Since the 1930s a dominant trend has existed within the scientific community and popular science that explains quantum mechanics with all kinds of idealistic and mystical interpretations. Dominant within this school of idealism has been the “Copenhagen interpretation” of quantum mechanics, which originated with academics such as Niels Bohr and Werner Heisenberg who were based in the Danish capital.

Any attempt to give a non-mystical, materialist explanation to the kind of “weird” behaviour observed at the subatomic level has been dismissed out of hand by many in the scientific community, despite the protests of many of the great pioneers in the field of quantum mechanics such as Einstein, de Broglie, Bohm and Bell. The prevalence of an idealist mode of thought in this field, in turn, has been used by all sorts of reactionary philosophers and theologians - not to mention New Age quacks - to peddle their wares.­

Now, however, a string of dazzling and unexpected discoveries in another field of physics - the field of fluid mechanics - has the potential to reopen the debate and reaffirm the case for a materialist and dialectical interpretation of some of the deepest mysteries in modern science. Although much of the new science remains to be elaborated, these discoveries could herald a revolution in the field of quantum mechanics, which will tremendously vindicate the dialectical and materialist approach to science and nature.

Scientific revolution

The story of the philosophical rift in quantum mechanics begins at the end of the 19^th Century. At that time it was believed that scientists had pretty much discovered everything that there is to discover in terms of natural, physical laws. Everything in the universe was thought to act either as a wave or as a particle, and the science underlying both was fairly well understood. Light acted like a wave, rippling through space like waves over the ocean; atoms, meanwhile, behaved like particles – essentially tiny billiard balls bouncing around in accordance with Newton’s laws of motion. With these physical laws science was verging on a complete description of the universe.

All that was left was to tie up the loose ends. However, as in all scientific revolutions, the crisis struck the old physics just when it appeared to have achieved its greatest perfection and completeness. These “loose ends” proved to be the threads that would unravel much of the fabric of the old physics. A number of startling experiments began to provoke unease in the scientific community.

First, an ingenious experiment by two American scientists, Michelson and Morley, proved that light doesn’t behave like any wave that we are familiar with. All known waves required some kind of substance to move through: we are familiar, for example, with how oceanic waves move through water, or sound waves move through air. This is not so for light, which could be transmitted through a vacuum.

When Einstein drew the logical conclusions from these experiments, which demonstrated how light travels through space without a substance to travel through, it necessitated a wholesale revolution at the very core of physics that would touch on some of the most surprising and elemental concepts that “common sense” had taken for granted. Einstein’s new Theory of Relativity showed that time and space themselves are not simple, fixed entities but are measured differently depending on the relative speed of the observer.

Furthermore, key physical concepts such as mass and energy were completely turned upside down as it was shown that one could transform into the other and vice versa. Einstein showed that Newton’s laws – which for so long appeared to be completely unassailable – were far from a complete description of our universe. In actual fact, they proved to be nothing more than a special case of a more general law, with the old physics breaking down entirely once applied at the scale of the very large or the very fast.

This further proves the dialectical notion that, when taken to their extreme, things turn into their opposite: order transforms into chaos; reason becomes unreason; and certainty is cast into doubt.

The revolution that Einstein’s Relativity achieved on the scale of the very large and very fast was about to be supplemented by a revolution on the scale of the incredibly small: quantum mechanics. Where Einstein shattered the old ideas concerning mass and energy, time and space, a growing number of experiments began to conflict with the old idea that something must be either a particle or a wave.

The discovery of the quantum world

Since Huygens’ treatise in the 17^th Century, light had always been understood to behave like a wave. As all other waves have a wavelength, so does light (different wavelengths being responsible for the different colours of the spectrum); and light was also observed to produce many of the patterns known to occur when waves crash into each other and interfere.

However, experiments such as Einstein’s “photoelectric effect”, showed that light also comes in discrete packets, or quanta, called “photons”; light suddenly appeared far more particle-like. What is more, the French physicist de Broglie showed that things previously thought to be quite clearly particle-like, such as electrons, also have a “wavelength” and in some circumstances are able to behave much like waves.

Suddenly the subatomic world proved far more complex than the classical physicists could have imagined – and far harder for common intuition to grasp. The idea that electrons, photons and other subatomic particles can be both waves and particles immediately presents a stark and very real contradiction: a particle is concentrated at a particular location in space. Think of a particle of sand for instance: we can pinpoint it under a magnifying glass and say, “there it is!” It does not spread out in space. A wave behaves very differently however – it does spread out through space, diffusing like ripples in water. A single wave flowing through a harbour can make all the docked ships bob up and down simultaneously because it does not act in one location but dissipates continuously; whereas a rock thrown in to the same harbour can only hit one ship at a time and therefore acts like a particle.

