Return to the audio for How to Science Episode 6, with scientist Tim McKay.
Monica Dus: Today with us on the podcast is our first non-biologist, Professor Tim McKay, who’s a professor of physics, astronomy, and education at the University of Michigan and also the director of the Digital Innovation Greenhouse. We’re really excited to have you, and thanks for coming here today.
TM: Thanks; it’s a pleasure to be here.
I was able to come here as a pretty traditional assistant professor. I had a research program in observational cosmology, which I was very focused on, working launching on a big, new project called the Sloan Digital Sky Survey. I came, I set up a lab, I hired graduate students and undergraduates to come work with me, and really focused a lot on my research in the very beginning of my career, with a sense that my research was this one narrow thing that I was after, and I was going to stay after that thing.
Since then–I’ve been here more than 20 years–and since then, I have seen both my research shift directions, and change in its nature, and I’ve had the opportunity to engage in activities that aren’t just scientific research, but are also teaching activities, and even going a little beyond teaching into administering a university–helping it to run. So I now think of myself maybe as much as a professor as I do as a scientist. Being a professor carries a whole set of tasks that many scientists don’t engage in.
How about we start with you the scientist? How did you get to become an astrophysicist?
TM: I came from a family that wasn’t very familiar with higher education. I’m a first-generation college student. My brother and I were the first people in our family to go to college. I went to college because the people in my family knew you should go to college.
Just to give a little bit of family background: My grandparents all came to the city of Detroit in the 1930s when the auto industry was exploding, because they saw for themselves a great prospect to be employed in an exciting new industry. They helped to found the United Auto Workers Union; my grandparents were in that generation. My parents were in kind of an intermediate generation, where my father didn’t go to college, but he worked for the A&P grocery store chain, starting out as a bag boy and working his way up to Vice President. A very American story, but without any formal education along the way.
And for us–they had reached the stage where it was clear that we should go to college. Why? Not so clear what we would turn into–who knew–but college was part of the pathway.
So at any rate, when it was time for me to go to college, a piece of very good fortune happened to me. Temple University, which is in Philadelphia, had a program at the time where they would go to each local high school and offer the high school a scholarship. The high school got to pick who would get this scholarship. I was not by any means the best student in my high school, but I took a lot of honors classes. So this scholarship came to my high school, and they started offering it to the top student in the class, and the second student in the class, and the third student in the class. Nobody wanted it. The top students in my high school were all planning to go to private universities, places like that. Even a scholarship was not enough to make them want to go to Temple.
But it got to me, and I was like, “Oh, sure. I mean, if you give me a scholarship I’ll go to school there.” So I ended up going to Temple University, which is a very fine public research university, but I liked science, so I took a physics class in my first year. The instructor of that course kind of picked me out in the back row, and I did sit in the back row, because I don’t know why I did, and recognized that I was doing well in the class and invited me to join his lab.
So the first big step for me was somebody recognizing me and picking me out.
And the professor who did that was a guy named Jack Crow, who played a really important role in my career, because he took the time to do some things for me. The first was bringing me into the lab, and my first lab experiences were not elegant. This was what’s called a condensed matter physics laboratory, and that means a couple different things: You’re studying very tiny things like electronic circuits, you’re working almost always in the basement of the physics building. For some reason, physics is always in the basement; it’s a funny thing.
So I was in the basement, and the job they gave me was cleaning the oil in diffusion pumps. They just had tasks to do in the lab, and I think this is true for a lot of scientists when they have their first experience with science. It’s fairly mundane. There’s a lot of work that has to happen in order to get science done.
Then as time went on, he arranged for me to spend a summer at Brookhaven National Lab, and that’s where I first got my really broadest experience of research–seeing the work I was doing at a lab, but also seeing a bunch of other young people doing research in different labs.
During this time, what was your perception of what it was like to be a scientist, and did you think of yourself as a scientist?
TM: I think the first time I really thought of myself as a scientist was my first summer at Brookhaven, and I’ll tell you the story of how that happened. But my image of a scientist began to be shaped by these faculty members I was encountering. I think the way you really come to know a community–a community of scientists–is to become embedded in it. It isn’t a thing you can learn from a book.
