Using a custom-made silicon skin and articulated morphing wings, researchers at Caltech and the University of Illinois at Urbana-Champaign created Bat Bot, an autonomous flying robot that mimics the key flight characteristics of real bats. Bat Bot weighs only 93 grams and is shaped like a bat with a roughly 1-foot wingspan. It is capable of altering its wing shape by flexing, extending, and twisting at its shoulders, elbows, wrists, and legs. The design has potential applications for environments where more traditional quadrotor drones—which have four spinning rotors—could collide into objects or people, causing damage or injury.
Credit: Fischer Laboratory/Caltech
How Plants Make Oxygen
The ability to generate oxygen through photosynthesis evolved just once, roughly 2.3 billion years ago, in certain types of cyanobacteria. This planet-changing biological invention has never been duplicated as far as anyone can tell. Instead, according to endosymbiotic theory, all the "green" oxygen-producing organisms (plants and algae) simply subsumed cyanobacteria as organelles in their cells at some point during their evolution. In March, geobiologists at Caltech and the University of Queensland in Australia finally fleshed out cyanobacteria's family tree. They added the genomes of 41 uncultured microorganisms, which helped to pin down the precise point in the evolution of cyanobacteria at which oxygenic photosynthesis arose.
A study published in April by researchers from Caltech, the Wharton School, Western University, and ZRT Laboratory tested the hypothesis that higher levels of testosterone increase the tendency in men to rely on their intuitive judgments and reduce cognitive reflection—a decision-making process by which a person stops to consider whether their gut reaction to something makes sense. The researchers found that men given doses of testosterone performed more poorly on a test designed to measure cognitive reflection than a group given a placebo. The results of the study raise questions about potentially negative effects of the growing testosterone-replacement-therapy industry.
An Explanation for Oxygen Mystery on Planets
A Caltech chemical engineer and his team showed, using lab experiments, how molecular oxygen may be produced on the surface of comets. The researchers fired high-speed water molecules at oxidized silicon and iron surfaces in the lab, and observed the production of a plume that included molecular oxygen. Similar conditions exist on the comet 67P/Churyumov–Gerasimenko, where the European Space Agency's Rosetta mission detected molecular oxygen. The new research implies that the molecular oxygen found by Rosetta need not be primordial after all but may be produced in real time on the comet.
Credit: Tsao Laboratory/Caltech
Cracking the Code of Facial Recognition
New research from Caltech, published in June, shows that the brain uses a simple and elegant mechanism to represent facial identity. The findings suggest a not-too-distant future in which monitoring brain activity can lead to a reconstruction of what a person is seeing. The main finding of the new work is that even though there exists an infinite number of different possible faces, our brain needs only about 200 neurons to uniquely encode any face, with each neuron encoding a specific dimension, or axis, of facial variability. These 200 neurons can combine in different ways to encode every possible face.
An Ultrathin Lensless Camera
In June, Caltech engineers announced the development of a new camera design that replaces lenses with an ultrathin optical phased array (OPA), which manipulates incoming light to capture an image. The OPA has a large array of light receivers, each of which can individually add a tightly controlled time delay to the light it receives, enabling the camera to selectively look in different directions and focus on different things. The ability to control all the optical properties of a camera electronically using a paper-thin layer of low-cost silicon photonics opens a new world of imagers and, once scaled up, could even have implications for astronomy by enabling ultralight, ultrathin enormous flat telescopes on the ground or in space.
Credit: Robert Hurt (Caltech/IPAC), Mansi Kasliwal (Caltech), Gregg Hallinan (Caltech), Phil Evans (NASA) and the GROWTH collaboration
Gravitational and Light Waves From a Neutron Star Merger
On August 17, scientists for the first time detected both the ripples in space and time known as gravitational waves as well as light produced and emitted during the same cosmic event: the spectacular collision of two neutron stars. The light-based detections—which included Caltech-led observations in infrared, X-ray, ultraviolet, and radio waves—show that the collision of the neutron stars released newly synthesized heavy elements into the surrounding universe, providing the first concrete proof that such smashups are the birthplace of half of the universe's elements heavier than iron. The gravitational-wave discovery was made with the twin LIGO (Laser Interferometer Gravitational-wave Observatory) detectors, which are funded by the National Science Foundation and were conceived, built, and are operated by Caltech and MIT.
40 Years of Voyager
Forty years ago, in the summer of 1977, NASA's Voyager spacecraft were launched into space on a mission to explore the mysteries of the outer planets. Though the spacecraft were designed with the same scientific instruments and both carry a Golden Record of Earth sounds, pictures, and messages, they would ultimately take different tours of the solar system. In 1979, Voyager 1 discovered the first known active volcanoes outside Earth, on a moon of Jupiter called Io. Voyager 2 is the only spacecraft to have flown by all four outer planets—Jupiter, Saturn, Uranus, and Neptune. In 2012, Voyager 1 (now almost 13 billion miles from Earth) became the first-ever spacecraft to enter interstellar space.
An App that Measures Heart Health
In September, engineers at Caltech, Huntington Medical Research Institute, and USC announced their development of a technique where the camera on a smartphone can noninvasively provide detailed information about heart health. What normally requires a 45-minute scan from an ultrasound machine can now be accomplished by holding a phone up to one's neck for a minute or two. The team developed a technique that can infer the left ventricular ejection fraction of the heart—a key measure of heart health—by measuring the amount that the carotid artery displaces the skin of the neck as blood pumps through it. The app is expected to be available for download in the coming year.
