Archive for October 23, 2012

The Tremors from L’Aquila

Posted in Bad Statistics, Open Access, Science Politics with tags , , , on October 23, 2012 by telescoper

I can’t resist a comment on news which broke yesterday that an Italian court has found six scientists and a former government official guilty of manslaughter in connection with the L’Aquila Earthquake of 2009. Scientific colleagues of mine are shocked by their conviction and by the severity of the sentences (six years’ imprisonment), the assumption being that they were convicted for having failed to predict the earthquake. However, as Nature News pointed out long before the trial when the scientists were indicted:

The view from L’Aquila, however, is quite different. Prosecutors and the families of victims alike say that the trial has nothing to do with the ability to predict earthquakes, and everything to do with the failure of government-appointed scientists serving on an advisory panel to adequately evaluate, and then communicate, the potential risk to the local population. The charges, detailed in a 224-page document filed by Picuti, allege that members of the National Commission for Forecasting and Predicting Great Risks, who held a special meeting in L’Aquila the week before the earthquake, provided “incomplete, imprecise, and contradictory information” to a public that had been unnerved by months of persistent, low-level tremors. Picuti says that the commission was more interested in pacifying the local population than in giving clear advice about earthquake preparedness.

“I’m not crazy,” Picuti says. “I know they can’t predict earthquakes. The basis of the charges is not that they didn’t predict the earthquake. As functionaries of the state, they had certain duties imposed by law: to evaluate and characterize the risks that were present in L’Aquila.” Part of that risk assessment, he says, should have included the density of the urban population and the known fragility of many ancient buildings in the city centre. “They were obligated to evaluate the degree of risk given all these factors,” he says, “and they did not.”

Many of my colleagues have interpreted the conviction of these scientists as an attack on science, but the above statement actually looks to me more like a demand that the scientists involved should have been more scientific. By that I mean not giving a simple “yes” or “no” answer (which in this case was “no”) but by give a proper scientific analysis of the probabilities involved. This comment goes straight to two issues that I feel very strongly about. One is the vital importance of probabilistic reasoning – in this case in connection with a risk assessment – and the other is the need for openness in science.

I thought I’d take this opportunity to repeat the reasons I think statistics and statistical reasoning are so important. Of course they are important in science. In fact, I think they lie at the very core of the scientific method, although I am still surprised how few practising scientists are comfortable even with statistical language. A more important problem is the popular impression that science is about facts and absolute truths. It isn’t. It’s a process. In order to advance, it has to question itself.

Statistical reasoning also applies outside science to many facets of everyday life, including business, commerce, transport, the media, and politics. It is a feature of everyday life that science and technology are deeply embedded in every aspect of what we do each day. Science has given us greater levels of comfort, better health care, and a plethora of labour-saving devices. It has also given us unprecedented ability to destroy the environment and each other, whether through accident or design. Probability even plays a role in personal relationships, though mostly at a subconscious level.

Civilized societies face severe challenges in this century. We must confront the threat of climate change and forthcoming energy crises. We must find better ways of resolving conflicts peacefully lest nuclear or conventional weapons lead us to global catastrophe. We must stop large-scale pollution or systematic destruction of the biosphere that nurtures us. And we must do all of these things without abandoning the many positive things that science has brought us. Abandoning science and rationality by retreating into religious or political fundamentalism would be a catastrophe for humanity.

Unfortunately, recent decades have seen a wholesale breakdown of trust between scientists and the public at large; the conviction of the scientists in the L’Aquila case is just one example. This breakdown is due partly to the deliberate abuse of science for immoral purposes, and partly to the sheer carelessness with which various agencies have exploited scientific discoveries without proper evaluation of the risks involved. The abuse of statistical arguments have undoubtedly contributed to the suspicion with which many individuals view science.

There is an increasing alienation between scientists and the general public. Many fewer students enrol for courses in physics and chemistry than a a few decades ago. Fewer graduates mean fewer qualified science teachers in schools. This is a vicious cycle that threatens our future. It must be broken.

The danger is that the decreasing level of understanding of science in society means that knowledge (as well as its consequent power) becomes concentrated in the minds of a few individuals. This could have dire consequences for the future of our democracy. Even as things stand now, very few Members of Parliament are scientifically literate. How can we expect to control the application of science when the necessary understanding rests with an unelected “priesthood” that is hardly understood by, or represented in, our democratic institutions?

Very few journalists or television producers know enough about science to report sensibly on the latest discoveries or controversies. As a result, important matters that the public needs to know about do not appear at all in the media, or if they do it is in such a garbled fashion that they do more harm than good.

