Sitting with scientists: MuMu Xu

Welcome to a new feature on An Independent Universe. It’s called Sitting with Scientists, and I’ll be interviewing awesome people from around the country with a passion for science that puts mine to shame. My first interview was with Mumu Xu, an assistant professor at the University of Maryland. She attended Harvard University for her undergraduate, where she got her bachelor’s in Mechanical Engineering, and recently got her doctorate in Mechanical Engineering from California Institute of Technology. She writes a blog (also sort of a podcast) about science, and obviously that’s one of the best things someone can do.

Tell me about your journey. What first sparked your interest in engineering?

As a kid I always loved taking things apart and putting them back together. I played with Legos and K’Nex all the time, so I thought engineering would be fun. It was kind of a process of elimination in terms of what type of engineering I wanted to do. I hated chemistry, was indifferent to a lot of biology, but loved physics so decided to major in mechanical engineering. That was pretty much my decision process on choosing a major. It was very quick.

Choosing a college and graduate school was more of a byproduct of my obsessive TV watching. In high school, I loved “Gilmore Girls”. The main character on that show, Rory, dreamed of going to Harvard. As a budding engineer, I had always thought I’d go to MIT but after watching the show, I thought, “I should try that.” Getting a liberal arts education was the perfect fit for me because I love literature and history and philosophy almost as much as I love engineering. Then in college, there was a show called “Numb3rs” that was set at Caltech. I fell in love with the campus from the TV screen, and decided to apply to a Ph.D. program there. It also helped that I grew up about an hour away.

What has been your biggest challenge in your career so far?

One of my biggest challenges is getting over self-doubt, or what is known as imposter syndrome. I’ve actually talked to many colleagues and friends in different fields who have felt much the same way. It’s the thought that ‘I’m the admissions exception, everyone else got in because they’re smart, but they made a mistake with me. Someone will find out that I’m just faking it.’ So, the hardest part has been to speak up and ask the questions that confuse me, or to get the courage to voice an opinion and not care that I come across as too bossy, or mean, or stupid. Confidence was and still is the biggest challenge.

I read about your UAV (Unmanned Aerial Vehicle, or Drone) research on your website. Can you tell me more about that?

I work in the area of controls and formal methods, with application areas in UAVs (aka drones). The short answer is that I write the software that goes on UAVs, and my research is on how to write that software correctly and safely.

1. Think about controls as anything that has to do with feedback. Cruise control on a car is the example I like to give. You set your speed to a reference velocity (e.g. 65 mph). Then you have a sensor that tells you what speed the car is actually going. If it’s faster than 65 mph, you tell the car to step on the brake. If it’s going slower than 65 mph, you tell the car to step on the gas pedal.

2. Formal methods is just using math and computer tools that we have to prove that what we build or design is safe. So instead of building an airplane and then checking that every possible scenario is safe, we design computer models of the airplane and test it in simulation and then in hardware.

3. Combining controls and formal methods, my research looks at how do you build an entire system (airplane, car, space shuttle) in a way that you can probably show everything is correct. Math, as always, is the answer. Some questions we can ask are: how do I plan a path that takes me from point A to point B, while avoiding “bad” areas? How do I sense obstacles in the area and avoid them? How can I tell what set of bad situations might happen to make my system unsafe (cascading failures), and design my system to avoid that?

photo courtesy of MuMu Xu

Did you consider other careers?

Growing up, I loved school and I loved nearly every subject. So there was a time I considered journalism and graphic design. In graduate school I toyed with the idea of law school, but nothing interested me as much as engineering, so I stuck with it.

What is it like to be a professor as well? Does it help or hurt your research?

Being a professor is wonderful overall. There are days where I probably wouldn’t agree with that statement, but it’s truly a privilege to be where I am. I love teaching undergraduates and grad students. I have the freedom to make my own hours, and to perform fundamental research, meaning that not every idea we have has to necessarily go toward an application. We’re free to explore the possibility of “what if?”, and there’s nothing better than surrounding yourself with people who love learning.

When did you start Beyond the Microscope? Why did you?

I think science in the mainstream is having somewhat of a resurgence, but what I noticed was that if you asked people to name some famous scientists or engineers, they could tell you Neil Degrasse Tyson and Bill Nye, and that was about it. Furthermore, on a lot of science-themed podcast shows, or even TV shows, all or most of the guests were men. I looked around at my friends and colleagues and realized that there were a lot of women doing really cool things, and I wanted to spotlight that. Well, this was all just me complaining until one day my friend Lindsay, who is a journalist and producer, called me out and said “just do it.” So, we started Beyond the Microscope as a way to highlight women in STEM (Science, Technology, Engineering and Mathematics) and STEM-related fields. Our interviews aren’t about what it’s like to be a woman in a male-dominated field. We just talk about their work, and how they got there. The material speaks for itself.

Any advice for a teenage science blogger?

Keep doing what you’re doing. Keep asking questions and challenging the status quo, and never be afraid to speak up. It’s cliche but absolutely true.

Anything you’d like to add?

Go Terps!

Also, I saw you like Harry Potter. That’s awesome.

There’s still a tiny part of me that’s expecting to see a letter from Hogwarts show up in my mailbox. #tenpointsforGryffindor