About the Lecture

About the LectureOne of the nation’s revered technology leaders dispenses anecdotes and wisdom on the slippery subject of engineering systems (or systems engineering). Norm Augustine just can’t get a handle on the discipline: “No one agrees on what it is, or what it does.” After years in industries like Lockheed Martin, Augustine has come up with “Norm’s Rules,” and can at least define ‘system’ as “having two or more elements that interact,” and ‘engineering’ as “creating the means for performing useful functions.” But these definitions don’t get you too far in the real world.Augustine shows a fuel control system, which some engineers might view as part of a propulsion system. In turn, aeronautical engineers might think of the entire airplane as a system, and transport engineers view aircraft as merely components in systems incorporating airports, highways, shipping lanes. Augustine continues up the ladder until “our system that started as a fuel controller…seems to have the whole universe as a system.” Like Russian Matryoshka dolls, systems can always be embedded within larger systems. Even if you try to simplify a system in terms of just a few objects with a binary, on-off interaction, things can get complex very quickly. Five elements in a system can exist in more than a million possible states. Says Augustine, “A typical earth satellite has nearly one million parts; a 747 over 5 million. How does that make you feel about flying?” Distinguishing the significant interactions and the important external influences on a system are central to designing and problem solving. And these days, engineers must include politics, public policy and economics as part of their systems. “The trick is to bound the scope of the system so it’s not too large to be analyzed and not too small to be representative.” Doing this right is “why systems engineers should be paid so much.” Augustine concludes with his “Dirty Dozen” systems engineering traps, which have led to embarrassing bust-ups, monumental failures, and real tragedies. Notable among these: “the ubiquitous interface,” (or absence thereof). He describes how two flight control groups used different metric units and accidentally sent a Mars-bound spacecraft whizzing off into deep space. There’s the “single-point failure,” exemplified by the collapse of a football field-sized satellite dish due to a poorly designed bracket. There’s software, “which like entropy, always increases:” a Mariner spacecraft headed in the wrong direction due to a missing hyphen in 100 thousand lines of code. The problem with most systems ultimately is that they “contain human elements … and humans sometimes do irrational things.”

In contrast to cardiovascular disease, few breakthrough remedies for psychiatric illness have emerged in the past half century. Edward Scolnick lays blame for this dismal situation on barriers to understanding the genetic basis behind such illnesses. But the research drought may be over, as the current revolution in human genetics opens wide a door into the molecular biology and brain physiology behind diseases like schizophrenia and bipolar disorder.These common, chronic and disabling mental illnesses are complex, involving abnormal behaviors that vary in expression. They have also lacked the kind of quantitative tests that enable precise diagnosis. While science has demonstrated that the single biggest risk factor for both schizophrenia and bipolar disorder is genetic, it has not been able to design tools for exploring how the genetics relates to the evolution of the disease in people. But just in the last two years, with the sequencing of the human genome and maps of human genetic variation, ignorance has given way to major findings.In schizophrenia and bipolar disease, researchers have discovered that gene deletions and duplications (called copy number variants) cause significant brain circuit mischief. They’ve also learned there are gene variants common to both diseases, as well as clusters of genes that malfunction. Scolnick describes diverse research at MIT, proceeding at a “breakneck pace,” that uses this genetic information “to delve into the malfunctioning of brain circuits.” Scientists have applied functional magnetic resonance imaging to compare the brains of ordinary people and schizophrenia patients, and discovered that the schizophrenic’s brain in a resting state is hyperactive. Other researchers found that schizophrenics generate the gamma brainwaves involved with higher mental activities in a different manner than control subjects.Another MIT lab has begun to manipulate specific brain circuits using optical technology -- shining different wavelengths of light at special interneurons that regulate the firing of other neurons, and which are postulated to have a critical role in the malfunctioning of schizophrenics’ brains. Two other MIT labs are examining the biochemical disruptions due to altered genes, and developing “safe, specific chemical inhibitors” that might yield potential treatments for schizophrenia and bipolar illnesses. In Japan, researchers are growing stem cells into brain cells, which may lead to precise experiments that relate genetic problems to malfunctions in brain wiring. Indeed, adding up this research, a central biochemical pathway central to the pathogenesis of psychogenic illness seems to be emerging, knowledge that “can be exploited to understand illness and to find drug treatments.”

Researchers are well along in designing a highly efficient, inexpensive solar cell, but the big barrier to the dissemination of solar power in society remains the problem of installation, says Marc Baldo.As an engineer, Baldo expresses confidence that “we’re going to mow down” the problem of producing a great solar cell and making it cheap. His own lab has developed a unique approach that’s found enthusiastic support from the federal government and others. Unlike conventional solar cells that use a single material such as silicon to perform both functions of absorbing light and converting it into electricity, Baldo’s cell “separates the functions and optimizes both.” His solar concentrator utilizes inexpensive material like glass or plastic onto which a thin film of dye has been painted. Sunlight strikes this surface, and the dye, which can be “tuned” or colored to trap specific wavelengths of light, emits light back to solar cells along the edge of the plate. There are enormous advantages derived from this design: The glass or plastic (considerably cheaper than silicon) catches diffuse light, so there’s no need to track the sun, and it concentrates the sunlight much more efficiently than conventional solar cells. But solar concentrators alone don’t signal the start of a new solar age. Baldo addresses the considerable uncertainty around the broad deployment of solar power. Installation costs for single homes appear formidably high, perhaps 2/3rd the cost of the entire system. Colossal solar fields that might replace fossil fuel burning plants must ship their energy across vast distances, losing electricity along the way. And right now the national power grid isn’t set up to handle the fluctuations in energy that large-scale intermittent energy sources such as solar or wind present. Clouds are a “big pain” for grid operators, says Baldo.He believes the best start for solar will be in commercial and industrial installations such as the rooftops of factories, supermarkets or warehouses, sites where there’s no loss moving power around, and where managers are already seeking ways to save on lighting and refrigeration, including smart electronics. His cost-effective concentrators could find their way to such installations in several years.In addition to solar concentrators, Baldo is researching biological models for making solar cells more efficient: He just received a $19 million grant from the U.S. Department of Energy to study exciton circuitry in plants -- how plants capture light in packets of energy and direct the energy to where it’s needed. Says Baldo, “This exciton is the last, great unexplored territory in solar cells.”