Santo Fortunato

“A lot of what I now do has potential practical applications, both in the business world and in science policy-making.”

Particle physicist on new paths

Santo_Fortunato_Photo_Maija_Astikainen_230x350px.jpgWho are you?

I am Santo Fortunato, professor of complex systems at the Aalto University School of Science.

What does your research group do?

We investigate complexity in various types of systems, with a focus on social and information systems. A system is complex if its behavior cannot be simply inferred from the behavior of its constituents. This happens because of nonlinear feedback effects in the interactions of the constituents. The spreading of epidemics in a population and the collective motion of pedestrians are examples of complex phenomena.

In the last few years, I have also been active in the so-called science of science, i.e., studying the activity of scientists based on their citation and collaboration patterns. This also involves the problem of how to evaluate the impact of a work or a scientist, so it is very relevant to policy-making.

How did you end up in this field?

I have wanted to study physics since as long as I can remember. My original dream was to study the fundamental laws of nature, which is why I chose theoretical particle physics as the topic of my PhD. Later, I was gripped by the new emerging field of complex system science, which I joined with enthusiasm for two reasons: 1) it offers the opportunity to study problems involving multiple disciplines and compare views with scholars from very different backgrounds; 2) being an emerging field, there was a realistic (albeit small) chance to make pioneering contributions.

What’s best about your work?

The most intriguing thing, in my view, is the possibility to invent new types of problems. There are, of course, some well-defined paths in this field and people are becoming increasingly specialized, but there is still room to strike out in new directions and open fresh fields of investigation. Also, in contrast to the more theoretical work I used to engage in as a particle physicist, a lot of what I now do has potential practical applications, both in the business world and in science policy-making.

What is the most difficult aspect of your work?

Working in a fairly new field has some drawbacks, too. The competition for jobs is tougher because, while we wait for new departments of complex systems to emerge, scholars like me must seek employment in traditional divisions, which often consist of scholars that do not appreciate this kind of research. Likewise, it is more difficult to receive funds due to the lack of dedicated calls in our topic(s). Fortunately, things are improving, both because the field is growing and becoming more visible, and because several scientific communities are starting to realize the potential applications that our concepts and methodologies could have in their own lines of work.

What part of your career are you proud of?

I was lucky enough to make my first steps in the world of complex systems working on a problem that was just starting to become popular, i.e., the detection of communities in networks. Communities are groups of entities that are strongly related to each other and not so much to the rest of the system they belong to. As an example, one could think of groups of friends in a social network. Methods to detect such groups by knowing only the network structure are very much in demand, and I happened to make some fundamental contributions in this field and that is what I am best known for at present.

I am also proud to be the chair of the ICCSS 2015, the first International Conference on Computational Social Science, which will take place in Helsinki in June 2015. I proposed this new conference because I knew that Aalto strives for excellence and would be on my side. Without this knowledge I would not have done it.


Text: Paula Haikarainen
Photo: Maija Astikainen

The original article has been published in the Aalto University Magazine issue 13 in June 2015. (

Page content by: | Last updated: 03.07.2015.