Interviewers are interns at The Kavli Foundation (http://www.kavlifoundation.
Editors’ Note: The following is based on excerpts from an interview Caltech Professor Nate Lewis (NL) conducted in Caltetch’s Millikan Library on August 16, 2011.
Nate Lewis is the George L. Argyros Professor of Chemistry at the California Institute of Technology. Dr. Lewis obtained his BS and MS degrees at Caltech under Harry Gray in 1977 and his PhD in chemistry from MIT in 1981. He was on the faculty at Stanford before returning as a professor to Caltech, where his current research interests include artificial photosynthesis and electronic noses.
Dr. Lewis is the Principal Investigator of the Joint Center for Artificial Photosynthesis at Caltech and was recently named Director of the U.S. Department of Energy’s Energy Innovation Hub, which develops revolutionary methods for generating fuels directly from sunlight. He has been an Alfred P. Sloan Fellow, a Camille and Henry Dreyfus Teacher-Scholar, and a Presidential Young Investigator. Among his many honors and awards are the Fresenius Award, the American Chemical Society Award in Pure Chemistry, the Orton Memorial Lecture Award, the Princeton Environmental Award, and the Michael Faraday Medal of the Royal Society of Electrochemistry. Dr. Lewis has published over 300 papers and is currently the Editor-in-Chief of the Royal Society of Chemistry’s journal Energy & Environmental Science. In 2010 Rolling Stone magazine named him #17 on their “Top 100 Agents of Change” list.
Where did you grow up? Did your family or childhood influence you towards a science career?
NL: I grew up near the LA airport, 30 miles from Caltech. My brother is 25 miles away and my sister is 25 miles away. So I’m actually “home,” which is pretty unusual for a scientist.
As far as I can tell, I’m the first scientist in my family. I definitely didn’t get pushed that way. In fact, I was always going to be the “wrong kind” of doctor! My mom always wanted me to be a medical doctor, not a doctor of philosophy: “What are you going to do with a career as a chemist, are you going to mix prescriptions at CVS? What do chemists do? You need to be a real doctor!”
Did you always want to be a scientist?
NL: I didn’t even know what scientists did when I was in high school. I wanted to be an engineer. I thought that building bridges would be cool.
And I had absolutely no idea what a chemist did. I kind of did think they worked at pharmacies wearing white lab coats, mixing beakers together and cooking and boiling and exploding stuff. Math and physics—that was science as far as I knew in high school, because you got answers.
So I thought that’s what scientists did: they either solved equations, or developed formulas, or figured out numbers. Well, actually that is pretty much what we do! Except that there is a lot more excitement and creativity involved in it than what you get in high school, when you’re studying stuff that everybody already knows as opposed to stuff that people don’t know.
Why did you choose to study chemistry in college?
NL: Three things. First was, well, Caltech is hard. It’s not a piece of cake. Although I, like most Caltech undergrads, got all As and was either valedictorian or salutatorian of my big high school, not everybody’s all equal here and you can’t all get As. So after the first quarter, as I was flunking math and flunking physics, but I was passing chemistry. So I decided, okay, I should do that! I figured it all out eventually, and in my second year I got good grades. But it took me a while to catch up and get the hang of it.
Second, I had a really fabulous freshman chemistry professor, who has inspired hundreds if not thousands of people to go into chemistry: Harry Gray. He’s my colleague now. So there’s the fact that I was only passing his class, plus it was fun.
Third, when I was doing my lab, one of Harry’s graduate students happened to be my TA and told me I was good at this and wanted to know if I would help them work a lab. I got hooked. I was in labs where I figured out what chemists do wasn’t beakers and lab coats and pouring chemicals all day long. I made a compound my first year as a freshman! I made a rhodium isocyanide complex. It was pretty neat because when I made that, I was the only person in the world with that compound in my hand. I walked out and was thinking, “This is mine! No one has ever made this before!” And it turned out it did something useful—but we didn’t know that. We were just making new stuff.
How did you balance your academic and social life in college?
NL: That was easy. Academics: 95–99%. Social life: 3%. You have to remember that when I was here, in 1973–1977, there were 800 undergraduates, of which about 30 were girls. Do you know what happens in chemistry when you dissolve a sodium ion in water, you have lots of waters around it? That’s about a good chemical model for every girl at Caltech! Lots of glommed-on guys moving around everywhere they went. I actually ended up halfway normal despite that, but got a great education and a really good start on science and engineering.
What kinds of environments do chemistry departments, like Caltech, foster in your estimation? Is there competition, collaboration, both?
