Robert L. Jaffe: Bringing scientific truths into public discourse

MIT Professor Robert L. Jaffe turned his attention to energy in 2005—after decades spent researching theoretical particle physics—because he saw the need to shine “the clear bright light of knowledge” on energy policy.

“I couldn’t stand the level of ignorance that characterizes the public debate about issues of energy,” says Jaffe, the Otto (1939) and Jane Morningstar Professor of Physics. “I think listening to talk of the ‘hydrogen economy’ pushed me over the edge.”

Proponents of the “hydrogen economy” posit the replacement of carbon-based fuels with hydrogen fuel extracted from molecules like water—but usually they ignore the energy necessary to break hydrogen free from its source, thus violating the first law of thermodynamics, which states that energy cannot be created or destroyed.

To ensure that MIT graduates are equipped to dispel this and other misconceptions, Jaffe teamed up with fellow physics professor Washington Taylor to start a new MIT subject, 8.21 Physics of Energy. The class centers on the fundamental physical principles underlying energy processes and introduces their practical application.

First offered in 2008, the subject is now part of the core curriculum of the Energy Studies Minor supported by the MIT Energy Initiative (MITEI). But in launching the class, Jaffe says he and Taylor had to start from scratch. “There are essentially no courses like ours—a survey at a scientifically literate level that gives people the operational skills to deal with the science of energy,” he says.

Jaffe and Taylor have since begun to compile their course notes into a textbook, Physics of Energy, hoping to catalyze the development of similar subjects at other universities. “We wanted a book from which a course like ours can be taught,” says Jaffe, noting that the book is forthcoming from Cambridge University Press.

Teaching is of central importance to Jaffe, who credits several of his own teachers with setting him on the road to a career in the sciences. At high school in Connecticut, he was first inspired by an excellent chemistry teacher. And later, at Princeton University, one of his freshman professors steered him into physics—the profession he would ultimately pursue.

Jaffe, who served as director of the Center for Theoretical Physics from 1998 to 2004, might even have become an experimental physicist had it not been for one frightening night the summer following his sophomore year.

It was 4 in the morning, and he was working as the sole operator of Princeton University’s cyclotron (an old-fashioned particle accelerator) when suddenly every alarm in the place went off. A hose had popped out and flooded the entire system, destroying $20,000 worth of equipment. “I was completely traumatized and never did another experiment in my life,” Jaffe says.

Instead, Jaffe spent decades engrossed in theoretical particle physics, specifically the quark substructure of matter. In the early 1970s, he and MIT colleagues formulated the first consistent description of quark confinement, the “MIT Bag Model.” In the 1990s and 2000s, Jaffe helped develop the modern understanding of Casimir forces, quantum forces that can affect the performance of micromechanical systems such as those central to smart phones.

He also taught, founding two MIT classes—Modern Physics and Quantum Mechanics III—and ultimately received MIT’s highest award for undergraduate teaching, the MacVicar Faculty Fellowship, in 1998. “I have always loved teaching,” Jaffe says. “I find the personal interaction satisfying, and it was a natural outlet for my interest in bringing an understanding of science to the public.”

Jaffe traces his interest in policy to his college days in the 1960s. He delivered the valedictory address at Princeton in 1968—within days of the assassination of Sen. Robert F. Kennedy and a few months following that of the Rev. Martin Luther King Jr. The subject of his speech, unorthodox at the time, was student activism.

Later, while attending graduate school at Stanford University, he founded the Stanford Workshops on Political and Social Issues, a series of classes designed both to teach scientific topics and to put research into useful action. SWOPSI, as it was called, lasted for over 20 years and spawned early efforts to address air pollution in California and to stop redwood logging.

“I’ve always been concerned about social and policy questions—especially as impacted by science,” he says. “I’m convinced scientists owe society a responsibility to use their insights into fundamental issues to try to clarify the discussion.”

Jaffe’s commitment to providing “a clear, plain, factual playing field for analysis” is ultimately what led him to launch the Physics of Energy course and—in a surprising extension—to investigate the use of rare and unusual chemical elements in energy-related applications.

“I realized many of the [energy] technologies I taught about were dependent on elements I only knew vaguely about,” says Jaffe, who went on to co-chair an April 2010 symposium resulting in the MITEI report Critical Elements for New Energy Technologies and to lead work on a February 2011 report for the American Physical Society’s Panel on Public Affairs (POPA): Energy Critical Elements: Securing Materials for Emerging Technologies.

For example, the classic photovoltaic cells used to convert solar energy into electricity employ silicon, one of the most common elements on Earth, but the leading candidate for newly developed “thin film” photovoltaics uses tellurium, which is rarer than gold.

The POPA report found that it would take 200 metric tons of tellurium to produce 500 megawatts of electric power—roughly the amount generated by a modest US coal plant. “Imagine that much gold,” Jaffe says. “How can that possibly be a reasonable economic goal?”

Other examples from the report include the use of neodymium to make powerful magnets for wind turbines and the addition of rhenium to toughen the steel in high-performance gas turbines. Neodymium is not particularly rare but has nevertheless become increasingly costly and difficult to obtain. Rhenium, however, is so rare that only 50 metric tons is produced globally each year.

“We have to look for earth-abundant materials that solve our energy problems,” says Jaffe, who has now turned his attention to helping MITEI formulate its upcoming Future of Solar Energy report, which is intended to lay out how solar energy might be deployed at a large scale.

“Energy technologies aren’t just little gizmos. These are very large systems. They require long-term investment and need to capitalize on economies of scale,” Jaffe says. Noting that the United States—which currently meets just 1% of its energy needs with solar power—would need to cover about 15,000 square kilometers with solar panels to meet all its electricity requirements, he adds: “It’s not impossible, but it’s a daunting task. What are the barriers to scaling [solar energy] up? How do you deal with the fact that it’s intermittent?”

Fortunately, Jaffe does not have to consider these questions alone. “MIT is like having another Internet at my disposal. The expertise here on subjects related to [energy] is phenomenal,” he says. “One of the things that makes it all hang together is MITEI, a wonderful clearinghouse that brings people together formally and informally.”

Jaffe says, “It’s easy to fantasize about solutions to the world’s energy needs if you don’t worry too much about the laws of nature and the limitations on the other resources Earth provides. The hard part is to find new technologies— from the smallest batteries to the largest solar array—that can work in practice and can be scaled up to the level where they can change the world. Good science has to be integrated into the discovery process from the beginning…. I do believe there are facts in the world and that facts matter.”

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