In more recent years, I’ve studied how it is we produce expertise in people. Expertise–the way it comes about–is only through embedding in a community. You can’t actually read books or papers and become a genuine expert; you’ve got to be in it.
When I went to Brookhaven in the first summer, they brought me into a laboratory that was going to work with positrons–anti-matter particles–which I thought was pretty cool. And they spent about an hour explaining an experiment they wanted to do that required forming a beam of positrons and then directing them at a target. And they said, “Here’s a paper that describes how we might do this. Build it.”
It was one of the first times that I had been given a much less scripted opportunity to explore something, and I was asked to make it happen. The really formative moment for me was the first time I built a piece of equipment. Now, that sounds maybe fancy, like I built a fancy piece of equipment; it was not. It was a piece of wire mesh, cut out into a rectangle, bent over into a cylinder, and then used to shape this beam of positrons.
So I actually built something with my fingers. And when I did that, and I installed it in the instrument, and it kind of worked! That was a big moment for me, because it was the first time that I realized that people just make this stuff. It’s not like you only buy equipment from a store or something. You actually just put it together!
And I got very excited about experimental science after that.
During that time, when did you decide to go to grad school?
TM: The crucial deciding factor for me going to graduate school is that someone told me it was free. It was a huge surprise to me.
I had in my mind this model that if you went to professional school, you would come out with $120,000 in debt. So when people told me that graduate students in the physical sciences, in the life sciences, across almost all the sciences–not only does someone pay their tuition, they also pay a stipend that allows you to live during that time. And all I had to do was send in graduate school applications, and I could get this kind of job, where I wouldn’t have to find another job, which was a really scary thought, to find another job.
I didn’t really know what would come after it, not very well, but who cares? It was a good next thing to do.
Did you have a thing you were really passionate about working on? Something that people were really excited about at the time or something that you were personally in love with?
TM: My own scientific interests have evolved with time in a complex mix of interests: intrinsic interests, what I know about an opportunity, what’s available to work on, what you can do something really good with.
So when I went to graduate school, I was thinking I wanted to do condensed matter physics, and I got admitted to a couple different graduate programs. The two I’ll mention: One is the University of Illinois in Urbana-Champaign in central Illinois, and the other was the University of Chicago in the city of Chicago.
Illinois, at the time and perhaps still, but certainly at the time, was a much better place for condensed matter physics. They had five or six Nobel laureates. It was really the best place to go for condensed matter physics. So I went to visit the two schools, thinking I’d probably go to Illinois. During that visit, I took a train from Chicago to Urbana, and I got off the train, and I got in a cab to go to my little hotel I was going to stay at, and the cab driver told me about how their cow had had a calf that day. And I thought, “This is not the place for me.”
I was a young person, and I wanted to live in an urban environment; I’d been at Temple University. So that was really a big part of what made me decide to go to the University of Chicago. Plus, there was an amazing music scene in Chicago…
I mean, so it was factors that weren’t really all about the science. I mean, I knew they were both good schools, so that was fine. So how else would you decide? Well, weigh the life impacts of the choices that you make. So I ended up at the University of Chicago for graduate school.
So they gave me a desk in a condensed matter group, which we’ve already established was deep in the basement of the building. And I joined this group, and they gave me this desk off in the corner, and really kind of...nobody said a word to me. So I didn’t quite immediately fall in love with it.
At any rate, what had happened is a group of people who were studying cosmic rays–these are very energetic particles that come from outer space and strike the Earth–
Is that why we see the aurora borealis?
TM: That is one form of cosmic rays. Relatively low-energy cosmic rays create the northern lights and the southern lights. When they strike the atmosphere, they create that glow.
So these people who had been studying cosmic rays made a discovery in the early 1980s. They came to believe that there were certain objects in space–black holes–that were emitting extremely high-energy gamma rays that were traveling from those black holes to the Earth, and then running into our atmosphere.
What was astounding about this discovery is that those gamma rays were so high-energy–they were much higher energy than anything we could produce on Earth–and we didn’t really understand how a black hole could be creating such high-energy particles. So that was really cool–black holes, that’s always cool–plus, super high-energy particles that we don’t understand. It was a really exciting discovery.
