Random Walk Elachi (left) and Stone at the press conference.

T HE L AB N AMES O NE OF I TS O WN

Charles Elachi (MS ’69, and so knows the school well. of Caltech, and I intend to the Space Shuttle that have PhD ’71) has been named He is an expert in remote continue that tradition. My allowed scientists to see the new director of the Jet sensing, and in recognition commitment is to continue through the clouds that Propulsion Laboratory (JPL), of his work, he was one of the tradition of excellence blanket Earth. (The technol- which Caltech manages for the youngest members ever and boldness in exploring our ogy also penetrates the top NASA, effective May 1. elected to the National solar system, understanding layer of soil in arid regions, President David Baltimore Academy of Engineering. the origin of galaxies, and revealing hints of what lies made the announcement at He has long been a leader of applying that knowledge to below.) He has participated a press conference on January planetary exploration at JPL better understand the changes in a number of archaeological 31, where Elachi and Balti- and is widely respected at the on our own planet.” The new expeditions in the Egyptian more were joined by retiring Laboratory. I look forward to post brings Elachi full circle, desert, the Arabian peninsula, JPL director Edward Stone, having a close working as he recalled being inspired and the Western Chinese the Morrisroe Professor of relationship with him.” as an 11-year-old in Lebanon desert, using satellite data to Physics; and NASA adminis- “Charles Elachi brings by JPL’s launching of Ex- search for old trading routes trator Daniel Goldin. Elachi formidable talents to his new plorer 1—43 years ago to the and buried cities. Some of has served in a variety of job, as both a scientist and a day, he noted. “Maybe that’s these expeditions have been research and management leader,” said Goldin. “In a good omen for me,” he featured in National Geo- positions at JPL since 1971. addition to already being joked. He grew up to receive graphic, on PBS, and in Most recently, he has been responsible for many of JPL’s a BSc in physics from the Caltech News (“The Road head of the Space and Earth missions in solar system University of Grenoble, to Ubar,” April, 1992). He Science Programs; other exploration, Earth sciences, France, and the Dipl.Ing. in has also served as principal positions include manager for and astrophysics, he has led engineering from the Poly- investigator on numerous radar development and leader efforts to create road maps technic Institute, Grenoble, NASA research and develop- of the radar remote-sensing of our exploration strategies both in 1968, and then ment studies and flight team. decades into the future. He earned his Caltech MS and projects. He is currently the Elachi “knows JPL better is both an effective adminis- PhD in electrical engineering. team leader of the Cassini than anyone and will be best trator and a visionary.” He also earned an MBA from Titan radar experiment and a able to lead the Laboratory in Elachi said he was honored USC in 1978, and an MS in coinvestigator on the Rosetta the coming years,” Baltimore to be entrusted with the geology from UCLA in 1983. Comet Nucleus Sounder said. “Charles has an extraor- leadership of JPL. “For the Elachi is perhaps best Experiment. He is the author dinary record of accomplish- last 40 years JPL has enjoyed known for his role in the of more than 200 publica- ment in his 30 years at JPL. a tradition of excellence as a development of a series of tions on space and planetary He is an alumnus of Caltech, NASA center and division imaging radar systems for exploration, Earth observa-

