The Quantum and the Lotus

fr The Quantum and the Lotus - for the science students..
Matthieu Ricard and Trinh Xuan Thuan


When we organize the remarkable harmony and precision of the universe, it is tempting to imagine that there is an all-knowing Creator, from the secular view, some sort of principle of creation that finely adjusted the evolution of the universe. The omnipotence of such a Creator would explain everything, and there would be no need for us to wonder about the origins of our astonishingly complex universe, or about how life arose, or how inanimate matter can be compatible with the animate matter of life. This question of whether of not there is a creating God is a key point of distinction between the world’s great spiritual traditions. For Buddhism, the notion of “first cause” does not stand up to analysis. Some scientists also dismiss the need for a God, arguing that the exceptional fine-tuning of the universe arose by chance. Others, however, believe that there is some kind of an organizing principle at work in our world. Can this notion of such a principle stand up to analysis? Is it necessary and logical?



T: Another scientific argument against the existence of God is that the very idea of cause and effect loses its meaning when applied to the universe. The notion presupposes the existence of time, so that cause reliably precedes effect. But according to the Big Bang, time and space appeared simultaneously with the universe. If time didn’t exist before this, then what does “and God created the universe” mean? The act of creating the universe is meaningful only in time. Is God in time, or outside of it? Time isn’t absolute, as Einstein said. It’s elastic and is stretched (or contracted) by accelerating motions or fields of intense gravity, such as those around black holes. A God contained in time would no longer be all-powerful, because he would be subject to the laws of time. A God outside time would be omnipotent, but unable to help us, since our actions happen in time. If God transcended time, then he would already know the future. If he knew everything in advance, why would he bother to become involved in the struggle of humankind against evil?


M: God must be either immutable, and thus unable to create, or else inside time and thus not immutable. This is one of the contradictions that the notion of a prime cause leads to. What are the justifications behind this argument?

First, if there is a prime cause, it should be immutable. Why? Because, by definition, it has no other cause than itself, so it has no reason to become different. Change would imply the intervention of another cause that wasn’t part of the prime cause.

Second, how could an immutable entity create something? If there is an act of creation, is the creator involved or not? If he is not, why call him “creator”? If he is involved, then because creation inevitably occurs in stages, the something or someone involved in theses stages is not immutable. One could agree with Saint Augustine that God created time and the universe. But even so, creation remains a process, and any process, whether temporal or not, is incompatible with immutability. This point did not escape Saint Augustine himself, who said that the notion of beginning involves an act of faith. Buddhism contends, by contrast, that such an act of faith in unnecessary provided one doesn’t cling to the position that there must be a beginning.
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The concept of interdependence lies at the heart of the Buddhist vision of the nature of reality, and has immense implications in Buddhism regarding how we should live our lives. This concept of interdependence is strikingly similar to the concept of nonseparability in quantum physics. Both concepts lead us to ask a question that is both simple and fundamental: Can a “thing” or a “phenomenon,” exist autonomously? If not, in what way and to what degree are the universe’s phenomena interconnected? If things do not exist per se, what conclusions must be drawn about life?

M: In Buddhism, the perception we have of distinct phenomena resulting from isolated causes and conditions is called “relative truth” or “delusion”. Our daily experience makes us think that things have a real objective independence, as though they existed all on their won and had intrinsic identities. But this way of seeing phenomena is just a mental construct. Even though this view of reality seems to be commonsense, it doesn’t stand up to analysis.
Buddhism instead adopts the notion that all things exist only in relationship to others, the idea of mutual causality. An event can happen only because it’s dependent on other factors. Buddhism sees the world as a vast flow of events that are linked together and participate in one another. The way we perceive this flow crystallizes certain aspects of the nonseparable universe, thus creating an illusion that there are autonomous entities completely separate from us.
In one of his sermons, the Buddha described reality as a display of pearls – each pearl reflects all of the others, as well as the palace whose façade they decorate, and the entirety of the universe. This comes down to saying that all of reality is present in each of its parts. This image is a good illustration of interdependence, which states that no entity independent of the whole can exist anywhere in the universe.