NL: At Caltech we have a competitive but collaborative environment. I actually do that on purpose as a professor. I have two types of questions that I give out as homeworks: first are ones you’re supposed to do yourself; the others have “no ground rules,” which means they are not designed to be done by yourself so you can talk to everybody and we expect that you will collaborate. We have them both because both are important skills. You can’t know it all. You’ve got to work with other people who are better at certain things than you are to get to a shared goal. But certain things you better know or else you won’t get to square one.
What would you say professional chemists do exactly?
NL: What chemists do is make new things to enable us, as humans, to do new things. Physicists figure out how the world works. Chemists make new things to make the world work differently. We are the ones that make the puzzle pieces. Physicists figure out the rules by which they get connected. But if chemists don’t like a shape, we can make a new puzzle piece.
We make new drugs, we make plastics, we make the clothes you wear, we make the rubber spring-back stuff in your tennis shoes. We make catalysts that catalyze reactions that make our petrochemicals, that make our fossil fuels into gasoline, that make our plastic bottles clear and malleable and thin and not brittle and hard. We make—maybe, if we’re good and smart—artificial leaves like nature figured out how to do; but we make them better, cheaper, faster. Chemists make all this stuff.We make bad stuff too: we make explosives and bombs and terrorist chemicals. Everybody has bad and good.
What motivates you to practice chemistry?
If you talk to my research group—my team of undergraduates, graduate students, and postdocs—we really are a team. We have fun, we go windsurfing, we go camping. Every one of them also feels they are doing this because it’s what they are supposed to do with their lives. If you ask them, they’ll tell you, “We’re trying to save the world.” Period. I don’t want people in my group who think they’re doing it because it’s like school and they’ve got to do it because it’s a processing institution: they get out, they get their PhD, they get a job. They should be doing it because, just like me, I am on this earth for a reason. My reason here is to figure out, one way or another, how to do something good. Now, you can do that as a medical doctor (you can save people), you can do it as an engineer (you can protect people from an earthquake), or you can do it as a chemist. In fact, I argue that if we don’t do this, then we aren’t doing what we’re supposed to be doing.
I had no clue when I was seventeen that chemistry and my career as a scientist would lead me to a path where I would feel such social responsibility and empowerment. You’re working on a drug to cure a disease, or a material to make the world better, or working on how to make clean renewable energy affordable. That’s what we do. It’s not like solving equations and bookwork just to get the answer.
What kinds of mathematics are used/deployed in your field?
NL: Science is rooted in facts. You can’t just wishy-wash over that. I haven’t solved a differential equation in ten or fifteen years in terms of my science, but I still have numerical-based results. I think science isn’t math-based, it’s really fact- and reasoning-based.
Science is much more like being a lawyer than it is like being a mathematician. At some level, it’s like CSI! You’ve got facts, and you’ve got puzzles, and you have to do reasoning, and you have to then try to prove or disprove your hypothesis. You get hunches that you follow, and maybe they’re dead ends—but maybe you test them out and that’s the real culprit! So it’s like finding the culprit in the CSI television show, where it’s fact-based and logic- and reasoning-based. That’s the hallmark of science. It’s testing your theory, your hypothesis, challenging it, trying to disprove it by all the ways possible you can you think of. So if people are good at that and like to do that, then they will have fun and be really good scientists. They just have to get through the core level of math in order to understand enough about statistics and what the numbers mean to make the case. That’s all the math is. But if you can’t add or do arithmetic, then it’ll be pretty hard to be a scientist!
So would that be your definition of “science”?
NL: Yes, I think I gave you my definition of science: the reasoning- and fact-based challenging of a hypothesis to decide, based on the outcomes, something new about the world. Now, that could include social science—I mean it does. I just heard about one social-science study, for instance, asking whether or not we are spending our money more effectively by rebuilding schools in Afghanistan or by giving commanders hundred-dollar bills to go out and just keep all of the locals happy by giving them money. That is a hypothesis that can be tested. What is the best way to bring calm and peace cost-effectively with limited resources in a social setting where there is unrest and upheaval and other dynamics? Is it better to just bribe the locals or build them a school? That’s science! That’s social science. Because you have hypotheses, you look at facts, you may not get the same numerical-based facts that you would get if trying to solve the sequence of everybody’s DNA involved because those are numbers and letters and data and molecules. But it’s reasoning- and fact-based deduction and analysis. That’s science.
A lawyer would be a scientist if their job were to always find the truth. But their job isn’t to find the truth; their job is to win the case. So you have one side whose job it is to do whatever is needed to prosecute, and the other side does whatever is needed to defend, to win. In fact the rule is: don’t figure out what the actual answer is. That’s not what they’re supposed to do. If both sides agreed that our job is to find out the answer—did they do it or not?—that would be science. But that’s not their job. It’s almost like talk radio. The job of the talk radio people is not to find or discuss or come to a consensus on the answer. It’s just to get more and more people to listen to their show, so they take as polarized a view they can to get people to listen on both sides.