Years ago I used to listen to radio interviews with scientists on the Today programme on BBC Radio 4. I even did such an interview once. It is a deeply frustrating experience. The scientist usually starts by explaining what the discovery is about in the way a scientist should, with careful statements of what is assumed, how the data is interpreted, and what other possible interpretations might be and the likely sources of error. The interviewer then loses patience and asks for a yes or no answer. The scientist tries to continue, but is badgered. Either the interview ends as a row, or the scientist ends up stating a grossly oversimplified version of the story.

Some scientists offer the oversimplified version at the outset, of course, and these are the ones that contribute to the image of scientists as priests. Such individuals often believe in their theories in exactly the same way that some people believe religiously. Not with the conditional and possibly temporary belief that characterizes the scientific method, but with the unquestioning fervour of an unthinking zealot. This approach may pay off for the individual in the short term, in popular esteem and media recognition – but when it goes wrong it is science as a whole that suffers. When a result that has been proclaimed certain is later shown to be false, the result is widespread disillusionment. And the more secretive the behaviour of the scientific community, the less reason the public has to trust its pronouncements.

I don’t have any easy answers to the question of how to cure this malaise, but do have a few suggestions. It would be easy for a scientist such as myself to blame everything on the media and the education system, but in fact I think the responsibility lies mainly with ourselves. We are usually so obsessed with our own research, and the need to publish specialist papers by the lorry-load in order to advance our own careers that we usually spend very little time explaining what we do to the public or why we do it.

I think every working scientist in the country should be required to spend at least 10% of their time working in schools or with the general media on “outreach”, including writing blogs like this. People in my field – astronomers and cosmologists – do this quite a lot, but these are areas where the public has some empathy with what we do. If only biologists, chemists, nuclear physicists and the rest were viewed in such a friendly light. Doing this sort of thing is not easy, especially when it comes to saying something on the radio that the interviewer does not want to hear. Media training for scientists has been a welcome recent innovation for some branches of science, but most of my colleagues have never had any help at all in this direction.

The second thing that must be done is to improve the dire state of science education in schools. Over the last two decades the national curriculum for British schools has been dumbed down to the point of absurdity. Pupils that leave school at 18 having taken “Advanced Level” physics do so with no useful knowledge of physics at all, even if they have obtained the highest grade. I do not at all blame the students for this; they can only do what they are asked to do. It’s all the fault of the educationalists, who have done the best they can for a long time to convince our young people that science is too hard for them. Science can be difficult, of course, and not everyone will be able to make a career out of it. But that doesn’t mean that it should not be taught properly to those that can take it in. If some students find it is not for them, then so be it. I always wanted to be a musician, but never had the talent for it.

The third thing that has to be done is for scientists to be far more open. Publicly-funded scientists have a duty not only to publish their conclusions in such a way that the public can access them freely, but also to publish their data, their methodology and the intermediate steps. Most members of the public will struggle to make sense of the information, but at least there will be able to see that nothing is being deliberately concealed.

Everyone knows that earthquake prediction is practically impossible to do accurately. The danger of the judgement in the L’Aquila Earthquake trial (apart from discouraging scientists from ever becoming seismologists) is that the alarm will be sounded every time there is the smallest tremor. The potential for panic is enormous. But the science in this field,as in any other, does not actually tell one how to act on evidence of risk, merely to assess it. It’s up to others to decide whether and when to act, when the threshold of danger has been crossed. There is no scientific answer to the question “how risky is too risky?”.

So instead of bland reassurances or needless panic-mongering, the scientific community should refrain from public statements about what will happen and what won’t and instead busy itself with the collection, analysis and interpretation of data and publish its studies as openly as possible. The public will find it very difficult to handle this information overload, but so they should. Difficult questions don’t have simple answers. Scientists aren’t priests.


Brighton Rock

Posted in Film with tags , , , , on October 23, 2012 by telescoper

Last night I watched the classic 1947 film of Graham Greene‘s novel Brighton Rock. Well, I thought I should get into practice for my tough guy role as Head of School when I move down to the South coast next year. Anyway, this great film is worth watching for many reasons, including a superb performance by Richard Attenborough as the young gangster, Pinkie. But what struck me watching it last night is that this is a rare example of an authentic British Film Noir, not only in terms of the nihilistic central character but also because of the expressionistic use of lighting, deep shadows, and strangely disorienting camera angles, as exemplified in this scene.