T: This “flow of events” idea is similar to the view of reality that derives from modern cosmology. From the smallest atom up to the universe in its entirety, including the galaxies, stars, and humankind, everything is moving and evolving. Nothing is immutable.


M: Not only do things move, but we see them as “things” only because we are viewing them from a particular angle. We mustn’t give the world properties that are merely appearances. Phenomena are simply events that happen in certain circumstances. Buddhism doesn’t deny conventional truth – the sort that ordinary people perceive of the scientist detects. It doesn’t contest the laws of cause and effect, or the laws of physics and mathematics. It quite simply affirms that, if we dig deep enough, there is a difference between the way we see the world and the way it really is, and the way it really is, we’ve discovered, is devoid of intrinsic existence.


T: So what has that true nature got to do with interdependence?


M: The word “interdependence” is a translation of the Sanskrit pratitya samutpada, which means “to be co-emergence” and is usually translated as “dependent origination.” The saying can be interpreted in two complementary ways. The first is “this arises because that I,” which comes down to saying that things do exist in some way , but nothing exists on its own. The second is “this, having been produced, produces that,” which means that nothing can be its own cause. Or we could say that everything is in some way interdependent with the world. We do not deny that phenomena really do occur, but we argue that they are “dependent,” that they don’t exist in an autonomous way. Any given thing in our world can appear only because it’s connected, conditioned and in turn conditioning, co-present and co-operating in constant transformation. Their way of “being” is simply in relation to one another, never in and of themselves. We tend to cling to the notion that “things” must precede relationships. This is not the case here. The characteristics of phenomena are defined only through relationships.
Interdependence explains what Buddhism sees as the impermanence and emptiness of phenomena and this emptiness is what we mean by the lack of “reality.” The seventh Dalai Lama summarized this idea in a verse:

Understanding interdependence, we understand emptiness
Understanding emptiness, we understand interdependence
This is the view that lies in the middle,
And which is beyond the terrifying cliffs of eternalism and nihilism.

Another way of defining the idea of interdependence is summarized by the term tantra, which stands for a notion of continuity and “the fact that everything is part of the whole, so that nothing can happen separately.”
Ironically, thought we might think that the idea of interdependence undermines the notion of reality, in the Buddhist way of thinking, it is interdependence that actually allows for reality to appear. Let’s think about an entity that exists independently from all others. As an immutable and autonomous entity, it couldn’t act on anything, or be acted on itself. For phenomena to happen, interdependence is required.
This argument refutes the idea of distinct particles that are supposed to constitute matter. What’s more, this interdependence naturally includes consciousness. The reality of any given object depends on a subject that is aware of that object. This is what the physicist Erwin Schrodinger meant when he wrote: “Without being aware of it, and without being rigorously systematic about it, we exclude the subject of cognizance from the domain of nature that we endeavor to understand. We step with our own person back into the part of an onlooker who does not belong to the world which by this very procedure becomes an objective world.”

Finally, the most subtle aspect of interdependence, or “dependent origination,” concerns what we call a phenomenon’s “designation base” and its “designations.” A phenomenon’s position, form, dimension, color, or any other of its apparent characteristic is merely one of its “designation bases.” This designation is a mental construct that invests a phenomenon with a distinct reality. In our everyday experience, when we see an object, we aren’t struck by its nominal existence, but rather by its true existence. If we analyze this “object” more closely, however, we discover that it is produced by a large number of causes and conditions, and that we are incapable of pinpointing an autonomous identity. Since we have experienced it, we can’t say that the phenomenon doesn’t exist. But neither can we say that it corresponds to an intrinsic reality. So we conclude that the object exists (thus avoiding a nihilistic view), but that this existence is purely nominal, or conventional (thus also avoiding the opposite extreme of material realism, which is called “eternalism” in Buddhism). A phenomenon with no autonomous existence, but that is nevertheless not totally inexistent, can act and function according to causality and thus lead to positive or negative effects. This view of reality therefore allows us to anticipate the results of our actions and organize our relationship with the world. A Tibetan poem puts it this way:

To say a thing is empty does not mean
It cannot function – it means it lack an absolute reality
To say a thing arises “in dependence” does not mean
It had intrinsic being – it means it is illusion-like.
If thus one’s understanding is correct and certain
Of what is meant by voidness and dependent origin,
No need is there to add that voidn ess and appearance
Occur together without contradiction in a single thing.


