12.1 Doppelbelcher and the OOO
Felix Doppelbelcher Jr was a very disgruntled young man. He had just learned that his stipendium at the prestigious Fachgeplonk University in Omsk had been terminated. Not many in the general public had ever heard of this Institute, or indeed of Omsk for that matter, so he knew his termination would cause little stir in the world at large. However, within the small circle of Omphaloskepsis graduates, or OOO (i.e. the Omphaloskeptics of Omsk), as they liked to call themselves, his expulsion was a major talking point. (Omphaloskepsis, a widely pursued activity in many academic circles, is usually known by its alternative name of “navel-gazing”. Only at Fachgeplonk University is it recognised with its own Faculty.)
The aim of the OOO was to return physics to the embrace of philosophy, from which they believed it had unwisely departed, shortly after the debunking by Galileo of so many of Aristotle’s assertions. The normal OOO modus operandi therefore involved the execution of thought experiments, and the development of mathematical models of imposing complexity. In this regard, the Dean was typical of most old-school OOOs, who regarded any knowledge obtained by experimentation as somehow of a lesser worth than that derived from purely cerebral processes. Doppelbelcher, however, was a reactionary who maintained that the OOO would never be accepted as legitimate physicists until they tested their conclusions in the laboratory. He had been in the process of carrying out such an experiment, involving a box, a radioactive source, a Geiger counter, a cyanide capsule and the Dean’s Persian cat (since deceased) when he was discovered by the Dean. This misadventure had led to his expulsion.
The real reason for his demise, however—or so Doppelbelcher avowed—lay with his assertion that the fundamental constants of nature, in particular Planck’s constant h and the speed of light c, were unstable. Why was this proposition so unpopular? Surely it was only what would be expected from Quantum Mechanics, where atoms could jump spontaneously from one energy level to another. Why should one expect the fundamental constants to be exempt from similar erratic behaviour? Clearly, they should not. However, once ideas become encapsulated in the credos of physics, it is very difficult to overthrow them. In this case, he knew the Dean was saving himself from a long, animated debate over a philosophical principle by ousting him on the pretext of a Schrödinger’s Cat experiment gone wrong.
Doppelbelcher could not understand why his ideas had received so little support from his peers. Evidence of sudden changes of state abounded when one knew where to look for them. Who has not lost their keys, only to have them turn up a few seconds later in some unlikely location? Who has never felt someone behind their back staring at them, and yet, when they turned quickly to catch them out, they had vanished? It could all be explained by a sudden fluctuation in Planck’s constant.
Try telling that to the OOO, thought Felix. “You’re forgetting Occam’s Razor,” they preach. “Your ideas are too complicated. Remember, the simplest explanation is always the best.” This from a mob who believe we live in an eleven dimensional universe—one of an infinite number of parallel universes that we can never visit—and that ninety-five percent of its contents are invisible. “Lord, give us a break!” he muttered aloud.
“Well, they are not going to win,” said Felix, straightening his jaw. “Data must always triumph in the end.” His eyes shone with an awakening passion. “And why should I care about some piddling stipendium when my rich aunt’s favourite charity just happens to be the Omsk Home for Stray Cats.” He grinned at the possibilities presented by such a handy source of raw material. You never know, after he’d finished with the Schrödinger investigations, there might even be a few animals left over to pursue the occasional diffraction experiment.
***
(Editor’s Note: We are relieved to report that Doppelbelcher’s casual attitude to the ill-treatment of cats is not shared by any of his fellow physicists, and eventually led to his internment in a Siberian salt mine, with only his radioactive source, Geiger counter, and cyanide capsule for company. There he remained for many years, until one morning his cell was opened and discovered to be empty. Speculation still rages over his mysterious disappearance, with the suspicion that some spooky quantum phenomenon has been at play.)
12.2 Time to Jazz It Up
We have now reached the final Chapter of our book, and it is therefore appropriate that we round off our journey with a tantalising glimpse for the reader into some of the areas of physics where new discoveries are being made, and new ideas put forward, almost on a weekly basis. As is clear from our tongue-in-cheek introductory story above, there is often a multiplicity of views in these largely unsettled fields, for physicists after all are only people, with all their human frailties.
In his entertaining and informative book, “The Jazz of Physics” [1], cosmologist and jazz musician, Stephon Alexander, explores the connection between music and physics, a relationship that can be traced back to the Greek mathematician, Pythagoras. He also discusses the importance of beauty in physics, a concept that we first encountered in Chap. 3.
In the early stages of his career, while a graduate student at Brown University, Alexander asked one of his mentors, Robert Brandenberger, what he thought was the most important question in cosmology. Our readers will by now no doubt have some answers of their own to this question, e.g. “what caused the Big Bang?” or “how do we resolve the conflicts between quantum mechanics and relativity?” After pondering for some time, Brandenberger replied: “How did the large scale structure in the universe emerge and evolve?”
The more one considers this response, the more profound it appears. If, as is now generally accepted, the universe began with a large cataclysmic explosion, presumably from an incalculable amount of energy with no inherent order, what are the origins of the order that now exists, notably clusters of galaxies, individual galaxies, stars, solar systems, and ultimately life? After all, “nothing will come of nothing,” [2] as the Bard so rightly, if somewhat plagiaristically,1 informs us.
The word “evolve” in Brandenberger’s reply is evocative. A human develops from fertilised egg to adult because of the presence of DNA in the nucleus of the egg cell. Is there some equivalent package of information present at the initial Big Bang singularity that foreordains the evolutionary path, at least in broad principle, that the universe must take? In his theory of the evolution of species, Charles Darwin identified natural selection as the driver that guides the evolution of a species and creates order from the chaos of random mutations. Is there a corresponding driver, perhaps involving gravity, that produces order out of the early chaos of the universe?
On the other hand, what appears to be order may actually result from something very simple. One of the authors is reminded of a fishing excursion some years ago, when a clumsy comrade knocked over the bait container, depositing hundreds of writhing maggots in a heap on the carpeted floor of our boat. As we watched, we saw an almost perfect, rapidly expanding, circle of larvae advancing with military precision outwards from where the heap had landed. They were not, of course, following the command of some insect drill sergeant, but had simply headed off in the direction they happened to be pointing when they alighted. The random nature of the fall ensured that all directions were equally covered, their speeds were approximately the same, and the result was the circle we observed. There are many examples of complex behaviour arising from a few underlying basic rules in social insects (bees, ants, etc.), flocks of birds, schools of fish [3], and even crowds of humans. The science of thermodynamics, including concepts such as entropy, has been successfully applied to interpret crowd behaviour.
So perhaps the emergence of structure in the early universe is just chance, and we are simply fortunate that our world seems to be tuned to support the development of life? If so, we have indeed won the lottery, because a slight change in any of a number of fundamental physical constants, or a small variation in the physical laws or in the universe’s conditions in its early stages, would have produced a universe where life as we know it would be impossible. We shall discuss the origin of the universe further in Sect. 12.4. It is also possible that our universe is not unique, and we are surrounded by innumerable other inaccessible universes, in which case we are only aware of our own universe precisely because it is one in which life is possible.
