The neutrino telescope IceCube at the South Pole has detected high energy neutrinos. You and your team were responsible for the data analysis. How were you able to tell what you found? And what are the implications of your findings?
The first observation of high energy neutrinos happened as soon as the full detector started data collection. IceCube has been constructed over 7 years and we took data in partial configuration until 2011. The first two very high energy neutrinos have been observed nearly by accident in an explorative analysis. This first hint has been then combined with a work I pioneered with my team years before in a different context, on strategies to reduce the atmospheric neutrino background. Next, a second search has been launched on the data revealing a sample of 27 high energetic neutrinos, the majority of them in excess, in respect to the expected background. This has been a magical moment for us, a truly new signal from the universe.
With IceCube, we have opened a new area of exploration. We look into very high energetic phenomena. It is presently too early to discuss the impact of such observations. At the moment, we are developing new methods dedicated to the identification of the responsible sources of the IceCube neutrinos. Like in other fields of astronomy, the first observation is in the so called 'diffuse' regime: the neutrino events are too few to reveal their complete origin. The overall picture is not yet clear enough - the exposure has been too limited yet. We have to collect more data and ideally finance a larger detector to resolve the universe in neutrinos. One thing is certain: the picture we will sooner or later reveal will look different from anything we have in mind at the moment.
During a lecture at the 'Berlin Minds' event, you explained that we are on the verge of understanding 'the music of the Universe' - an new way to conduct astronomy. Could you explain that, please?
Oh, this has been an experiment. In that presentation, I have compared the universe to an orchestra, or better an orchestra that plays an unknown music. Our goal as scientists is to reveal and understand the instruments involved as well as the underlying sheet music. Following up on this analogy, I freely associated each particle type in the universe to an instrument: photons are a keyboard for their wide range over the entire electromagnetic spectrum, charged particles are like a percussion for their heaviness and high energies, and neutrinos are like a violin for their faint nature. With the advent of IceCube, we have started to 'hear' the neutrinos playing a new part of the Universe's music sheet. That's just fantastic to me.
In Germany, there is an ongoing discussion how to increase the number of female professors across disciplines. You've been working in Germany since 2005, but you've studied and received your PhD in Italy. What is your impression on the discussion of this topic in both countries?
This is an important and difficult topic. Moving to Germany, I was assuming I was going to meet a more emancipated society compared to the one I was coming from. If this was true in some aspects, I had to learn that in some parts of Germany, the fact that a woman with children aims to have an exciting career is not supported and not even well seen. Without generalizing too much, there is still a very classical vision of the role of mothers in Germany: ideally at home taking care of the house and the children, as well as of fathers: fully active in the working environments.
Both women in academia, as well as fathers taking time off for parental time, are still challenged. This has various consequences at various levels: from schools where girls are not enough encouraged in math, physics and chemistry, to biases in the working environments. I have also to recognise that during the last 10 years, the situation improved a lot, with more childcare opportunities and more awareness about this topic. To increase the number of female leaders in academia or industry, one has to address the issue at multiple levels: in schools, giving more examples to young students, in the society, offering help to young parents, and in the working environments towards the reduction of biases.
In your research, what inspires you on an everyday basis?
I am driven by the ambition to observe and study new phenomena in particles as well as in astrophysics. Fundamental science is by definition the investigation of the new: new rules that govern nature, new symmetries, new phenomena, new theories. The constant struggle towards the new pushes boundaries to the extreme, but also technologies, organisations, and relationships. I am constantly challenged in my hunt from many sides, not only the purely technical one. This is what eventually moves me, every day.
Dear Prof. Resconi, thank you very much for this inspiring interview!
Interview: Ann-Kristin Flögel
The IceCube telescope | at the South Pole: Thousands of optical sensors are embedded in the Antarctic ice, covering about one cubic kilometre. With hot water drills, sensors are sunk as deep as 2,45 km. In this remote, undisturbed environment, researchers were able to detect high energy neutrinos.