Science Tribune - Article - August 1997
Zen and the art of Theories of Everything
James Rennell Division (Room 254/30), Southampton Oceanography Centre, European Way, Southampton SO14 3ZH, UK
E-mail : firstname.lastname@example.org
keywords: theory of everything, particle physics, superstrings, implicate order
I have a theory of everything. That's right. Everything. I can tell you how the universe was born, how life originated and how the universe will end. I can predict precisely what the weather will be like, not only tomorrow, but on this day next year or in a million years' time, anywhere on Earth. I know how evolution will work its magic on today's algae, bacteria, earthworms and modern homo sapiens, and which new species will develop on this and other worlds throughout the cosmos. I know what consciousness is and how it arose. I know your most intimate thoughts. I know what your next move will be. I know when, where and how you will die. I know everything.
Just kidding. But isn't it fun to imagine it may be possible one day ? On the other hand, perhaps the thought terrifies you. Then again, do you ever wonder why some physicists seem obsessed about nearing a Theory of Everything (TOE)? They don't really mean being able to do all of the things listed above. No, of course not. Let's just accept that they are mischievous fellows (for most of them are indeed men). They simply love being bold and provocative. After all, some of them have got books to promote! And ponder this: was it a coincidence that not so long ago we were nearing The End of History, according to the writer Francis Fukuyama? Yet another example of the social sciences attempting to hijack the certainty and respectability of the most fundamental of the natural sciences? But that's enough pondering on that touchy topic.
A cosmic TOE
We all know - including the physicist, if he's honest - that a cosmic TOE is really a modest little appendage. He dreams of expressing the cosmic beauty of all universal forces and particles in one short, elegant equation. But no matter how much he manipulates said equation (should it ever be found), he will be forever at a loss to explain such mysteries as why Mozart was a musical genius, the secret behind the global domination of McDonald's, or the success of 'Friends', the American sit-com.
Well, what's the point of having a TOE, even the physicist's knocked-down version of a TOE? Ah, but there doesn't have to be a point, answers the physicist. Or the point is simply to encapsulate our understanding in the most compact, sylph-like form possible, the highest achievement of the rational brain. It is the search for truth and beauty that propels the physicist forward into the quantum unknown, often with an almost Zen-like appreciation of the absurd. Common sense has no virtue here.
The 'Standard Model' : interactions between fundamental entities
The ultimate encapsulation of these eternal verities of truth and beauty eludes physicists at present. The best effort till now has been the so-called Standard Model. First developed in the 1970s, the Standard Model describes four fundamental interactions between particles: the electromagnetic, strong nuclear, weak nuclear and gravity forces. These interactions occur between families of point-like objects known as leptons (such as the electron) and quarks which most physicists believe are the building blocks of all matter.
The Standard Model has withstood severe experimental testing by physicists and is arguably their greatest creation to date. In 'supersymmetric' versions of the model, every fundamental particle is considered to have a partner in a mirror world. Such supersymmetries will, physicists hope, enable a unification of nature's forces, revealing a mathematical elegance and beauty which would be the hallmark of a true TOE. However, it is accepted that the Standard Model is still incomplete. For example, it does not predict the masses of particles nor the strengths of the interactions between them. Certain theoretical parameters therefore have to be added by hand in an ad hoc manner.
Updated versions of the 'Standard Model'
A particular sticking point is the merging of quantum mechanics and gravity, a feat which not even Albert Einstein, toiling for the last few decades of his life, was able to achieve. Such a grand unification was the motivation for the physics industry generated by superstring theory, which expanded rapidly in the 1980s. In superstring theory, the fundamental object is no longer a zero-dimensional point particle, such as an electron, but a tiny, one-dimensional object known as a string. Such strings are very small, just ~ 10-35 metres. This is many, many orders of magnitude smaller than the size of an atomic nucleus. Just as a violin or guitar string can yield many different overtones of its fundamental frequency, so can the theorist's string exist in many different vibrational states. However, since the hypothetical strings are so small, they cannot be directly observed.
Although the proponents of superstring theory have great hopes of reconciling quantum mechanics and gravity, a grand unified theory remains tantalisingly out of reach. Recently, interest has shifted to some extent to the latest hot potato called M-theory, where the 'M' stands for 'membrane' or 'mother of all strings' or even 'mystery'. Here, the fundamental object is not the zero-dimensional point particle, or even the one-dimensional string, but a multi-dimensional membrane. An everyday example of a two-dimensional membrane would be a soap bubble. It turns out that M-theory, which is postulated in eleven dimensions, reconciles five different competing versions of superstring theory which are formulated in ten dimensions. In M-theory, one can show that the five superstring theories are actually equivalent. The apparent success of M-theory leads some physicists to speculate that grand unification of nature's forces may come via this approach.
