On July 4th, scientists at CERN (the European Organization for Nuclear Research) announced they had discovered what, as they cautiously put it, looked like the ‘Higgs Boson’. One week later, Rolf-Dieter Heuer, Director General of CERN, visited Dublin in occasion of the ESOF (European Science Open Forum) conference and kindly agreed to answer some questions for the readers of Trinity News.
How did you first become interested in physics and were you ever tempted to pursue a different career path?
It started in high school. I was always interested in physics because physics is logic and you can explain, or at least try to explain, everything by logic. Of course at some stage you need math, but if you don’t know the logic forget the math. Logic is first, then math. So I was already interested in school and the teacher also told me if I didn’t study physics, I would make a mistake. So I didn’t make this mistake and I studied physics. I never had anything else in mind other than to study physics.
Did you have some good mentors and teachers along the way?
The first teacher I had in school was very good because he put a lot of emphasis on logic. Then I had a very good supervisor for my diploma and then a very good supervisor for my PhD. So I was lucky with the people I worked with over the course of my studies. And from from each person I took a little bit, which forms my personality now I guess.
What does the future hold for the Large Hadron Collider (LHC)?
We have a program until 2030 for the LHC. Our main concern will be to measure at higher energies and hopefully shine light on dark matter. If it’s the Higgs, which I guess it is, its discovery and investigation essentially closes the chapter of the Standard Model, because the Higgs was the last missing cornerstone. But now you’ve decribed 5% of the Universe: there’s still 95% to be explored. I really hope that the next step will be something on dark matter and that would be a giant leap from nearly 5% to 25%, nearly 30%. That would be fantastic.
A simulated event in the Compact Muon Solenoid (CMS) detector, where
the particle thought to be the Higgs Boson is produced following the collision of two protons
The theoretical idea of the Higgs Boson has been around for 48 years. Why did it take so long to find what we think is the Higgs Boson?
It’s a question of mass: the heavier, the more difficult it is to produce because we need more energy. But it’s not only the mass, it’s also the probability that it will be produced. If you make two particles collide then the energy can be transferred into different masses, but depending on the underlying process, it can have a high probability for a certain particle or a low probability. For the Higgs, it’s a relatively low probability and then, once you have produced it, it immediately decays again. Now, the trick of this beast is that it can decay in different images. You can have image A, B, C, D again with different probability depending on the mass of the boson. So if it has a certain mass, it decays, let’s say, just to make it easy, 50% in A and 50% in B. If it has a little higher mass, then 20% in A, 50% in B and 30% in C. So the probability of it showing up in your experiment and in your digital camera changes also with mass. It is really difficult to find that thing because the images can always be faked by normal, known processes from the Standard Model. So you always look for a tiny surplus compared to what you expect from the Standard Model itself and that in many, many different images. Then you have to gather everything together and you have to be very careful not to be fooled by statistics.
So how many images did you get?
One experiment looked at the 2 most promising images, the other experiment looked at 5. But there are more and now we will continue to evaluate them. If it’s a Higgs Boson, this is only the beginning. We need to investigate its properties and this might help us understand dark matter. The first thing we have to do is measure the spin of this particle. The Higgs Boson has no spin, it’s a scalar, so if this particle is a scalar, then we are close to the Higgs Boson and it would be the first fundamental scalar to be discovered. Hopefully towards the end of the year we might be able to have an answer on the spin of this particle.
Who are the primary financial backers for the research that goes on at CERN?
CERN is funded by its member states. Actually, we have just refedined the “E” in CERN from “Europe” to “everywhere”. Now we accept members from outside Europe.
Are the member states the only financial backers?
To a large extent yes. Of course we get some voluntary contributions from non-member states. This is for the infrastructure. The researchers have to contribute to the experiments, we don’t aid the experiments. For the laboratory, it’s essentially the member states, plus we are relatively successful in our proposals to the European Commission for the Marie Curie [Programme] and some infrastructure funding – especially in E-science, like grid computing, etc. But one of the big successes is the Marie Curie [Programme], because we get excellent people, they get international education, and so our proposals are pretty well ranked.
Ireland is the only country in Western Europe not to be a member of CERN. Could you comment on this?
That’s a question for Ireland! I think Ireland should be a member of CERN because it is prestigious, it does good science. Ernest Walton was one of the pioneers of the accelerators. [Cormac] O’Rafferty made several contributions in supersymmetry theory. So I think Ireland belongs to our family. That’s my message.
The late Ernest Walton, fellow of Trinity College Dublin and former
Erasmus Smith’s Professor of Natural and Experimental Philosophy,
who is the only Irish Nobel laureate in science (Physics, 1951)
The Higgs Boson is often referred to as “God Particle” in the media. Do you find this frustrating?
I don’t embrace the expression. It has nothing to do with God, but it’s a special particle, that’s clear. The expression gave it some visibility but people interpret too much into it. But ok, I’ve learned to live with it.
If it’s not too personal a question, are you religious?
