Innovation

Researchers have used Caltech’s John W. Lucas Adaptive Wall Wind Tunnel and its historic 10-foot predecessor to test everything from military and commercial aircraft to Olympic bicycles and electric cars. Insights made possible by the tunnels have led to more fuel-efficient vehicles and inspired research on hypersonic technology.

Caltech chemist Ahmed Zewail developed a technique, ultrafast electron microscopy, that allows researchers to study atomic-level images of chemical reactions as they occur. The method relies on extremely short laser pulses—so brief they last mere femtoseconds, each one-millionth of one-billionth of a second.

Caltech physicists Nai-Chang Yeh and David Boyd created a commercially feasible method of producing graphene, a wonder material made of a single layer of carbon atoms. Graphene is 200 times stronger than steel, several times more conductive than silicon, and has the potential to transform electronics manufacturing. Yeh imagines, for example, a graphene-based cell phone screen that generates its own power.

Caltech psychobiologist Roger Sperry’s split-brain experiments revealed the separate functions of the brain’s two hemispheres: the left half controls verbal and mathematical functions as well as analytic and sequential reasoning, while the right controls spatial and conceptual reasoning, visualization, and creativity.

Caltech researchers launched the field of behavioral and social neuroscience, providing experimental insights into how individuals choose between healthy and unhealthy foods, why consumers pay more for goods they can touch, and why (and when) people are willing to take risks.

Caltech electrical and medical engineer Yu-Chong Tai helped develop a retinal prosthesis that allows blind patients to see again through electrical stimulation. The prosthesis acts as biological photoreceptors normally do, stimulating neurons in the retina to create an image.

A team at JPL developed the Robot Assisted MicroSurgery (RAMS) system that enables surgeons to perform operations with 20 times more accuracy than can be achieved by the human hand alone. This method is widely used, including in 40 percent of prostate surgeries nationwide.

In the 1980s, Leroy Hood (BS ’60, PhD ’68) built the automated DNA sequencer, helping launch the field of genomics and making possible the Human Genome Project, the successful effort to sequence all 3 billion base pairs of DNA. Since then, Caltech biologist Barbara Wold (PhD ’78) has pioneered next-generation sequencing technologies that are building understanding of how groups of genes direct the development of a fertilized egg, for example, or how DNA mutations cause cancerous tumors.

In the mid-1990s, David Ho (BS ’74) discovered that HIV is never dormant but constantly mutates in order to continue its assault on the immune system. His insight led to the development of antiretroviral therapies that have dramatically increased the lifespans of HIV-infected patients.

Caltech microbiologist Sarkis Mazmanian discovered a connection between the microbiome—the bacteria living in the human gut—and the motorskill deterioration associated with Parkinson’s disease. This research is part of broader investigations on the manner in which good bacteria promote or protect human health.

In the 1930s, Caltech seismologists Beno Gutenberg and Charles Richter (PhD ’28) developed the Richter scale, a numerical scale for measuring earthquake magnitude. Nearly 50 years later, Caltech seismologist Hiroo Kanamori and graduate student Thomas C. Hanks (PhD ’72) developed the moment magnitude scale, allowing for more accurate readings of larger quakes at greater distances.

Caltech physicist Carl Anderson (BS ’27, PhD ’30) provided the first empirical proof that antimatter exists with his discovery of the positron. Today’s positron emission tomography (PET) scanners—which produce detailed 3-D images of metabolic activity in the body—are a result of his discovery.

Caltech physicist Richard Feynman—whose work set in motion the fields of nanotechnology, quantum computing, and quantum electrodynamics—authored and delivered a series of lectures that became one of the most popular physics books ever written, The Feynman Lectures on Physics.

Caltech physicist Willy Fowler, working with research fellow Margaret Burbidge and other colleagues, showed that all but the very lightest elements—making up everything from the ground underfoot to the air all around to human muscle and bone—were created by nuclear reactions within stars.

Caltech theoretical physicist Murray Gell-Mann and graduate student George Zweig (PhD ’64) independently discovered quarks—subatomic particles that are the main components of protons and neutrons.

