Determinism

In the early years of the 19th century, science was on a roll. The dark days of alchemy were beginning to give way to the modern science of chemistry as we know it today, the world of physics and the study of electromagnetism were starting to get going, and the world was on the brink of an industrial revolution that would be powered by scientists and engineers. Slowly, we were beginning to piece together exactly how our world works, and some dared to dream of a day where we might understand all of it. Yes, it would be a long way off, yes there would be stumbling blocks, but maybe, just maybe, so long as we don’t discover anything inconvenient like advanced cosmology, we might one day begin to see the light at the end of the long tunnel of science.

Most of this stuff was the preserve of hopeless dreamers, but in the year 1814 a brilliant mathematician and philosopher, responsible for underpinning vast quantities of modern mathematics and cosmology, called Pierre-Simon Laplace published a bold new article that took this concept to extremes. Laplace lived in the age of ‘the clockwork universe’, a theory that held Newton’s laws of motion to be sacrosanct truths and claimed that these laws of physics caused the universe to just keep on ticking over, just like the mechanical innards of a clock- and just like a clock, the universe was predictable. Just as one hour after five o clock will always be six, presuming a perfect clock, so every result in the world can be predicted from the results. Laplace’s arguments took such theory to its logical conclusion; if some vast intellect were able to know the precise positions of every particle in the universe, and all the forces and motions of them, at a single point in time, then using the laws of physics such an intellect would be able to know everything, see into the past, and predict the future.

Those who believed in this theory were generally disapproved of by the Church for devaluing the role of God and the unaccountable divine, whilst others thought it implied a lack of free will (although these issues are still considered somewhat up for debate to this day). However, among the scientific community Laplace’s ideas conjured up a flurry of debate; some entirely believed in the concept of a predictable universe, in the theory of scientific determinism (as it became known), whilst others pointed out the sheer difficulty in getting any ‘vast intellect’ to fully comprehend so much as a heap of sand as making Laplace’s arguments completely pointless. Other, far later, observers, would call into question some of the axiom’s upon which the model of the clockwork universe was based, such as Newton’s laws of motion (which collapse when one does not take into account relativity at very high velocities); but the majority of the scientific community was rather taken with the idea that they could know everything about something should they choose to. Perhaps the universe was a bit much, but being able to predict everything, to an infinitely precise degree, about a few atoms perhaps, seemed like a very tempting idea, offering a delightful sense of certainty. More than anything, to these scientists there work now had one overarching goal; to complete the laws necessary to provide a deterministic picture of the universe.

However, by the late 19th century scientific determinism was beginning to stand on rather shaky ground; although  the attack against it came from the rather unexpected direction of science being used to support the religious viewpoint. By this time the laws of thermodynamics, detailing the behaviour of molecules in relation to the heat energy they have, had been formulated, and fundamental to the second law of thermodynamics (which is, to this day, one of the fundamental principles of physics) was the concept of entropy.  Entropy (denoted in physics by the symbol S, for no obvious reason) is a measure of the degree of uncertainty or ‘randomness’ inherent in the universe; or, for want of a clearer explanation, consider a sandy beach. All of the grains of sand in the beach can be arranged in a vast number of different ways to form the shape of a disorganised heap, but if we make a giant, detailed sandcastle instead there are far fewer arrangements of the molecules of sand that will result in the same structure. Therefore, if we just consider the two situations separately, it is far, far more likely that we will end up with a disorganised ‘beach’ structure rather than a castle forming of its own accord (which is why sandcastles don’t spring fully formed from the sea), and we say that the beach has a higher degree of entropy than the castle. This increased likelihood of higher entropy situations, on an atomic scale, means that the universe tends to increase the overall level of entropy in it; if we attempt to impose order upon it (by making a sandcastle, rather than waiting for one to be formed purely by chance), we must input energy, which increases the entropy of the surrounding air and thus resulting in a net entropy increase. This is the second law of thermodynamics; entropy always increases, and this principle underlies vast quantities of modern physics and chemistry.

