Sunday, June 29, 2014

Scepticism is Essential to Good Science

I am, as I claim in the sidebar to this blog, something of a science nut. I read widely on a range of scientific issues, often delving into a level of detail that most non-scientists would avoid. My favourite scientific discipline is physics, particularly the fields of cosmology and quantum mechanics and I like to think I have an understanding of these fields that eludes the casual reader. I don't claim that my understanding is due to any particular intellectual strength but rather a perseverance when it comes to deciphering scientific jargon together with some grounding in university-level mathematics. So I was very interested to read in this Quanta magazine article that a group of scientists are challenging the consensus around quantum mechanics.

Quantum mechanics is the area of physics that covers the behaviour of particles at the smallest scale. It is established scientific wisdom that sub-atomic particles do not behave as do larger objects with 'classical' physical properties. The properties of particles at the quantum level are said to be 'probabilistic', that is they cannot have a particular position and velocity at any one time but rather only a probability of being in a set position and velocity. But the Quanta article suggests that 80 years after Danish physicist Niels Bohr and others of the 'Copenhagen' school gave us the probabilistic interpretation of quantum mechanics, a classical explanation of the behaviour of sub-atomic particles is rearing its head again. If it is proven right (and we are a very long way from that), it will justify Albert Einstein's own scepticism about the probabilistic interpretation when he famously said, 'God does not play dice'.

It is not unusual for long-held, consensus scientific theories to be overturned by new evidence. Indeed, that is the way of science. Copernicus and Galileo overturned the earth-centric view of the cosmos, Einstein himself overturned the belief that the speed of light could not be constant, and in 1982 the long-held modern medical consensus that stress is the primary cause of stomach ulcers was overturned by Australian scientists Dr. Barry Marshall and Dr. Robin Warren, who correctly identified a bacteria, Helicobacter pylori, as the culprit.

Which, of course, brings me to climate change. We are told by such luminaries as President Obama that there is a 97% consensus amongst scientists that climate change has a predominantly anthropogenic (i.e. human) cause. The 97% figure comes from this paper by John Cook and others that was based on their review of scientific literature. Leaving aside the thorough debunking of the research that has been done by the likes of meteorologist Anthony Watts, when faced with such as a claim of scientific consensus we should ask, so what? 

Einstein apparently said that 'genius abhors consensus because when consensus is reached, thinking stops', and I agree with him on that. When introduced to the climate change debate by a well-known (pro-anthropogenic) New Zealand scientist about ten years ago, I decided to do my own investigation. Hundreds of published scientific papers and articles later, I am as sceptical as ever on the theory that all, or even most, climate change in the modern era is man-made. Physical experiments have proven that mankind's carbon emissions have some impact on heat retention in the atmosphere, but the dire predictions of ever-increasing global temperatures resulting from mankind's emissions depend on feed-back mechanisms that have not been proven. In fact the slow-down (or complete absence, depending on how you look at the trends) of global temperature rises since the mid-late 1990s has proven that the mechanisms do not work as climate science models up till then predicted.

I don't know where the on-going search for knowledge in the fields of quantum theory and climate change will lead us but, as John Bush, the MIT professor of applied mathematics in the Quanta article says, 'time will tell...the truth wins out in the end.' In the meantime I will, like Einstein, remain a sceptic.

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