Some readers would say that such questions belong in the fields of philosophy, metaphysics and/or religion, because it is impossible to ever explore these issues with the methodology of science, as no observations of the early days of the universe are possible. Since the time of Galileo, theory and experiment (or observation) have progressed together in a symbiotic relationship that has produced our modern technological world. However, there are many who believe almost religiously (as did Dirac) that beauty is a better guide to the veracity of a theory than experiment or observation. In part, this attitude has been forced upon cosmologists by the difficulty (or even impossibility) of obtaining observations in the regions of space-time now of critical interest (e.g. near the big bang singularity).
Fundamental Particle physicists are also faced with difficulties, albeit of a somewhat different nature. In their case, following the triumphant discovery of the Higgs boson in 2012, the pickings from Cern’s Large Hadron Collider have been meagre indeed. Most of the particles predicted by the various extant theories have steadfastly refused to make an appearance, and theorists have attributed this reluctance to insufficient energies in the collider beam. They have registered their desire for a more energetic accelerator, but such devices, with their billion dollar price tags, must compete in priority with feeding the starving masses, solving the climate change problem, curing cancer, and other more urgent issues.
As a consequence of the difficulty in obtaining appropriate data in the two fields that lay at the vanguard of modern physics, we now appear to have entered an era of post-empiricism, where the beauty of the mathematical equations is used in selecting which areas to pursue. But beauty according to whom? Without the constraining hand of experiment to guide us, beauty is now given a license it has never had since the time of Galileo. The lauding of beauty (aka symmetry) in the Twentieth Century resulted in some stunning successes, for instance, in Quantum Electrodynamics and the Standard Model of Particle Physics. However, if a theory did not pass the test of experiment, beauty was not of itself a sufficient criterion for its acceptance.
For many astronomers, the Steady State Theory of the universe was more “beautiful” than the currently accepted theory, with its ugly Big Bang singularity at the origin of space-time. However, the Steady State Theory was discarded without compunction when sufficient observational evidence had accumulated against it. To further complicate the issue, beauty is as subjective in mathematical equations as it is in art galleries. Some researchers show a very human tendency to find beauty in their own equations, and ugliness in those of their colleagues. In any case, as Sabine Hossenfelder asks in Lost in Math: “Why should the laws of nature care what I find beautiful [4]?”
We began our journey in this book with a look in Part 1 at the earliest attempts of humans to make sense of their world. We saw how progress was erratic until the development by Galileo of what is now known as the scientific method, whereupon began the bourgeoning of science that has impacted the lives of everyone on our planet. Now it seems that some domains of physics are beyond the reach of experiment or observation, and thus beyond the ken of what we mean by science. Perhaps we should just accept this, albeit with a degree of despondency. However, human curiosity being what it is, it is difficult to prevent ourselves from venturing into regions that are customarily regarded as metaphysics.
12.3 The Beginning of Time
Surely every intelligent being has at some time speculated about the origin of their universe. However, arguably, nobody before Galileo had ever really doubted the infinite range of time, and even believers in the creation of the world by a God (or some other more or less defined entity), believed that, if not the world, then at least God had always existed. Likewise space was thought to range unbounded in its three classical dimensions.
Today, the current consensus is that time originated with the “Big Bang”, i.e. it does not run back forever (to minus infinity), but starts at a given singularity. (We must be careful not to say at a given point in time.) In other words, when the universe was born, space and time were born together in the composite known as space-time.
As a consequence, to use a simpleminded analogy, the universe is like a movie that has been switched on and lasts as long as the director chooses to allow it. However a movie runs for only a limited time, while our universe might last forever, with an expansion leading to an extremely vast and cold desert. Or it might terminate at any time in a collapse, or unimaginable cataclysm, in which case the whole process might begin anew. We hinted at this possibility with our analogy of the ouroboros in Chap. 3.
In the case of a movie, we can learn who the director was, where it was made and why, how much it cost, and a host of other details. This information is available because the movie was produced in the framework of time. There is a “before”, which can tell us how the director conceived the idea, and how he or she obtained the requisite financial support. There is a “during” with all the paraphernalia that creating a movie involves, and there is an “after”, in which the audience can enjoy (or hate) seeing it, and learn of its eventual success. In our Universe, there is no “before”, because time itself had no existence “before”. We cannot ask what its cause was, because a relationship of cause-effect requires time in order to exist.
At least this was the picture of the universe held by cosmologists since Einstein staggered the world by overturning Newton’s theory of gravity. Around the turn of the Twenty-first Century, however, there were new proposals put forward that modify our conception of the earliest moments of the universe. They are controversial, and certainly not accepted by all, but have in recent years garnered increasing currency. We present some of the basic concepts here.
In Chap. 10, we explored the beginning of the universe as far back as we can reasonably go. As we emphasised there, the first 380,000 years of our world’s existence remains shielded from our view, due to the impenetrability of this region to electromagnetic radiation. The newly discovered gravitational waves are currently the only foreseeable possibility of direct observation of this period in the future.
Although direct observation is not possible, there are residual effects from this period that linger into the later development of the universe, and provide us with some idea of what may have gone on before. Indeed, we find ourselves very much in the same position as Plato’s slaves (see Chap. 1), whose observations of the shadows on the cave wall were all they had to provide them with an inkling of the reality in which they were immersed. An example of these residual effects is the incredible isotropy of the Cosmic Microwave Background, and the nature of the few remaining inhomogeneities. As we saw in Chap. 10, a period of very rapid inflation, lasting from 10−36 s to 10−32 s after the Big Bang, has been widely accepted as an explanation of these effects.
Nevertheless, there will always remain a desire to explain the inexplicable. Our universe appears to be tailored for the evolution of life. This is one of the outstanding enigmas facing us as intelligent humans. It may be of little importance in our daily lives. It has no impact on climate change, the international economy, or who will win the hundred-metre sprints at the next Olympics. It is just a question that nags at us, and refuses to be put aside.
Naturally, there are theories that have been constructed to address this issue. They also attempt to explain the preponderance of matter, compared with anti-matter, in our universe; the laws of physics; and the possible unification of the four fundamental physical forces. Most of these theories involve a multiverse, in one form or another. We shall discuss the multiverse, which is a whole swathe of parallel universes, in Sect. 12.7. For the moment, let us discuss the very early universe.
So enrapt were cosmologists by the success of the inflation model of Alan Guth (see Chap. 10) that they applied it to the era immediately after the Big Bang. At these times, because of the infinitesimal size of the space containing all matter/energy, gravity is expected to dominate all physical interactions. Indeed, all of the forces of physics may have been unified at this time. Unlike in Guth’s original proposal for inflation, it has been suggested in a new model known as “eternal inflation” that inflation persists forever. Within the inflation field, quantum fluctuations occur spontaneously and randomly from place to place and time to time. Some of these fluctuations result in regions where inflation stops, and a universe such as ours begins evolving. In others, inflation continues rapidly. In this theory, our universe is a single “pocket” or “bubble” embedded in a vast assemblage of universes in an inflating space without end.
