Towards the end of the last century many physicists feared that their work was done and that the end of physics was in sight. In 1894, for instance, Albert Michelson said that “it seems probable that most of the grand underlying principles [of physical science] have been firmly established”. Of course, the discovery of X-rays, radioactivity, the electron, relativity and quantum mechanics around the turn of the century proved him wrong.
A few years ago in his book The End of Science, the journalist John Horgan claimed that the end was in sight, again, because experimental tests of the major theories of particle physics and cosmology would never be possible. (He also quoted the science historian Stephen Brush’s view that the alleged “Victorian calm in physics was a myth”, but that is a different story.) The physics community is still happily and regularly disagreeing with Horgan. In recent years, however, it has become clear that physics is facing a different challenge, and that if no action is taken, this could well develop into a crisis. Put bluntly: there will be lots of physics left to discover, but not many physicists left to discover it.
Much of the evidence for these fears was presented at a meeting organized by the European Physical Society in Malvern last month. Delegates at Securing the Future of Physics heard that the number of first-year physics students in Germany had fallen from almost 10 000 to just over 5000 during the past seven years, and that there has been an alarming drop in the number of physics graduates who are training to become teachers in both Sweden and the UK. The number of students graduating with degrees in physics has also fallen significantly in the US in recent years.
It is not all doom and gloom, however. In the US, for example, the proportion of students taking physics courses in high schools reached 28% in 1997, a record for the period after the Second World War, while the number of girls studying physics has increased to near parity with boys over the past decade. Moreover, the number of physics teachers has remained constant, despite an increase in retirements. And in the UK, students starting physics degrees have much better qualifications than those studying all other science and engineering subjects, with the exception of medicine.
To see if there is a crisis we need to look at various populations: the numbers of students studying physics at school and university, the number of graduates who remain in research, and the number of physics teachers (which depends on the numbers entering and leaving the profession). These different populations are all obviously interconnected with various feedback loops in operation. The number of physics teachers is probably the most crucial measure at present: fewer teachers means fewer students, which means fewer teachers in a downward spiral.
Some factors are beyond the control of the physics community, such as the state of the global economy – when the economy is strong, fewer science graduates move into teaching. Physicists can, however, have an input in some other areas, such as national education policies, and there is evidence that this is happening. In the UK, for instance, both the Institute of Physics and the Salters organization have developed new curricula for 16-19-year-old students that place physics in a modern context and that should be more fun to both learn and teach.
Ultimately the physics community needs to answer the question: how many physicists do we need? Taking the UK as an example again, the number of new physics graduates every year has remained fairly constant at around 2500 for more than a decade. This is a perfectly satisfactory state of affairs, even if the number of students going to university has more than doubled in this period. However, the shortage of trainee physics teachers is a worry outside the physics community as well – in engineering, for example. There are signs that the government has started to take the problem seriously with a “fast track” for new teachers. And with new forward-looking curricula coming on-line, physics students at all levels – from first-year undergraduates to postgrads who are spell-checking their thesis – might find teaching a more attractive proposition than it was in the past.
