Q: Please send us a short presentation of you including, if possible, a picture.

After my graduation in 1983 at Utrecht University, I started a PhD at SLAC (Stanford, California). I worked 4 years to find 4 great events. In this period I also made my greatest discovery: my current wife Mieke.
After my PhD in 1988 I moved to CERN (Geneva, Switzerland) to work on the L3 experiment at the LEP accelerator. These were very productive years: 10 doctoral students, more than 200 publications and 2 wonderful children: Kim and Jeroen. In 1993, this resulted in a professorship at the University of Amsterdam. In this period I changed from a shy science-student (with glasses and without acne) to an impatient, hard-working and not too diplomatic scientist.
Between 1993 and 1995 I gradually switched from LEP data-analysis to LHC detector development, in particular for the huge ATLAS experiment. In 2000 I definitely(?) returned to the Netherlands. Until 2004 I was the leader of the Dutch ATLAS efforts. From December-2004 to December-2009 I fulfilled my first term as Nikhef director; currently I am in my second and last term. My first term ambitions were to broaden Nikhef’s research activities in the exciting and new field of astroparticle physics and to increase outreach activities and industrial collaboration. This all went rather well. Presently I am looking forward to harvest the results of the LHC running (and I have to safeguard Nikhef’s budget).
Throughout my career I always enjoyed teaching (for university- and high-school students alike) and I love to give lectures aimed at the general public. I have collaborated with artists on films and Theater plays. Fond memories I have of the “Lightning Lecture” in the NEMO science museum for kids aged 7-12. Presently I am involved in a cosmic-ray exhibition (notably large spark chambers) for the NEMO science museum.
In my free time I enjoy windsurfing, mountain biking and (wave)kayakking. Living in the Netherlands (to be specific in the polder-town of Almere, 3 meters below sea level) makes mounting biking a strange name, a more appropriate name would probably be mud biking. In the past I have flirted with snowboarding and parapenting, but I decided I am too old for those sports now. I furthermore love to play board games (la Citta, Genius, Blokus, Rumis, Catan, etc.). A constant factor in my life has always been that I lack sufficient time for my wife and children. I fear that will still continue for a while.

Q: What are you working at now and what are your ambitions or expectations?

Today I am the director of Nikhef (a national research institute in elementary particle physics in the Netherlands). This means management and science policy. Not my favorites. Part time I am involved in the ATLAS experiment at the Large Hadron Collider and I am setting up a small group to search for Dark Matter interactions at the deep underground Gran Sasso laboratory (XENON experiment). My ambitions are two-fold:
(1) To finally find the elusive Higgs boson supposed to be responsible for the masses of elementary particles (ATLAS experiment); and
(2) To resolve the issue of Dark Matter. Ideally by a direct detection of Dark Matter interactions (XENON experiment); and/or by the creation of Dark Matter particles in LHC’s proton-proton collisions (ATLAS experiment); and/or by the observation of high-energy neutrinos point-sources hypothesized to originate from Dark Matter particle annihilation in massive objects like the Sun or the center of our own Galaxy (future KM3NeT neutrino telescope at the bottom of the Mediterranean Sea).

Q: How and for what reason was your interest for physics born? Which characters have influenced this choice? What is the most beautiful memory of your life as a student?

Already as a high-school student I wanted to go to CERN in Geneva. For a brief moment I have considered to study Theology and Dutch literature. Anyway: I ended up studying Astronomy and Mathematics. And I became an experimental elementary particle physicist. I am very happy with my work.
I fear the simple fact that I liked to mess around with chemicals, bikes and technical things (like making a mirror-based telescope) is what set me on a career in science. Astronomy was the compromise me and my long-time high-school friend came up with. I guess one of my physics high-school teachers also played a role. The fact that chemistry, physics and mathematics were a piece of cake for me in my final high-school years certainly also helped.  
My best memories as a student were the 14 months I spent at CERN working my head off on an elegant experiment at CERN. Witnissing the first anti-proton beams and listening to a private lecture on stochastic cooling from my fellow Dutchman and future Nobel laureate Simon van der Meer (jointly with Carlo Rubbia) were certainly unique experiences. Close matches were the first time I myself resolved the energy spectrum of the hydrogen atom (which I still can do) and the moment I understand the theory of Lebeque integration (which I do not anymore …).

Q: Which difficulties did you have to deal with in your career? What has given you the strength to carry on? Which was the most significant event of your career?

I fear I had no difficulties. I basically always got landed with the next job before I started to look for it myself. I guess I was very fortunate being at the right moment at the right place (notably at CERN when the LEP accelerator, the LHC predecessor, started-up). So I had not trouble whatsoever to continue.
Beyond any doubt the most memorable events in my career were during the first days of LEP data-taking: unraveling the intricacies of the first electron-positron collisions and really extracting the number of particle families from the first short LEP run. I hope the coming generation will have comparable fun when the LHC starts up! I also once at night had a great idea which could (I though: should) lead to the discovery of the Higgs boson. In the middle of the night I rushed off to my computer at CERN and frantically started to code and analyze data. I even got a peak (for any particle physicist the indication of the existence of a particle/resonance). Regretfully it turned out to be an art-effect. 

Q: Which do you believe will be the next discovery in physics, and how this might contribute in changing our lives?

