By Russell Stannard
How many of us appreciate just how fortunate we are to be living at a time of scientific discovery? How many realise that the scientific age is but a brief, transitory phase in the evolution and development of humankind? One day it will all come to an end.
I am not talking about technology; there will always be scope for developing new applications of scientific knowledge. No, I refer to fundamental science – the process of understanding the basic laws of nature, what the world and ourselves are made of, and how things come to be the way they are.
Many assume that, by its very nature, science always makes fresh advances, and this will continue indefinitely. Others disagree, pointing out that fundamental science must come to an end when our knowledge of the world is complete – nothing left to discover. My own position is that the end will come much sooner than that. Science will grind to a halt when we have discovered whatever is open to us to discover. Not the same thing at all.
Why is our knowledge likely to be limited? Three reasons come immediately to mind:
Firstly, we must ask what we do our science with. Our brain obviously. But what is the brain, and how do we come to have it? It is a product of evolution by natural selection. Ancestors with superior brains had a better chance of surviving to a point where they could mate and pass on their advantageous genes to their off-spring. That was the brain’s basic function; it was not something ‘designed’ to understand everything about the world.
Secondly, there are practical considerations to take into account. The Large Hadron Collider at the CERN laboratory is currently the world’s most powerful particle accelerator. It is 27 kilometres in circumference. But suppose it would take a much larger machine to unlock the last of nature’s secrets? A favourite theory of physicists these days describes the fundamental building blocks of nature (the electron, neutrino, quarks, etc.) as tiny vibrating strings. But these strings are expected to be tiny – so small we would need an accelerator the size of a galaxy in order to be able to see them. There is no reason why the experiments needed to verify a final, complete theory of everything should be geared to what we can afford and can physically build.
Finally, there is the suspicion that, down certain lines of investigation, we might already be up against what I call the boundaries of the knowable. These are questions that have been around for so long, and are of such a nature, that one suspects that the answers to them are inaccessible to us. It is an intriguing exercise to lay out all the deepest questions facing science today and to then speculate as to which of them, if any, come into that category. And it is an important exercise – certainly for budding research scientists. After all, one presumably does not want to devote one’s entire career to addressing a question that cannot be answered – especially if one could have opted for a different line of research more amenable to producing a worthwhile result.
I use the word ‘speculate’ advisedly. There is, after all, no way of proving that a particular question is, for whatever reason, unanswerable. Which leaves us with an uncomfortable thought. I have said that fundamental science will come to an end. But how will we know that the scientific age has ended? We, or more likely our descendents, will not know. Looking back, they might note the lack of any recent significant advances. But who knows? Perhaps science is just going through a ‘bad patch’. The next Newton or Einstein might be just round the corner. Or not, as the case may be. I suppose when it is noted that the physics text books have not required updating for the past millennium the penny might drop.
One final point. Please don’t tell me that there have been previous claims that science has ended. As everyone knows, towards the end of the 19th century some prominent scientists expressed the view that with the formulation of Newtonian mechanics and Maxwell’s laws of electromagnetism, everything was just about wrapped up. And that was before relativity, quantum theory, and elementary particles came along! And indeed, in our own time there have been those, like John Horgan, who claimed that science was now finished. I make no such claim. I foresee many, many years of exciting and important discoveries being made. All I am saying is that at some point in the future science must come to an end, and that for certain lines of investigation we might already have encountered the boundaries of the knowable.
Russell Stannard is Emeritus Professor of Physics at the Open University where for 21 years he headed the Department of Physics and Astronomy. A high-energy nuclear physicist, he has carried out research at CERN in Geneva and at other labratories in Europe and the USA. Among his awards he has the OBE, the Bragg Medal from the Institute of Physics, and is a Fellow of University College London. His many books includes the bestselling Uncle Albert trilogy, which introduces younger readers to relativity and quantum theory, and Relativity: A Very Short Introduction. His latest book is The End of Discovery, out in the UK on September 23.