T : I find everything you’ve told me about interdependence striking. Science, too, has discovered that reality is nonseparable, or interdependent, both at the subatomic level and in the macrocosmic world. The conclusion that subatomic phenomena are interdependent was derived from a famous thought experiment conducted by Einstein and two of his Princeton colleagues, Boris Podolsky and Nathan Rosen, in 1935. It’s called the EPR experiment, from the initials of their surnames.

To follow the experiment, you need to know that light (and matter, too) has a dual nature. The particles we call “photons” and “electrons”, as well as all the other particles of matter, are Janus-faced. Sometimes they appear as particles, but they can also appear as waves. This is one of the strangest and most counterintuitive findings of quantum theory. Even stranger is the finding that what makes the difference about whether a particle is in the wave or particle state is the role of the observer – if we try to observe the particle in its wave state, it becomes a particle. But if it is unobserved, it remains in the wave-state

Take the case of a photon. If it appears as a wave then quantum physics says that it spreads out in all directions through space, like the ripples made by a pebble thrown into a pond. The photon in this state has no fixed location or trajectory. We can then say that the photon is present everywhere at the same time. Quantum mechanics states that when a photon is in this wave state, we can never predict where the photon will be at any given position. The chances might be 75 percent or 90 percent, but never 100 percent. Since Einstein was a committed determinist, he couldn’t accept that the quantum world was ruled in this way by probability or chance. He argued famously that “God does not play dice,” and stubbornly set about trying to find the weak link in quantum mechanics and its probabilistic interpretation of reality. That’s why he came up with the EPR experiment.
The experiment goes like this: First imagine that you have constructed a measuring apparatus with which you can observe the behaviour of particles of light, called photons. Now imagine a particle that disintegrates spontaneously into two photons, a and b. The law of symmetry dictates that they will always travel in opposite directions. If a goes northward, then we will detect b to the south. So far, so good. But we’re forgetting the strangeness of quantum mechanics. Before being captured by the detector, if quantum mechanics is correct, a appeared as a wave, not a particle. This wave wasn’t localized, and there was a certain probability that a might be found in any given direction. It’s only when it has been captured that a changes into a particle and “learns” that it’s heading northward. But if a didn’t “know” before being captured which direction it had taken, how could b have “guessed” what a was doing and ordered its behavior accordingly so that it could be captured at the same moment in the opposite direction? This is impossible, unless we admit that a can inform b instantaneously of the direction it had taken. But Einstein’s cherished theory of relativity states that nothing can travel faster than light,. The information about a’s location would need to travel faster than the speed of light in order to get to b in time, because, after all, a and b are both particles of light and are therefore traveling themselves at the speed of light. “God does not send telepathic signals,” Einstein said, adding “There can be no spooky action at a distance.”

On the basis of these thought-experiment results, Einstein concluded that quantum mechanics didn’t provide a complete description of reality. In his opinion, the idea that a could instantaneously inform b of its position was absurd: a must know which direction it was going to take, and tell b before they split up; a must then have an objective reality, independent of actual observation. Thus the probabilistic interpretation of quantum mechanics, which states that a could be going in any direction, must be wrong. Quantum uncertainty must hide a deeper, intrinsic determinism. Einstein thought that a particle’s speed and position, which defined its trajectory, were localized on the particle without any observation being necessary. This is what was called “local realism.” Quantum mechanics couldn’t describe a particle’s trajectory because it didn’t take other “hidden variables” into account. And so it must be incomplete.