What then of a quantum “wave-particle”? This appears to have many of the properties of a wave, but at the same time we can also pinpoint its location by the use of detectors. This strange behaviour is excellently demonstrated in the celebrated “double slit experiment”. When a beam of quantum wave-particles are fired at two slits, its probability of being in one location or another appears to form a wave pattern when it comes out the other side. A wave of course can travel through both slits as it disperses through space and can interact and interfere with itself on the other side. A particle however can only pass through one slit at a time. How then does the particle travel through just one slit but appear in a position on the other side that suggests it has somehow travelled through both simultaneously and interfered with itself? If this leaves the reader in a state of confusion then they are in good company. As the great physicist Richard Feynman once said, “If you think you understand quantum mechanics, you don't understand quantum mechanics!”

God steps into the gap

The fundamental underpinning of all truly scientific investigation is materialism. This states that irrespective of our existence there is a real, material world that exists independently of our own being and of which we form only a part. In other words, whether an electron passes through the slit to the left or right, or somehow passes through both, it nevertheless exists within space and time, and it exists independent of our ability to observe it.

In the face of such strange behaviour on the nano-scale a number of prominent physicists, led by Neils Bohr and Werner Heisenberg, began to question the very essence of materialism itself in what has come to be known as the “Copenhagen Interpretation” of quantum mechanics.

The quantum world is far removed from our intuitive daily experience, and answering the question “where is the electron at any one moment in time?” - when a wave-particle appears to behave as if it is in more than one place at once - is clearly a non-trivial question.

It is quite another thing altogether though to deny the solubility of this problem by claiming that the material world, as such, does not exist at all independent of our observation. However, this was precisely the interpretation presented by Neils Bohr and others, which today occupies the position of accepted scientific truth. According to this view, it is meaningless to even ask what path a quantum particle takes when going from A to B. Rather, all that exists are a set of “probabilities” that the particle will be here and not there, and that the particle only receives a “real” position, momentum and other properties in the very act of being observed by us. Thus the problem is “solved” (or rather, swept under the carpet) at the cost of denying the existence of material reality itself!

Such a view inverts the real relationship between mind and matter. Now, rather than matter being primary, it is conscious observation which takes precedence and which summons into existence the material world by the very act of observation. Such a world view falls definitely into the camp of philosophical idealism, according to which consciousness, spirit or mind - be it the mind of man or the mind of God - are primary and exist independently of matter and the material universe.

Such a worldview can quite clearly be shown to be absurd by simply asking the question: what is consciousness? A human being is clearly conscious and can observe by experimentation the position of an electron in space. But can the conscious observation of a dog or a mouse or even a nematode worm “collapse the wave function” and thus give a fixed reality to the material world? What appears as a solution to the mysteries of quantum mechanics is clearly no solution at all. However, whilst the idealist Copenhagen interpretation only gives the impression of having resolved the problems of quantum mechanics, can any materialist explanation offer greater success?

The popular success of the Copenhagen interpretation can be explained by many factors: not least being the fact that the press, university departments, religious orders and the ruling class (which all of the aforementioned serve to one degree or another) have a clear interest in the propagation of mystical and idealist nonsense. Such mysticism helps to divert the eyes of the masses upwards towards heaven and away from the material world and their conditions within it. Philosophy and science itself can never be “neutral” in a society divided into hostile classes. Every philosophical doctrine, to the extent that it is adopted by this or that section or class in society and guides their action, is able to play a reactionary or revolutionary role.

However, another apparent strength that the idealists rest on in quantum mechanics is how different and unintuitive the quantum world appears. There are no analogues in the large scale, day-to-day world that display this “wave-particle duality” and which would be able to help us conceptualise what is going on at the subatomic level. As usual, God lives on in the gaps, thriving on human ignorance.

When seeking a materialist solution to this problem a return to the old, Newtonian, clockwork view of the universe is clearly impossible. The revolution in quantum mechanics has disposed of this view once and for all; the quantum world is governed not by a crude mechanical determinism but by the preponderance of chaos and nonlinearity.

However, a startling set of discoveries branching unexpectedly from the world of fluid mechanics, which combines recent discoveries in chaos theory with the classical laws of fluid dynamics, are grabbing attention and threaten to carry a revolution into the field of quantum mechanics, capable of toppling the philosophical idealist garbage accumulated over decades.

Bouncing droplets as wave-particles

In 2007, in a lab in Paris, a number of scientists led by Yves Couder were experimenting with small droplets bouncing on the surface of a fluid when they discovered something remarkable: a macroscopic analogue for quantum mechanics that we can see and reproduce in a simple laboratory setup.

When the droplet bounces off the fluid’s surface it sends ripples out in all directions. As these ripples disperse and bounce around the surface of the fluid they are able to “kick” the droplet in one direction or other as it bounces – causing the droplets to essentially “walk” across the fluid’s surface under the influence of its own ripples.

What Couder and others had produced – in conditions of astonishing simplicity – was something never before seen in the large scale world that we are used to: a connected wave-particle system. Clearly the particle they had created only existed in one point in space; but when we studied its motion across the surface of the liquid it was influenced by the guiding force of the wave that it was intimately connected with.

