Page141: From Cause to Effect
The findings of relativity theory and quantum physics, as well as those of the relatively new sciences of chaos and complexity theory, have seriously challenged the laws of cause and effect inherited from Newton.
Relativity theory tells us that the motion of an observer can modify the temporal succession of events.
Quantum mechanics reveals that at the heart of matter, uncertainty rules.
Chaos and complexity theory show that the relationship between cause and effect is often anything but linear.
Do all of these findings suggest that we must adopt a radically revised notion of cause and effect? And if so, how might this new conception conform to Buddhist ideas of mutual causality, based on interdependence and global reality?
pp. 143-146: Relativity of simultaneity
MATTHIEU: Buddhist logicians say that two simultaneous "real" entities cannot have any causal relation.
THUAN: We can return to the example of the lightning hitting the train in order to understand this better. The order of events in this case is changeable (B sees the order in the reverse that C does) because the interval between the two events is zero. This is so because A sees the lightning bolts strike the front and the back of the train at the same time. The light doesn't have time to travel from one bolt to the other. In that case, the two lightning bolts are not causally related, and the order in which they occur can change, depending on the movement of the observer.
On the other hand, if event b is preceded by event a in a long enough interval so that the light has time to travel from a to b, then a always comes before b for all observers. Light has plenty of time to travel from eggs to the omelette during the interval of time between cracking the eggs and the appearance of the omelette—and for this reason no one will ever see an omelette made before the eggs which made it are broken. For the same reason, a child cannot be born before his mother.
Werner Heisenberg explained this finding this way:
As a consequence of the theory of special relativity, two events at distant points cannot have any immediate causal connection if they take place at such times that a light signal starting at the instant of one event on one point reaches the other point only after the other event has happened there, and vice versa. In this case the two events may be called simultaneous. Since no action of any kind can reach from one event at the one point in time to another event at the other point, the two events are not connected by any causal action. For this reason any action at a distance of the type, say, of the gravitational forces in Newtonian mechanics was not compatible with the theory of special relativity... Therefore, the structure of space and time expressed in the special theory of relativity implied an infinitely sharp boundary between the region of simultaneousness, in which no action could be transmitted, and the other regions, in which a direct action from event to event could take place.
The Special Theory of Relativity is perfectly consistent with the principle of causality. This is just well, because if the principle of causality wasn't respected, then we'd find ourselves in totally illogical situations. In principle, I could travel back in time and stop my parents from meeting, thus making my birth impossible, which is absurd. This well-known example is called the mother (or father) paradox.
MATTHIEU: Don't physicists argue that causality could be reversed if information could travel faster than light?
THUAN: Contrary to what most people think, relativity doesn't outlaw the existence of particles and phenomena that travel faster than light. In fact, physicists have a name for particles that travel faster than light, even they have never been observed. These hypothetical particles are called tachyons from the Greek takhos, meaning "fast". If they really did exist, then they would cause all sorts of physical paradoxes! Traveling faster than light would allow us to go back in time, and would raise the possibility of interfering with causality, such as in the mother paradox.
MATTHIEU: But tachyons could exist only in a theoretical world in which the cause-and-effect relationship was the opposite of ours.
THUAN: That's right. In a world of tachyons, logic as we know it would become meaningless. Effects would become causes, a nail would be driven down before being hit by a hammer. Einstein was well aware of the consequences of tachyons, and categorically declared in his 1905 paper (in which he presented the Special Theory of Relativity) that traveling faster than lightwas not permitted. But there's no mathematical clause in the paper that forbids their existence.
What Einstein's theory does explicitly forbid is for any object, or observer, to cross the barrier of the speed of light—in other words, to travel from a speed slower than the speed of light to one faster than it. No object, or person, can go from our universe, where all objects move slower than light, to a tachyon universe, where all objects move faster than light.
If an object (or piece of information) could accelerate from a speed slower than light to a speed faster than light, it could catch up to a light beam in front of it, and overtake it. The apparent speed of light for an observer on such an object would initially decrease until it became zero, and then increase in the opposite direction, which contradicts the fact that an observer always measures the same speed of light (186500 miles per second), regardless of his motion. The invariability of the speed of light is in fact one of the basic postulates of special relativity. In the same way, no object can cross the wall the other way, from a speed faster than light to a speed slower than the speed of light.
