In This Issue
Fall Issue of The Bridge on Space Exploration
September 1, 2021 Volume 51 Issue 3
Close collaboration between engineering and science has enabled marvels of space exploration over decades. Eight exemplary missions are described in this issue, conveying the excitement, challenges, and breakthroughs involved in efforts to better understand the wonders and mysteries of this solar system.

An Interview with . . . Bill Hammack, Engineer Guy

Thursday, September 2, 2021

Author: Bill Hammack

RON LATANISION (RML): We’re delighted to have an opportunity to talk with you, Bill. Your degree is from the University of Illinois, is that right?

BILL HAMMACK: My bachelor’s degree in chemical engineering is from Michigan Tech and I have a master’s and a PhD from UIUC, also in chemical engineering. I taught at Carnegie Mellon for a decade before returning here.

Bill HammackRML: What distinguishes you from other chemical engineers are things like your public radio broadcast and your Engineer Guy videos. How did that transition occur?

DR. HAMMACK: The first transition was to public radio and communicating to the public. That would have been about 20-plus years ago.

I was a young professor at Carnegie Mellon, doing the standard research and things. But there was a kind of a push and a pull.

The pull was that it interested me. My mother was a botanist, my father was a theater professor. Talking to people and working in media felt natural to me, and obviously talking about science.

The push was that chemical engineering was undergoing a lot of changes with biological and nano people moving in. I had to retool, I couldn’t just continue the research I was doing. If I were going to retool, I thought deeply about how I would want to build a career. What would I want to do that was different? Instead of retooling in one of the new areas, which would have been difficult, I chose to pick this area of communicating to the public. The first part of it was on public radio and the second part has been on new media and YouTube. That’s the larger part now.

CAMERON FLETCHER (CHF): Did you approach public radio to offer your skills?

DR. HAMMACK: Yes. I had read a book on sales and how to sell things and the ways you go through your pitch. I went to the program director’s office and said, ‘I would like to do these short commentaries on engineering.’ He looked at me and said yes. I said, ‘But I’m not done. I have all these steps I have to go through to sell it to you.’ He said, ‘No, let’s start tomorrow. The way you do these things if you’re going to do them is you just start.’ That was a guy named Jay Pierce who’s still in public radio. That was a lot of fun. Radio is a wonderful medium.

CHF: Are you still doing public radio?

DR. HAMMACK: No. After about a decade I took a year’s leave to work at the State Department as a ­Jefferson Fellow, in a program to integrate scientists into the department and the foreign policy mission.

Hammack 2.gifRML: What was your mission?

DR. HAMMACK: I had two things. I was part of the Korea desk. The desks deal with the embassies and answer questions for them. One of the interesting issues was the nuclear weapons program of North Korea (the DPRK, as we said). I also served in nuclear safety and security, as the point of contact for Department of ­Energy people who were gathering up unenriched uranium at research reactors.

RML: I’m curious about outreach in terms of informing the public of the merits of engineering but also public policy issues associated with engineering. Why do you think there are so few engineers who seem to be interested in getting involved in politics, in elected office, for example? There are at most a handful of ­people in Congress who have backgrounds in engineering. Why do you think that is and do you think it should change?

DR. HAMMACK: I suspect it’s just because it’s messy. If you’re an engineer, you’re used to ‘let’s start this’ and ‘let’s do this.’ You’re bound by all sorts of things.

The most I’ve done with public policy was at the State Department. The idea there was to get engineers more involved in the decision making. Most of the Jefferson Fellows worked in scientific offices in the department, and they actually had large impacts on export controls and that kind of thing.

CHF: Did you feel that you made a difference, that you had an impact, while you were there?

DR. HAMMACK: That’s hard to tell. First of all, there are some impactful things that I can’t tell you, which is frustrating and alien obviously to what I normally do.

CHF: How did you get assigned to the Korea desk?

DR. HAMMACK: They were looking for people and it sounded interesting to me. A number of sections had scientific support already; this one did not.

RML: I want to follow up on the question of engineers or technologists in Congress. When you look at all the impacts of science and technology, doesn’t it seem to you unacceptable that policy decisions are being made largely by people who have no understanding of engineering? Doesn’t it seem like there should be better representation?

DR. HAMMACK: It absolutely does. In fact, Sam ­Florman wrote in an article that engineers are always “‘on tap,’ never ‘on top’” in relation to the political process.[1]

RML: Sam is a great guy. He is sort of the godfather of this column, to be honest.