And yet Einstein was wrong. Eventually, physicists showed that exactly what Einstein thought couldn’t happen in the EPR experiment did happen. Since its invention, quantum mechanics – and its probabilistic interpretation of reality – has never slipped up. It has always been confirmed by experiments and it still remains today the best theory that we have to describe the atomic and subatomic world.


M: When was EPR effect confirmed experimentally?


T: EPR remained only a thought experiment for some time. No one knew how to carry it out physically. Then, in 1964, John Bell, an Irish physicist working at CERN, devised a mathematical theorem called “Bell’s inequality,” which would be capable of being verified experimentally if particles really did have hidden variables, as Einstein thought. This theorem at last allowed us to take the debate from the metaphysical plane to concrete experimentation. In 1982 the French physicist Alain Aspect, and his team at the University of Orsay, carried out a series of experiments on pairs of photons in order to test the EPR paradox. They found that Bell’s inequality was violated without exception. Einstein had it wrong, and quantum mechanics was right. In Aspect’s experiment, photons a and b were thirteen yards apart, yet b always “knew” instantaneously what a was doing and reacted accordingly.


M: How do we know that this happens instantaneously, and that a light bean hasn’t relayed the information from a to b?


T: Atomic clocks, connected to the detectors that capture a and b, allow us to gauge the moment of each photon’s arrival extremely accurately. The difference between the two arrival times is less than a few tenths of a billionth of a second – it is probably zero, in fact, but existing atomic clocks don’t allow us to measure periods of under 10-10 seconds. Now. In 10-10 seconds, light can travel only just over an inch – far less than the thirteen yards separating a from b. What is more, the result is the same if the distance between the two photons is increased. Even though lighe can dfinitely not have had the time to cross this distance and relay the necessary information, the behaviour of a is always exactly correlated with that of b.
The latest experiment was carried out in 1998 in Geneva by Nicolas Gisin and his colleagues. They began by producing a pair of photons, one of which was then sent through a fiber-optic cabel toward the noth of the city , and the other toward the south. The two pieces of measuring equipment were over six miles apart. Once they arrived at the end fo the cables, the two photons had to choose at random between two possible routes – one short, the other long. It was observed that they always made the same decision. On average, they chose the long route half the time, and the short route half the time, but the choices were always identical. The Swiss physicists were sure that the two photons couldn’t communicate by means of light, because the difference between their response time was under three-tenths of a billionth of a second, and in that time light could have crossed just three and half inches of the six miles separating the two photons. Classical physics states that because they can’t communicate, the choices of the two photons must be totally independent. But that is not what happens. They are always perfectly correlated. How can we explain why b immediately “knows” what a is doing? But this is paradoxical only if, like Einstein, we think that reality is cut up and localized in each photon. The problem goes away if we admit that a and b are part of a nonseparable reality, no matter how far apart they are. In that case, a doesn’t need to send a signal to b because these two light particles (or, rather, phenomena that the detector sees as light particles) stay constantly in touch through some mysterious interaction. Wherever it happens to be, particle b continues to share the reality of particle a.


T…Some physicists have had problems accepting the idea of a nonseparable reality and have tired to find a weak link in these experiments or in Bell’s theorem. So far, they’ve all failed. Quantum mechanics had never been found to be wrong. So phenomena do seem “interdependent” at a subatomic level, to use the Buddhist tem.

