| ZEN PHYSICS (what is this?) The Science of Death, the Logic of Reincarnation David Darling 
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I think I can safely say that nobody understands quantum mechanics.
– Richard Feynman
A century ago, science might still have claimed confidently that, as far as the universe as a whole is concerned, consciousness appears to have no special relevance. But not any longer, By peering into the workings of nature at the very smallest of scales – at or below the dimensions of the atom – physicists have uncovered what appears to be an intimate connection between the mind of conscious observers and the bringing into being of what is real.
Around the end of the nineteenth century, it became clear that classical, Newtonian science was in serious trouble. It appeared unable to account for some of the observed properties of radiation given off when matter is heated. The only way to bring theory back into line with this aspect of the world seemed to be by making an astonishing and, at the time, seemingly ad hoc assumption: namely, that energy could only be traded back and forth in discrete packets. An electron, for instance, in the outer part of an atom, could not just gain or lose energy indiscriminately. It had to do so in definite, prescribed amounts that came to be known as “quanta.” The man who first made this bold proposal in 1900, the German physicist Max Planck, was not at all happy with the idea of quantized energy. Nor were his contemporaries, and, to begin with, Planck’s quantum theory, which was simply patched onto classical physics in an effort to repair the dangerous hole that had opened up, failed to make much of an impression. It was only in 1905, when Einstein brilliantly accounted for the so-called photoelectric effect in terms of quanta of light kicking electrons out of a metal surface, that the idea really caught hold.
Einstein showed that although light generally behaves as if it were made of waves, it can at times behave instead as if it consists of a stream of particles – quanta of light, or photons. His successful explanation of the photoelectric effect using this idea focused the attention of physicists on Planck’s quantum theory and led to its rapid development into an entirely new and revolutionary field of modern science known as quantum mechanics.
Soon, researchers found themselves staring into the maws of a monstrous paradox. For not only light, it transpired, revealed this curious wave-particle duality. So, too, did particles of matter. Electrons and every other material constituent of the subatomic world apparently exhibited a schizoid nature. Whereas on some occasions an electron would act as a tiny speck or bullet of matter, on other occasions it would just as obviously manifest itself as a wave.
At first, it was suspected that the wave associated with a subatomic particle might be a physical effect – a kind of smearing out of the particle’s substance or of the electrical charge which it carried. According to this idea, the smeared-out particle would have to condense in an instant at a single point as soon as any attempt was made to detect it. But such instantaneous shrinkage would run counter to Einstein’s special theory of relativity, which forbids matter and energy to be accelerated to a speed greater than that of light. Therefore an alternative proposal was put forward by the German physicist Max Born in 1926. Born suggested that the wave associated with a subatomic particle was not physical at all but mathematical: it was a wave of probability. It could be described by a mathematical artifact called the “wave function,” which effectively gave the odds of finding the particle at any given point in space and time should an attempt be made to look for it. Einstein railed against such a blatant probabilistic motion at the heart of nature and issued his now famous proclamation “I shall never believe that God plays dice with the world.” But most of his contemporaries disagreed with him, quantum uncertainty won the day, and mainstream science began to acquaint itself with the bizarre idea that, at its most basic level, the material universe is not concrete and well determined but, on the contrary, is curiously abstract and conditional.
It was no longer meaningful to think of an electron, for instance, as always being definitely somewhere and “somewhen” in between the times when it was being observed. Unless an attempt was made to detect it, the sum total of what was and could be known about the whereabouts of a particle was contained in its wave function – a purely statistical description.
It could not be claimed, in the new quantum picture of the world, that particles even truly exist outside of observations of them. They have no independent, enduring reality in the familiar classical sense of being like tiny beads of matter with a definite (if not necessarily known) location in space and time. The distinguished American physicist John Wheeler has expressed the central quantum mystery in these terms:
Nothing is more important about the quantum principle than this, that it destroys the concept of the world as “sitting out there,” with the observer safely separated from it by a 20-centimeter slab of plate glass. Even to observe so minuscule an object as an electron, he must shatter the glass. He must reach in. He must install his chosen measuring equipment ... The measurement changes the state of the electron. The universe will never afterward be the same. To describe what has happened, one has to cross out that old world “observer” and put in its place the new word “participator.” In some strange sense the universe is a participatory universe.Somehow, through the act of observation, subatomic particles are briefly summoned out of a kind of mathematical never-never land of potentiality and possibility into the solid world of tangible things and events. In quantum parlance, an observation results in the “collapse” of the wave function – an instantaneous telescoping-down of the probability spread to a localized point, a real particle. But what counts as a valid observation in this respect? Who or what qualifies as an effective quantum observer – a measuring instrument such as Geiger counter, a human being, a committee of people? No one is sure. But the most widely accepted viewpoint, first advocated by the Danish physicist Niels Bohr and referred to as the Copenhagen interpretation, is that the sudden change in character or collapse of the wave function is brought about, ultimately, by conscious observership — the registering of an event, such as the reading of an instrument, in the mind.