2 ENGINEERING & SCIENCE NO . 4     tion from space, active microwave remote sensing, wave propagation and scattering, electromagnetic theory, lasers, and integrated S NIFF M E A T UNE optics, and he holds several patents in those fields. He has written three textbooks on remote sensing and has taught EE/Ge 157, Introduc- When Hamlet told the iorally relevant to them. tion to the Physics of Remote courtiers they would eventu- But the study likely applies Sensing, since 1982. ally “nose out” the hidden to other animals, including In 1988, the Los Angeles corpse of Polonius, he was humans, because the olfactory Times selected him as one of perhaps a better neurobiolo- systems of most living crea- “Southern California’s rising gist than he realized. Accord- tures appear to follow the stars who will make a differ- ing to research by Caltech same basic principles. After ence in L.A.” In 1989, neuroscientists, the brain placing electrodes in the Asteroid 1982 SU was creates subtle temporal codes brains of individual fishes, renamed 4116 Elachi in to identify odors. Some neu- they were subjected to recognition of his contribu- ral signals change over the sequences of 16 odor compo- tions to planetary exploration. duration of a sniff, giving nents found in foods they Elachi is the second Caltech first a general notion of the normally seek. Analyzing the alumnus to be named director type of odor, then a more signals from the mitral cells of JPL. The first, William subtle discrimination that showed that the information Pickering (BS ’32, PhD ’36), leads to precise recognition the fish could extract about a headed the lab from 1954 to of the smell. In the February stimulus became more precise 1976. ■—JP 2 issue of the journal Science, as time went by. The finding Gilles Laurent, associate was surprising because the professor of biology and signals extracted from the computation and neural receptor neurons located systems, and postdoc Rainer upstream of the mitral cells W. Friedrich, now at the Max showed no such temporal Planck Institute in Heidel- evolution. “It looks as if the berg, Germany, report that brain actively transforms certain neurons respond to an static patterns into dynamic odor through a complicated ones and in so doing, man- process that evolves over a ages to amplify the subtle brief period of time. These differences that are hard to neurons, called mitral cells perceive between static because they resemble patterns,” Laurent says. miters—the pointed hats “Music may provide a use- worn by bishops—are found ful analogy. Imagine that the by the thousands in the olfactory system is a chain of human olfactory bulb. choruses—a receptor chorus, “We’re interested in how feeding onto a mitral-cell ensembles of neurons encode chorus, and so on—and that sensory information,” each odor causes the receptor explains Laurent. “So we’re chorus to produce a chord. On February 12, NEAR Shoemaker became the first spacecraft to land on an less interested in where the Two similar odors evoke two asteroid—all the more impressive when you consider that this legless relevant neurons lie, as very similar chords, making revealed by brain mapping discrimination difficult. orbiter was never designed to land on anything. NASA’s Near Earth Asteroid studies, than in the patterns What the mitral-cell chorus Rendezvous mission, which was renamed in honor of the late Eugene of firing these neurons pro- does is to transform each Shoemaker (BS ’47), the father of planetary geology, had been in close orbit duce and in figuring out from chord it hears into a musical around the 21-mile long Eros for a year. The craft touched down at a these patterns how recogni- phrase, in such a way that the tion, or decoding, works.” difference between these gentle four miles an hour and in an orientation that allowed its solar The researchers used zebra phrases becomes greater over panels to continue to function, so jubilant scientists turned its gamma-ray fish because these animals time. In this way, odors that spectrometer back on to get a close-up analysis of Eros’s surface mineral- have comparatively few initially ‘sounded’ alike pro- ogy. In this image mosaic, taken from an orbital altitude of 200 kilometers, mitral cells and because much gressively become more easily is already known about the identified.” the arrow points to the landing site. Gene’s gotta be happy…. types of odors that are behav- In other words, when we

    ENGINEERING & SCIENCE NO . 4 detect a citrus smell in a garden, for example, the odor is first conveyed by the receptors to the mitral cells. This initial firing allows for little more than the generic detection of the citrus nature of the smell. Within a few tenths of a second, however, new mitral cells are recruited, leading the pattern of activity to change rapidly. This quickly allows us to deter- mine whether the citrus smell is actually a lemon or an orange. T HE I NS AND O UTS OF O VER - AND U NDERVOTES However, the individual tuning of the mitral cells first stimulated by the citrus odor does not become more specif- ic. Instead, the manner in In December, following ballots with hand-marked study is complete, it will which the firing patterns the contentious vote counting votes, lever machines, punch encompass presidential unfold through the lateral in the presidential election, cards, optical scanning elections going back to 1980, circuitry of the olfactory bulb Caltech and MIT decided to devices, and direct-recording and will examine a finer is ultimately responsible for join forces to develop a voting electronic devices (DREs), breakdown of the different the fine discrimination of the system that will be easy to which are similar to auto- technologies, and a break- odor. “Hence, as the system use, reliable, secure, and matic teller machines. down of residual votes into evolves, it loses information modestly priced. The project The study focuses on its two components: over- and about the class of odors, but was the brainchild of the so-called “undervotes” undervotes. A final report becomes able to convey infor- institutions’ two presidents— and “overvotes,” which are will be released in June. mation about precise iden- Caltech’s David Baltimore combined into a group of The analysis is complicated tity,” says Laurent. ■—RT and MIT’s Charles Vest—and, uncounted ballots called by the fact that voting sys- with $250,000 funding from “residual votes.” These tems vary from county to the Carnegie Corporation, include ballots with votes county and across time. faculty from both campuses for more than one candidate, When a system is switched, began collecting data and with no vote, or that are say from lever machines to studying the range of voting marked in a way that is DREs, the number of residual methods across the nation. uncountable. votes can go up due to voter Early in February, the Cal- Careful statistical analysis unfamiliarity with the new tech/MIT Voting Technology shows that there are system- technology. Project submitted a prelimi- atic differences across tech- “We don’t want to give nary report to the task force nologies, and that paper the impression that electronic studying the election in ballots, optical scanning systems are necessarily Florida. Their nationwide devices, and lever machines inaccurate, but there is much study of voting machines have significantly lower room for improvement,” said offers further evidence residual voting rates than Thomas Palfrey, Caltech supporting the task force’s punch-card systems and professor of economics and call to replace punch card DREs. Overall, the residual political science. voting in Florida. The voting rate for the first three “Electronic voting technol- statistical analysis also systems averages about 2 ogy is in its infancy and uncovered a more surprising percent, and for the last two seems the most likely one finding: electronic voting, as systems averages about 3 to benefit significantly from currently implemented, has percent. new innovations and in- performed less well than was This study is the most creased voter familiarity,” widely believed. extensive analysis ever of the states the 13-page report. The report examines the effects of voting technology Other Caltech members effect of voting technologies on under- and overvotes. of the Voting Technology on unmarked and/or spoiled The study covers the entire Project are Michael Alvarez, ballots. Researchers from country for all presidential associate professor of political both universities are elections since 1988, and science, and Jehoshua Bruck, collaboratively studying five examines variations at the professor of computation and voting technologies: paper county level. When the neural systems and electrical