DR. HAMMACK:  I still draw on some of his ideas. For example, why is the last engineer everybody can name Thomas Edison? What has happened? I suppose today we could mention Elon Musk. There’s something ­poignant and something important about the question. It’s partly a measure of our success, isn’t it?

RML: Tell us about Engineer Guy.

DR. HAMMACK: While I was in Washington, which is well over a decade ago, I discovered this thing called YouTube. It seemed really interesting. Part of its appeal was that it was new media, which I will define.

There are two components to making what people our age call new media: means of production and of distribution. Before the digital revolution, you had no means of production. You couldn’t get a good camera and film without spending a lot of money. Now, though, you can use an iPhone if you need to. And we didn’t have means of distribution. You could make something, but you couldn’t get a theater to run it, and you certainly couldn’t get it on NBC, ABC, PBS, or CBS.

Hammack 3.gif

Now I can flip on a live YouTube feed and reach a million viewers right from my office. In fact, I accidentally broadcast an oven mitt out of focus when I was trying to play with livestreaming not long ago. I was a little surprised because I was trying the live broadcast and I thought I had set it to private and people started commenting on it. I took it down and people got to hypothesizing what it was so I just put it back up.

Anyway, after that time in Washington I came back and I thought about options. When I was in public radio we had a lot of gatekeepers. I had my local station where I produced commentaries, which would play regionally. If I wanted to be on Marketplace, we would pitch them a piece. There was an editor named Celeste who would then take it to Barbara and take it to one more level and they would decide whether to accept the proposed piece. That’s how old media works.

In new media, there are no gatekeepers. Of course, there’s a huge downside to that—we can see that with people who Tweet and post things that they regret. Gatekeepers would have helped them!

But the possibility of directly reaching an audience appealed to me. I had never worked in video so I read a book called the Grammar of the Film Language. I got a camera. My department gave me an old lab, which I turned into a studio. I still have it. I sat on the floor and tried different angles and different things and made six or seven videos. And I utterly failed in YouTube land.

I started by making videos that were kind of goofy, because at the time on YouTube that’s what was really popular, like all those cat videos. I was treating it as if it were not a serious medium at all.

Humor, as I knew from public radio, distances people. It attracts some people but puts off about an equal ­number. So I rethought it and we did videos that are a little more serious, they’re authentic. It’s the same advice you get for dating: Be yourself. If you’re an obese middle-aged man and you like to talk about pop cans then do that.

But this is also an interesting thing about new media. If I had to pitch my idea to ABC, CBS, NBC, ­maybe even PBS—‘how about if a middle-aged man talks 11 minutes about a pop can?’—that wouldn’t make it anywhere. But with new media failure is cheap and we can try things and see what works. That appealed to me. That and just be yourself, talk about things you enjoy—your passion and authenticity will come through. That turned out to be extremely successful.

CHF: I watched your Engineer Guy video on the engineering of a disposable diaper because it’s such an unlikely topic. You’re right: You come across as serious, authentic, and genuinely interested. You’re very clear and effective in explaining everything. And, as I’m sure you already know, you have a fabulous radio voice—that helps.

DR. HAMMACK: The origins of that video were that I have small children. I had changed at that point 2000 diapers.

CHF: You counted them?

DR. HAMMACK: My wife, who’s a veterinary oral surgeon now, trained and previously worked as an engineer. So we estimated it: how many times a day, how often…. Changing diapers was one of my tasks, so I got to thinking: ‘How do these things work?’ My natural inquisitiveness led to the video.

I had changed 2000 diapers and I got to thinking,
‘How do these things work?’

It’s nice of you to say that it’s clear. We make storyboard versions of each video (they’re on We send them out to sets of viewers—1000 people have signed up to look at these and maybe 100 look at them. We use their comments to find out what they didn’t understand, streamline the video, or we get an expert who corrects us. We like both ends of the spectrum, the people for whom this is new and the people for whom it’s old. For example, in the early draft of the video we used yellow food coloring and we got a clear message: Don’t do that. We changed to blue.

CHF: A little too realistic.

DR. HAMMACK: Once it was pointed out to me, I could see that also.

RML: What kind of film crew do you have?

DR. HAMMACK: Over the years I’ve made them with two or three undergraduate students. They stick with me for a couple of years. I wrote a book with two of them and still pay them royalties!