This is a staggering conclusion. And it appears the more so when one remembers that all of the material universe is comprised of subatomic particles. Not one of these particles, according to modern physics, can be “actualized,” or made properly real, without an observation that collapses the wave function. Almost unbelievably, our most fundamental branch of science implies that what had previously been assumed to be a concrete, objective world cannot even be said to exist outside of the subjective act of observation. Furthermore, if the Copenhagen interpretation is correct, then it is the mind – the mirror in which the object is reflected and becomes the subject – that serves as the essential link between mathematical possibility and physical actuality.
The intervention of mind in the affairs of the subatomic world was spectacularly demonstrated a few years ago. In 1977, B. Misra and George Sudarshan at the University of Texas showed theoretically that the decay of an unstable particle – say, a radioactive nucleus – is suppressed by the act of observation. Like any quantum system, an unstable particle is described as fully as it can be by its wave function. Initially, this is concentrated around the undecayed state. But as time goes on, the wave function spreads out into the decayed state so that the probability of decay gradually increases. Misra and Sudarshan showed that every time an observation is made it causes the wave function to snap back, or collapse, to the undecayed state. The more frequent the observations, the less likely the decay. And if the observations come so close together that they are virtually continuous then, as in the case of the proverbial watched pot that never boils, the decay simply doesn’t happen. This astonishing prediction was verified by measurements carried out by David Winehead and colleagues at the National Institute of Standards and Technology, Boulder, Colorado, in 1990, using a sample of beryllium ions.
An even more remarkable insight into the strangeness of the quantum world is provided by a modified version of the famous double-slit experiment. The original, “classical” form of this experiment was first conducted in the early nineteenth century by the English physicist Thomas Young. He showed that if a beam of light is split in two by shining it onto a pair of narrow slits, an interference pattern of alternating light and dark bands is created when the beams recombine on the other side and are allowed to fall onto a screen. Interference is exclusively a wave phenomenon and so its appearance clearly reveals light to have wavelike characteristics. But the same experimental setup in a more sophisticated form can be used to show light behaving either in a wavelike or a particlelike way.
Quantum mechanics makes a remarkable prediction about the double-slit experiment. It says that even if photons are allowed to pass through the slits one at a time, an interference pattern will still gradually build up. This prediction is perhaps the outstanding quantum mystery because, no matter how we try to imagine what is going on in the interval between when a single photon leaves its source and when it arrives at the screen, we cannot make sense of the situation that reality presents us with. In our minds, a photon must be either a particle or a wave. If it leaves its source as a particle and passes through just one of the slits as a particle, then how on earth, we wonder, can it subsequently manage to interfere with itself as if it had gone through both slits as a wave? We might suppose that we could get to the bottom of the mystery by closely monitoring the progress of each photon through the apparatus — and, in particular, if we arrange to detect which of the two slits each photon passes through. But nature forbids us to peek behind the scenes in an attempt, as we see it, to find out what is “really” happening without irreversibly changing what is happening. If we arrange to track the path of each photon, quantum theory predicts, the interference pattern will be destroyed. In other words, simply by pinning down which slit each photon passes through, we force the experimental system as a whole to make a definite decision between particlelike and wavelike behavior in favor of the former. Our intrusion causes the interference pattern to vanish and be replaced instead simply by two bright lines corresponding to the images of the slits formed by photons striking the screen as if they were particles traveling in straight lines from the source. The American physicist Richard Feynman put forward this basic rule: if the paths of photons are distinguishable, then light behaves as particles; if they are indistinguishable, then light behaves as waves. And every experiment carried out in recent years to test this fundamental prediction has upheld it beyond a shadow of a doubt.
What does this mean? Apparently, just by inquiring into the state of a system we inevitably and profoundly affect the very nature of that system. The desire to have a yes-no, either-or, particle-wave determination actually influences reality in a most fundamental way. More to the point, our intervention fragments the continuous wavelike nature of the world into separate, discrete particles. Just as with words and analysis on a macroscopic scale we break our surroundings down into isolated objects, so with our objective intrusions at the subatomic scale we force a dualistic split from the normal, ongoing state of continuity to a transient state of individualism.
Such a conclusion is far-reaching enough. But recent experiments have led to even more sensational revelations about the world in which we live, again in full accord with the expectations of quantum theory. These experiments have demonstrated that not only is observership a mandatory requirement for making reality tangible, but every component of the universe – down to the level of each individual subatomic particle — is in some peculiar sense immediately “aware” of what is going on around it. The very idea of subatomic particles having an elementary form of consciousness strains credibility to breaking point. And although there is great excitement among the physicists involved in this field, there is also profound bewilderment at the implications of the results they are uncovering.
