Here are two related problems. First, the number of applicants to UK university courses in the physical sciences has fallen by 26% over the last three years. Second, there is an increasing tide of opinion – not only among opinion-formers, but also among those who set research priorities – that the future of physics in the 21st century lies in its role as a “service industry” for other fields, in particular biomedicine.

Is there any reason to worry about this? You might think that we can face the future with confidence, following the government’s recent decision to invest an extra £1.1 billion in scientific research over the next three years (see Big boost for British science), following similarly ambitious investments in the US and Japan. However, we believe that there is real cause for concern, even for those of us who work in university physics departments that expect to survive and prosper.

The 26% fall in the number of applicants will mean that there will be fewer physics departments and fewer physics courses. According to some recent press reports, the provenance of which is unclear, the number of courses in the physical sciences is expected to drop by 5% by next year in the UK, while the number of business degrees will increase by 33%. This drop in numbers and the widespread opinion that physics is not useful is a consequence of an underlying problem that affects us all.

Scientists in general – and physicists in particular – must try harder to explain why spending public money on physics is not only justified but essential. We must strengthen the “physics is useful in its own right” argument by pointing out the long-term advantages of physics to culture and society. However, we must also show how physics can benefit short-term wealth creation, which is generally in areas where physics adds value to other disciplines.

Most important, we must show more forcibly how pure and applied research are connected, and not shy away from explaining how seemingly esoteric research fields do have practical applications. Making the link from curiosity-driven research to wealth creation should become second nature to us.

The danger of oversell

One danger of stressing the long-term benefits of physics is that some of the claims that physicists make are simply misleading. It is pretty clear that the work of Röntgen and the Braggs led to X-ray crystallography, and from that one can make a plausible intellectual link to molecular biology. However, to claim – as some physicists do – that physical scientists founded molecular biology will infuriate those legions of chemists, biochemists and biologists who laboured for decades to make the subject what it is.

Similarly, it is true to say that quantum mechanics grew from work that was then at the frontier of high-energy physics, and that without quantum mechanics, electronics would probably not have gone beyond the cathode-ray tube. However, high-energy physicists who claim the trillion-dollar electronics industry as their own are simply being fatuous. Indeed, the transistor emerged from an industrial, not a university laboratory.

The extreme case of this arrogance came from physicists on the Superconducting Super Collider project in Texas, who claimed that scientific progress – and possibly civilization – would halt if its funding were cut. It was, and neither did. What this case showed was that the best way for politicians to cut a physics project is to get other physicists to wield the axe. Particle physicists and astrophysicists have, after all, enjoyed a large fraction of the science funding “pot” ever since the Manhattan atomic-bomb project during the Second World War. This has been to the detriment of other worthwhile disciplines, and particle and astrophysicists have sometimes felt threatened by other physicists jealously clamouring for some of their money. Now all physicists are under threat from the advocates of other sciences.

Hard science for the millennium

Ironically, progress in the pure physical sciences has recently been so fast that funding for physicists has never been more necessary. There are, after all, many challenges lying round the corner. Particle physicists around the world are gearing up for the Large Hadron Collider, which should come on-line at CERN in Geneva by 2005. This accelerator will put particle physicists in the ideal position to discover the origins of mass, and to understand why the universe is matter and not a mixture of matter and antimatter. Astrophysicists, meanwhile, are rolling up their sleeves and licking their lips at the prospect of ever more finely resolved temperature maps of the universe, as well as a host of new tools to study extreme data.

Some of the key questions we face concerning the beginning of time, the structure of the universe, and the nature of matter will be addressed – and perhaps even answered – in the next ten years. There is also increasingly compelling evidence that neutrinos have mass, which, if true, would mean that they completely dominate the universe’s mass (See Weekly News : Super-Kamiokande finds neutrino mass and Physics World: Neutrino mass discovered). This would be the first real evidence that our best picture of the universe – supplied by the Standard Model of particle physics – is just a small part of what must be more all-embracing and more beautiful. Indeed, we may now be at the beginning of what will in future be regarded as a “golden age” of discovery; we are simply too close to the action to realize where we are.

How can we convince those wise and influential people who question our need to undertake this research? Some of them consider physics to be useful only because it allows better medical imaging, faster electronics or terrific risk-brokerage. Why, they say, should we spend so much money studying stuff that existed for only 10^-15 s or – God help us – 10^-45 s after the big bang?

Our response is that particle physicists and astrophysicists must not simply shrug and say, as they often do, “Well, it’s fun, it’s cultural, it’s what separates us from the apes.” If that sort of frivolity had its place once, it has long since gone. As physicists, it is clear that our top priority must be to try to answer the big questions. That requires huge investment in explaining to people who are not interested in charge-parity violation, quantum gravity or evaporating black holes why these questions are important. To do so effectively, we must also champion the applications of physics and the physical sciences.

