Science is a truly international activity: indeed, Einstein told us that the laws of physics are the same everywhere in the universe, not just everywhere on Earth. Mobility between nations has always been a trademark of the physics community, first between the historic university centres of Europe, and later back and forth across the Atlantic. In the run up to the Second World War many physicists left Europe for the United States to escape persecution by the Nazis; now they leave in search of higher salaries and research funding. Although hard data are difficult to find, there can be little doubt that the US is the key beneficiary of this mobility. In the past two years, for instance, the holders of three of the top jobs in European astronomy have left for the US. The question is: what effect does this “brain gain” – and the resulting “brain drains” elsewhere – have on physics in countries outside the US?
There is no doubt that time spent in North America can be a crucial element in the training of a research physicist, and that European universities benefit when young physicists return to take up permanent positions and start their own research programmes. However, there are worries that the very best physicists might not return, or that they will only return after they have done their best work. Various countries in Europe have realized this and are starting to offer competitive packages to attract and retain the best talent. However, these packages have not been enough to tempt those physicists interviewed in the following news story about the US brain gain.
The brain drain was one of the reasons why the UK government recently announced a major increase in the national science budget, including £1bn for infrastructure and new equipment. However, one criticism that featured strongly among the otherwise positive reaction to the fund was that the government has not done enough to address the fact that academic salaries in the UK are generally lower than those in the US, often by a factor of two or more.
Paying academic scientists the international “going rate” would appear to be an obvious solution, and might seem inevitable given that universities are increasingly being run as “businesses” in the international education market. Ignoring the obvious problems – there is no way that the government is going to agree to substantial across-the-board pay rises for academics – this approach poses other threats to physics departments. In the business model of a university, physics has the disadvantages of low income (i.e. relatively low student numbers) and high costs (physics is expensive). In the short term, the high salaries for physicists look set to remain on one side of the Atlantic.
Quantum largesse
In 1935 Erwin Schrödinger proposed a thought experiment to show the absurd consequences of applying quantum mechanics to everyday objects. Schrödinger imagined placing a cat in a box, along with a vial of deadly poison that is connected to a radioactive atom. If the atom decays, it releases the poison and kills the cat. When the box is closed we do not know if the atom has decayed or not, which means that it can be in a “superposition” of two states (decayed and non-decayed) at the same time. Therefore, protested Schrödinger, the cat can be both dead and alive at the same time – which is clearly absurd. There was obviously, he thought, some boundary between the microscopic world of atoms and quantum mechanics, and the macroscopic world of cats and classical mechanics.
Some 65 years later, physicists have demonstrated a quantum superposition of macroscopically distinct states for the first time (p23). Admittedly, there is little room to swing a cat in a micron-sized superconducting ring, but as quantum mechanics approaches its 100th anniversary in December, it remains in very good shape.