Another fascinating and famous experiment in physics shows that interdependence isn’t limited to the world of particles, but applies also to the entire universe, or in other words that interdependence is true of the macrocosm as well as the microcosm. This is the experiment often referred to in short as Foucault’s pendulum.
A French physicist, Leon Foucault, wanted to prove that the Earth rotates on its axis. In 1851 he carried out a famous experiment that is reproduced today in displays in many of the world’s science museums. He hung a pendulum form the roof of the Pantheon in Paris. Once in motion, this pendulum behaved in a strange way. AS time passed, it always gradually changed the direction in which it is swinging. If it was set swinging in a north-south direction, after a few hours, it was swinging east-west. From calculations, we know that if the pendulum were placed at either one of the poles, then it could turn completely around in 24 hours. But because of the latitude of Paris, Foucault’s pendulum performed only part of a complete rotation each day.
Why did the direction change? Foucault answered by saying that the movement was illusory. In fact, the pendulum always swung in the same direction and it was the Earth that turned. Once he’d proved that the Earth rotated, he let the matter drop. But Foucault’s answer was incomplete, because a movement can be described only in comparison with a fixed reference point; absolute movement doesn’t exist. Long before, Galileo said that “movement is as nothing.” He understood that it exists only relative to something else. The earth must “turn” in relation to something that doesn’t turn. But where to find this “something”? In order to test the immobility of a given reference point, a star for instance, we simply set the pendulum swinging in the star’s direction. If the star is motionless, then the pendulum will always swing toward it. If the star moves, then the star will slowly shift away from the pendulum’s swing. Let’s try the experiment with know celestial bodies, both near and far. If we point the pendulum toward the Sun, after a few weeks, there is a clear shift of the Sun away from the pendulum’s swing. After a couple of years, the same happens with the nearest stars, situated a few light-years away. The Andromeda galaxy, which is 2 million light-years away, moves away more slowly, but does shift. The time spent in line with the pendulum’s swing grows longer and the shift away tends toward zero the greater the distance is. Only the most distant galaxies, situated at the edge of the known universe, billions of light-years away, do not drift away from the initial plane of the pendulum’s swing.

The conclusion we must draw is extraordinary. Foucault’s pendulum doesn’t base its behavior on its local environment, but rather on the most distant galaxies, or, more accurately, on the entire universe, given that practically all visible matter is to be found in distant galaxies and not in nearby stars. Thus, what happens here on our Earth is decided by all the vast cosmos. What occurs on our tiny planet depends on all of the universe’s structures.
Why does Foucault’s pendulum behave like this? We don’t know. Ernst Mach, the Austrian philosopher and physicist who gave his name to the unit of supersonic speed, thought it could be explained by a sort of omnipresence of matter and of its influence. In his opinion, an object’s mass – that is to say, the amount of its inertia, or resistance to movement – comes from the influence of the entire universe. This is what is called Mach’s principle. When we have trouble pushing a car, its resistance to being moved has been created by the whole universe. Mach never explained this mysterious universal influence in detail, which is different from gravity, and no one has managed to do so since. Just as the EPR experiment forces us to accept that interactions exist in the microcosm that are different from those described by known physics, Foucault’s pendulum does the same for the macrocosm. Such interactions are not based on force or an exchange of energy, and they connect the entire universe, Each part contains the whole, and each part depends on all the other parts.


M: In Buddhist terms, that’s a good definition of interdependence. It’s not a question of proximity in time or space, or of the speed of communication and the physical forces whose influence wanes over great distances. Phenomena are interdependent because they coexist in a global reality, which functions according to mutual causality. Phenomena are naturally simultaneous because one implies the presence of the other. We are back with “this can only be if that also exists; this can change only if that also changes.” Thus we arrive at a n idea that everything must be connected to everything else. Relationships determine our reality, the conditions of our existence, particles and galaxies.


T: Such a vision of interdependence certainly agrees with the results of the experiments I’ve just mentioned. The EPR experiment, Foucault’s pendulum, and Mach’s inertia can’t be explained by the four fundamental physical forces. This is extremely disturbing for physicists.