My advisor, Jim Cronin, recognized that these very high energy gamma rays were really particles. He’s a particle physicist–he knows how to detect particles really well. So he would turn his attention from Fermilab–the particle accelerator that he had helped to build–and use space as his particle accelerator and detect and study those particles.
I had the good fortune to join that experiment when it was in the design phase, so we went through a period of time when we were trying to figure out how to build an experiment that would do this really well.
How big are we talking?
TM: It’s very big. The instrument that we built was assembled out of 1,089 individual detectors. Each detector was a five-foot by five-foot car top carrier, and those detectors were then spaced on a grid 15 meters apart. So one detector, then 15 meters to the next detector, 15 meters to the next detector.
So how many football fields is that?
TM: The whole grid was about a half a kilometer in size–a little over 500 meters on an edge. And it was a 33 by 33 grid; that is the 1,089 detectors. So you need a big place to put it, and you need a safe place to put it. So we ended up building it on an army base, in the desert in western Utah.
A place like a desert seems like a good place; you can put it anywhere on some big desert. The problem is: Most empty spaces, if you put a bunch of objects out in them, people shoot holes in them. Think about road signs you may have seen in rural places.
TM: Well, they just sort of stand out as targets! So if you want something to be safe, you put it in a place like an army base, where people don’t do that freely.
So that’s why we ended up at the Dugway Proving Ground in western Utah. It's mostly a big, empty desert. The federal government uses it as our place for storing chemical and biological weapons, among other things. But it’s mostly big empty space, so we built our detector out there. I ended up spending probably about a year and a half residence out there in the desert.
And did you actually build it? Like did you put screws in the equipment?
TM: We actually built it. You remember, I said I like building. There was, first, design and construction of a few of the elements of this, to figure out how to do it. And then there was kind of an industrial-scale operation.
We built them all in Chicago, then we would load them into semis, and take them out to the desert. I became a certified forklift operator, so I could load the trucks. We shipped them all out to the desert, and then we would take teams of people out to install them, because you have to take them out of the trucks, and then spread them out in the desert, make the place level, wire them all up. It took three years of construction to build this object.
It gets at a feature of scientific life that people don’t always get. We do a lot of different things. So when you say you “are a scientist” or you “do science,” it’s not a narrow thing.
We had to deal with, for instance, mice. We built a big detector out in the desert, very high altitude–it gets cold. Inside our boxes were electronics that stay warm. So all the mice who lived in the desert would chew through the boxes and build their nests on top of our electronics.
Did they chew through the wires, too?
TM: Yeah, they chewed through wires!
So there were mice. There were also rattlesnakes and scorpions. You just have to deal with whatever you have to deal with when you’re doing a scientific experiment. I find that one of the most attractive parts of being a scientist is solving problems that are not maybe the central problem–we were there to study ultra-high-energy gamma rays–but figuring out how to do difficult, interesting, technical things that probably nobody has ever done before.
The journey to get to it.
TM: So the process of science is where most of the fun comes from.
We do it for the results, and because those are important, and so on. But if you didn’t love the process, the results probably wouldn’t be enough to get you there. And all that variation of work–I just love that part of it. That you never know what you are going to need to figure out in order to make your experiment work. In a way, you reach a certain level of training where it’s not even your training anymore; no one’s trained to do these things. You just are trained to have the right kind of attitude and the right kind of critical thinking, so that I think you could give me any problem, and I have some skills for working on that, almost no matter what it is.
So you had a detector. Did you detect?
TM: We built the detector. As it turned out, all of those experiments in the early 1980s–that said that there were ultra-high-energy gamma rays coming from black holes–all of those experiments were wrong.
TM: What we did was build a giant detector, spend all of these years of effort, turn it on–it worked. It worked really great. It did exactly what we expected.
We detected a lot of cosmic rays, but there were no gamma rays.
And our detector was so much more sensitive than everyone else’s detector that we were able to prove with a lot of confidence that they were wrong. It's kind of like, if you imagine someone saying, “I think I see a bird over there.” And everybody looks and says, “Yeah, maybe there’s a bird over there.” And then someone brings a really great telescope, and you look through it, and you realize, no it's not a bird, it's a lump of leaves. If you’re a bird watcher, you know this happens all the time. A leaf bird that you see over there.