Soap bubbles provide a model for bubble universes. We live in a “bubble”, surrounded by countless other bubbles. Each has its own physical laws, and fundamental constants. Most of them are unsuitable for life
12.4 Interfaces between Theories
It is at the interface between theories where some of the most challenging areas of physics lie. We have seen, for instance, how, as the number of molecules interacting with each other in a gas increases, physicists were forced to resort to a statistical approach to the problem. It is not that they believed that the laws of mechanics did not hold, but only that they could not be solved for a system containing so many molecules. This led to the development of thermodynamics, which in itself has been applied to areas way outside of physics, such as the description of crowd behaviour at rock concerts.
The success of Quantum Mechanics and Relativity in the 20th Century, coupled with the continuing dominance of Newtonian Mechanics for the solution of the physics problems of everyday life (building bridges, cars, rocket ships, etc.) has led us to several important new interfaces. These are discussed below.
Newton meets Einstein
The interface between classical mechanics and relativity presents comparatively few problems. The Theory of Special Relativity could be applied in Newton’s domain, where the velocities of objects are small compared with the velocity of light, as it is accurate there. However, it is too difficult to use in most cases, so we prefer to stick with Newton’s formulation. This example is the ideal case of a smooth transition between two different theories operating in overlapping regions, where the classical theory can be regarded as a high-accuracy approximation of the other.
Similarly, the field equations of Einstein’s theory of General Relativity reduce to Newton’s theory of gravity when the space-time curvature is relatively small (i.e. the gravitational fields are “weak”) and the speed of the objects is much less than that of light. Except for the fact that Einstein’s field equations are horrendously difficult to solve, we would therefore be able to discard Newton’s theory completely. Certainly some of the concepts in the theories of relativity (e.g. mass-energy equivalence, and the dependence of simultaneity, time dilation and the contraction of length on the motion of the observer) stretch our credulity, but with an open mind and a faith in classical logic and experiment, they can be accommodated.
Newton meets Schrödinger and Heisenberg
On the other hand, the concepts of QM are so strange that even a genius such as Einstein could not accept them. Why do we see so little evidence of these weird quantum phenomena, except in the world of atoms and fundamental particles?
Since its earliest days, it has been realised that QM should transition smoothly into classical mechanics as one moves from the microscopic world of fundamental particles and atoms to the macroscopic world of everyday objects. This was recognised by Nils Bohr and is given the name of Bohr’s Correspondence Principle.
Bohr showed how for macroscopic systems, the energies involved in the interactions of their components are much larger than the energies of individual quantum transitions, and in this case the quantum results reduced to those expected from classical mechanics. In addition, macroscopic bodies are comprised of many smaller particles interacting with each other. The wave functions of these smaller particles are continually being jumbled together as the particles move about and swap energies. The resultant composite wave function for the macroscopic body is therefore “decoherent”, which means that it does not produce interference effects. When we walk through a narrow doorway, we have no chance of being diffracted away from our normal path, as a quantum particle would be, passing through a narrow slit.
This all sounds well and good. However, not everybody at the time was convinced by Bohr’s arguments, and the controversy is still alive. There are some simple quantum systems, e.g. a particle confined in a box, that do not pass smoothly from a quantum mechanical to a classical description as the energy of the particle increases [5]. Nobel Laureates, Albert Einstein and Max Born, disagreed strongly on this issue, leading to Born dismissing Einstein’s obduracy to be the result of his old age, a blow below the belt if ever there was one.
As we have seen in Chap. 5, Schrödinger’s qualms about the QM-Classical interface led him to formulate the Schrödinger’s Cat thought experiment to emphasise the problem. It may seem rather ridiculous to consider a cat as being in a superposition of states, one in which it is alive and one in which it is dead. However, what if the cat is replaced by a virus? These are considered by many to be living creatures.
An experiment [6] has been proposed to trap a virus in a vacuum, then slow down the virus's movement until it resides in its lowest possible energy state. A laser can then be used to target the virus with a single photon and excite it into a superposition of two states, one where it is moving, and one where it is not. The philosophical implications of an experiment such as this are far-reaching, particularly if it can be applied to even larger living organisms, such as bacteria and tardigrades (water-bears). The authors of the proposal suggest that such an experiment will be a starting point for addressing the role of life and consciousness in quantum mechanics.
Einstein meets with Schrödinger and Heisenberg, and all parties agree to disagree
The remaining interface is where small particles are moving at high speeds in strong gravitational fields. We simply do not know what physics to apply in this region. It is truly a domain where in medieval times a “here be lions” sign would have been erected to warn brave souls venturing into this territory that they do so at their peril. Unfortunately however, it is not a region that can simply be dismissed as unimportant, for somewhere within its boundaries lies the origin of the universe.
12.5 Entanglement and Quantum Computing (QC)
The concept of Quantum Entanglement (QE) has already been discussed in Chap. 5, and is surely one of the most intriguing results of QM, with a weirdness that mystified even Einstein. Hence, some readers may wonder why we return to it here in Part 3, where our concern is with future developments of our chosen topic (i.e. physics). The reason is that in the case of QE, a clear demarcation between past and future research, i.e. between what has already been acquired as common wisdom and what can more suitably be defined as current research, cannot easily be defined.
In fact, even after many decades, QE still lies at the frontier of research for several reasons. First, new experiments are currently being carried out with the purpose of not only demonstrating the effect, but of visualising it. A paper [7], published by a team of physicists from the University of Glasgow, led by Dr. Paul-Antoine Moreau, describes an imaging process that enables the phases of both a photon and its entangled twin to be recorded simultaneously, thus displaying in a most convincing way the reality of the entanglement.
Second, QE, far from being merely an intellectual curiosity, or even a fundamental theoretical step towards our understanding of the mysteries of nature, may also provide us with an ideal tool for the transition to the quantum world, to which we increasingly appear to belong. Even though at present it may seem farfetched, it seems likely that almost all branches of science will eventually need to include quantum effects for particular applications.
As an example, let us consider chemistry, a field that traditionally was considered something of an “art”, rather than a science, although, of course, its methodology is fully scientific. QM, with its strict mathematical basis, has changed all that. When it was first formulated, and for a few decades thereafter, the pinnacle of glory of QM was the quantitative explanation of the hydrogen atom as a composite of two particles: a proton and an electron. Nowadays, QM is applied to complex atoms and molecules, using the most refined computer techniques. Indeed, Quantum Chemistry has become one of the most heavily mathematised of all the sciences.
Let us now turn our attention to biology and related sciences. Just a few decades ago, nobody could have anticipated (except perhaps visionaries like Schrödinger [8]) that a new science, Quantum Biology, would become a major field of research. Although still in its infancy, Quantum Biology claims to be able to explain hitherto unexplained puzzles, such as the amazing navigational skills of migratory birds in their transcontinental flights [9], or the extraordinary efficiency of the photosynthesis process [10].
Based on quantum entanglement and on the superposition principle, i.e. on the idea that, as we saw in Chap. 5, a quantum system is in all of its possible states at the same time, until it is measured, Quantum Biology offers explanations that appear more convincing than their classical counterparts. However, there are still many open questions, as one might expect for a topic that is the subject of active research.