4 ENGINEERING & SCIENCE NO . 4     T HE J UPITER E FFECT

In a study that strengthens Saturn—is no longer present ized” by impacts. “A comet the likelihood that solar sys- in the sun’s stellar vicinity in the size of Hale-Bopp, for tems like our own are still sufficient quantities to form example, would vaporize being formed, an interna- new planets. much of Earth’s oceans if it tional team of scientists has “We looked at only three hit there. The impact from a reported that three young stars, but the results could 500-kilometer object—about stars in the sun’s neighbor- indicate that it’s easier to ten times the size of Hale- hood have the raw materials make Jupiter-sized planets Bopp—could create nearly necessary for the formation than previously thought,” 100 atmospheres of rock of Jupiter-sized planets. Data said Geoffrey Blake (PhD vapor, the heat from which engineering. Participating obtained from the European ’86), professor of cosmochem- can evaporate all of Earth’s from MIT are Stephen Space Agency’s Infrared Space istry and planetary sciences oceans.” Ansolabehere, professor of Observatory (ISO) indicate and professor of chemistry at The researchers did not political science, and Nicho- for the first time that molec- Caltech and the correspond- directly detect any planets las Negroponte, chairman of ular hydrogen is present in ing author of the study, which in the study, but nonetheless the Media Lab. the debris disks around young made the cover of Nature on found that molecular hydro- Check the web at nearby stars. The results are January 3. “There are over gen was abundant in all three www.vote.caltech.edu important because experts 100 candidate debris disks disks. In the disk surround- for further information, or have long thought that within about 200 light-years ing Beta Pictoris, a Southern see www.vote.caltech.edu/ primordial hydrogen—the of the sun, and our work Hemisphere star that formed Reports/report1.pdf for the central building block of gas suggests that many of these about 20 million years ago report itself. ■—JP giants such as Jupiter and systems may still be capable approximately 60 light-years of making planets.” from Earth, the team found The abundance of Jupiter- evidence that hydrogen is sized planets is good news, present in a quantity at least though indirectly, in the one-fifth the mass of Jupiter, search for extraterrestrial life. or about four Neptune’s A gas giant such as Jupiter worth of material. The debris may not be particularly around 49 Ceti, which lies hospitable for the formation near the celestial equator in of life, but experts think the the constellation Cetus, was mere presence of such huge found to contain hydrogen in bodies in the outer reaches of a quantity at least 40 percent a solar system protects small- of the mass of Jupiter. er rocky planets like Earth Saturn’s mass is just under a from catastrophic comet and third that of Jupiter. 49 Ceti, meteor impacts. A Jupiter- which is about 10 million sized planet possesses a years old, is roughly 200 gravitational field sufficient light-years from Earth. Best to kick primordial debris into of all was a 10-million-year- the farthest reaches of the old Southern Hemisphere star solar system, as Jupiter has about 260 light-years away presumably done by sending that goes by the rather perhaps billions of comets unpoetic name HD135344. Alan Alda is Richard Feynman in QED, a new play based on Tuva or Bust! safely away from Earth into That star’s debris disk was the Oort Cloud, which lies found to contain the equiva- and other Feynman tales. Fittingly, the world premiere is at the Mark Taper beyond the orbit of Pluto. If lent of at least six Jupiter Forum, just down the Pasadena Freeway from Feynman’s old haunts. It runs comets and meteors were not masses of molecular through May 13; tickets are available at www.TaperAhmanson.com or (213) ejected by gas giants, Blake hydrogen. 628-2772. On a recent visit to campus to soak up the atmosphere, Alda said, life on Earth (and any The study also confirmed other Earth-like planets) that planetary formation is dined with president Baltimore and assorted campus luminaries. could periodically be “steril- not limited to a narrow