I learned so many wonderful lessons from that experience. One of them had to do with the fact that science is very difficult to fully settle, so scientists are always in the process of answering questions. There are things we really really know, but where scientists work is not in the areas that we really really know–they work in areas we don’t really know. Where we think or we expect or wonder or hypothesize. And our job is to gradually dismiss those things into the region of what we know, and then we move on. We stay in that zone of uncertainty. So I learned that even when a significant number of scientists say something, it might not be true.
And that was important for me, because it made me critical about science in a different way. As a student, I picked up the notion that if something’s in a peer-reviewed paper, then it must be right. And that’s really not true. And the kind of questioning that I learned to do was very personal. So if somebody asks me my opinion about ultra-high-energy gamma rays from black holes or something, I want to read all those papers, and I really need to decide for myself.
I’m curious: After you published the articles saying there are no gamma rays from black holes, how was that perceived in the community? Or even before you published, when you talked about it?
TM: Right–it’s another great set of lessons I learned. How do scientists come to confident conclusions? What is the process that the community of scientists uses to move from hypothesis or hesitant expectancy to confident?
As I think about what I think is real–or even interesting, exciting, what I want to invest my time and energy in–I apply a kind of criticism to thinking about how to choose what to do, that is very much shaped by that early experience that I had.
Because you have to imagine my own circumstance at that moment. I’d just spent six years working on this experiment. My thesis paper came out and basically said, “This is a dead field.” That is not what you want your Ph.D. thesis to be. You would like your Ph.D. thesis to be the announcement of some exciting new thing, which of course is what I thought I was going to be doing.
So I came out of graduate school well trained in a field that was now dead. Not very promising. Personally, as scientist, this occurrence–the fact that this happened–was really scary.
And by this point, I had met my wife, and we’d gotten married, were thinking about establishing a life together.
So you were 27 or so?
TM: Yeah, I was getting into my late 20s, and so all of a sudden, I had a level of career uncertainty that I really hadn’t hoped to have–life uncertainty, right?
So after that occurred, I thought, “Okay, I’m gonna have to do something new.” And remember, I’d been trained by a particle physicist, I knew how to analyze a lot of data, I knew how to build things, so I looked for a place where I could get a job analyzing data, building things, using the methods of particle physics.
At the same time, my wife had taken a job–she was a lawyer at the time, as a state's attorney in a county in Illinois that was near Fermilab. So I was drawn there by personal reasons, but also this confluence of my training and what they do there.
Fermilab is a big, national laboratory, funded by the Department of Energy in the remote suburbs of Chicago. It is a place that was created to build large particle accelerators to study the fundamental properties of particles. So although it is a laboratory funded by the government, they do no secret research there. When they first built it, they decided they would not put a fence around it. And everybody in the government freaked out: “You have to have a fence around a national laboratory!” But that’s because their model of natural laboratories was laboratories that are oriented toward secret defense research and not toward pure science. So they gave me this job, and they brought me in, and they said, “Take the first month to examine all of the experiments that are happening at Fermilab and decide which one you want to work on.
TM: Isn’t that nice? And they were kind of in different categories. There were collider experiments, where protons and antiprotons collide; there were fixed-target experiments, where you collide protons into big pieces of metal and see what happens; there was also one very different new experiment, just getting started. They gave me a list of all the experiments, typed out, and they wrote on the bottom a project called the Sloan Digital Sky Survey. It was a new consortium of these astronomers coming from a tradition of doing very small projects with just a few people, particle physicists coming from a world of doing really big projects with big teams.
And they were going to come together to build a new telescope that was going to map the universe. Now, they weren’t actually going to map the whole universe–it's a big universe. But they were going to make the biggest map of the universe that had ever been made.
So they had this plan to build new instruments–kind of like I had done before–that were going to make a map of a region of the universe 100 times bigger than what we’d seen before. Galaxies are kind of the tracers of the distribution of mass in the universe. They glow, you can see them, and so we had done that with, at the time, a few tens of thousands of galaxies. We were going to do it for over a million galaxies. To make that big jump, we had to build a big, new instrument.