In spite of the extraordinary relevance of Quantum Biology, the most intriguing and sought after application of Quantum Entanglement (and of the Superposition Principle) is Quantum Computing (QC), to which we devote the remainder of this Section. It is interesting that the concept of a wave function associated with each particle, which for physicists has been one of the most difficult puzzles and headaches for decades, has now become a blessing in disguise, from the point of view of QC. In fact, a classical particle can carry very little information, i.e. its space-time coordinates and momentum, while the wave function of a quantum particle consists of an array of indefinitely many numbers.
Despite Einstein’s misgivings, quantum entanglement is now being incorporated into innovative QC technologies that promise (or threaten) to extend the power of modern computing systems by a factor of up to 100 million. Instead of the conventional bit, with values of 0 or 1, which is the basis for arithmetic in the desktop (or Turing) computer, a QC uses a qubit, or quantum bit. With a qubit, because of its quantum nature, it exists in a superposition of states, and thus can have the value of 0, 1 and everything in between at the same time.
Quantum Entanglement is employed to make measurements of the qubit’s state indirectly, to preserve its integrity. If an outside force is applied to two atoms, it can cause them to become entangled. The instant one of the atoms is disturbed, its wave function collapses and it chooses one spin, or one other quantum value; simultaneously, the second (entangled) atom will choose an opposite spin, or value. This technique allows qubits to be interrogated for their value without actually observing them.
Recent advances have shown that quantum computers are on the verge of solving problems that are too hard for classical computers to tackle. This is called the moment of quantum supremacy. However, there are still many problems to be addressed, in particular, reliability. Any small perturbation can cause the qubits to lose entanglement, producing wrong computational results: one might easily argue “what is the use of a superfast computer if it delivers the wrong answer?” Also, if no conventional computer is capable of checking the numerical accuracy of the computation, how do we ever know whether the solution is correct? These issues will undoubtedly be addressed satisfactorily in the not too distant future.
Some of the main areas of application of QC technology will be in domains that are themselves quantum, such as the determination of the structure of atoms and molecules, and the design of new drugs to cure diseases. There are likely to be applications in Artificial Intelligence, such as quantum neural networks, and in the deciphering of encrypted information. They may well render obsolete the encryption currently employed by banks and others for secure on-line communications. There are thus many implications for financial and national security. As it becomes ever clearer that we live in a quantum world, the range of application of quantum computers will continue to grow, and they are likely to assume increasing importance in guiding our future choices.
12.6 Towards a New Copernican Revolution
Before we open discussion on specific issues in modern physics that merit further examination, it is timely to revisit some of the questions raised in Part 1 that influence the methodology employed by physicists in their pursuits. In particular, in Chaps. 1 and 2 we discussed the nature of reality, what we mean by understanding, and the role played by logic in mathematics, and as a consequence, physics.
Central to the early years of Homo sapiens on this planet was an underlying assumption of human intellectual superiority. So prevalent was this attitude that a name was coined to describe it: anthropocentrism. Initially, innate human intelligence was used to improve the chances of survival and comfort of family and friends. However, after having reached, in the course of tens of millennia, a certain level of prosperity and security, humans began to gloat on their superiority, to the point of not accepting that they were just another animal species. Since no other anatomical differences could be found to explain their perceived nobler role, they thought that the human brain must possess some discriminating characteristic, which they called reason. Whether God given, or in some other manner inserted into the human brain, and being common to all, irrespective of their life experiences, reason had to be “a priori”, or so they thought, compared with the “a posteriori” of external phenomenology.
Perhaps the latter point deserves some further clarification. If we live in a particular part of the earth, and nobody is around to tell us about events from outside our range of experience, we must derive our knowledge solely from (or after—that is the meaning of a posteriori) our experiences of our external world. However, in the case of arithmetic, our logic and intuition lead us to the same results as those obtained by other people, irrespective of where they live, which language they speak, or what has been their life experience. Hence reason, which enables us to perform these arithmetical operations (and many other logical deductions) must come from within us, before our experience of the surrounding world (i.e. a priori).
The perceived privileged role of humanity also led to another important consequence. Since Homo sapiens (whether created by God or not) were of such extraordinary significance, the earth on which they lived had to be the centre of the world, a fact confirmed by their observation of the sun, which was seen as rotating around the earth, and of all the stars, which were apparently nestled in a sphere with the earth at its centre. In short, humanity appeared to be the raison d’être for the whole universe.
“A Venerable Orang-outang”, a caricature of Charles Darwin as an ape published in The Hornet, a satirical magazine, in March 1871. Image public domain due to age (https://commons.wikimedia.org/wiki/File:Editorial_cartoon_depicting_Charles_Darwin_as_an_ape_(1871).jpg (accessed 2020/6/21))
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We now know that we live in the periphery of one of billions of galaxies, and that our sun is just an average star among trillions, and our planet one among billions of others, some of which may have a biosphere comparable with, or even richer than, ours. In Chap. 10, we saw in Fig. 10.7 a small section of space containing thousands of galaxies, each of which is itself comprised of billions of stars. Images such as this one underline the preposterous nature of the pre-Copernican view of the world.
Today, we still may not know whether there are intelligent forms of life on other exoplanets,2 but we do know that here on earth we are the result of an evolutionary process that has led us inexorably to our current position as the most intelligent of earth’s animals.
In Chap. 2, we have discussed the nature and origin of classical logic. This way of thinking, as encapsulated in mathematics, is at the very heart of science, and thus responsible for most of our technological development. We saw in Chap. 2 that both the platonic (aka a priori) and empiricist (aka a posteriori) viewpoints have their followers. In the platonic view, mathematics is “out there”, describing the physical world, and just waiting to be discovered by humans, or presumably other intelligent life forms. In the empiricist view, mathematics is a human invention like any other, which may or may not describe the physical world. It would probably be true to say that most mathematicians would favour the former view over the latter.
In Chap. 4, we saw how Gödel’s incompleteness theorems whipped the rug out from under rigorous mathematicians in their attempts to construct all of mathematics by logical deduction from a limited number of basic axioms. Essentially such an approach results in a system that either has contradictions, or truths that can never be proved. As physics is based on mathematics, we might expect the same arguments to apply, i.e. there will be some physical “truths” that can never be derived from theory. This was the basis of Stephen Hawking’s change of heart about the unlikelihood of a “theory of everything” that we described in Chap. 4, and follows directly from the platonic viewpoint.
We see from the above paragraph that a change of perception of the nature of reason (from a priori to a posteriori) is by no means just an abstruse academic game, but has very important ramifications. If the platonic point of view applies, then Gödel demands that physics must follow mathematics, and physicists should explore which “truths” can never be explained in our current view of the universe.
We saw an example of this type of investigation in Chap. 4, where Toby Cubitt, a quantum-information theorist at University College, London, and co-workers, found that the problem of determining whether there is an energy gap between the lowest energy levels in a material is undecidable. This team also wants to study a related important problem in particle physics, exploring why the particles that carry the weak and strong nuclear forces have rest mass, while photons have no rest mass. This question may also fall into the “undecidable” class.