Remember that these kids are saturated in the digital age. They’ve probably been making videos since age 12 on mom and dad’s phone. They’ve also watched ­YouTube and they want to be part of something big on YouTube. Most of the videos include their names at the end. I’ve done a few by myself, but usually it’s with a group of undergraduate students.

RML: And they participate either in the filming or onscreen?

DR. HAMMACK: The roles vary from developing the ideas to writing the scripts to making the props and things. It depends on the student. Everything you see in a video is usually modified. We have a machine shop and often have things that are specially made to allow you to see them a little better, for example. In the shop they can cut things open and make models for us.

RML: How do you choose the subjects of your videos?

DR. HAMMACK: That is difficult. The overarching thing that I want to communicate is that engineering is a creative thing, like Richard Blanco writing a poem.[2] You’re being creative and using the creative parts of your mind. We want to highlight something that’s ­clever, that’s unexpected, and that reminds you of that ­creativity. We would really like it to be something that you can have or hold.

A pop can is an ideal example of one of our subjects. Most people haven’t ever really looked at it. I hear from people who never noticed the numbers on the bottom of the cans—they tell me they now look at them. Or when they go to the store, they pick something up and look at it and think about it in ways they didn’t think about it before—and that takes them back to the creative process of designing. Those are the main criteria. Obviously, the object has to interest me too.

Because the items are touchable, we end up doing a lot more mechanical engineering. The hard part actually is chemical engineering. The closest I’ve gotten to that is the diaper. That is really quite difficult to communicate visually in an interesting way.

CHF: You did a great job with the polymer in the disposable diaper.

DR. HAMMACK: Those things are fantastic. They’re amazing. I have a colleague here who helped me quite a bit in developing some of the things used in the diaper video.

My next videos are based on this book that I just sent to the publisher, there will be a set of companion videos that go with it. It’s a book about how engineers think—what are the principles and methods and ­heuristics they use in order to do things? It’s filled with stories about engineers, how they’ve created things with this superstructure of the engineering method.

CHF: Who’s your intended audience?

DR. HAMMACK: It’s a popular book. As I like to point out, it may not be popular, but it’s a popular book in the sense in that it’s for a general audience. Same as the YouTube videos. I like introducing people to things. For example, I tend to teach freshman and sophomore courses. I like the first time somebody is seeing something. That may be because I get confused with mathematical details in the higher-level courses, or it may be because I prefer it.

Once an Uber guy picked me up (this was pre­pandemic) and when I got in the car he said, “Man, I love your videos.” That’s who I’m making them for. I’m not making them for my fellow engineers. I’m making them for somebody who’s driving Uber and wants to think. That was a nice moment.

RML: Let me follow up on that. I know you’ve been the recipient of some prestigious awards.[3] That kind of “feedback” is obviously very good. What about the public? Do people write to you and say, “You explained something I’ve been thinking about for decades and never understood.” What kind of feedback do you get?

DR. HAMMACK: I get lots of feedback, especially on YouTube. I also have a text number for Engineer Guy and people text me. They’re very polite. And I get emails, from young people to the most recent one from somebody who was 75 and watching the videos. The feedback is almost completely positive. I also hear from people who say they’ve become an engineer because of this, which always feels good to me. That’s part of the purpose: to broadly educate the public. 

The videos are licensed under Creative Commons, which allows anyone to use them without asking permission, and hidden in the large number of views is a stunning range of uses. A small sample (from the few who asked permission!) demonstrates how the videos exemplify the key reasons for communicating engineering to the public.

I like introducing
people to things.
I like the first time somebody is seeing something.

The videos have been used to create a technologically savvy workforce: Around the globe large industrial firms use them to train their employees—General Motors, Disney, Hitachi, telecommunications giants in the US and Japan, and aluminum can manufacturers in Spain and Brazil. Small firms essential to the industrial supply chain also use them to train their workers: an Ohio injection molding firm that supplies Toyota, one in Michigan that serves the automotive sector, and a Texas manufacturer of figurines. A fire safety company uses the Faraday video series to educate and train firefighters on the science of flame.

They’ve been used in classrooms in the US and around the world—Germany, Canada, the Netherlands, and ­Turkey—to demonstrate and clarify for students central concepts for engineering science and to introduce K-12 students to engineering. So in a sense these videos are a public service—as done in this digital age.

RML: We live in such a technologically intense world. People have questions and don’t know where to turn to get information that they can understand. I think what you’re doing is very important.