The best part, though, was: We were going to measure galaxies. And I was pretty sure that galaxies were real.
So there was really no doubt that this project was going to measure a bunch of things, and that was one of the number-one priorities that I had. I really wanted to measure stuff; I wouldn’t get into this to measure nothing.
So even though this was an astronomy project, and I have never taken an astronomy class, it really looked like the one I wanted to work on. So I talked to my wife about it. It was crazy; people would say you can't do this–you can’t change fields. But she heard me talk about it and said, “Look. It's obvious, the one you are interested in. Why don’t you do it?” I don’t know; maybe at the time it was easier for me because my wife was a lawyer. We had a partnership that had two legs to stand on and everything else, so maybe that gave me the opportunity to be freer about taking a risk.
But I did choose to take this risk, and that turned out to be a really great decision for me. The Sloan project became an extremely important experiment in the evolution of astrophysics. It became a model for many other experiments that are now going on in astronomy and astrophysics that aim to gather really comprehensive data sets about the universe, survey-like projects. In fact, these are emerging in many fields of science. Genomics is a great example of that, where comprehensive gathering of sequence data–
TM: Yeah–go get all the data. And then work on it and see what you can learn from it.
So Sloan emerged with some specific questions in mind, but we knew from the start that we were gathering data that would answer many more questions than the questions we were asking. It ended up being a very scientifically rich project. And that, for a young scientist–you want to work on a project that’s scientifically rich, because there will be a whole realm of opportunity that wouldn’t have been there otherwise.
I often think that I was given a really fortunate opportunity to come work here at the University of Michigan that grew out of accidents of my history and good chances. I don’t feel like when they hired me at Michigan I had earned it in the way that you might feel you need to. I was working on an experiment that wasn’t taking data yet. The Sloan survey was very promising–yeah, we could say we’re going to map the universe; it sounded really cool...We hadn’t done it yet.
So when I got hired here, it was on the promise of what we were doing and some knowledge of me as a scientist that came from my prior work and the experience people had working with me.
I would say that when I first applied for the job, I didn’t get it. They told me, “Oh, you’re a really exciting applicant, but we’re going to give it to someone else.” And and then, later that year, they called me and said, “Actually, that first person turned us down. Are you still interested?”
I feel super fortunate about having gotten that opportunity, and I guess when I think about telling other people about science, it’s not some system that just rewards excellence in some perfect way. I wish it was, maybe, but it probably can’t be, and it certainly isn’t. There’s a lot of chance and good fortune that governs who succeeds in science, so if you’re a young scientist, and you’re struggling, you can’t take what happens as entirely a judgment on you as an individual or your qualities. And yet, we so often do that.
So that step for me was obviously a huge one. Because if you can get a job as a scientist at a place like the University of Michigan, in a way, you kind of have an obligation to do some great stuff, because you‘ve just been given the keys to everything that you might like to do.
Once I was here, the opportunity space opened up in all kinds of really great ways, and I kept getting reinforced in this notion: If you see something new, and you think it’s interesting, maybe you should do that. It might not be crazy or the wrong choice; it might actually be the right choice to pursue something new that’s interesting to you, even though other people might advise that that’s risky.
I certainly wouldn’t say you always should be chasing after a new thing. In each case, you want to chase after a new thing and then become an expert in it and deliver something valuable to the field. And maybe then you start looking for a new thing, but there’s a part of me that has a kind of five-year, eight-year cycle in mind. And as I’m reaching the midpoint of one of those, I want to start looking for another one.
How much do you think your graduate advisor influenced you in developing this reaching out for the next thing?
TM: I really think Jim was a formative figure–Jim Cronin–for me in this regard.
Some people become successful by finding a thing, and they’re totally passionate about it, it’s the only thing they really care about, and they work on that. And I think that’s great. If your mind is like that, and you really want to go after a thing, and it really is the only thing you’re passionate about, whatever–great. But Jim was the kind of person...I remember one time telling him, “I just learned this new thing.” And I said, “That’s really amazing.” And Jim said to me–he looked at me in all earnestness and said, “Everything is amazing.” And it was kind of like I was given license, then, to be excited about a lot of things.