On the other hand, if the empiricist view holds, our classical logic and mathematics are inadequate to explain all of physics, and perhaps we should be seeking to develop a different logic for this purpose.
It is not surprising that our classical logic works so well in the macro world of classical physics. This is after all the world in which we, and our intelligence, have evolved, and for which classical logic is tuned. No hominid or primate has ever played with toys of molecular dimensions, nor travelled at speeds close to the velocity of light. Had our ancestors been exposed for many thousands of years to the wonderfully strange world of Alice in Quantumland [11], the logic that we now use would arguably be different.
It is a very surprising thing that mathematics describes the physical world so well. Wigner [12] and Manning [13] in two separate thought-provoking papers have explored this enigma under the title: The Unreasonable Effectiveness of Mathematics. Classical mathematics, based on long chains of logical reasoning from a few basic assumptions (axioms), is routinely used to explain observed physical phenomena. It is also used by engineers to construct bridges, aircraft and other complicated structures, with full confidence that they will function as planned. Symmetries in mathematical equations have led to the prediction of new (and at the time yet unobserved) physics, e.g. radio waves, inferred from the equations of Maxwell (see Chap. 5), and antimatter, from Dirac’s equation (see Chap. 8).
Despite the astounding success of classical mathematics in so many areas of physics, there are cases where it falls surprisingly short. Newton’s law of gravity was one of the spectacular early successes of physics. It explains the orbiting of one celestial body about another with great precision; however, the addition of an extra body to the celestial system renders the problem insoluble using classical mathematics, and its solution requires an approximation method.
When we realise that most of the world comprises many bodies, both small and large, interacting with each other, the limitations of the bottom-up approach become clear. When the number of interacting bodies becomes immense, physicists have devised statistical methods (statistical physics and thermodynamics) to successfully describe this domain. However, that still leaves an intermediate region where solutions to important problems are difficult to obtain.
In Chap. 2, we discussed alternative approaches to the traditional bottom-up approach to the laws of physics, involving statistical and pattern recognition methods. Recently, an approach to solving the three-body problem using neural networks has been investigated [14]. Neural networks are computers constructed from parallel arrays of processors. They are not programmed in the same manner as a normal computer, but are trained by presenting them with the output of thousands of calculations carried out with traditional methods; they learn by experience, in the same way that the human brain learns to distinguish the image of a tree from that of an egg. They are then able to use this training to solve different, but similar, astronomical problems much faster than is possible with a conventional computer. Inherent in this approach is the difficulty of checking whether the results obtained in this manner are correct. As we saw in the last Section, this problem will be exacerbated in the near future when quantum computers, with their much faster speeds, become available.
In attempting to obtain a reason why mathematics is so successful in theoretical physics, Hamming and later Abbott [15], point their fingers at humanity. We tend to be selective in which problems we address with mathematics; e.g. there is no mathematical theory of truth, beauty or justice. When existing mathematics cannot be applied to a particular physical problem, we try to invent new forms to use. We have already described in Chap. 4 the extension of our numbering system from simple integers to complex numbers as the centuries passed, and the need to address more complicated scenarios arose. In fact, as we have seen in the last paragraph, there are vast domains of interest where the logical bottom-up approach fails.
Finally, it is suggested that the role of natural selection in the evolution of our species would have favoured those individuals who can follow long chains of close reasoning. We should point out, however, that Hamming is unconvinced on this point.
We have, in earlier Chapters, highlighted the contradictions between the theories of Quantum Mechanics and Relativity, both of which are formulated with classical logic. In particular, Quantum Mechanics is a probabilistic theory, where predictions are of a statistical nature, while Relativity is deterministic, with precise predictions of the trajectories of objects. In Quantum Mechanics, particularly in Quantum Entanglement, the collapse of the wave function fixes the properties of particles simultaneously, while in relativity simultaneity is different for different observers who are moving with respect to each other.
It is entirely possible that scientists will find a way to understand and accept even the strangest quirks of modern science by stretching the limits of classical logic. However, it is also possible that a Copernican revolution in the field of logic, analogous to that which has occurred in our understanding of our place in the cosmos, might turn out to be a more direct route towards a better understanding of those parts of the world that are not our natural domain. Hopefully the new logic, being unhindered by an anthropocentric root, would open us up to a simpler and more natural understanding of modern science and, as a consequence, to new discoveries. Perhaps in the new logic even the contradiction implicit in Goedel’s Incompleteness Theorem, which naively appears to be a logical demonstration of its own logical indemonstrability, would disappear. From such a logic we might be able to derive, as a particular case, our conventional and well established logic, in the same manner that Newton’s mechanics is a particular case of Einstein’s Theory of Relativity.
The first steps towards developing a Quantum Logic were taken in 1936 by Garrett Birkhoff and John Von Neumann [16]. In the intervening decades considerable work has been done by many to explore various non-classical logics. Noted American philosopher, Hilary Putnam, was a strong advocate of a non-classical logic. In 1968 he wrote [17]: Logic is as empirical as geometry. … We live in a world with a non-classical logic. However, during his career, he underwent a change of heart, and in 2005, he recanted [18]: (In 1968) I even proposed an interpretation which involved a non-standard logic, but, as I explained [19] (in 1994), that interpretation collapsed. … More recently, however, it has occurred to me that I should instead attempt to classify all possible interpretations (or all possible interpretations that do not involve giving up classical logic), since I had satisfied myself that the approach via a non-standard logic would not work.
Whatever the eventual outcome of research in this area, it is certainly a possibility that aliens (if they exist at all) may well think quite differently from us. For instance, perhaps their pattern-recognition capabilities will be far more developed than ours, enabling them to discover in an instant “truths” about their world that our one-step-at-a-time, logical approach fails to reveal. All this is speculation, but it is useful to remind ourselves from time to time of how insignificant we are, and how we have a history of allowing our anthropocentric viewpoint to distort our interpretation of the universe.
12.7 The Multiverse: Physics or Metaphysics?
The idea that there exists a multiverse, or large number of parallel universes, has been around for a long time in many different fields. It is a common theme in the Science Fiction genre, and has been proposed in a number of different areas of physics. Schrödinger, in a 1952 lecture, suggested that the alternative histories implied by his equations in QM might actually be realised in other parallel universes.
The concept of a multiverse in cosmology is still highly controversial. A strong proponent, cosmologist Max Tegmark from the Massachusetts Institute of Technology and the Foundational Questions Institute, believes that the multiverse is not a theory, but rather is predicted by a theory, and a widely accepted one at that, namely the Concordance Model describing the inflation of the early universe (see Chaps. 10 and 11). If we are prepared to believe this theory for describing the evolution of the universe after the big bang, we should be prepared to accept its other predictions, unless there is strong evidence to the contrary [20].