The analogy to quantum mechanics did not stop at wave-particle duality however. This wave-particle droplet was observed to undertake some extremely peculiar motion observed nowhere else in nature until now – except of course in the subatomic, quantum mechanical world.  Couder’s “wave-droplets” have been shown to possess a whole number of quantum-like characteristics. One of the most stunning of these is the manner in which two bouncing droplets interact as they approach each other. Influenced by each other’s incoming waves, these particles are observed to orbit one another. They do not form just any old orbit however, but orbits of fixed distances with certain orbits being excluded, depending on the wavelengths of their interacting ripples. In the quantum world it has long been known that electrons orbit the nucleus of an atom only at fixed orbits, and we refer to this as the quantisation of orbits; until now, no such similar behaviour was observed to occur on the macroscopic scale.

A whole host of other quantum effects were also observed to occur including the extremely strange phenomenon of “quantum tunnelling”, during which a particles “leaps” through apparently opaque barriers in a way that an ordinary particle would not. Perhaps most remarkable of all, however, these scientists reproduce the same behaviour as that observed in the double slit experiment! The ripples of the wave-particle system are of course able to move through both slits, whereas the particle does indeed move through only the one.

There are naturally limits to which the analogue of bouncing droplets can be applied to the quantum world – for one thing quantum mechanics occurs in the three dimensions of space whereas the droplet walks in two dimensions only as it crosses the surface of the fluid. Much of the work of mathematically describing this newly discovered system remains to be done, and there is a great deal of investigation to be carried out. This will also be aided, of course, as knowledge of this experiment further penetrates into the scientific circles of quantum physicists, which will bring a much greater knowledge of the broader processes at play in the subatomic world.

The dialectics of nature

To the extent that this new analogue offers a glimpse into the reality of the quantum world, it in many ways appears to represent a return to the well described concepts of classical physics. However, in another sense it returns to this starting point on a higher level, in a dialectical negation of the negation. No longer does a quantum particle represent a simple billiard ball, bouncing around through space. Instead we have a far more complex and chaotic motion, which is at the same time unpredictable and yet able to produce only a limited set of patterns and behaviours. There is a dialectical unity of opposites: order and chaos; predictability and uncertainty; simplicity and complexity.

One of the key characteristics of the philosophy that underpins the old, mechanical Newtonian view of the world was its neglect of history. When we run Newton’s laws backwards we see that they apply just as well in both directions in time. Time itself has no arrow under Newton’s laws, contrary to our everyday experience; and in the hands of the crude, metaphysical materialist history as such suffers complete neglect. If we imagine two billiard balls colliding and moving away from each other, we could equally run the tape backwards and it would describe motion that satisfies Newton’s laws just as well.

In the chaotic model that emerges from the motion of the bouncing droplet, however, we see that each impact produces a new ripple that dissipates through space, interacting with other ripples, reflecting off surfaces and ultimately giving the particle what Couder and others describe as a “memory” of its previous path and development. The historicity of such a conception represents a far more dialectical view of nature than the old, mechanistic view of Newtonian mechanics.

As yet, the new discoveries in fluid mechanics are making slow progress in their penetration into the field of quantum mechanics. In part this is doubtless due to the conservatism of human consciousness, especially when academic careers have been built up that depend upon this or that interpretation of the existing physics. To a far greater degree, however, the entire pursuit of “getting to grips” with what is actually going on at the subatomic level is wholly neglected by quantum physicists. What is regarded as more important is the accuracy of our predictions; whereas philosophy departments can spend their time speculating over the “real nature” of the subatomic world. Such a view would be fundamentally mistaken, and physicists should endeavour to defend the fundamental tenets of materialism.

All real scientific investigation takes as its starting point the real and independent existence of the material world itself, within which we form merely a part. The ideas of science up to the most abstract and profound laws are but the generalised descriptions of the material world based on our observation and interaction with it, what Marx described as sensuous human activity. As technology and science progress, our knowledge of the material universe acquires a greater “truth”, but at all times remains simply a closer approximation. Like light propagating out into an infinite darkness, the sphere of our knowledge is constantly expanding, but at all times that which is yet to be known remains as infinite as nature itself.

It is the inherent optimism of the materialist method that states that what might be unknown today will be known tomorrow. For the materialist there is an unknown, but there is no unknowable. The confusion of the unknown for the unknowable represents a retreat from materialism towards idealism and solipsism. Such a reactionary philosophy raises the drawbridge on science and encourages a retreat into the ideal world of speculation – and ultimately to the religious cloister, as shown by the tremendous succour that all kinds of religious groups have taken from the Copenhagen interpretation. Such a point of view is a threat to science itself, and for this reason it must be the duty not only of Marxists and materialists but of scientists in general to combat such idealistic ideas where they appear.

In this light, the discoveries of Couder and others, which are increasingly being taken seriously in wider academic circles, represent a tremendous vindication for a dialectical and materialist understanding of nature. Indeed, every such step forward in the progress of science represents such a vindication, because this method is nothing more than a true description of how nature, society and the whole of reality develop according to the most generalised laws of motion.

Sooner or later quantum mechanics will be shaken by a thoroughgoing revolution that will leave no rock unturned in the field, and the latest discoveries suggest that the field may be entering into a pre-revolutionary crisis quite imminently.