First: a discovery in physics does not necessarily have to influence our life! It often is like art, music (or love as a matter of fact): they can create moments of great pleasure, but they do not change our lives as the development of radio, television, mobile phones WWW, nuclear energy, steam engine, microscope, GPS, nuclear medicine, PET/CT/NMRI scanners do. Incidentally: all of these technologies rely on (or were discovered) by particle physic(ist)s. So often physics discoveries do impact our life. To name a few which have not and which I nevertheless certainly cherish as well: CP-violation, neutrino mixing, neutral currents, Big Bang nucleo-synthesis, cosmic microwave background radiation (and my apologies if some of these are akadabra to you).
Having said that: for me the next great breakthrough in physics will be the resolution of the Dark Matter and Dark Energy mysteries. Together they comprise 96% of our Universe. Given that with the mere 4% of our Universe we do understand today we can do so much, I would think the other 96% should, once we understand it, also open up things we can not even imagine at this moment. Stay tuned.  

Q: In your opinion, what has been the biggest discovery in physics and who has been your "reference-scientist"?

My “reference-scientist”:
Professor Tini Veltman, a theoretical particle physicist and Nobel laureate. I followed his classes as a student and he still comes every week to the colloquium at Nikhef. A great teacher and a great physicist who realizes that physics is an experimental science (despite the fact that he himself is a theorist).
Biggest discovery in physics:
A hard one. I opt for quantum mechanics i.e. the realization that physics at the smallest scales behaves very different from everyday physics and common sense.

Q: What characterizes research workplace and how is scientific collaboration organized?

Difficult questions.
In my field (experiment elementary particle physics = large international collaborations) the keyword is collaboration. Not always easy, but the only way to really get (literally!) to the heart of the matter. A free bonus is that you get to know many different nationalities. My friends are scattered across the globe and my view of our society is not a narrow minded one (I claim).
Workplace:
Like many researchers a fair fraction of the work takes place behind a computer: C++ coding: idea-code-run-check and iterate/fine-tune this cycle until you discover a great result. The other part of the work focuses on detector develop-construct-commission-calibrate. Also in an iterative manner. I like both sides. In addition I also like to get to the details of why we do it i.e. linking experiment to theory and vice versa. And all this happens in a very stimulating environment with the brightest minds (I claim) of our world and permanently replenished with youngsters i.e. the new generation of Master and PhD students i.e. you! As a bonus: even I keep up with the latest trends in music and dancing.
Collaboration organization:
Too many (unavoidable) meetings. Reviews. Fund-raising. I fear this is the part I like less. To avoid misunderstandings: I do like to collaborate. I dislike the organizational aspects of a collaboration.     

Q: Considering the crisis of inscriptions in scientific faculties, which do you retain are the reasons of the gap between young people and scientific studies and what may the world of research do in order to change this trend?

To be honest: first year enrolments in science (and physics) are increasing in my country as they are in many other countries. What we have to do (and are doing) is present science to the public at large. Just like some people like art and music, some people also like to listen to good science discourses, ranging from the Big Bang to the Microcosmos (including the fantastic developments in modern Biology).

Q: How can a scientist be defined and how do talent, intuition and study influence his profession?

Scientist’s definition:
Foremost a scientist is creative and original i.e. a non-conformist (apart from being intelligent of course) not afraid to shy away from the standard path (think about Einstein).
Impact of talent, intuition and study:
I fear talent is a sine-qua-non i.e. if you do not have talent for science find an other mission in your life (and there are many). Intuition is for me the same as originality and creativity and I see that as essential assets of a good scientist. You must study. Whether you do that in an organized environment like a university or you study yourself is in principle irrelevant. However, I fear that given the massive knowledge our predecessors accumulated you better take the benefits of studying at a well-known university with a well thought thru curriculum. After your Bachelor/Master you have ample opportunity to follow your own course as a scientists. But do not try to re-invent the wheel a zillion times over because that way you do not come much further than the wheel. I want the Higgs boson, Dark Matter and Dark Energy to name just a few.   

Q: How do you spend your free time?
Playing games (999 games), reading, windsurfing, mountain biking and keeping my house (and garden) in order. And beyond doubt my real favorite: being with my wife, my two fantastic children and friends

Q: In this period of economic crisis, how do you see the future of research and what do you think about the employment of nuclear energy for energetic aims?

Economic crisis:
Any sensible government should not save on research since (science) research is really the single thing which propels our society forward. Moreover it is cheap in view of the investment-return ratio. Save on military, encourage inflation, downsize lawyer communities i.e. the ones who make nothing but only talk or pump stuff (money, words) around and reduce the cost of health (give medical doctors a normal academic salary and give nurses a fair salary).
Nuclear energy:
For me nuclear energy is probably cleaner than fossil fuels once you account for the full impacts of both (i.e. take into account beach/water pollution and climate change due to the use of fossil fuels). Nevertheless, I am not a real proponent of nuclear energy (fission and fusion alike). I see a very clear long-term solution for the global energy problem: mount solar panels/plants in the Sahara and make lots of hydrogen i.e. convert to a hydrogen driven society. Doing this in the Sahara means you maintain the money flow into the Arab countries and instead of oil you simply ship liquid hydrogen all over the world. This source (in essence really nuclear fusion...) will last as long as the sun shines: still 4.5 billion years to go. If humanity lasts that long that will be the moment to find a more hospital planet to continue life…