In addition to your commitments to alternative-energy science and inventing things like artificial leaves, you have another fascinating invention: the electronic nose. Can you explain this device and how you got your idea for it?
NL: I was at the beach one day and I was a little bored with what I doing in science at the time. There was this dog playing Frisbee with its owner and I asked myself: “How does that dog know who its owner is? How can that dog find me when he’s never met me before?” My wife opined that I was crazy when I told here I was going to invent an electronic version of a dog’s nose. But I did!
I had no idea how a nose worked. I had no idea it was a lot of math and matrix algebra that I had to remember from 20 years ago as an undergraduate. We invented the materials and the idea of doing this, and we built them and then put the devices on robots. Then we asked questions: How do animals hunt? Why do wolves hunt in packs? You can watch how long it takes them to find food. If you’ve got robo-wolves, two of them actually find the food a lot more quickly than one of them because they talk to each other. They explore different parts of this room and when one picks up a scent, it beacons to the others, “Come over here! I’ve got it!” And the others say, “Yup, you’re right” or “No, you’re wrong.”
So I’m a chemist, but I have projects and videos of robots running around like wolves!
Are there other kinds of uses for an electronic nose?
We are working on how to use them for detecting terrorist weapons. I have visits by GIs and school children who have lost limbs in Cambodia and Thailand. Twenty thousand people are injured or killed every year, mostly school children walking home, when they hit a land mine. The only way to find them now is you either poke a stick every square inch until you blow yourself up or clear the space of mines—or you get Fido, you get a dog. Well, if we could build something that does what a dog does 24 hours a day/7 days a week, we can save a lot of lives. We are still working in that general area because detection of explosives is very difficult. You have to be very sensitive to detect the parts per quadrillion of explosive in the vapor phase.
In the presence of lots of clutter, we’ve also trying to smell patients’ breath for diseases like tuberculosis and lung cancer. Dogs can smell these things. Linus Pauling ran gas-chromatography experiments in the 60s trying to show there must be signatures in human breath. What if you had a little gizmo you could breathe into that tells you you have tuberculosis or you have lung cancer or you have something else? Star Trek did this. But chemists have to figure out how to do this in reality, not just in science fiction.
We’re learning that women are having a much stronger presence in the sciences today, particularly in the biological and brain sciences. What is your impression of women’s status in science today is?
NL: Let me make a declaration: I’m married to one! I’m definitely a skewed member of the set. I voted with my feet, so obviously I have a lot of respect for women scientists. When I was in graduate school in my group of 25 graduate students at the time at MIT, there were two women: one was a nun, the other one I met and married. So I guess I won the lottery there! My wife, Carol, is currently at Caltech’s Jet Propulsion Lab. Her last flight project for NASA was to successfully deploy and build a little invention that went on the space shuttle and international space station—it was called an electronic nose and happened to be developed and invented by her husband!
Women do tend to go more into the biochemical and organic chemistry fields; we see somewhat less of them in physical and inorganic statistically. I will do everything I know how to do to change that. But you’ve got to take the cards you’re dealt too. I can’t make the pool different than what the pool is. We know all of the social reasons. There are changes in junior high to high school: statistically girls are better than boys in math during the early stages, and then all of these other factors kick in. There are well-documented social pressures and fears and other things—lack of confidence or all that other stuff that you hope goes away. But there’s absolutely zero reason why it should be this statistically skewed.
Do you think “analytical” and “creative” modes of thinking are mutually exclusive within the practice and progress of science? Would you suggest college students who are pursuing science tracks try to balance their coursework between the sciences and courses in other fields, like foreign languages or the creative arts?
NL: Science is really equal parts inspiration, motivation, and perspiration. You have to be curious and be especially interested in the outcome. But that is, in fact, part of human nature. You have to ask the right questions so that the answers are meaningful and impactful. And then you have to do the work—sometimes tedious, sometimes analytical, sometimes creative, sometimes repetitive, and sometimes exhilarating—in order to find the answer and then challenge it from all angles possible to ensure that it is bulletproof and definitive, as opposed to ambiguous. Only in this way can we learn and build upon our previous knowledge and move forward, continuing the discovery process that underpins the scientific enterprise.
Balance is always helpful. There is no problem with doing that, as long, of course, as the student has the technical background and depth of knowledge to be able to handle advanced study in science and engineering, which involves as much of the core sciences as it does the foreign languages or arts and humanities.
We know great thinkers sometimes report making their discoveries, receiving their inspiration, or arriving at their pivotal “aha” moments during times of idleness, times of actually not working directly on their projects, sometimes even in their dreams. This seems, at first blush, paradoxical to solving problems. Have you heard of scientists, artists, or others speak of this phenomenon? Have you ever had this kind of experience in your work?