    ENGINEERING & SCIENCE NO . 4 “window” early in the life of a star, as previously thought. O F C ELL P HONES , M EMORY C ELLS , AND Because molecular hydrogen F LASHY N ANOCRYSTALS is quite difficult to detect from ground-based observato- ries, experts have relied on measurements of the more easily detectable carbon monoxide (CO) to model the Scientists at Caltech and “flash” memory, which gas dynamics of developing Agere Systems, formerly continues to store informa- solar systems. But because known as the Microelectron- tion even when the device is the CO tends to dissipate ics Group of Lucent Tech- turned off. This information quite rapidly early on, nologies, have developed a could include personal phone researchers assumed that the technique that could result directories in a cellular phone molecular hydrogen likewise in a new generation of reli- or the pictures captured by vanished. This presumed able nanoscale memory chips a digital camera. A typical lack of hydrogen limited the and smaller, less expensive flash-memory chip stores 16 time in which Jupiter-sized cellular phones and digital to 32 million bits of data, planets could form. However, cameras. Announced Decem- with each bit in a separate the new study, coupled with ber 13 at the International “cell.” As chip sizes decrease, recent theoretical models, Electron Devices Meeting, the cells become more diffi- shows that CO is not a the work applies to so-called cult to make leakproof, and particularly good proxy for the total gas mass surround- ing a new star. Blake said the study opens new doors to the understand- ing of planetary growth processes around sun-like stars. He and his colleagues anticipate further progress when the Space Infrared ¿O YE , CHICOS, D ONDE E STÁ EL O BSERVATORIO ? Telescope Facility (SIRTF) and the Stratospheric Obser- vatory for Infrared Astronomy (SOFIA) are launched in 2002. SIRTF, which will Los Angeles-area high Sylmar, Van Nuys, and among the high schools. have its science headquarters school students will team Harvard Westlake High A large array of this type will at Caltech, alone could detect up with Caltech researchers Schools. enable the study of ultrahigh- literally hundreds of stars that to study ultrahigh-energy The research will be energy cosmic rays through still contain enough primor- cosmic rays on their own coordinated by Professor of the detection of “showers,” dial hydrogen in their debris campuses, thanks to a recent Physics Robert McKeown. several kilometers in radius, disks to form Jupiter-sized grant from the Weingart The program will also of secondary particles the rays planets. Foundation, which donated incorporate a high school create in the Earth’s atmo- The other authors are pro- $100,000 to establish the teacher education component sphere. These are the fessor Ewine F. van Dishoeck California HIgh school coordinated by Dr. Ryoichi highest-energy particles ever and Wing-Fai Thi, the Cosmic-ray ObServatory Seki at California State observed in nature, and thus study’s lead author, both of (CHICOS) on four campuses University, Northridge. are of great current interest in the Leiden University in the in the Northridge area initial- Teachers will develop the astrophysics and particle- Netherlands; Jochen Horn ly, expanding to at least 25 curriculum materials to help physics community. Thus, and professor Eric Becklin, and possibly hundreds of sites their students participate in while establishing a state-of- both of the UCLA Depart- eventually. Three of the four this research. Caltech will the-art experimental facility, ment of Physics and As- initial schools have a high host a summer workshop this project will provide an tronomy; Anneila Sargent number of students who where physics teachers and exceptional educational (MS ’67, PhD ’77), professor are underrepresented in students can participate in experience for local high of astronomy at Caltech; the sciences, which means the construction of new school students. When a Mario van den Ancker of the the program may assist in detector stations for deploy- majority of the 25 sites are Harvard-Smithsonian Center increasing the number of ment at additional sites. operating, it is expected that for Astrophysics; and Anto- future scientists in the United The detector hardware, the project will yield signifi- nella Natta of the Astrophysi- States. The schools are the associated electronics, and cant scientific results that cal Observatory of Arcetri Sherman Oaks Continuing computer equipment will will be reported in the in Florence, Italy. ■—RT Education School, and form a networked system scientific literature. ■—JP