M: I think that we have a good example here of the difference between the scientific approach and Buddhism. For most scientists, even if the global nature of phenomenon has been demonstrated in rather a disturbing way, this is merely another piece of information, and no matter how intellectually stimulating it may be, it has little effect o their daily lives. For Buddhists, on the other hand, the repercussions of the interdependence of phenomena are far greater.
The notion of interdependence makes us question our basic perception of the world and then use this new perception again and again to lessen our attachments, our fears, and our aversions. An understanding of interdependence should demolish the wall of illusions that our minds have built up between “me” and “the other”. It makes a nonsense of pride, jealousy, greed, and malice. If not only all inert thins but also all living things are connected, then we should feel deeply concerned about the happiness and suffering of others, The attempt to build our happiness on others’ misery is not just amoral, it sis also unrealistic. Feelings of universal love (which Buddhism defines as the desire for all beings to experience happiness and to know its cause) and of compassion (the desire for all beings to be freed of suffering and its causes) are the direct consequences of interdependence. Thus knowledge of interdependence leads to a process of inner transformation, which continues throughout the journey of spiritual enlightenment. For, it we don’t put our knowledge into practice, we are like a deaf musician, or a swimmer who dies of thirst for fear of drowning if he drinks.
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Why is Buddhism interested in the science of elementary particles, given that studying them does not apparently have any particular effect on our daily lives? Well, if we ask questions about whether the world around us has a solid existence, it is important to study the nature of what are supposed to be its basic “building blocks.” Buddhism is not alone in raising doubts about the “reality” of phenomena. The dominant explanation of quantum physics, known as the Copenhagen Interpretation, also suggests that atoms are not “things” but are “observable phenomena” This is a fascinating topic, because it places the human mind, or human perception, in the midst of what we call “matter” and “objective reality.” If doubts can be raised regarding their “solidity,” then many other conceptual barriers will fall down as a result.

M:…Alan Wallace wrote,” Human beings define the objects and events of the world that we experience, Those things do not exist intrinsically, or absolutely, as we define or conceive of them. They do not exist intrinsically at all. But this is not to say that they do not exist. The entities that we identify exist in relation to us, and they perform the function that we attribute to them. But their very existence, as we define them, is dependent upon our verbal and conceptual designations.”


T: I agree with this view because quantum theory backs it up. The discovery of light’s dual nature was certainly a great surprise for the physicists. But what’s even stranger is that matter has exactly the same duality. What we call an electron, or any other of the elementary particles, can also appear as a wave. Thus the particle and wave aspects cannot be dissociated; rather they complement one another. This is what Niels Bohr called the “principle of complementarity.” He saw this complementarity as the inevitable result of the interaction between a phenomenon and the apparatus used to measure it. According to him, it isn’t so much reality that is dual, but the results of experimental interactions.

The act of observing also introduces quantum fuzziness. This is expressed in Heisenberg’s uncertainty principle, which tells us that it is impossible to define precisely at the same time an electron’s position and its speed. To determine the position of an electron, we have to shed light on it. But the photons in the light relay their energy to the electron in this process, and the higher the energy, the more they disturb its movement. We are thus up against a dilemma; the more we decrease the uncertainty of the electron’s position by shining light on it, so that we can see it, the more we increase the uncertainty of its movement. On the other hand, if we use only low-energy light, we don’t disturb its movement much, but we increase the uncertainty of its position. The act of determining the one aspect of the electron eliminated the possibility of determining the other. Thus, talk of an “objective” reality without any observer is meaningless, because it can never be perceived. All we can do is to capture a subjective aspect of an electron, depending on the observer and the apparatus. The form that this reality then takes is inextricably bound up with our presence. We are no longer passive spectators faced with a tumult of atoms, but full participants.


M: But this still tells us nothing about the ultimate reality of this particle – if such a reality exists. Neither the particles nor the wave, nor, for that matter, any other entity, exists inherently. For example, I suppose that we can’t affirm that the particle existed before it was observed.


T: Before measurement, all we can talk about is a wave of probability.


M: If when we say “particle” we mean something with an intrinsic or even permanent reality, and if it didn’t exist before it was observed, nothing could bring it to life. How could an entity that contains all the qualities we usually attribute to a particle abruptly pass from nothingness to existence? When a particle appears, either it does not exist independently as an entity, or it has been created ex nihilo.


T: And yet before, there was a wave. There was something, not a complete vacuum!


M: Buddhism doesn’t talk about a complete vacuum- that would be nihilistic- but “lack of intrinsic existence.” It is for this reason that, depending on the circumstances and on the experimental technique, an unreal phenomenon can appear to be either particle or a wave.


