In conversation with Benjamin Marussig

Benjamin Marussig: “Working in research is the best job I can think of”

Benjamin, very happy to have you as our second guest. I would like to know how you would describe your main research focus and how you got involved in this topic? 

My main research focus is to establish a better connection between simulations on geometric models and the way that the models are created. So, I look at different points of view to the problem, but the main goal is to improve the interaction between computer-aided design and numerical simulations.

I got involved in numerical analysis by accident. I was studying civil engineering and I never wanted to program anything.  I wanted to work for a big firm and build bridges or skyscrapers. Luckily, I had a very good lecturer who had an interest in boundary elements. As he was so convincing, I decided to do my master’s thesis on this topic. Only then I started to actually learn what you can do when you know how to program and when you have the power to tell the computer what to do.  So during this master’s thesis I learned the basic principles of programming and here I started to appreciate the benefit of numerical simulations.

 If I look back now at my master’s thesis, it was just a simple finite elements code, the hardest part and my main achievement was learning to program.

 And how did your master’s project evolve to your PhD topic?

During my master’s thesis I was asked if I ever considered doing a PhD, which was indeed something I was interested in. I was lucky that my PhD supervisor had the right proposal at the right time then. The topic of this project proposal was on Isogeometric (IgA) boundary elements. This was a completely different focus than my master’s thesis. If I look back now at my thesis, it was just a simple finite element code, the hardest part, and my main achievement, was learning how to program. Nevertheless, it was the perfect experience to get into this topic and to learn the basics. I was also very lucky with my PhD supervisor Gernot Beer. I think he did a perfect job in guiding me and, at the same time, giving me enough freedom to pursue my own research focus. We had quite some intense discussions, which in retrospective, was a great training for advocating and assessing research ideas.

Can you explain how you have experienced doing a PhD on this topic? 

When I started with my PhD, I think there was only one paper out on IgA with boundary elements so there were many open questions. At TU Graz, there were many researchers working on boundary elements, so it was a fruitful environment to go into this direction. As soon as I was going forward from my study of finite elements to boundary elements and learning the concepts and ideas behind IgA, I automatically got more involved also in computer-aided design (CAD). 

The expectations of many people starting in IgA were once we use splines in our simulations, everything will be solved because splines are used in computer-aided design and that is a perfect match, so it will also work in simulations.

But, as people learned now, this is not the case. Part of the challenges can be solved from a numerical point of view, but there are also many open challenges in computer-aided design itself. Learning about those is also how my research focus has developed. I started figuring out how numerical simulations work, then I learned the ideas of IgA and how to incorporate these into the context of boundary elements. And then I realized: there are not only numerical problems, but also challenges due to the nature of how the geometry is built in computer-aided design. And the last paper that we published was mainly on this last topic: how can we actually make geometric operations work in an analysis-suitable way. The objective of this research is to somehow create technologies that both communities (geometric modellers and numerical analysts) will appreciate.

You have to set yourself goals, but you cannot plan everything

And after your PhD you continued with a postdoc in Austin. How was the switch from TU Graz to the University of Austin, Texas?

I indeed did my postdoc in Austin in the group of professor Tom Hughes. I got there on my own initiative after a small conference (not more than 50 people) I attended in Germany during my PhD. Professor Hughes approached me after my talk and after a chat, he told me I should visit Austin. Then I applied for funding and started my postdoc there. 

The entire post-doc was fascinating. In general, UT Austin is an amazing environment with so many great researchers and professor Hughes is a great researcher and person. It was always a pleasure to have discussions with him. He is so engaged with his students: I think he interacted more with his students than most of the professors I have met anywhere else.  

Another thing that was really obvious was how easily all the work we did was picked up in the scientific community. I still remember my first paper in Austria in which I put a lot of work and of which I thought it was a very good paper.  But it took quite some time before it got actually cited in the community. While in Austin, only one week after the publication, I already had the first citation! But when you are in such an amazing environment and research facility, people look at what you are doing and this is such a great motivator for doing the best you can do.  

I’m also the father of a one-year old and I really appreciate having grandparents near

And now you have a tenure track position at TU Graz. Was this also what you wanted: to be back at home.

Yes and no. Once I decided that I wanted to do a postdoc, I knew that it was almost impossible to find a position in Graz, which is also my hometown. But I was lucky there was an open assistant professor position here for which I applied and got. Now, I’m very happy I got this position in Graz as I’m also the father of a one-year old and I really appreciate having grandparents nearby. So again, it was a very lucky circumstance. But I think that is also what you need in life: You have to set yourself goals, but you cannot plan everything. 

Have you always had an interest in pursuing an academic career?

In general, education has a very high value in my family. My brother also obtained his PhD, but in a completely different field as he studied Law. I remember a colleague once asking me why I was interested in doing my PhD as I could earn much more money in a company. But I always liked to figure out why some things do not work and to thoroughly understand the problem and the solution to it. Therefore I think the PhD was the perfect thing to do. 

I did say to myself though that I didn’t want to go from a non-permanent contract to another. Of course, the postdoc position in Austin was a no-brainer, but I promised myself that I would only accept one other postdoc position and then apply for a tenure-track position. If I then wouldn’t have gotten it, I will continue to industry. Luckily I didn’t have to think about this anymore, as I got this tenure-track position in Graz. 

Every time you finish your presentation, take a look in the audience, watch the applause, take your time, and enjoy

Do you have any lessons learned during your PhD or student life that you would like to share with our PhD students? 

I don't see myself in a position where I can give advice to students yet to be honest. But I think when it comes to a PhD, I would say: Do it! It is the best way to study and it is the best way to learn about a problem and how to approach a new topic. For me, working in research is the best job I can think of.

A lesson I learned from teaching is that it doesn't matter if you're talking in front of 20 people or in front of 200. And if you present something, try to enjoy it as much as possible. It is an opportunity to speak to the leading figures in the field and to present your ideas. It does not make sense if you spend all the time in your office working on a problem while nobody knows about this. You want other people to benefit from it as well and in the best case, as it was in my situation in Germany, someone will approach you and you come up with new ideas. So, every time you finish your presentation, take a look in the audience, watch the applause, take your time, and enjoy.