to improve their studies by using <a href="https://scienceexchange.caltech.edu/topics/quantum-science-explained/entanglement">entanglement</a>, a phenomenon in quantum physics whereby two remote particles can remain connected even without being in direct contact. In this case, the researchers developed a new method for entangling arrays of molecules, which serve as probes for measuring the symmetry violations. By entangling the molecules, the arrays become less sensitive to background noise that can interfere with the experiment and more sensitive to the desired signal.</p><p data-block-key="1hi7r">"It's like anchoring a bunch of rubber duckies together," Hutzler says. "If you wanted to measure the movement of the duckies across a tub, they would be less sensitive to the background noise of splashing water if you connected them altogether. And they'd be more sensitive to something you may want measure like the flow of a current since they would all respond to it collectively."</p><p data-block-key="1god7">"We want to be sensitive to the structure of the molecules," Zhang says. "Uncontrolled electric and magnetic fields from the experimental setup get in the way of our measurements, but now we have a new protocol for entangling the molecules in such way to make them less sensitive to the noise."</p><p data-block-key="akt4f">More specifically, this new method can be used to look for tiny tilts in electrons that may occur in response to electric fields within the molecules. "The slight rotations would indicate electrons or nuclear spins are interacting with electric fields, and that's forbidden according to the Standard Model," Hutzler says.</p><p data-block-key="1cs4f">"Other approaches that use entanglement would typically increase sensitivity to noise," he adds. "Chi has figured out a way to reduce the noise while still giving us a sensitivity gain from entanglement."</p><p data-block-key="ep14a">A different recent experimental study <a href="https://www.science.org/doi/10.1126/science.adg8155">published in <i>Science</i></a>, led by Hutzler and John M. Doyle of Harvard University, showed that the polyatomic molecules used in these kinds of studies have other unique abilities to shield themselves from electromagnetic noise, though without the sensitivity boost from entanglement. In that study, the researchers showed they can tune the molecule's sensitivity to external fields and in fact make the sensitivity vanish, thereby rendering the molecules largely immune to noise. "With the advantages of entanglement, researchers can push these experiments to probe increasingly exotic sectors of new physics," Hutzler says.</p><p data-block-key="fdnhk">The study titled "<a href="https://journals.aps.org/prl/pdf/10.1103/PhysRevLett.131.193602">Quantum-Enhanced Metrology for Molecular Symmetry Violation using Decoherence-Free Subspaces</a>," was funded by the Gordon and Betty Moore Foundation, Alfred P. Sloan Foundation, the National Science Foundation, the Ellen Lee Postdoctoral Fellowship, and the Eddleman Graduate Fellowship from the Institute for Quantum Information and Matter (<a href="https://iqim.caltech.edu/">IQIM</a>). Other Caltech authors include graduate student Phelan Yu and postdoc Arian Jadbabaie (Jadbabaie is also an author on the <a href="https://www.science.org/doi/10.1126/science.adg8155"><i>Science</i> paper</a>).</p>