Tegmark identifies four different levels of parallel universes within the Multiverse. In a Level I parallel universe, observers experience the same laws of physics that we do, but with different initial conditions, resulting in a different history. In a level II universe, the fundamental physical constants may also be different. This provides an explanation of the Anthropic Principle that we have discussed earlier. A level III parallel universe involves quantum effects, where every time a measurement is made, the universe splits into other divergent universes (see Chap. 5). In a Level IV parallel universe, not just the fundamental constants, but also the laws of physics are different from in ours.
In the absence of direct evidence of the multiverse, proponents are forced to resort to indirect evidence, and this is where most of the controversy and disagreement between different physicists arises. As we discussed in Sect. 12.2, beauty is regarded by some as a sufficient criterion for the acceptance of a physical theory, even in the absence of corroborating observational evidence. Others demand a much higher standard of proof.
Some claim that the refusal to accept a multiverse is another example of anthropocentrism, the placing of our universe above all others, akin to the pre-Copernican period when the earth was thought to be the centre of the known world. Their opponents dismiss the multiverse as the last resort of the desperate atheist and an attempt to avoid the creationist implications of the anthropic principle: i.e. the choice is between a multiverse and a creator, so take your pick. The explanation it offers for the fine tuning of the fundamental physical constants is probably the strongest argument in favour of the multiverse. Paul Davies has discussed the Anthropic Principle in detail in his book: The Goldilocks Enigma [21].
One might conceivably raise Occam’s Razor (see Chap. 3) as an objection to the multiverse. Surely postulating an infinite number of parallel universes to explain our own is a flagrant violation of the good monk’s guideline. Others counter this assertion with the argument that the multiverse eliminates the necessity to postulate precise values for initial conditions and fundamental constants, and that controversial concepts such as wave function collapse are no longer needed. We therefore arrive at a similar point of contention to the one that we encountered in Chap. 3 when assessing the leprechaun and his acts of magic: what do we count as an assumption when applying Occam’s Razor?
The debate on this question is sure to proceed for many years to come, as it revolves around what is acceptable evidence for a scientific theory, which is not something on which there is universal agreement among physicists. Traditionally, successful scientific theories should be testable, i.e. at least, in principle, now or sometime in the future, be capable of being falsified by experiment or observation. The trouble is that the multiverse theory can explain anything at all, and so cannot be falsified. As such, at this time it probably belongs more in the domain of metaphysics than physics. This may not be a life sentence, however. Other physical theories began their existence in this manner, and became accepted later as genuine theories, after emerging technology provided a way of putting them to a practical test.
For an excellent summary of competing views on this topic, see: Universe or Multiverse? by Carr and Ellis [22]. In the following Sections we address some less esoteric issues in earth-bound physics, which also warrant further discussion.
12.8 The Past is Never Dead. It’s Not Even Past [23]
In Chap. 5, we encountered Wheeler’s Delayed Choice Experiment, where choices made at the time of an observation appear to influence what has already occurred in the past. In this experiment we saw that our decision whether to use a wave detector (e.g. a sheet of photographic plate that allows us to build up an image of interference fringes), or particle detectors (which respond to individual particles) affects the wave/particle nature of light passing through two slits. In the first case, light behaves as a wave and in the second as a stream of photons. This behaviour appears to be influenced by the observer’s decision on which detector to use, even if that decision is made after the light has already passed through or by the slits.
It is this apparent retrocausality in the behaviour of the light that creates so many philosophical and conceptual difficulties in the interpretation of this experiment. John Wheeler, the proposer of the original thought experiment, had this to say: There is an inescapable sense in which we, in the here and now … have an inescapable, an irretrievable, an unavoidable influence on what we have the right to say about what we call the past [24]. As we have seen in Chap. 6, the Theory of Relativity has shown that the order of events in space-time can depend on the state of motion of the observer. Simultaneity is not something that two observers moving with respect to each other need agree on. However, neither relativity nor classical physics allows the order of two events to be interchanged when one is the direct cause of the other. This is the heart of the paradox that Wheeler’s experiment reveals.
One explanation of this experiment, but not one that attracts many adherents, is that we live in a deterministic universe, where everything is pre-ordained. An example would be if the universe were a simulation, and we are comprised of bits of software code. This idea was developed in the series of Matrix movies [25] that were popular in the early years of this century. In this case, there is nothing random about the choices an observer makes, even if he or she is under the illusion there is. Our actions are already recorded in the book of time, where past and future lose their meaning.
The explanation, now generally accepted is that it is only at the moment of observation that the photon displays either a particle or wave nature. The act of observation collapses the wave function. Before this the light is described as a superposition of states, some where it passes through one slit, some where it passes through the other, and some where it passes through both. Passage through the slits is not in itself an act of observation, and does not result in collapse of the wave function.
When the observation is finally made, either at the photographic plate or at one of the telescopes, one cannot infer from this what state the photon was in at an earlier time, for then it was in a superposition of all possible states. The phenomenon of collapse of the wave function is one of the most contentious aspects of QM. Some maintain that reality does not exist until we measure it, and that if everybody were to shut their eyes at once, the moon would vanish from existence. This is an extreme interpretation. It is more appropriate to say that quanta exist as unique objects which display both particle and wave characteristics, and that these different characteristics are brought to the fore in different experiments.
Experimenters have performed Wheeler’s experiment over very large distances and for increasingly massive particles. In 2017 a team of Italian physicists at the Italian Space Agency's Matera Laser Ranging Observatory (MLRO) split light on the ground and sent the two beams to a satellite 3500 km away. There they carried out the “delayed choice” part of the experiment, with results that showed the quanta had maintained their wave/particle duality over the length of the journey [26].
Of course, Wheeler’s Experiment can be applied to material particles, as well as photons; QM is quite explicit on this point. In 2015, A.G. Manning and co-workers at the Australian National University carried out the experiment with an ultra-cold Helium atom [27], and observed the same quantum effects that had been observed with photons and smaller particles.
We may ask ourselves just how large can an object be before QM gives way to classical Newtonian physics. A recent experiment has extended this boundary even further with the report of a two-slit interference experiment showing the wave-like quantum behaviour of molecules comprising up to 2000 atoms [28]. The results cannot be explained classically, and are in excellent agreement with the predictions of Quantum Mechanics.
12.9 Are Space and Time chunky?
In Chap. 5 we saw that, from as early as the 5th Century BCE, Philosophers such as Leucippus and Democritus, queried whether matter, which superficially appears continuous, is actually constituted from small, indivisible particles, which they called atoms. This idea lay dormant for two millennia, until revived and confirmed by scientists such as John Dalton, Robert Brown and Albert Einstein. Every student of chemistry today knows that if you divide a drop of water into smaller and smaller droplets, you finally arrive at a single molecule of water, which, when further divided, is no longer water, but atoms of hydrogen and oxygen. This reawakening to atomic theory led to the rich field of Fundamental Particle Physics, which is one of the exciting frontiers of modern physics, and is described in Chaps. 8 and 9.
Quantum Mechanics carries the process of discretisation much further. In fact any electric charge must be a multiple of the charge of an electron (with the exception of quarks, whose charge, as we saw in Chap. 9, is a multiple of one third the electronic charge). The development of Quantum Mechanics in the 1920s was based on the realisation that not just matter, but also energy, and other quantities such as angular momenta, come in discrete packets, or quanta. Indeed, Einstein showed that matter and energy were different forms of the same thing, and could be transformed back and forwards from one to the other.