Searching for distant objects at the edges of the solar system, Caltech astronomer Mike Brown discovered a dwarf planet, Eris, that is more massive than Pluto. His discovery triggered Pluto’s demotion to dwarf-planet status. Then, in 2016, Brown and Caltech planetary scientist Konstantin Batygin (MS ’10, PhD ’12) published theoretical evidence of a true ninth planet—one 10 times more massive than Earth—tracing a bizarre orbit around the sun. The announcement of a potential new Planet Nine ignited a worldwide, sky-wide hunt.

Students and researchers from the Guggenheim Aeronautical Laboratory at Caltech (GALCIT) were the driving force behind the creation of JPL in the 1930s. JPL, which Caltech manages on behalf of NASA, is the leading center for exploration of the solar system. Lab scientists launched the nation’s first satellite, Explorer 1, in 1958; the twin Voyager spacecraft in 1977; and the Mars Science Laboratory in 2011, among many other missions.

Led by Caltech physicists Kip Thorne (BS ’62), Ron Drever, and Barry Barish, along with MIT’s Rainer Weiss, the Laser Interferometer Gravitational-wave Observatory (LIGO) made the first-ever detection of gravitational waves—ripples in spacetime—in September 2015. The detection, which came 100 years after Albert Einstein predicted the existence of gravitational waves in his general theory of relativity, opened a new window onto the cosmos, ushering in the field of gravitational astronomy.

Caltech researchers have designed and built the world’s most sophisticated telescopes and astronomical observatories, including the W. M. Keck Observatory, whose twin telescopes are currently the largest and most scientifically productive on Earth. The Keck telescopes have made possible the observation of young stars, ancient galaxies, and dozens of planets—some potentially habitable—outside the solar system.

In the 1940s, Caltech chemist Arie Haagen-Smit became the first scientist to directly link smog to automobile exhaust, ultimately prompting the formation of the California Air Resources Board. Since then, Caltech researchers have continued to influence air-pollution management with new insights into urban smog formation and discoveries about the origin, chemistry, and evolution of particles in the atmosphere.

Attempting to calculate the age of the earth (4.55 billion years), Caltech geochemist Clair Patterson unexpectedly discovered that toxic lead contaminated everything from his lab instruments to canned fish, ocean water, Antarctic ice, and, most alarmingly, the human body. Despite skepticism about his findings throughout the 1960s, Patterson’s research drove efforts to remove lead from gasoline and to implement environmental protections including the Clean Air Act of 1970.

In the 1990s, Caltech chemical engineer Frances Arnold pioneered the technique of directed evolution, which mimics the process of natural selection to create new enzymes that can be used in medicine, neurobiology, and alternative energy. For example, Arnold has used directed evolution to engineer enzymes that can convert plant waste into fuel.

As director of research and development at Fairchild Semiconductor and, later, co-founder of Intel, Gordon Moore (PhD ’54) developed memory chips and microprocessors that paved the way for personal computers. His 1965 prediction, popularly known as Moore’s Law, correctly surmised that the number of transistors on a single chip would double approximately every two years.

Caltech engineer Carver Mead (BS ’56, MS ’57, PhD ’60) validated the science behind Moore’s Law in 1972. Through a process known as very-largescale integration (VLSI), Mead made it possible for tens of thousands of transistors to be packaged on a single silicon chip. VLSI revolutionized electronics, enabling the building of processors that today drive devices such as laptops, tablets, smartphones, and DVD players.

A high-voltage laboratory built on campus in 1923 was the first in the country to have a million-volt power source. The laboratory helped Southern California Edison develop high voltage transmission lines, which would furnish lightning protection to oil storage tanks and address other power needs of a rapidly industrializing Southern California.

Tasked with miniaturizing cameras for future spacecraft, engineers at JPL invented a new kind of image sensor that functions as a camera on a chip. That technology, the complementary metal-oxide semiconductor (CMOS), is ultimately responsible for putting cameras in cell phones.

Fiber optic communications systems rely on distributed feedback semiconductor lasers, developed in the 1970s by Caltech’s Amnon Yariv, an engineer and applied physicist. Today, such lasers are the main information carriers of internet traffic.