Among the most extraordinary demonstrations of quantum weirdness to date have been a number of experiments involving what physicists have dubbed “quantum erasers.” These are extensions and elaborations of the basic double-slit apparatus, the first of which was successfully implemented at the University of California, Berkeley, by Raymond Chiao and his team in 1992.
The idea behind the quantum eraser is to make the paths of photons initially distinguishable, but then erase that “which-path” information before the light actually reaches the screen. If an interference pattern reappears then it is a clear indication that a photon approaching the slits somehow “knows” whether or not there is an eraser further down the line, so it can decide whether to pass through both slits as a wave or through only one slit as a particle. The existence of this advance knowledge or remote sensing was precisely what the Berkeley team confirmed in its inaugural quantum eraser experiments.
More recently, a team at the University of Innsbruck, in Austria, has taken work in this direction an important step further. In particular, these researchers have shown clearly that the “which-path” information is not carried by what might be called the interfering photon itself. Rather it is carried by a second photon created, in the first stage of the apparatus, as a twin of the first and directed along a different path. The Innsbruck experiment was conducted in such a way that it elegantly demonstrated not only that the second photon somehow knew what lay ahead, but also that it had instantaneous access to information about its twin’s physical status. This latter remarkable property is known to quantum physicists as “nonlocality.”
Bluntly, nonlocality amounts to zero-delay communication between two particles no matter what their separation distance. It was first derived by Einstein as a fundamental prediction of the equations of quantum mechanics – and was used, in fact, by Einstein as an argument against the completeness of quantum theory. It was absurd, Einstein said, to imagine that one of a pair of particles, which might be light-years away from its partner, could effectively react immediately to a change in the state of its twin. This led to a statement of the so-called Einstein-Podolsky-Rosen (EPR) effect and the throwing down of a gauntlet to quantum physicists to demonstrate its reality.
Say an atom emits two photons simultaneously and in different directions. One way to define the state of these photons is by their polarization, that is, the direction in which the electric field associated with them is vibrating. Quantum theory predicts that, as soon, as an observation is made, one of the photons emitted from the atom would be found to have a definite “up” or “down” polarization. This would also fix the direction of polarization of its twin, since, for conservation reasons, this would have to be in the opposite sense. However, unless and until such a measurement is carried out, the quantum state of the photons would be undefined – not just unknown, but physically undetermined. The EPR effect is that the fixing of the state of polarization of one of the pair of photons instantaneously causes the polarization state of its partner to be decided, irrespective of the distance between the particles. Einstein argued that such an effect, implying faster than light travel, is nonsensical and would never be vindicated. But as the Innsbruck quantum eraser experiments and other recent investigations have shown it is real and inescapable. The quantum world is in practice every bit as outrageous as its mathematical formalism suggests.
Slowly, and reluctantly, science is trying to come to terms with the truths it has found at nature’s heart. Out of matter is made mind, which sees and interprets the world and thereby makes matter real. The universe creates itself out of itself, moment by moment, through a mutual interaction between subject and object. Sir Arthur Eddington put it this way:
We have found that where science has progressed the furthest, the mind has regained from nature that which mind has put into nature. We have found a strange footprint on the shores of the unknown. We have devised profound theories, one after another, to account for its origin. At last, we have succeeded in reconstructing the creature that made the footprint. And lo! it is our own.Incredibly, modern physics, which is the most advanced product of our dualistic way of thinking, has shown that dualism is no longer tenable. Consciousness is an inextricable and essential property of the real world. Subject and object cannot be treated apart; there is no gap, no delay, no difference in the real world between being and experiencing. There is no existence without the conscious act.
Nor, it seems, can there be existence without contingency. Everything and every event is meaningful only in how it stands in direct relationship to the rest of the cosmos. Whereas previously, under Newtonian physics, we were able to sustain a belief in the separate reality of particles and waves, rest and motion, energy and mass, time and space, now we have no such confidence. Einstein showed that rest and motion are relative concepts, while energy and mass, and space and time, are interchangeable. Quantum physicists have discovered that, at its most fundamental level, the world cannot be accurately viewed as a complex of distinct things. What we took to be sharply bounded objects – particles of matter – have turned out to be interwoven, overlapping aspects of each other. Every thing and every event in the universe seems to be attached to an all-embracing quivering web that interconnects it with every other thing and event. Nothing stands apart. The cosmos as now portrayed by relativity and quantum mechanics is less like a loose collection of jiggling billiard balls and more reminiscent of a single, giant universal field – an unbreakable unity which Alfred North Whitehead dubbed “the seamless coat of the universe.”
Physicists have caught a glimpse of the infrastructure of the real world. Yet oddly enough, they have been able to do this only through the use of advanced technology. And all of our technology – the panoply of tools and devices at our disposal – has been developed starting from the assumption that the world can be taken apart and analyzed. Our map-making, bounding, and classifying is what has given us power over nature. But now, because of the sophisticated technology that has allowed us to experimentally probe the subatomic domain, we have found that reality has no boundaries.