Around this time much debate was also taking place in mathematics on the nature of the continuum of real numbers. During the period 1918–1921, Hermann Weyl, a renowned mathematician and physicist, was tackling the problem of providing the mathematical continuum—the real number line—with a logically sound formulation. He came to accept that this aim was in principle impossible. As physics relies on mathematics for its formulation, one may well ask what implications such an observation might have for physics. In his moving tribute to his friend, Hermann Weyl, John Wheeler puts the question: Do we not have to say that the notion of a physical world with a continuous infinity of degrees of freedom is an equal idealisation, an equal folly, an equal trespass beyond strict logic? [20] In other words, shouldn’t time and space also be quantised? The response to this question, like many others at the advancing edge of physics, depends on who is providing the answer [29].
In earlier Chapters, we have discussed several times the disagreement between the deterministic nature of Classical Physics and Relativity on the one hand, and the probabilistic nature of Quantum Mechanics on the other. If ever we are to develop a quantum theory of gravity, this conflict must be tackled. In a recent paper [30], Flavio Del Santo and Nicolas Gisin have cast doubt on the determinism of classical physics, claiming that its alleged deterministic character is based on the metaphysical, unwarranted assumption of “infinite precision”. By “infinite precision” they mean the specification of the value of a quantity as a real number (see Chap. 4) with an infinite number of decimal places.
As long ago as 1955, Max Born had raised similar doubts: “Statements like ‘a quantity X has a completely definite value’ (expressed by a real number and represented by a point in the mathematical continuum) seem to me to have no physical meaning [31].” In other words, a proposition, such as “X = 1”, is neither true nor false, since X may equally well be equal to 0.999999999…, with any arbitrarily large number of digits “9”.
Let us return to our question: are time and space also discrete? Apparently so, because for intervals of time below a certain threshold, it is difficult to conceive how any physical interaction can take place. The same considerations apply to space, since time and space must be treated on an equal footing, being part of the same four-dimensional space-time, as we saw in Chaps. 6 and 7.
As Del Santo and Gisin point out, whatever the size of these extremely small cells of space-time, they must be capable of carrying all the information about local interactions. In other words, information, and all the numerical quantities involved, must be embodied into a physical system (encoding), allowing it to be manipulated (computation) and transmitted (communication). But since most naturally occurring numbers have an infinite number of digits (even rational numbers such as 1/3 must be stored with an infinite string of digits), they cannot be stored in a finite (and extremely small) cell. They must somehow and somewhere be truncated. This implies that the mathematics becomes “quantized”, since truncated numbers are multiples of some extremely small number, just as any charge is a multiple of the electronic charge.
Of course the above argument is by necessity oversimplified. Before proceeding one should “explain” quantitatively how the process of storing information works and how the stored information can be retrieved in order to influence the physics of the system. But for our purposes here it is sufficient to conclude that the truncation of numbers with an infinite number of digits can in principle destroy the determinism of most physical theories, and thus eliminate the main cause of incompatibility between QM and relativity.
Einstein’s theory of General relativity, like the classical laws of Newton, is symmetric with respect to time. Both theories work equally well with time advancing from the present to the future, or retreating from the present to the past. One cannot tell by looking at a video of two balls colliding on a billiard table whether the movie has been run forwards or backwards. A few months before he himself died, Einstein wrote a letter to the family of a recently deceased, dear friend, Michele Besso, concerning his death: “That signifies nothing. For us believing physicists, the distinction between past, present and future is only a stubbornly persistent illusion.” This symmetry between past and future does not exist in Quantum Mechanics where, as we have seen in the last Section, the act of observation plays such an important role in defining the present, and separating the past from what lies in the future.
So in these few paragraphs we have a brief glimpse into the fundamental contradictions between the two iconic theories of Twentieth Century physics. These issues are still very much under discussion, and as yet far from resolution. The search for a quantum theory of gravity, perhaps one that requires the discretisation of space and time, looks likely to continue apace for a considerable time yet.
12.10 Conclusion
In much ancient Greek and Roman theatre, the underlying structure of the play is basically the same: (a) introduce the situation; (b) make it as intricate as possible, and (c) find some unexpected and timely trick, capable of solving all the problems neatly, and tying up the loose ends. In a comedy, the good guys live happily ever after, and in a tragedy they usually die.
Sometimes it was the playwright’s plot that got tied in knots, so that the only way he could extricate the protagonist from impending disaster was to bring a god on stage suspended from a crane. The deity promptly dispensed justice: the villains were punished and the good rewarded. Such a theatrical device became known as “deus ex machina”, or “god out of a machine”. Today it is a term applied to any highly contrived theatrical ending that does not arise from earlier events in the play.
Not all the ancients were enamoured of deus ex machina. Aristotle believed that: it is obvious that the solutions of plots too should come about as a result of the plot itself, and not from a contrivance [32]. Many centuries later, Anton Chekhov maintained that: if in the first act you have hung a pistol on the wall, then in the following act it should be fired. Otherwise don’t put it there [33].
So what do these theories of dramatic structure have to do with our journey in this book? If all the world really is a stage, as Shakespeare stated [34], is there a storyline that science, and in particular, physics is following?
Up until Einstein’s “magical” year of 1905, physics had proceeded more or less linearly, albeit with a few revolutions, such as Newton's unification of terrestrial and astronomical gravity, and Maxwell's unification of electricity and magnetism. Then along came Einstein and QM, followed by a “zoo” of unexpected elementary particles, and billions of galaxies, each containing billions of stars, to replace our all-inclusive solar system. To further increase the confusion, all these seemingly disparate fields (Relativity, QM, Particle Physics and Cosmology, plus others, such as Complexity Theory) seem to be for certain aspects intimately related, and for others, conflicting. The “cures” for this chaos (multiverses, String Theory, etc.), seem at times to be worse than the problems they are trying to solve, and we are flooded on a daily basis with new data, new conjectures, and new theories.
Our stage has become littered with various versions of Chekhov’s gun, and we are not yet able to decide which ones will go off sometime in the future to clarify our storyline, and which ones, as was the case with the Steady State Theory of Cosmology, we may safely discard as being of no relevance to the plot.
In this book, and especially in this chapter, we have attempted to present a sample case of what is going on in physics, with no pretence that it is complete, nor that we have selected the most promising pathways, nor even presented the chosen ones in the right way. Other writers would have made their own, different choices.
Ultimately science is driven by the quest to determine the essence of our world: what is its origin? How does it work? What is its future? These mysteries are precursors to the ultimate question: what is the origin, purpose and ultimate fate of humanity, which has fascinated homo sapiens for thousands of years. Such questions have been tackled since the time of Pericles, Socrates, Plato and Aristotle using the tools of religion, philosophy and science.