Let me ask another question. I’m thinking of the engine failure on a recent United Airlines flight.[4] People saw pieces of engine shrapnel, but the parts that fell to the ground were not the failure. The failure was in the engineering, apparently, in some of the turbine blades. Do you deal in your broadcast with engineering failures and try to put the public mind at ease in terms of what happened?

DR. HAMMACK: We did a series on failure, but it was a different angle. It was more to debunk urban myths. I tackle that a little bit in the book.

When we judge engineers and their performance, we need to look at what was the state of the art at the time, because an engineer is solving with incomplete information and doing the best they can. If you want to wait for complete information, then you are not going to have, for example, some of the medicines and other products that people rely on. Part of being an engineer is solving with incomplete information.

Engineering is never more successful than when it’s invisible. In a video I like to make something apparent that wasn’t apparent before, to make it visible.

Another point I make in the book is to understand engineering methods. It helps to understand how a failure might have happened and how it might be fixed and what are reasonable expectations.

That brings us to that old joke: If it’s a success, it’s a scientific marvel. If it doesn’t work, it’s an engineering failure.

Actually, engineering is never more successful than when it’s invisible. How often do most people think about their furnace or what it is? I didn’t think about mine until it failed. So our success as engineers can make us anonymous because of the reliability of the things we do. What I like to try to do in a video is make something apparent that wasn’t apparent before, to make it visible.

CHF: Have you done a video on how refrigerators work?

DR. HAMMACK: I have an air conditioning unit the machine shop has helped me cut up and take apart. I haven’t gotten around to doing that yet.

CHF: Are you still doing the Engineer Guy videos?

DR. HAMMACK: Yes, although I’ve slowed down a bit, what with writing the book, and being at home with two small children during the pandemic—my wife was as busy as ever since animals’ jaws did not stop breaking during the pandemic. But I’m anticipating getting back in the studio in a few weeks to produce the videos that go with the book. I’m excited about that.

CHF: Did you choose your moniker, Engineer Guy, as an intentional counterpart to Bill Nye the Science Guy?

DR. HAMMACK: No. At the time, it had to be tied into a domain name. We struggled with finding a domain name that was a reasonable kind of title and that was available and we ended up there. I didn’t think of that connection; it was probably somewhere in the back of my head.

CHF: Like you, he was a winner of the Carl Sagan Award for Public Appreciation of Science.[5]

DR. HAMMACK: Yes. I’m pretty sure he’s a mechanical engineer.

RML: Bill, I have a pragmatic question. You produce videos basically on your own schedule, you don’t have any contractual obligation to produce x number of videos every month, is that right?

DR. HAMMACK: Right. Just as professors have a research program, the department regards this as my research program. They would not monitor whether you published your paper yet or not; they’re interested in the integral over time.

CHF: Do your students get credit for helping you with the videos?

DR. HAMMACK: They’ve gotten credit if they worked on tasks that involve technical aspects of working out the problem—like maybe the polymer chemistry in that diaper video. Then yes, they can earn credit.

CHF: You’ve done some interesting travel for some of your presentations—the sewers and Eiffel Tower in Paris, the Icehotel in Sweden, which I personally want to go see. Obviously, all travel was called off during the past year. Do you have other travels and sites in mind?

DR. HAMMACK: No. The Icehotel is the favorite of all the pieces I’ve done. It was −40° Fahrenheit. The batteries in my recorder would last 3 minutes at a time. It took me 3 or 4 hours to realize this; ‘Why,’ I said to myself, ‘do I keep bringing bad batteries?’

Hammack 4.gifWe don’t have much travel scheduled now. We’ve debated whether to bring the cameras out and see if we could go around the world and look at engineering things. I would like that. I think you could go all over the world and find things that you haven’t seen before that are engineered.

In Russia, there’s a statue of Peter the Great on a horse, and it’s mounted on a huge rock that weighs 1500 metric tons. Somebody had to move that rock in the 17th century, and the apparatus they used is fascinating. I think there are all sorts of stories like that out there to tell.

RML: I agree with that. I’m a corrosion engineer. The first time my wife and I were in Japan, we were visiting in Kamakura, where there’s a giant Buddha built in the 13th century. Carolyn, who’s a painter, was looking at this Buddha, taking photographs from 100 yards away to try to capture it all. I was up close looking at all the corrosion around the base, and I said to her, “I don’t think this thing is going to last.” [laughter]

DR. HAMMACK: There’s a famous ancient iron pillar in Delhi that doesn’t corrode.