If we extrapolate this situation backwards, we realise that the universe must have had a definite beginning at some point; a starting point of order from which things get steadily more chaotic, for order cannot increase infinitely as we look backwards in time. This suggests some point at which our current universe sprang into being, including all the laws of physics that make it up; but this cannot have occurred under ‘our’ laws of physics that we experience in the everyday universe, as they could not kickstart their own existence. There must, therefore, have been some other, higher power to get the clockwork universe in motion, destroying the image of it as some eternal, unquestionable predictive cycle. At the time, this was seen as vindicating the idea of the existence of God to start everything off; it would be some years before Edwin Hubble would venture the Big Bang Theory, but even now we understand next to nothing about the moment of our creation.

However, this argument wasn’t exactly a death knell for determinism; after all, the laws of physics could still describe our existing universe as a ticking clock, surely? True; the killer blow for that idea would come from Werner Heisenburg in 1927.

Heisenburg was a particle physicist, often described as the person who invented quantum mechanics (a paper which won him a Nobel prize). The key feature of his work here was the concept of uncertainty on a subatomic level; that certain properties, such as the position and momentum of a particle, are impossible to know exactly at any one time. There is an incredibly complicated explanation for this concerning wave functions and matrix algebra, but a simpler way to explain part of the concept concerns how we examine something’s position (apologies in advance to all physics students I end up annoying). If we want to know where something is, then the tried and tested method is to look at the thing; this requires photons of light to bounce off the object and enter our eyes, or hypersensitive measuring equipment if we want to get really advanced. However, at a subatomic level a photon of light represents a sizeable chunk of energy, so when it bounces off an atom or subatomic particle, allowing us to know where it is, it so messes around with the atom’s energy that it changes its velocity and momentum, although we cannot predict how. Thus, the more precisely we try to measure the position of something, the less accurately we are able to know its velocity (and vice versa; I recognise this explanation is incomplete, but can we just take it as red that finer minds than mine agree on this point). Therefore, we cannot ever measure every property of every particle in a given space, never mind the engineering challenge; it’s simply not possible.

This idea did not enter the scientific consciousness comfortably; many scientists were incensed by the idea that they couldn’t know everything, that their goal of an entirely predictable, deterministic universe would forever remain unfulfilled. Einstein was a particularly vocal critic, dedicating the rest of his life’s work to attempting to disprove quantum mechanics and back up his famous statement that ‘God does not play dice with the universe’. But eventually the scientific world came to accept the truth; that determinism was dead. The universe would never seem so sure and predictable again.

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SCIENCE!

One book that I always feel like I should understand better than I do (it’s the mechanics concerning light cones that stretch my ability to visualise) is Professor Stephen Hawking’s ‘A Brief History of Time’. The content is roughly what nowadays a Physics or Astronomy student would learn in first year cosmology, but when it was first released the content was close to the cutting edge of modern physics. It is a testament to the great charm of Hawking’s writing, as well as his ability to sell it, that the book has since sold millions of copies, and that Hawking himself is the most famous scientist of our age.

The reason I bring it up now is because of one passage from it that spring to mind the other day (I haven’t read it in over a year, but my brain works like that). In this extract, Hawking claims that some 500 years ago, it would be possible for a (presumably rich, intelligent, well-educated and well-travelled) man to learn everything there was to know about science and technology in his age. This is, when one thinks about it, a rather bold claim, considering the vast scope of what ‘science’ covers- even five centuries ago this would have included medicine, biology, astronomy, alchemy (chemistry not having been really invented), metallurgy and materials, every conceivable branch of engineering from agricultural to mining, and the early frontrunners of physics to name but some. To discover everything would have been quite some task, but I don’t think an entirely impossible one, and Hawking’s point stands: back then, there wasn’t all that much ‘science’ around.

