In January, Caltech researchers announced that they had found evidence of a giant planet in the outer solar system. Nicknamed Planet Nine, the object has a mass about 10 times that of Earth and would take between 10,000 and 20,000 years to make just one full orbit around the sun. The researchers discovered the planet's existence through mathematical modeling and computer simulations. Now they are refining those simulations and learning more about the planet's orbit and its influence on the distant solar system while also joining in searching the skies in hopes of observing the object directly.
A Hormone for Cooperation
Caltech behavioral economists published a paper in February on their finding that arginine vasopressin (AVP), a hormone implicated in monogamy and aggression in animals, also promotes trust and cooperation in humans in risky situations. Research in rodents has shown that AVP promotes monogamous pair bonding and parental behavior. In the new study, researchers tested the hypothesis that AVP might also play a role in social bonding in people and could help explain our species' cooperative tendencies. The discovery that AVP increases the likelihood of cooperation in these situations could have practical applications, such as in a high-stakes military operation where mutual trust and cooperation is vital to success.
Gravitational Waves Detected 100 Years After Einstein's Prediction
On February 11, scientists announced that they had, for the first time, observed ripples in the fabric of spacetime called gravitational waves, confirming a major prediction of Albert Einstein's 1915 general theory of relativity and opening an unprecedented new window onto the cosmos. The physicists concluded that the gravitational waves were produced during the final fraction of a second of the merger of two black holes. The waves were detected by both of the twin Laser Interferometer Gravitational-wave Observatory (LIGO) detectors, located in Livingston, Louisiana, and Hanford, Washington. In June, the LIGO and VIRGO collaborations announced a second detection, also of a black-hole merger. The LIGO Observatories are funded by the National Science Foundation and were conceived, built, and are operated by Caltech and MIT.
Credit: Ismagilov Lab, Caltech
Counting Molecules with an Ordinary Cell Phone
Using a technology called SlipChip, invented at Caltech, researchers here described the invention of a new visual readout method that uses analytical chemistries and image processing to count single nucleic-acid molecules using a cell phone camera. The visual readout method is described and validated using RNA from the hepatitis C virus in a paper published in February. This work could help bring emerging diagnostic capabilities out of laboratories and to the point of care.
Dawn Completes its Primary Mission
NASA's Dawn spacecraft completed its primary mission at the end of June, exploring protoplanet Vesta and dwarf planet Ceres. This was the first mission to orbit two extraterrestrial solar system targets and the first to orbit any object in the main asteroid belt between Mars and Jupiter. Since launching in 2007, Dawn has traveled 3.5 billion miles and has made 2,450 orbits around Vesta and Ceres.
Credit: Courtesy of M. Kohler/Caltech
Network Detected Air Pulse from Refinery Explosion
When a refinery explosion in Torrance in 2015 caused ground shaking equivalent to a magnitude-2.0 earthquake, Community Seismic Network sensors—part of a project to seed the Los Angeles area with low-cost seismometers to provide detailed information on what happens to buildings during shaking—noted and recorded the motion on every floor of a 52-story high-rise in downtown Los Angeles. In June, Caltech seismologists reported on the building's response to the explosion, noting that it shifted, at most, three-hundredths of a millimeter in response but that the building's seismometers noted and recorded the motion of each individual floor. This tight network of detectors is improving seismic data gathering and could offer crucial information on building damage after a quake.
Juno Enters Orbit Around Jupiter
After an almost five-year journey to the solar system's largest planet, NASA's Juno spacecraft successfully entered Jupiter's orbit during a 35-minute engine burn. On July 4, JPL announced confirmation that the burn had completed. Juno's principal goal is to understand the origin and evolution of Jupiter. With its suite of nine science instruments, Juno is now investigating the existence of a solid planetary core, mapping Jupiter's intense magnetic field, measuring the amount of water and ammonia in the deep atmosphere, and observing the planet's auroras.
Engineers Teach Machines to Recognize Tree Species
This summer, Caltech engineers revealed a new method that uses data from satellite and street-level images, such as the ones that you can see in Google maps, to create automatically an inventory of street trees that cities may use to better manage urban forests. To do this, the engineers created visual recognition algorithms that can see and understand images much as a human would. Eventually, cities could continuously collect data about urban street trees from satellite and street-level images; that information then could be incorporated into software that would help the city understand how its urban forests are evolving and help in the creation of long-term plans for future street-tree investments.