Making the link with applications

Some of our colleagues say that the link between the pure “hard” physical sciences and spin-offs is tenuous, difficult to quantify and actually a bit “grubby”. We disagree. Of course, it is vital to get the balance of explanation right: the transistor would not have been invented without the quantum mechanics developed 30 years earlier, but the key contributions came from those industrial scientists who were specifically targeting such a device. However, we must not ignore the fact that there is a good story to tell. And if we can justify our work in terms of tangible spin-offs – what businesses now call “deliverables” – then we get the wondrous quantum gravity stuff for free.

The argument we can make goes something like this. The characteristic feature of today’s physics research is that it is at the extreme. In the case of particle physics and astrophysics, this means being at the limits of what is possible in terms of electronics, detectors, materials and measurement. Theorists in these disciplines, meanwhile, exist at the limit of (and sometimes a bit beyond) human comprehension, although even they help to push technological barriers. In other words, by solving the technological problems of particle physics or astrophysics, physicists are solving similar technological problems elsewhere. At the very least this problem-solving process trains people who can also solve problems elsewhere, which is possibly just as valuable.

Examples of spin-offs abound. Some are well known and carefully monitored by the funding agencies, such as the number of postgraduates who go into industry or the proportion of the subscriptions to international collaborations – like CERN or the European Space Agency – that benefit high-tech industry. Other spin-offs, such as collaborative research programmes between universities and industry, are deliberately encouraged. However, some spin-offs go completely unrecorded. The Blackett Laboratory, here at Imperial College, has long been a source of new, high-tech firms, such as ICOS, Infrared Industries, Chelsea Instruments, Queensgate Instruments, Kidger Optics and even Psion. But such companies are rarely mentioned in discussions about the “usefulness in science”, even though they employ hundreds of physicists and make profits of millions of pounds.

The common thread is that while research is a high-risk endeavour if assessed as a wealth generator, it does pay off handsomely in the end if considered over a broad enough front. Unfortunately, the investor who is asked to pay for this research – usually the taxpayer – does not see this clearly enough. The problem is that it is not currently part of our ethos to explain.

Physics should be more than just a part of biomedicine’s back-up team. While physicists obviously ought to be working with the life scientists wherever and whenever they can, neglecting our own discipline on its own merits will be bad for everyone, including life scientists. Grant proposals should therefore emphasize outward-looking as well as inward-looking publications: a publication in Physical Review Letters may bring job satisfaction and the admiration of one’s peers, but a book, press article or media appearance is more likely to maintain government funding. Our subject will die if we persist with an “ivory-tower” culture that sees any publication with coloured illustrations as irrelevant, and any contact with industry as grubby.

Showing off the spin-offs

So what spin-offs can we point to? One in three of us faces cancer. The software of choice in simulating the way that particles used in radiotherapy interact with matter is derived from well known Monte Carlo computational techniques that were developed for high-energy physics. (Indeed, the entire field of computer simulations was one of several benign spin-offs from the Manhattan project.) The huge magnets used in magnetic resonance imaging (MRI) techniques, the gamma-camera technologies used in advanced medical applications, and the detector arrays used to diagnose patients are all based on technologies developed at CERN and elsewhere (see the feature articles in this issue for more on recent developments in medical physics).

And who invented the World Wide Web? It was Tim Berners-Lee, while he was working at CERN trying to solve the problems that particle physicists faced in transferring data. Some say that the Web could be CERN’s biggest legacy. After all, the Web’s contribution to global commerce is already much bigger than the CERN budget and is growing faster all the time.

In the UK, the Particle Physics and Astronomy Research Council’s mission is also highly conducive not just to spin-off firms but also to specialist post-doctoral analysts. Meanwhile, many former physics students from Imperial earn huge salaries as “rocket scientists” in banks and financial houses.

It is important to emphasize that not all pure research can lead to spin-offs and that the connections of a research project in the physical science with wealth creation are not always obvious. However, research funding is a bit like forestry: we plant seedlings because we know that they will grow into saplings and larger trees, even though we cannot say in advance which small fraction of those seedlings will survive. In fact, some seedlings are there merely to protect the eventual winners. The problem is that in much university research – especially in the physical sciences – researchers do not even look for connections and applications.

What can you do?

How can “pure” scientists convince those who pay for their research that it is useful? The answer is that they must make the effort. Too few physicists feel obliged to tell the people who pay their salaries why they do what they do. This must change. Physicists ought to be able to say exactly why their research proposal is “of use”, and they ought to be able to do this on two sides of A4 paper and in a language that anybody who is interested can understand. (Black-hole evaporation specialists and quantum-gravity insiders can have three sheets.) They should know how to feed this to a wider audience. We cannot turn our backs on this issue because it is arrogant to expect society’s generosity without explanation.

While we welcome the UK government’s extra money for science, we feel that the lucky recipients must redouble their efforts to explain to those from whom we get this money why it is money well spent. It means talking about spin-offs. It means providing explanations. Doing nothing is not an option.

If we do not accept the need to inform our masters of our merits then we can be sure that nobody else will.