Sometimes yes, sometimes no, it depends. One is always struggling with this. But it’s interesting to discuss with philosophers and we will have a workshop, a very restricted one, on the question of the interface of knowledge in October. The main thing I hope will come out of that workshop is a common language. Because if a philosopher talks about a topic and a particle physicist talks about a topic, I’m pretty sure they are not talking in the same way. So they have to understand what the other really means. Because talking means not only listening but usually you also interpret what is said. What you think is said is not necessarily what the person who said it thinks he said. So one needs a common language.
And the language of physics is a very objective one, is it not?
Yes, but the philosopher has to understand what we mean and then we have to understand what they mean when they say something. That, I think, is the first challenge.
So is an interdisciplinary approach to knowledge the way forward?
Yes. I am always confronted with the question of what was before the Big Bang and I cannot answer that. I don’t think anybody can answer that, but it’s interesting to discuss it at least.
Do you think we will ever be able to answer that?
(whispers) I don’t think so.
“What was before the Big Bang?
I don’t think anybody can answer that.”
Is that perhaps the greatest mystery of the Universe?
I don’t know if there are other mysteries. We are pushing the frontier of knowledge but there is always something on the other side of the frontier of knowledge which we don’t know. But since we don’t know it, it’s belief or interpretation.
Are you optimistic about the future of our planet?
Well if I wasn’t an optimist, that would be very bad. I think to some extent it will regulate itself, once you realise you are no longer having certain resources and you have to get to other resources- not to get the same resources, but to get the effect of the resources. The problem is that it might be a bit too late before people realize it, but it’s a self-regulating process I would hope. I think the biggest challenge is to throw overboard too many self interests and really try to balance interests all over the planet. And this is a challenge, because if it was only science or research, you could do it, but there are always emotions and politics and that makes it very difficult. Everyone has his or her agenda, that’s human. The future of humans and the planet are strongly linked. It’s very difficult, but I think I’m still optimistic.
You mentioned interdisciplinary approaches. Do you think that art and science often complement each other and should be viewed more as an interconnected entity, particularly in education?
Absolutely. I have introduced a new program at CERN which collides artists with scientists. We now have the first two artists in residence. The funding is from sponsors not from base funding. I want to show the fascination of artists in our science, because we get a lot of requests, and to show that science may be made of difficult research, but in principle it’s easy because you can interpret it in art. The first one is a digital artist and the second one a dancer. And I’m really eager to see what approaches they come up with. I think at the very beginning of science, it came out of art, it was connected. There is a quote from Paul Klee, the German painter: “Art is not reproducing the visible. Art makes the invisible visible.” Well, we do the same: we make the invisible, visible! So there are a lot of connections.
‘Castle and Sun’ by German expressionist Paul Klee,
“Art is not reproducing the visible. Art makes the invisible visible.”
In Ireland there is an ongoing debate in relation to science funding. Funding seems to be increasingly provided to applied sciences rather than basic sciences. Could you comment on this?
I think it’s a mistake to concentrate only on one. I think you need to achieve a balance. You have to balance between, in the words of the Commissioner [Máire Geoghegan-Quinn, European Commissioner for Research, Innovation and Science], curiosity-driven and challenge-driven, for me it’s easier to say between basic and applied research. There is only one research and then you have the more basic and the more applied part, but if you stop doing basic research, at some stage you lose the basis for the applied research. Many things have come out of basic research because it’s curiosity-driven, you have a target, which is knowledge gain, and once you have this, then suddenly you can have gain in applications. If you had asked Mr Röntgen at the time he discovered X-rays to find a mechanism to look into the body and find deformations for example, he would never have thought of the radiation. Maybe I’m not inventive enough, but I think he would have looked for something mechanical. So curiosity-driven research is the one which makes the big leaps and I think you can make a simple example: suppose you have one sack of corn left over, do you eat it (that would be applied research) or do you plant some into the earth to grow for the next year? But you don’t survive if you plant it all, so you have to find the balance: some corn into your mouth and some into the earth.
Is there any advice in particular you’d like to give young people who might be reading this, to the students of Trinity College Dublin?
Don’t give up even if things are difficult at the beginning. [I say this] because people tend to give up too early. It’s too easy to give up and do something else. If I had done that, I would have not studied physics, because at the beginning it was very difficult for me. Show some stamina. Don’t give up and sometimes follow your stomach, not only your brain but also your stomach. If you have a choice between topic A and topic B and you only use your brain, I’m not sure that you always make the right decision. Ask your stomach: what do I like more? And go in that direction; you can change afterwards anyhow. If you finish your studies you’ll be doing something else afterwards anyway, but you will have done something which you like. Then you will also have shown that you have learned how to work on a project, for example. If you are not performing well enough, change. But don’t change too often. If you do that, you don’t know what you’re doing and whomever will employ you afterwards, realises this. If you change too often, you are seen as giving up too quickly and sometimes you have to bite through. I had to do that too! Another word of advice: never take the advice of only one person.
To end on a light note… Are you a dog or a cat person?
I never had an animal at home, so I’m neither… I’m in between. I’m like the Higgs, I’m neither this nor that!
Do you like reading popular science books?
Sometimes yes, but not too often because I have to read so many other things. I like to read, but I’m not a good reader.
Are you afraid of death?
It comes at some stage. That’s all. So if I was afraid of death, I wouldn’t fly so often and I wouldn’t sit in a car. I take it as it comes.