T: Our debate here is precisely the one that went on between Einstein and the originators of the Copenhagen Interpretation of Quantum Physics, Niels Bohr, Werner Heisenberg, and Wolfgang Pauli. The interpretation is given this name because the institute run by Bohr, where Heisenberg and Pauli were frequent visitors, was in Copenhagen. In simpler terms, it says that “atoms form a world of potentials and possibilities, rather than of things and facts.” According to Heisenberg, “in quantum physics, the notion of a trajectory does not even exist.” This view could not be further from Einstein’s dogmatic realism.

This is how Heisenberg summed up Einstein’s counterargument: “This interpretation does not describe what actually happens independently or in between the observations. But something must happen, this we cannot doubt….The physicist must postulate in his science that he is studying a world which he himself has not made and which would be present, essentially unchanged, if he were not there.” We could cal this position of Einstein’s one of material realism.
Heisenberg’s response to this objection of Einstein’s is complex, but I think it is important to offer in his own words:

It is easily seen that what this criticism demands is again the old materialistic ontology. But what can the answer from the point of view of the Copenhagen interpretation be?...The demand to “describe” what “happens” in the quantum-theoretical process between two successive observations is a contradiction in adjecto, since the word “describe” refers to the use of classical concepts, while these concepts cannot be applied in the space between the observations…The ontology of materialism rested upon the illusion that the kind of existence, the direct “actuality” of the world around us, can be extrapolated into the atomic range. This extrapolation is impossible, however.


M: A Buddhist philosopher would be in complete agreement with his answer.


T: Personally, I also agree with Heisenberg. As I’ve already said, quantum mechanics has always been confirmed by experimentation and has never been caught out. Einstein got it wrong, and his material realism cannot be defended, According to Bohr and Heisenberg, when we speak of atoms and electrons, we shouldn’t see them as real entities, with well-defined trajectories. The “atom” concept is simply an image that helps physicists put together diverse observations of the particle world into a coherent and logical scheme. Bohr also spoke of the impossibility of going beyond the results of experiments and measurements: “In our description of nature the purpose is not to disclose the real essence of phenomena but only to track down, so as far as possible, relations between the manifold aspects of our experiences.

T:….macroscopic objects, such as table, or this book, are made up of particles governed by quantum uncertainty. So why can’t the book suddenly vanish and reappear outside in the garden? The laws of quantum mechanics state that such an event is possible in principle, but it is so improbable that it could happen only if we waited for all eternity. Why is it so unlikely? The reason is that macroscopic objects consists of such a huge number of atom that the effects of chance cancel each other out. The probability of finding this book in the garden is infinitely small, because a large number of atoms also implies a large mass and so high inertia. Ordinary objects are not really disturbed when observed under light, because the energy relayed by the light is negligible. Thus the speed of such objects can be accurately measured along with their position. Quantum uncertainty is eliminated. But where does the borderline lie between the microcosm, ruled by quantum uncertainty, and the macrocosm, where it fades away? Physicists are unable to define this frontier, even though they are daily rolling back the limits of the quantum world. A molecule of fullerene, made up of sixty carbon atoms, is the largest object that had so far been seen to behave in a wavelike manner.

T:….Before Rutherford’s experiment, physicists thought that atoms occupied almost all the space inside a solid object, like apples in a barrel, with only a tiny gap between them. If that was the case, then none of the particles Rutherford sent toward the gold leaf should have been knocked back. The explanation must be that atoms had a hard, dense nucleus capable of reflecting particles. This nucleus must occupy a tiny space in comparison with the total volume of the atom, since the majority of the projectile missed it and continued their journey unaffected. We now know that an atom’s nucleus occupies the same space as a grain of rice in a football stadium. Thus, all of the matter around us, that sofa, the chair, the walls and so on, is almost completely empty. The only reason we can’t walk through walls is that atoms are linked together by the electromagnetic force.


The entire book is interesting and there were many interesting experiments that were included. If you are interested after the excerpts above, do check out the book. There are just too much to type for me so I am only drawing some parts of it out.