NL: Yes, of course, there are “aha” moments when you’re not working directly on the project when you get the inspiration or idea or way to solve the problem. But these build on all of the contact hours with the real world, and with the experiments, and with the systems and the data in laboratory. They get assimilated in a nonlinear creative way, which only humans and not computers can do. Otherwise we could just program science, and there’d be nothing left for scientists to do except run a big computer program!
Accounts of “aha” moments are all over science. I got the inspiration to develop my electronic nose at a conference when I took off the afternoon and, instead of going to talks, I went to the beach where I saw that dog playing Frisbee with its owner. We have group retreats every year where we go away from lab and brainstorm about what good ideas we should be working on next—sometimes from a clean slate, other times taking a fresh look at our problems and trying to solve them. This is a critically important part of science and of the creative as well as analytical processes that are involved in the balancing act between just doing something new and doing something new and important.
Are there any movies or television shows about science or scientist characters that you particularly enjoy or particularly do not enjoy?
NL: Characterizations of scientists on TV shows and movies are not true representations of the human nature or personalities of scientists who I interact with and know. We are professional people, like doctors or lawyers or dentists or CEOs, who also happen to have a job that we would never trade for anything else; that allows us to interact with continually renewing generations of young, smart, talented students and postdocs; that allows us to explore our curiosity and answer questions; that allows us to feel like we are contributing in a positive way to the scientific enterprise and humanity every day.
Almost no one is a quote “mad scientist”! I’m not frustrated by that characterization particularly, but it’s completely out of touch with how scientists actually approach their job/hobby/fashion. It’s a great job all in all. And most scientists wouldn’t trade it for anything.
If you weren’t a practicing scientist, what could you see yourself doing?
NL: I would do a lot of different, interesting things. There are opportunities to be CEOs of high-tech companies, to be involved in Washington in science or technology policies, to be involved in national security. There are so many scientific and technical details nowadays behind all these treaties we either do or do not sign. There’s a lot of science and technology involved in diplomacy, in security, in homeland security, in counter-terrorism, in climate change.
So I could be a science-policy person. It’s good to have people who know what the science and technology is behind the policy. They don’t always win the day in Washington. But it’s good to have people knowledgeable and informed, as opposed to ones who aren’t, in any system.
Can you name one scientist in history, or working today, that you greatly admire or are influenced by, and one non-scientist?
NL: It’s not even really fair to answer because there are all sorts of scientists I don’t know personally but have heard of. And I happen to be on a campus where of my twenty chemistry colleagues, three of them are Nobel Prize winners. But I really admire our current U.S. Secretary of Energy and Nobel Prize Laureate Steven Chu—that’s a great combination of things to be! George Pimentel was a fabulous educator and led an influential lab at Lawrence Berkeley Lab. Melvin Calvin, Linus Pauling, Burton Richter, Richard Feynman—I’m not going to pick one of them!
What about a non-scientist you might admire or have been influenced by in some way?
NL: I don’t know about “influenced by,” but I definitely have some people I admire. I met a president or two. But I try to be non-political and non-partisan. If I tell you one person, everyone says, “Oh, that means he’s blue!” or “He’s red!” But I really am inspired by a particular president I met. It was a past president—just very smart, thinks in many dimensions all at once, yet it seems like you’re the only one in the room he’s talking to when there are 200 people there at the same time. Just a tremendous combination of skills. It was great. But I’m not going to tell you which one!
Why do you think it’s important for younger people to be engaging in science right now, even if they’re not going to pursue a career in it?
NL: Because, first, you have to know how to vote. When I give my energy talk, I end by saying, “This isn’t our problem; this is your problem.” Because it’s your generation that has to decide whether or not it’s going to do something. The best scientific knowledge says the lifetime of CO2 in the air, if you stopped in 2050, will take 500 years to come back to three-quarters of where it is now and 10,000 years to go the rest of the way. So you and 25 generations of your kids, grand kids, great–grand kids are never going to see the planet we see today.
So it’s your problem to vote on and help decide the solution and implement it. It’s up to chemists to figure out how to build the materials to make better windmills, how to build things that use CO2 in a carbon neutral way that’s cheap and affordable. Technology got us into this mess and it’s the only way to get us out of it. I can help, and I will help everyday that I get a chance to lead people to help find the answers.
So you should definitely know enough about the science to know intelligently what to do. Now, I didn’t tell you whether or not you should vote to continue to do what we’re doing now. There are technical analyses and scientific information that need to be, just like in a court of law, brought forth. Then people have to vote at their ballot box to either do something or not and then let the planet react to what we do. That’s a pretty good reason why you should figure out something about science, right?!