And now look at it. Someone with an especially good memory could perhaps memorise the contents of a year’s worth of New Scientist, or perhaps even a few years of back issues if they were some kind of super-savant with far too much free time on their hands… and they still would have barely scratched the surface. In the last few centuries, and particularly the last hundred or so years, humanity’s collective march of science has been inexorable- we have discovered neurology, psychology, electricity, cosmology, atoms and further subatomic particles, all of modern chemistry, several million new species, the ability to classify species at all, more medicinal and engineering innovations than you could shake a stick at, plastics, composites and carbon nanotubes, palaeontology, relativity, genomes, and even the speed of spontaneous combustion of a burrito (why? well why the f&%$ not?). Yeah, we’ve come a long way.

The basis for all this change occurred during the scientific revolution of the 16th and 17th centuries. The precise cause of this change somewhat unknown- there was no great upheaval, but more of a general feeling that ‘hey, science is great, let’s do something with it!’. Some would argue that the idea that there was any change in the pace of science itself is untrue, and that the groundwork for this period of advancing scientific knowledge was largely done by Muslim astronomers and mathematicians several centuries earlier. Others may say that the increasing political and social changes that came with the Renaissance not only sent society reeling slightly, rendering it more pliable to new ideas and boundary-pushing, but also changed the way that the rich and noble functioned. Instead of barons, dukes and the nobility simply resting on their laurels and raking in the cash as the feudal system had previously allowed them to, an increasing number of them began to contribute to the arts and sciences, becoming agents of change and, in the cases of some, agents in the advancement of science.

It took a long time for science to gain any real momentum. For many a decade, nobody was ever a professional scientist or even engineer, and would generally study in their spare time. Universities were typically run by monks and populated by the sons of the rich or the younger sons of nobles- they were places where you both lived and learned expensively, but were not the centres of research that they are nowadays. They also contained a huge degree of resistance to the ideas put forward by Aristotle and others that had been rediscovered at the start of the revolution, and as such trying to get one’s new ideas taken seriously was a severe task. As such, just as many scientists were merely people who were interested in a subject and rich and intelligent enough to dabble in it as they were people committed to learning. Then there was the notorious religious problem- whilst the Church had no problem with most scientific endeavours, the rise of astronomy began one long and ceaseless feud between the Pope and physics into the fallibility of the bible, and some, such as Galileo and Copernicus, were actively persecuted by the Church for their new claims. Some were even hanged. But by far the biggest stumbling block was the sheer number of potential students of science- most common people were peasants, who would generally work the land at their lord’s will, and had zero chance of gravitating their life prospects higher than that. So- there was hardly anyone to do it, it was really, really hard to make any progress in and you might get killed for trying. And yet, somehow, science just kept on rolling onwards. A new theory here, an interesting experiment here, the odd interesting conversation between intellectuals, and new stuff kept turning up. No huge amount, but it was enough to keep things ticking over.

But, as the industrial revolution swept Europe, things started to change. As revolutions came and went, the power of the people started to rise, slowly squeezing out the influence and control of aristocrats by sheer weight of numbers. Power moved from the monarchy to the masses, from the Lords to the Commons- those with real control were the entrepreneurs and factory owners, not old men sitting in country houses with steadily shrinking lands that they owned. Society began to become more fluid, and anyone (well, more people than previously, anyway), could become the next big fish by inventing something new. Technology began to become of ever-increasing importance, and as such so did its discovery. Research by experiment was ever-more accessible, and science began to gather speed. During the 20th century things really began to motor- two world wars prompted the search for new technologies to enter an even more frenzied pace, the universal schooling of children was breeding a new generation of thinkers, and the idea of a university as a place of learning and research became more cemented in popular culture. Anyone could think of something new, and in that respect everyone was a scientist.

And this, to me, is the key to the world we live in today- a world in which a dozen or so scientific papers are published every day for branches of science relevant largely for their own sake. But this isn’t the true success story of science. The real success lies in the products and concepts we see every day- the iPhone, the pharmaceuticals, the infrastructure. The development of none of these discovered a new effect, a new material, or enabled us to better understand the way our thyroid gland works, and in that respect they are not science- but they required someone to think a little bit, to perhaps try a different way of doing something, to face a challenge. They pushed us forward one, tiny inexorable step, put a little bit more knowledge into the human race, and that, really, is the secret. There are 7 billion of us on this planet right now. Imagine if every single one contributed just one step forward.