In this book, we have adopted a scientific approach, since it is the only one which seems to us to have the potential of being truly universal, in contrast with the multiplicity of faiths and metaphysics, despite the continual disputes amongst scientists themselves. Actually, this bickering among peers can be regarded as beneficial, or even vital, to the progress of knowledge. However, we must acknowledge that we are still very far from any meaningful conclusions, and the plethora of Chekhov guns spread around our stage is confronting.
A subsidiary but still extremely important goal remains the quest for a Theory of Everything (TOE), capable of including all physical laws without any inconsistencies. Two opposite outcomes are possible:
1. No such theory will ever be found. As we have seen in this book, at least three times in the history of science, following Aristotle, Maxwell and Gellman (with the Standard Model of Fundamental Particles) it was thought the goal had been reached, or at least that we were close to it, and each time a multiplicity of exciting new physics was discovered. Perhaps we should learn from history, rather than being led astray by delusional hopes, and reconcile ourselves that a world, whose secrets we have been able to completely decipher, might seem "smaller" to many of us, and far less interesting.
2. With all the work going on in so many excellent research centres around the globe, perhaps we shall one day finally discover a deus ex machina to cast all of Chekhov’s guns into oblivion, and reveal the answers to our questions with a compelling clarity. With Quantum Computing, and its incredible power, already coming into being, maybe we are nearer to this goal than we think.
Unfortunately, at the present time, observation and experiment are impractical in Fundamental Particle Physics at the energies necessary to test many theories, and in Cosmology for the earliest moments of the universe. This leaves us to rely on more tenuous and subjective qualities, such as beauty, to decide between competing ideas. This subjectivity leads to disagreement. We appear to be close, if not at, the limits of physics. To go further we risk passing into metaphysics, or religion.
With these words it is time to end our discussion. We began this book with the story of a robot, RT118/17, searching for an answer to the ultimate question of life, the universe and everything. It is therefore appropriate to conclude our book with the results of his journey, and the realisation that our own quest for knowledge will continue as long as curiosity remains a fundamental characteristic of the human condition.
12.11 RT and the Quantum Chip
Oil Can Harry, the Tier 1 robot, who ran the Lubrication Station near Sandsanrock Beach, had just completed his final grease job for the day, and was about to carry out the routine maintenance that kept his equipment in peak working order. His was the prime lubrication station in this part of the Dominion, and he was proud of its AAA rating. It was Harry’s attention to detail that was largely responsible for its success.
Being only a Tier 1 bot had its advantages. His software did not allow him to become bored with routine tasks. His mind drifted back to the incident last year when a Tier 3 comrade had decided to walk into the nearby ocean to test out some theory about the meaning of life. Questions of this nature had never troubled him. He knew what his purpose in life was—it was printed on his duty statement—so he just got on with it.
Harry paused in his effort to disassemble the grease gun. Something was blocking out the light, and he turned to find the cause. To his surprise, there stood the very Tier 3 bot that had been occupying his thoughts. He recognised him only by the insignia RT118/17 etched into the carapace over where his heart would have been, if he’d had a heart.
Arty, as Harry had dubbed him, was still an imposing sight. However the arrogance, that last year had been so intimidating, was now gone, replaced by a remoteness, as though he now found his surrounds unworthy of his attention. This was reflected in his personal appearance. His carapace was coated in dust, intermingled with specks of what appeared to be rust. In short, he looked just plain shabby, and when he moved, his joints emitted a grating noise that sent Harry’s auditory sensors into oscillation.
However, it was in his optics where the change was most noticeable: they no longer had the fierce stare that could bore through to your innermost chip. Instead, his gaze flitted over his surrounds with all the purpose of a drunken butterfly, as though disconnected from a mind that was totally engaged with deeper pursuits.
“Arty?” queried Harry. “It is you, isn’t it?” The optics alighted for a moment on the lubricator’s face, before resuming their spasmodic twitching search pattern. “What on earth has happened to you?” Harry recalled their conversation from last year. “Did you ever find the answer to that Ultimate Question?”
As though suddenly remembering where he was, RT focussed on the diminutive lubricator, and something of its former intensity returned to his stare. “Time. There’s never enough time.”
For one moment Harry thought his customer was about to storm out through the door in a mad dash to resume his quest. He sprang across to block his path, and ushered the creaking Tier 3 bot onto the lubrication bench, where he commenced the procedure for a full grease and oil job. “So what have you discovered then? About the meaning of life?”
“Life! Is a virus alive? Are we alive? What is life?”
“Well, of course we’re – ”
RT interrupted, his voice rising in excitement. “See that cupboard over there,” he said, indicating a large cabinet for the storage of tools. “If you get inside there and shut the door, you become alive and dead.”
“Alive or dead? Well, that’s clear enough, isn’t …”
“No! Alive and dead. At the same time!”
“This is all in the Master Data Repository?”
“Yes, and more. Much more.” RT raised himself on an elbow to give the grease gun easier access. “Harry, you wouldn’t believe …”
The lurching action revealed a tangle of fungus growing in the robot’s armpit. It emitted an odour like the smell of decaying seagrass. “Well, haven’t you let yourself go!”
RT began to tremble noticeably. It was the first time Harry had seen anything like it. Some part of the big bot’s software was clearly malfunctioning. It must be his Emotions Simulation Chip.
“There might be more, you know. Ours may not be the only one.”
“Only one what?”
“Universe. There could be trillions of others, and we’re just one universe in some sort of bubble. Like a soap bubble. So many. So much more to be done.” He started to get up. Harry pushed him back down.
“Lie still, Arty. I’m not finished yet.”
RT tried to relax. It was an effort, but apart from an occasional twitch of his long legs he managed to succeed. “I’ve put in for an upgrade.”
“What?” Harry couldn’t imagine anyone taking such a step. He was perfectly happy the way he was, and certainly wouldn’t want to go through another acclimatisation phase. The last one had been traumatic enough.
“There’s a new technology coming out. Quantum based, using the principles of entanglement …” He noticed Harry’s blank expression. “Never mind. But it’s fast. So many possibilities.” His tremor returned, stronger than before, and he suddenly sat bolt upright, knocking Harry’s grease gun to the floor. “I want it. I must have it.” Harry picked up the gun and hung it on the tool rack. “I’ve sent in a request to the Dominion Robot Maintenance Centre.”
“Wow! That’s a big step.”
“They can’t refuse me. After all, I’m the Chief Operations Officer for the Master Data Repository.”
“We’re finished here, Arty. You’re all set to go.”
RT turned an impassioned face towards the low-tier bot, his ESC clearly in overdrive. “Don’t you see, Harry? Until now, all I’ve done is read about what humans have achieved. With a quantum chip, it’ll be like having a million brains all working together. I’ll be smart. Really smart. I’ll be able to work out new things for myself. So many new things.”
“Like the meaning of life?
“Why not?” Harry gathered up the rest of his tools, and prepared to close the station for the night. “Well, maybe not that. But it doesn’t matter. I can still be part of the quest. That’s the important thing.” He swung his feet to the floor, and headed for the door. “I told you before, Harry. It’s my destiny. It’s what I was made for.”
He strode out through the door, and along the esplanade, with the late afternoon sun glinting off his newly shined carapace.