As Director-General of CERN, I am often asked: "What has particle physics achieved?" "What may it achieve in the future, what in particular will CERN's next project the Large Hadron Collider (LHC) contribute, and what may come after the LHC?" and "Why should the public support particle physics?"
The launch of a new-look Courier provides an opportune moment to reflect on these questions. I will consider the first two questions in the second of these essays, which will survey the achievements of the past and argue that prospects for the foreseeable future are excellent, especially at CERN where the LHC will be the world's front-line facility for exploring the fundamental properties of matter in the first two decades of the next century. Here I consider the arguments that we particle physicists use when explaining the importance of particle physics to the public.
The primary argument is the intrinsic interest of understanding the nature of the matter of which the universe is made, to which I will return in my second essay. Readers of the Courier have been exposed to the fascination of the science, and also to the fact that particle physics has many important secondary benefits. These include spin-offs (devices developed to do particle physics that turn out to have other uses, such as the World Wide Web, or particle detectors and accelerators now used in medicine), stimulation of the technological capabilities of industry, training and the creation of networks between young scientists and engineers who go on to work in industry, and the ability to excite the interest of schoolchildren in science and technology. All these are of course very important, and it is also conceivable that particle physicists will discover new laws of Nature that can be exploited in novel and important ways (see my article at "http://www.cern.ch/Public/bs_1.html" for a general discussion of the importance of basic scientific research). These factors are, however, secondary in justifying support for particle physics the science must come first.
What does the general public think? Two years ago a British newspaper published a poll which asked (responses added in brackets):
"Each year, the UK contributes £55m towards CERN, a European project based in Geneva where scientists are trying to understand what matter is made of and the basic laws of Nature. What do you think of the UK's spending money in this way? Do you think that
- this should not be funded because no public money should be spent on science [5%]
- this money would be better spent on more practical issues such as health and transport [56%]
- it is very important that public money is spent on trying to answer the fundamental questions of science [22%]
- more should be spent on answering these and other basic scientific questions [8%]
- don't know/not interested [8%]."
I find it encouraging that in a random sample of people, some of whom had presumably never previously heard of CERN, 30% thought that public expenditure on research such as that at CERN is justified, or should even be increased. Furthermore, those who felt that the money would be better spent on health might have expressed a different opinion if they had known that one person in eight in the developed world will at some time or other be treated for cancer with accelerators originally developed for research in nuclear and particle physics (see page 20), and that if they need a PET scan it is quite likely that the detectors in the scanner will use the BGO crystals developed originally for the L3 experiment at CERN's electronpositron collider, LEP.
In fact, in my experience, most people are interested in the discoveries of particle physics, and are ready to accept that mankind as a whole should continue to explore the fundamental nature of matter. The fact that the LHC will be a unique facility and that construction of the collider itself and the detectors is a collaborative global effort helps the case, and those who start with the erroneous idea that the cost of particle physics is going up are reassured to discover that this is not the case. In fact, despite the increasing sophistication of CERN's facilities, the CERN budget corrected for inflation is actually 20% less than it was twenty years ago, while gross national products in the CERN Member States have typically gone up some 60% in real terms in this period.
Presenting the arguments
However, although the importance of particle physics in general, and the LHC in particular, is generally accepted by those to whom it has been explained, their number is limited. It is the job of particle physicists to present the arguments as widely, as well, and as fairly as they can. In fact, I believe that we particle physicists have an obligation to try to share the excitement of our science, which I view as a contribution to culture, with the public that supports us. I am therefore very pleased to see the increasing effort devoted to promoting public appreciation of particle physics worldwide, and in particular I welcome the launch of the new-look CERN Courier. I hope these initiatives will allow a greater number of people to share the excitement of the discoveries that lie before us in further unravelling the secrets of Nature.