Interview with Dudley Herschbach
Emeritus Member of the Creativity Foundation Junto
Junto* member spotlight: Dudley Herschbach
(*The Creativity Foundation’s Junto, the board of the foundation, is modeled on the group Benjamin Franklin gathered and named the Junto, from the Latin “to join.” Ben Franklin’s Junto acted as a forum for founding institutions, for writing and publishing critical pamphlets, and for exploring creative ideas not aligned with or encumbered by religious, political or royal affiliations.)
Although Creativity Junto member Dudley Herschbach is now officially retired, and an Emeritus Professor at Harvard, I found out in a recent phone conversation that he is still fully occupied. Not only is he doing research on both theoretical and experimental questions in chemistry, but he is also attempting to solve a mystery related to Benjamin Franklin!
Dudley Herschbach’s curiosity and enthusiasm are infectious. He is also the master of clear, simple metaphors that make science accessible to anyone. Even though he is a Nobel Prize winner in chemistry, and a professor at Harvard, he’s totally unpretentious. I’ve been with Dudley when he’s introduced himself simply as “a teacher.” He considers teaching to be the highest calling; the class he enjoyed teaching the most at Harvard was his Freshman seminar.
Q: What are you doing, now that you are retired?
A: As you know, Ben Franklin has been a hobby of mine for decades. I have a Franklin research project now, having to do with a painting of Franklin made in 1777, shortly after he arrived in France, to raise money for the American Revolution. When I saw it, there was something odd about it. If you flip it 180 degrees, it looks just like the Mona Lisa! It’s incredible! Using power point to map the two paintings, it’s almost a perfect match. So I want to know: did the painter do this as a standard pose? Or was it a joke of Ben Franklin’s? In his autobiography, Franklin said he was annoyed at having to sit for all these portraits. I’ve written to the editor of the Franklin papers, to find out what they know.
Q: Are you still doing scientific research?
A: Oh yes. My most recent work is on the subject of entanglement. It’s a fashionable word these days, and goes back to an Einstein paper objecting to the basic properties of quantum mechanics. According to quantum mechanics, you can only predict probabilities at an atomic scale and lower. Einstein did a thought experiment: Suppose you had a pair of atoms, associated in a certain way, and you separated them, then allowed them to travel far apart, without bumping into anything on the way. If you measured the value of a particular property in one atom, according to quantum physics, you would know the value that property had in the other atom, too. It seems bizarre, since you’d expect that once widely separated, the atoms would forget the correlation. Einstein complained that quantum mechanics implied “spooky action at a distance!”
A postdoc of mine who’s now at Purdue recruited me to work on a paper with him about entanglement, making some predictions for quantum computing. I hadn’t messed with entanglement before, but I knew about the molecules they were looking at. It turns out entanglement is not mystical at all. In doing the calculations, you get used to it.
In a sequel, we treated molecules that spin like symmetric tops. These symmetrical molecules precess when they rotate, unlike diatomic molecules resembling little barbells that tumble when they rotate. The symmetric tops offer interesting properties for quantum computing. Both papers have appeared in the Journal of Chemical Physics. They are entirely theoretical; it was a satisfying challenge to demystify entanglement. Nobody had paid any attention to the advantage of using symmetric top molecules for quantum computing. Lots of people are interested now. (Dudley laughs.) You can say I’ve been engaged in child’s play – toying with spinning tops!
In the Fall, I also visit Texas A&M University one week each month.
Q: What are you doing there?
A: I’m cheerleading an experiment that required building a simple table top apparatus that chemists can use to create molecular beams. We want to slow the molecule down so much that they act like waves, not particles. To do this at room temperature, we’re letting the molecules do the work, using a high speed hollow rotor with a pinhole in it. It works somewhat like a Filene’s Basement sale. Inside the rotor, the molecules are like a a big crowd of customers. When the door opens, the molecules, just like people, rush in and collisions organize the flow, bringing them to about the same velocity and direction. In fact, the molecules emerge with the speed of rifle bullets, but we spin the rotor in the opposite direction so fast that the net velocity of the molecules in the lab becomes very small.
Experiments of this kind are pretty challenging. But it’s a fine project for grad students and postdocs, and I’m enjoying keeping in touch with them by email.
Q: Your work is certainly varied.
A: Yes, the theoretical work gets a bit mathematical, whereas the experimental parts include a lot of wiring and plumbing. Years ago, my first grad student remarked: “Dudley, you are a queer duck. The theorists think that you are an experimentalist and the experimentalists think that you are a theorist!”
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Before we hung up, Dudley mentioned two more things:
he’s just finished serving on a National Academy committee to provide new national standards for K-12 science teaching.
he’s also scheduled to give a talk in April about the Ig Nobel Prizes, given annually at Harvard, with the aim “First you make them laugh, and then you make them think. ” His talk, titled “Silly Serious Science,” will include Benjamin Franklin’s proposed study of flatulence, and his own speculation about the mysterious Mona Lisa-like portrait of Franklin.
DUDLEY HERSCHBACH, Emeritus member of the Creativity Foundation Junto, joined Harvard as a Professor of Chemistry in 1963 and won the Nobel Prize in Chemistry in 1986. The major path of his research developed experiments and theory to elucidate molecular dynamics of reaction dynamics in single collisions. That work, considered "lunatic fringe" at its inception, opened up a wide frontier. For descriptions of his other research, teaching and further activities, see his website, https://faculty.chemistry.harvard.edu/dudley-herschbach. The site includes items from a Festschrift published in Molecular Physics, 2012. Emeritus at Harvard since 2003, he is now enjoying a"perpetual sabbatical." His current research includes strategies for quantum computation; transformations of electronic structure induced by superintense laser fields; and generic properties of phase transitions in molecular fluids. He also continues to give, in visits to schools and other public venues, evangelical talks about science and science education. One of his perpetual passions is the study of the life and work of Benjamin Franklin.