RML: Some structures are made with materials that appear to have the characteristics of what are today called metallic glasses. These materials are non­equilibrium solids and they’re produced by rapid solidification; if you cool a liquid fast enough, you can inhibit its crystallization. How the ancients did this, we don’t know, but they constructed mirrors and other structures that have resisted corrosion for centuries. When you look at their structure, they seem to be amorphous, as in amorphous glasses.

DR. HAMMACK: I worked in that a little bit years ago when I was studying some materials in high pressure. The way you make a liquid metal amorphous is to put it on a wheel going 60 miles an hour.

RML: That’s right. You get rates that are tens of thousands of degrees per second. It’s fascinating.

DR. HAMMACK: But how do you do that in the 13th century?

RML: That is exactly the question.

DR. HAMMACK: I think that would be interesting to look at in the context of our buildings, things, cars….

RML: My point was that some of this is obviously in the eye of the beholder. My wife was looking at the aesthetics and the beauty and the art involved and I was looking at the structure. We both appreciated these magnificent pieces of ancient history, but we looked at them from different perspectives.

With every medium I need to play with it to understand it, otherwise the temptation with a new medium is to make it like the old one.

We all have different perspectives on what we do, what we see, how we see things, how we express our views of things. I think that’s symptomatic of what it means to be a human being.

DR. HAMMACK: I think so. Remember Henry Petroski’s great phrase, To Engineer Is Human.

RML: Oh yes. Henry’s a wonderful writer.

CHF: Bill, looking at the long term and given what you’ve done—books and videos and radio ­commentaries—where do you see yourself going with your interests in outreach and communication?

DR. HAMMACK: I’m not sure. It’s only in the last 4–5 years that we’ve been able to go live. I can go up to my studio, we have the computers and the apparatus, we can stream high-resolution live video. That’s been on my mind, although I don’t know what to do with it. My wife, who has a lot of wisdom, says I should not be live. But I’m fascinated by it.

Is some kind of real-time interactivity possible? Can something happen in real time that attracts a viewer or a listener to engage in real time? I don’t know.

I find with every medium that I need to play with it to understand it, otherwise the temptation with a new medium is to make it like the old medium. My favorite example is early movies, which had curtain drops in them because that’s how stage shows worked.

So I tend to get in there and play with a new medium and find out what use evolves. My longer-term horizon is figuring out what “live” means and asking what can be done with that.

RML: My sense, Bill, is that much of what you’re doing is instructional in both the topics you choose and the way you treat them. And with any instructional process, people usually have questions. If you could do this live, I think it would further improve understanding because people could express their uncertainties and get a ­reaction or an answer.

DR. HAMMACK: That’s one aspect. Also, you can make an event somehow. On Twitch, for example, there’s a guy with an engaging personality and 100,000 viewers commenting as they go along. You get very raw thought there. It’s fascinating to me.

CHF: Cool. Another idea that occurred to me for one of your Engineer Guy videos is the engineering of dentures, since your wife works on veterinary dentistry and orthodontistry, jaws and that kind of thing.

DR. HAMMACK: I did a little bit based on her work in the Nitinol video I did, which is what they make drills out of for doing root canals. She does a lot of root canals.

One recent thing that’s interesting to me, I bought a sous vide and have been using it. We’ll see where that goes.

RML: Bill, we’re approaching the end of our hour and I want to say I’ve enjoyed this enormously.

CHF: Thank you, Bill. This was a pleasure.

DR. HAMMACK: Thank you for inviting me to chat.


[1]  Florman SC. 1989. The civilized engineer. Issues in Science and Technology 5(4):82–88 (p. 85).

[2] Richard Blanco, poet and civil engineer, was interviewed in the fall 2014 issue of The Bridge. 

[3]  Bill Hammack has most recently received the 2021 National Science Board’s Public Service Award, the 2020 Hoover Medal from the American Institute of Chemical Engineers, and the 2020 Ralph Coats Roe Medal for Significant Contribution to the Public Understanding and Appreciation of the Engineer’s Worth to Society from the American Society of Mechanical Engineers. 

[4]  On February 20 a Pratt & Whitney engine on a Boeing 777 failed shortly after takeoff from Denver International Airport; engine debris fell in a residential area 18 miles north of the city. There were no fatalities or injuries. 

[5]  Bill Hammack won the award in 2019, Bill Nye in 1997.

About the Author:Bill Hammack in his Engineer Guy video studio at the University of Illinois at Urbana-Champaign. Photo credit: L. Brian Stauffer.