But perhaps not. Will M-theory be superceded by F-theory ('F' for father)? What next? Grandparent-theory? Will particle physicists continue to generate a hierarchy of theories, one inside the other, with the innermost theory most closely approximating 'reality', whatever that may be? In this cosmic series of Russian dolls, will the final one (and why should the succession end?) represent the long sought-after TOE? But let us stop and consider this approach. In the quest for such a TOE, with its attendant fixation on fundamental objects, are we not tilting at windmills of our own devising?
The testing of the Standard Model by smashing together particles at ever-increasing energies is symptomatic of this object-obsessed approach. One of the stalwarts of the Standard Model is the electron. However, it turns out that the electron, which this year celebrates the centenary of its discovery in 1897, may not be a fundamental particle after all. Experiments carried out recently at Germany's national particle physics laboratory near Hamburg suggest that the electron may occasionally merge with quarks in high-energy collisions, forming a 'leptoquark', a previously undiscovered hybrid particle.
It may be that neither leptons nor quarks are fundamental particles at all but are themselves made up of even smaller objects. Particle physicists say that if the statistics of these results hold up after undertaking more repeat experiments, then the Standard Model will have to be extended or even rejected. And so the path to a TOE proceeds. However, the discovery of a TOE revealed in this way would arguably constitute a hollow victory; a mere outline, at best, of the richness of the universe and simply the consequence of a dead-end route.
Do fundamental entities exist ? Anaxagoras versus Democritus
For, despite the early 20th century's amazing revolutions in modern physics, physicists are still hidebound by the ancient Greek philosopher Democritus' conjecture of reality being constructed out of building blocks which he called atoms. An alternative route is to dispense with this object fetish by reworking the thoughts of another ancient Greek philosopher, Anaxagoras. He postulated the concept of 'something in everything'. In other words, there are no fundamental entities in the cosmos. Instead, each separate part of the universe, whether it be an atom, molecule or living creature contains, in some sense, the whole universe.
The challenge from Bohm : Undivided wholeness
The physicist David Bohm, who died in 1992, developed a sophisticated approach to this concept of the universe, which he termed 'undivided wholeness'. Bohm outlined his approach in the classic 1980 book, 'Wholeness and the Implicate Order'. He used the analogy of the hologram to illustrate the concept of undivided wholeness. A hologram is a special kind of photographic plate produced with the highly coherent light of a laser source, i.e. light which is all of the same frequency and which does not disperse. Whereas an ordinary photographic plate records a flat image of an illuminated object, a hologram provides a three-dimensional reconstruction of the object. If a hologram is illuminated with the same coherent light with which it was produced, then the optical effect is as if the original object were being observed. When the observer moves his/her head around, different perspectives of the object can be seen. A remarkable property of holograms is that even if only a portion of the plate is illuminated the whole of the object is reconstructed, although the resolution of the reconstruction is not as great as when the complete plate is illuminated. One may say that the reconstructed object is embedded in any arbitrary segment of the plate.
Now, the physics of holograms is well understood. The point here is that the hologram serves as a simple analogy for Bohm's concept of undivided wholeness. The universe is like a hologram, in which the whole image is contained within every segment. In other words, the whole is enfolded within each segment. By shining laser light on a part of the hologram, an unfolding occurs in which the form and structure of the whole become apparent. Similarly, processes of unfolding occur continually in the universe, yielding the patterns and structures which we can see and measure.
Bohm argued that the fundamental particles and fields so beloved of most physicists are no more than what he termed the explicate order, that part of the universe which is made manifest by use of our senses (or, extending our senses, scientific instruments). In the explicate order, which essentially corresponds to the Standard Model, objects occupy only their own particular region of space (and time), distinct from regions occupied by other objects. These explicate objects (e.g. quarks, leptons) are essentially unchanged when interacting with each other.
However, underlying this explicate order, is an implicate order in which the 'totality of existence is enfolded in each region of space (and time).' In other words, any apparently independent object such as a 'fundamental' particle actually contains within itself the sum of all other seemingly independent objects. Bohm restated Anaxagoras's hypothesis as follows: 'Ultimately, the entire universe…has to be understood as a single undivided whole, in which analysis into separately and independently existent parts has no fundamental status.'