6 ENGINEERING & SCIENCE NO . 4     stored data can be lost. professor of applied physics several advantages over the Using an aerosol technique and materials science, and conventional lithographic developed at Caltech, silicon project director. Atwater; techniques used to make nanocrystals were sprayed Richard Flagan, the McCol- today’s flash memory cells. through a bath of high- lum Professor of Chemical Because it requires fewer temperature oxygen to create Engineering; postdoc Mark steps, it is less expensive and memory cells comprised of Brongersma; grad students the chips take less time to silicon on the inside with a Elizabeth Boer (MS ’96), Julie produce. In addition, the silicon dioxide outer shell. Casperson, and Michele aerosol approach will allow The silicon nanocrystals store Ostraat (MS ’98); and Jan de researchers to continue mak- the electrical charge, whereas Blauwe and Martin Green at ing smaller and smaller the insulating silicon dioxide Agere Systems developed a devices. The cells are also shell makes the cells leak- method to break up each cell extremely robust—one cell resistant. “As compared to into 20,000 to 40,000 small- has gone through a million conventional flash memories, er cells. Therefore, even if charge-discharge cycles with- these silicon nanocrystal several of the smaller cells out significant degradation, memories offer higher perfor- spring a leak, the vast major- whereas 10,000 cycles is con- mance, simpler fabrication ity of the charge will not be sidered satisfactory for a tra- processes, and greater promise lost and the bit of data stored ditional chip. The research for carrying memory minia- in the whole memory cell will was supported by the Nation- turization to its ultimate be retained. al Science Foundation and limit,” said Harry Atwater, The aerosol approach has NASA. ■—RT

Caltech scored first, Caltech scored last, but That Other Institute of Technology scored more often in their first ever women’s basketball matchup in front of a packed house in Braun Gym on January 5. I N S EARCH OF THE M IND ’ S E YE Final score: CIT 46, MIT 80.

A study of patients await- surgically removed. human brain are involved The problem has been ing brain surgery has shown During their extended in memory and can respond difficult to address because that humans use the same hospital stay, the patients selectively to a wide variety the techniques that yield very neurons to conjure up mental were asked to look at photos of visual stimuli as well as precise results in animals are images that they use when of famous people, pictures of stimulus features such as generally not suitable for they actually see the real animals, abstract drawings, facial expression and gender. humans, and because the object. In the November 16 and other images. While According to Koch, the study brain imaging techniques issue of Nature, UCLA neuro- they were looking at the helps settle long-standing suitable for humans are not surgeon and neuroscientist images, the researchers noted questions about the nature of very precise, Koch says. Such Itzhak Fried and Caltech the precise neurons that were human imagery. Particularly, techniques can image only neuroscientists Christof active. Then, the subjects the research sheds light on large portions of the brain, Koch, professor of computa- were instructed to close their the process at work when each containing on the order tion and neural systems, and eyes and vividly imagine the humans see things with the of one million very diverse grad student Gabriel images. Again, the research- mind’s eye. “If you try to nerve cells. “Recording the Kreiman report on results ers noted which neurons were recall how many sunflowers activity of single cells allows obtained by questioning nine active. It turns out that a there are in the Van Gogh us to investigate the neuronal patients who had been fitted subset of neurons in the hip- painting, there is something correlates of visual awareness with brain sensors. The pocampus, amygdala, ento- that goes on in your head that at a detailed level of temporal patients, all suffering from rhinal cortex, and parahippo- gives rise to this visual and spatial resolution,” says severe epilepsy uncontrolled campal gyrus would fire when image,” Koch says. “There Kreiman. The work was with drugs, were being the patient looked at the has been an ongoing debate supported by the National observed for a period of one image and also when he about whether the brain areas Institutes of Health, the to two weeks so that the or she imagined the image. involved in perception during National Science Foundation, regions of their brains The results build upon ‘vision with your eyes’ are the and the Center for Conscious- responsible for their seizures work by Fried’s group show- same ones used during visual ness Studies at the University could be identified and later ing that single neurons in the imagery.” of Arizona. ■—RT

    ENGINEERING & SCIENCE NO . 4