News & Events


New Breed of Optical Soliton Wave Discovered


Kerry Vahala, Ted and Ginger Jenkins Professor of Information Science and Technology and Applied Physics, and colleagues have discovered a new type of optical soliton wave that travels in the wake of other soliton waves, hitching a ride on and feeding off of the energy of the other wave. Solitons are localized waves that act like particles. Professor Vahala likens these newly discovered solitons to pilot fish, carnivorous tropical fish that swim next to a shark so they can pick up scraps from the shark's meals. And by swimming in the shark's wake, the pilot fish reduce the drag of water on their own body, so they can travel with less effort. [Caltech story]

Tags: APhMS research highlights Kerry Vahala

Counting on Grains of Sand


José E. Andrade, Professor of Civil and Mechanical Engineering; Executive Officer for Mechanical and Civil Engineering, and colleagues have developed a new method that measures the way forces move through granular materials—one that could improve our understanding of everything from how soils bear the weight of buildings to what stresses are at work deep below the surface of the earth. [Caltech story]

Tags: research highlights MCE Jose Andrade

The Utility of Instability


Professors Dennis M. Kochmann and Chiara Daraio along with colleagues from Harvard have designed and created mechanical chains made of soft matter that can transmit signals across long distances. Because they are flexible, the circuits could be used in machines such as soft robots or lightweight aircraft constructed from pliable, nonmetallic materials. "Engineers tend to shy away from instability. "Though there are many applications, the fundamental principles that we explore are most exciting to me," Kochmann says. "These nonlinear systems show very similar behavior to materials at the atomic scale but these are difficult to access experimentally or computationally. Now we have built a simple macroscale analogue that mimics how they behave." [Caltech story]

Tags: research highlights Chiara Daraio GALCIT MCE Dennis Kochmann

Improving Computer Graphics with Quantum Mechanics


The Schrödinger equation, the basic description of quantum mechanical behavior, can be used to describe the motion of superfluids—fluids, supercooled to temperatures near absolute zero, that behave as though they are without viscosity. Professor Peter Schröder and his colleagues realized that the same equation with some small modifications can also be used to describe vorticity dominated phenomena of fluids at the macroscopic level--from smoke gently rising from a flame to the concentrated vorticity of a twister. [Caltech story & video]

Tags: research highlights CMS Peter Schröder

Counting L.A.’s Trees


Professor Pietro Perona, has developed a method using Google Earth and Google Street View to count the trees in the city of Los Angeles. The process of counting the trees using human tree counters is very expensive and would cost about $3 million today. The last time the city did such counting was more than two decades ago and at the time there were 700,000 street trees. Perona has tested the methodology in a section of Pasadena where the city recently commissioned a sidewalk survey. By comparing the results to the known inventory, he determined that the computer was about 80% accurate. [LA Times story] [KPCC story]

Tags: EE research highlights CMS Pietro Perona

A Microscopic Glowing Van Gogh


Paul Rothemund, Research Professor of Bioengineering, Computing and Mathematical Sciences, and Computation and Neural Systems, and colleagues have developed a technique that allows manmade DNA shapes to be placed wherever desired; to within a margin of error of just 20 nanometers. This technique removes a major hurdle for the large-scale integration of molecular devices on chips. As a demonstration of the technique’s capabilities the group has created one of the world's smallest reproductions of Vincent van Gogh's The Starry Night. [Caltech story]

Tags: research highlights CMS Paul Rothemund

Community Seismic Network Detected Air Pulse From Refinery Explosion


The Community Seismic Network’s (CSN) tight network of low-cost detectors are improving the resolution of seismic data gathering and could offer city inspectors crucial information on building damage after a quake. On February 18, 2015, an explosion rattled the ExxonMobil refinery in Torrance, causing ground shaking equivalent to that of a magnitude-2.0 earthquake and blasting out an air pressure wave similar to a sonic boom. Traveling at 343 meters per second the air pressure wave reached a 52-story high-rise in downtown Los Angeles 66 seconds after the blast. The building's seismometers, which are part of the CSN, noted and recorded the motion of each individual floor. "We want first responders, structural engineers, and facilities engineers to be able to make decisions based on what the data say," explained Monica Kohler, Research Assistant Professor of Mechanical and Civil Engineering, and the lead author of a paper detailing the high-rise's response that recently appeared in the journal Earthquake Spectra. [Caltech story]

Tags: research highlights MCE Monica Kohler

Realtime Camera Planning


Yisong Yue, Assistant Professor of Computing and Mathematical Sciences, is working with colleagues at Disney Research to develop machine-learning algorithms to make automated cameras more human-like.  Professor Yue's research group is generally interested in building AI systems that imitate demonstrated behavior, including laboratory animals, basketball players, humans playing video games, etc.  In this recent work with Disney Research, they are developing an automated camera system that learns how best to film sports matches by watching how human camera operators behave at particular moments. Early testing shows that its shots are far smoother than other automated cameras. [Learn more about the applications] [Learn more about the theory] [techradar story] [Sports Illustrated story]

Tags: research highlights CMS Yisong Yue

Best Paper At Conference on Uncertainty in Artificial Intelligence


Leonard J. Schulman, Professor of Computer Science, and postdoctoral scholar Piyush Srivastava have won the best paper award at the 2016 Conference on Uncertainty in Artificial Intelligence for their paper, Stability of Causal Inference. [Read the paper]

Tags: research highlights CMS Leonard Schulman Piyush Srivastava postdocs

Microseismicity and Large Earthquakes


Nadia Lapusta, Professor of Mechanical Engineering and Geophysics, and Caltech alumnus Dr. Junle Jiang, have linked the patterns of microseismicity to the depth extension of large earthquakes, both through modeling and observationally. They argue that fault segments which do not have concentrated microseismicity at the bottom of the seismogenic zone must have had deeper, larger earthquakes than currently believed. A number of segments on the San Andreas fault appear to fall into that category. The potential for such deeper earthquakes in the future would imply higher seismic hazard. [Science article] [KPCC coverage] [New Yorker Article]

Tags: research highlights MCE Nadia Lapusta alumni Junle Jiang