However, Bohm did much more than this. He developed a direction for quantum physics in which both relativity and quantum theory were themselves abstractions (i.e. approximations or limiting cases) of the underlying implicate order. He also formulated a consistent mathematical description of this implicate order. Even more significantly, he opened up a path linking matter and consciousness as an unbroken whole. Intriguingly, there are links between Bohm's ideas and aspects of Buddhism. If fundamental physicists seek beauty in the universe then they can do worse than look more seriously at Bohm's work.
The challenge from Chew : The 'Bootstrap' approach
Another physicist whose work challenges the assumptions underlying the Standard Model is Geoffrey Chew, now Dean of Physics at the University of California, Berkeley. In the 1970s and 1980s, Chew, together with several collaborators, developed a 'bootstrap' approach to subatomic particles in which no particle is to be considered as more fundamental than any other. In fact, in this approach, there are no fundamental objects of any kind, whether they be particles, laws or equations. Instead, the universe is represented as a self-consistent web of interrelations. Chew regards consciousness as forming a part of this web, so that matter and consciousness are part of an undivided whole.
These concepts are reminiscent of Bohm's work. Indeed, in Fritjof Capra's excellent book, 'Uncommon Wisdom', Chew acknowledges that the 'two approaches have so much in common that they might well merge in the future.' Although David Bohm is sadly no longer alive, Geoffrey Chew continues to work on his own challenging and intriguing ideas. Chew's ideas have since evolved and he no longer talks about bootstrap physics. However, in his own words, 'the original spirit of [the bootstrap] approach remains.'
For the last decade, Chew has been working on a cosmological model in which stable, repetitive patterns of 'events' give rise to particle identities. The concept of 'event' is quite subtle but refers to an interaction which is localized both in space and in time, and in which energy is transferred. Individual 'events' are characterized by an incredibly short time scale, called the Planck time scale (~10-43 seconds), so that particle-scale patterns actually comprise a huge number of events. However, Chew's model requires no fundamental particles; the concept of energy-transferring events stands on its own! There is a link in the model between the smallest meaningful event scale (Planck) and the largest meaningful time scale (the age of the universe). The model therefore makes certain predictions about the large-scale structure of the universe which are amenable to deep-space observations made by, for example, the Hubble telescope. The fact that the model predictions are verifiable is tremendously exciting and will undoubtedly lead to fruitful future developments in Chew's theory.
The holy grail
In short, the view of David Bohm, Geoffrey Chew and a number of other physicists is that the search for fundamental entities will be no more successful than the search for the mythical holy grail. And yet, the mainstream view, espoused by Stephen Hawking et al., is that the search for a theory of everything, distilled into one elegant and fundamental equation representing interactions between fundamental particles, is not only within our reach but meaningful. Most physicists claim that such a TOE would represent our understanding of the universe. However, 'understanding' here is reductive and therefore of dubious validity in this holistic-thinking era. What does this mean? Well, the physicist's concept of understanding is tied up with predictability and falsifiability of hypotheses. As an example, if we can predict the outcome, even in a statistical sense (i.e. by looking at a large number of occurrences), of a subatomic reaction then understanding is allegedly attained.
David Peat argued in his popular book, 'Blackfoot Physics', that this identification of 'understanding' with 'predictability' is closely linked to notions of causality and the linear flow of time. The problem with this, as Peat showed, is that linear processes tend to exclude the naturally occurring interdependent cycles of birth, growth, decay and death, which are of particular importance when we consider living systems. In other words, such a restricted sense of understanding is bound to be a poor and incomplete representation of nature.
A fuller concept of understanding must incorporate an appreciation of balance, harmony, relationships and interconnections. The separateness between past, present and future would dissolve. Fortunately, the insights of other paradigms for investigating the universe around us - from Native American cultures to Eastern philosophies - have been made more accessible through the work of Peat and similarly open-minded physicists such as Fritjof Capra. There is a rich seam of potential here for a stimulating dialogue between these paradigms and those of modern physics.
It is customary to quote Albert Einstein at a juncture like this. Appropriately so, since, in 1945, after searching for a Theory of Everything for almost three decades, he had the good grace to write in a letter to an enquirer, 'We have to admire in humility the beautiful harmony of the structure of this world as far as we can grasp it. That is all.' They could have been the wise words of a Zen master.
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Bortoft H. The wholeness of nature. Floris Books, Edinburgh, 1996.
Capra F. Uncommon wisdom. Flamingo, London, 1988.
Kaku M. Into the eleventh dimension. New Scientist, pp. 32-36, N° 2065, 18 January 1997.
Peat FD. Blackfoot physics. Fourth Estate, London, 1994.
Penrose R. The large, the small and the human mind. Cambridge University Press, 1997.
Witten E. Duality, spacetime and quantum mechanics. Physics Today, pp. 28-33, May 1997.