Caltech scientists published research in September demonstrating that humans and jellyfish actually start and end their days with the same behavior: sleep. To prove that jellyfish sleep, the team monitored them around the clock by camera, discovering that the jellyfish go through periods of inactivity at night, only pulsing about 39 times per minute, compared to about 58 times per minute during the day. Other tests confirmed an increased arousal threshold during this period of decreased activity and an increased sleep drive when deprived of sleep. This finding—that jellyfish sleep—implies that sleep is an ancient behavior largely untouched by millennia of evolution.
Cassini's Grand Finale
NASA's Cassini mission reached its dramatic finale on September 15 when it plunged into Saturn's atmosphere, concluding 13 years of exploration around the ringed planet. Designed in the 1980s and '90s, and launched in 1997, Cassini passed by Jupiter in 2000 and reached Saturn in 2004, where it orbited until this year. The spacecraft made many dramatic discoveries over the years, including a global ocean within the moon Enceladus and liquid methane seas on Saturn's largest moon, Titan. In the months before the end, the spacecraft performed a series of 22 dives through Saturn's rings, during which it collected a host of valuable information too risky to obtain earlier in the mission.
Credit: Ella Marushchenko for Caltech
Microchip Technology to Track Smart Pills
In September, researchers at Caltech announced they had developed a prototype miniature medical device that could ultimately be used in "smart pills" to diagnose and treat diseases. A key to the new technology—and what makes it unique among other microscale medical devices—is that its location can be precisely identified within the body, something that proved challenging before. Called ATOMS, which is short for addressable transmitters operated as magnetic spins, the new silicon-chip devices borrow from the principles of magnetic resonance imaging, or MRI, in which the location of atoms in a patient's body is determined using magnetic fields.
Caltech Scientists Win Nobel Prizes
The 2017 Nobel Prize in Physics was awarded to three key players in the development and ultimate success of LIGO. One half of the prize was awarded jointly to Caltech's Barry C. Barish, the Ronald and Maxine Linde Professor of Physics, Emeritus, and Kip S. Thorne (BS '62), the Richard P. Feynman Professor of Theoretical Physics, Emeritus; and the other half was awarded to MIT's Rainer Weiss, professor of physics, emeritus. Caltech alumnus Michael Rosbash (BS '65), the Peter Gruber Endowed Chair in Neuroscience and professor of biology at Brandeis University and an investigator with the Howard Hughes Medical Institute, was awarded the 2017 Nobel Prize in Physiology or Medicine.
A Center for Autonomous Systems and Technologies
On October 24, Caltech officially opened its new Center for Autonomous Systems and Technologies (CAST), a 10,000-square-foot facility where machines and researchers will work together and learn from one another. At CAST, researchers from the Division of Engineering and Applied Science, the Division of Geological and Planetary Sciences, and the Jet Propulsion Laboratory will collaborate to advance the fields of drone research, autonomous exploration, and bioinspired systems. Researchers will continue pioneering work on technologies ranging from prosthetic legs that use machine learning to automatically adjust to a wearer's gait to a flying, self-driven ambulance.
Credit: Caltech Optical Observatories
Zwicky Transient Facility Opens Its Eyes to the Volatile Cosmos
A new robotic camera with the ability to capture hundreds of thousands of stars and galaxies in a single shot took its first such image of the sky, an event astronomers refer to as "first light," on November 1. The recently installed camera is part of a new automated sky-survey project called the Zwicky Transient Facility (ZTF). Every night, ZTF, based at Caltech's Palomar Observatory, which is located in the mountains near San Diego, will scan a large portion of the northern sky, discovering objects that erupt or vary in brightness, including exploding stars (also known as supernovas), stars being munched on by black holes, and asteroids and comets.
Credit: Floris van Breugel/Caltech
An Answer to the Mystery of Scuba Diving Flies
In November, a Caltech biologist and his team were, for the first time, able to explain how certain flies at Mono Lake have adapted uniquely to their environment and are able to crawl underwater without getting wet. Using a combination of high-speed video and micro-force measurements in which they plunged flies into a variety of different chemical solutions, the researchers found that the Mono Lake fly creates a protective bubble of air around its body when crawling into the lakewater. The flies are able to do this, the researchers discovered, because they are hairier than the average fly and coat their bodies and hairs with waxes that are particularly effective at repelling the carbonate-rich water of Mono Lake.
Credit: David Chen and Yan Liang (BeautyOfScience.com) for Caltech
Bacteria That Can Make Boron-Carbon Bonds
Caltech scientists created bacteria that can, for the first time, make chemical compounds containing bonds between boron and carbon. Before now, such boron-carbon bonds came only from the laboratories of chemists and could not be produced by any known life form. The finding (published in November) is part of a new wave in synthetic biology, in which living organisms are taught—using a method called directed evolution—to make chemical compounds needed for pharmaceuticals, agricultural chemicals, and other industrial products. By using biology, researchers can potentially make the chemical compounds in greener ways that are more economical and produce less toxic waste.
During the last 12 months, Caltech researchers have detected gravitational waves from the collision of two neutron stars, developed an ultrathin lensless camera, figured out how flies crawl underwater in Mono Lake, and coaxed bacteria into making boron-carbon bonds.
And that's just for starters. In case you missed any of the year's news, here are 17 of the most notable moments from 2017.