Credit: Sergio Pellegrino/Caltech
Developing Space Telescopes that Assemble Themselves
Seeing deep into the universe requires large telescopes, but typically they are limited in size due to the difficulty and expense of sending outsized items into space. In July, Caltech's aeronautical engineers published a paper on how to circumvent that issue by shipping a 100-meter mirror up into space as 300 separate modular components, which would be assembled by spider-like, six-armed "hexbots" that would build the trusses and then crawl across them to attach the mirror plates. Though the realization of such an assembly is still decades away, the Caltech team is already working on the various technologies that will be needed to make it possible.
Credit: Barth van Rossum for Caltech
Taking Ultrasound Imaging to the Next Level
In an August paper, chemical engineers at Caltech explained how they engineered protein-shelled nanostructures called gas vesicles to exhibit new properties useful for ultrasound technologies. In the future, these gas vesicles could be administered to a patient to visualize tissues of interest and help to take ultrasound imaging to the next level by allowing for the imaging of specific cells and molecules deep in the body. The modified gas vesicles were shown to give off more distinct signals, making them easier to image. They also were able to target specific cell types and help create color ultrasound images.
Linking Intestinal Bacteria and Parkinson's Disease
Caltech scientists announced in December that they have discovered for the first time a functional link between bacteria in the intestines and Parkinson's disease. The researchers found that changes in the composition of gut bacterial populations—or possibly gut bacteria themselves—actively contribute to and may even cause the deterioration of motor skills that is the hallmark of this disease. The findings have important implications for the treatment of Parkinson's, potentially leading to drugs that would only have to be delivered to the gut to help patients—a task that is much easier than delivery to the brain.
Credit: Courtesy of the Chens
Chen Institute for Neuroscience at Caltech
Spearheaded by a $115 million gift from visionary philanthropists Tianqiao Chen and Chrissy Luo, Caltech and the Tianqiao and Chrissy Chen Institute announced the launch of a campus-wide neuroscience initiative to create a unique environment for interdisciplinary brain research. The goal of the new endeavor is to deepen our understanding of the brain—the most powerful biological and chemical computing machine—and how it works at the most basic level as well as how it fails because of disease or through the aging process.
Surgeon, writer, and public health researcher Atul Gawande, spoke at Caltech's 122nd annual commencement ceremony in June. "Science is not a major or a career," he told the graduates. "It is a commitment to a systematic way of thinking, an allegiance to a way of building knowledge and explaining the universe through testing and factual observation." Then, in October, Microsoft founder and billionaire philanthropist Bill Gates visited Caltech and participated in a question-and-answer session with Caltech students in Beckman Auditorium. "Touring the campus," he later wrote in his GatesNotes blog, "I was struck by what an amazing time it is to be a student at an institution like Caltech. In every field—from engineering and biology to chemistry and computer science—I learned about phenomenal research underway to improve our health, find new energy sources, and make the world a better place."
Among the new faculty we welcomed to Caltech this year are a neuroscientist who uses tarantulas to study what happens in our brains when we are under threat, a historian who focuses on slavery and emancipation in the American North, and a quantum chemist with a fascination for high-temperature superconductivity.
Credit: Ryan Forbes Photography
Awards and Honors
Many members of the Caltech community were recognized this year with honors in their fields of study. Frances Arnold, the Dick and Barbara Dickinson Professor of Chemical Engineering, Bioengineering and Biochemistry, was awarded the Millennium Technology Prize in June. Dianne Newman, the Gordon M. Binder/Amgen Professor of Biology and Geobiology, and Victoria Orphan, the James Irvine Professor of Environmental Science and Geobiology, were selected as MacArthur Fellows in September. Alexei Kitaev, the Ronald and Maxine Linde Professor of Theoretical Physics and Mathematics, was awarded the American Physics Society's 2017 Oliver E. Buckley Condensed Matter Prize in October. The founders of LIGO, meanwhile, were honored at various points throughout the year with the Kavli Prize, the Shaw Prize, the Optical Society Award, the Special Breakthrough Prize, and the Gruber Cosmology Prize.
During the last 12 months, Caltech researchers presented evidence of a new planet, discovered how to count molecules with a cell phone, taught machines to recognize trees, and designed telescopes that could someday assemble themselves in space. And they—alongside an international team of colleagues—announced the first-ever detection of the ripples in the fabric of spacetime called gravitational waves.
But that wasn't all. In case you missed any of the year's news, here are 16 of the most significant moments from 2016.