I definitely remember as an undergrad, everything was amazing. And then, as I progressed through my scientific career, it feels like I was given license to only care about one or two things, because I needed to deliver the funding, or you need to be very focused to produce a paper that has a certain impact, and so I think it’s really important to be reminded that, in fact, everything is amazing, and it’s important to keep perceiving the scientific world that way.
TM: My current work on education began when I started in the Honors Program, because all of a sudden, I was in charge of all these students. They were doing all these different things. I had to think about not just physics classes, or one discipline, but I had to think about, What is an undergraduate experience? What should undergraduates do for intellectual breadth? I had to ask myself all these questions. What is a liberal arts degree about?
It set me off down this path of questions, answers, and new questions. That’s what scientists do, is they get into a realm, and they ask a first question. A good first question leads to ten more questions, which leads to more questions, and you seek to do experiments to answer those questions. All this kind of stuff started to open up in front of me, because of just trying to do my job as the honors director, first.
It started with a problem that I had. The problem I had was that I teach seven hundred students.
I’m not going to complain about my four hundred anymore.
TM: Well, four hundred is plenty. It’s the same problem really, right? So the problem is: We need to be able to speak to everybody personally, individually, but we can’t.
So what I discovered is that we have a team of people in our School of Public Health here who were building digital health coaching tools, and they were thinking exactly about, How do you build systems that will learn about the details about a whole bunch of people and be able to speak individually to them all?
So when I learned about this, I was like, “You have solved my problem.” And I’m going to learn from you about how to do this.
Now, the people who do that work here–they’re very focused on behavior change, because in public health, that’s everything, right?
You’ve got to quit smoking, you’ve got to control your diabetes, you’ve got to make a difficult health treatment decision. So they had studied psychology. They had studied behavior change and thought about what supports and motivates people to do difficult things.
So here I am, trying to get people to learn physics. It’s actually not easy to learn physics; it’s difficult. And I want to change their behavior, so that they can be successful doing that. So I started collaborating with them in conjunction with Vic Strecher, who is a really fantastic guy in our School of Public Health, a great innovator who had been working for 25 years on digital health coaching.
My interest in education has definitely grown way beyond physics. I actually love college and higher education maybe even more. Higher education is this huge, transformative power in the world, and I’m thinking now about, How do we make the higher education experience for all students at Michigan the best it can possibly be? And once we do that, how do we use that example to make higher education for the United States and the world the best it can possibly be?
I want to make the whole system much better by applying the things that I’ve learned in physics and astronomy and in the Honors Program. I want to put those things to work to make a much larger thing much better.
We talked a little bit about how you get excited about science and how you get started and so on, so sometimes it’s that really fascinating thing nature is doing that just gets you, and you really want to work on it. Impact on humanity is another thing that really motivates people. I feel like I’ve had the opportunity to work both on abstract stuff like black holes and gamma ray bursts and just really cool things that nature does. And as my career has evolved, I’ve turned my attention more and more, I’ve been drawn more and more toward impacting people and the world and their lives. I feel very fortunate to have gotten to do both things. I don’t think it’s clear that only was is the right thing, but I’m really excited now to be working on things that I think are going to make people’s lives much better.
I mentioned that I was a first-generation college student, and how that changed my life. I’ve become a professor–who knew, right? I want that for other people. So if I could get even just a couple hundred more people to go to college–I’m done. I can retire. That’s a very proximate, possible goal.
To make it possible for two hundred people, who wouldn’t gone to college, to successfully do it and find a new array of possibilities open to them...You know, that’s enough. I would love to do it for a 100,000 people. And maybe I will. But you don’t have to solve the most immense problems in order for it to be super valuable.
You have to start somewhere. When you had to build all those arrays in the desert, you had to start with a few to lay them down.
TM: Everything begins with the first steps. So thinking about those larger issues is really where my passion is now. An element of that is getting them to learn physics really well. So in the fall, I’ll be going back to teach our Physics 140 class–this 700 student course–and I will be applying to that particular context all the things I’ve been learning and working on, and I hope that we will be able to use that as a model for how you can take a big class like this and make it a much better kind of class than it has been in the past, by being able to personalize more deeply in it.
Return to the audio for How to Science Episode 6, with scientist Tim McKay.