MATTHIEU: By stating that causality depends on the speed of light, you seem to be limiting causality to the world of forms, of particles and photons. You also seem to be envisaging a purely linear type of causality in which "a leads to b, and b leads to c", without taking into account the fact that all of the universe's phenomena are inextricably linked together, as shown in quantum mechanics. I don't see why the speed of light defines the range of causality. Heisenberg thought that the principle of causality dictated by the Special Theory of Relativity made a bad fit with the vision of the global nature of phenomena—of global interdependence—revealed by quantum mechanics. Both the experiment of Focault's pendulum and the EPR experiment have clearly shown that two phenomena can be inherently correlated—that two phenomena can act on one another—without any information having been relayed between them.
THUAN: The fact that there's a zone of causality determined by the speed of light isn't incompatible with the global world revealed in the EPR experiment and Focault's pendulum. As you say, in neither the EPR experiment nor the experiment of Focault's pendulum is there any transmission of information. In fact, that's the crux of both experiments, to show that it isn't necessary for information to be transferred from one particle to the other, or from the distant universe to the pendulum, in order for it to adjust itself according to the most distant clusters of galaxies. So these experiments do not really contradict the law of causality governing cases in which information is being transferred.
pp 148-152: Determinism vs. chaos
MATTIEU: Nature doesn't measure itself. If a ruler falls besides a plank, this doesn't constitute a measurement. As soon as there is a notion of measurement, we must directly or indirectly introduce the consciousness that planned the measurement, whether the result is immediately perceived or not. Thus consciousness is irreversibly part of the interdependent, global phenomena that we are studying.
Buddhism also says that the observer and the observed can't be separated. They interact and shape each other in a global universe, like two knives sharpening each other. We're structured by our environment, just as we affect our world through our perceptions, concepts and habits. Any attempt to pull them apart or to conceive and describe a world totally independent is doomed to failure. In the Avatamsaka Sutra there are these words attributed to the Buddha:
There is neither a painting in the mind
Nor a mind in the painting;
And yet, where else can you find a painting
Than in the mind?
Something struck me while you were explaining how Einstein thought that the past, present, and future were all present. This seems to lead to a totally deterministic vision. All we'd need to do would be to read the book of time in order to know the past and the future. It would be pointless to try to change anything, ourself included, since the die would already have been cast, and neither God nor quantum uncertainty play dice.
THUAN: You're absolutely right about that. I don't agree with this deterministic vision, either. Einstein was the intellectual heir of Newton and Laplace. Newton thought that the universe was a huge machine made up of inert material particles submitted to blind forces. Using a small number of physical laws, the history of an entire universe could be explained and predicted if we managed to characterize it perfectly at a given moment. Laplace summed up this triumphant determinism in his famous declaration:
Consider an intelligence that, at any instant, could have a knowledge of all forces controlling nature, together with the momentary conditions for all entities of which nature consists. If this intelligence were powerful enough to submit all these data to analysis, it would be able to embrace in a single formula the movements of the largest bodies in the universe and those of the tiniest atoms; for it, nothing would be uncertain, the future and the past would be equally present to its eyes.
Time is, in this way, abolished. This inspired Friedrich Hegel's famous remark, "There is never anything new in nature". This sterile, rigid, and dehumanizing determinism dominated until the end of the nineteenth century. In the twentieth century it was swept away by the liberating view of quantum physics. The role of chance, or what we would call contingency, was recognized in such varied fields as cosmology, astrophysics, geology, biology, and the cognitive sciences. Our world has also been molded by a succession of historical events, such as the asteroid that hit the earth, causing the disappearance of the dinosaurs and thus giving our mammal ancestors the chance to proliferate.
MATTHIEU: Laplace accounted for such contingent effecs in his argumen, didn't he? He believed that even they could eventually be explained within his deterministic view.
THUAN: Henri Poincaré, the French mathematician and one of the pioneers of chaos theory, replied as follows to Laplace's deterministic credo:
A course so small as to escape our attention, determines a considerable effect that we cannot help but see. We then say that this is the result of chance. If we knew the laws of Nature exactly and the precise situation of the universe at the initial moment, we could predict the situation of this same universe at some future moment. But even if the laws of Nature held no more secrets for us, we could have only an approximate knowledge of the initial situation. If this allows us to predict a future situation with the same approximation, then this is all we need. We then say that the event has been predicted and that it is governed by laws. But this is not always the case. It can happen that small differences in initial conditions create very largeones in the resulting phenomenon. A tiny error in the initial state then leads to an enormous error in the final state. Prediction becomes impossible.
In this way, Poincaré refuted the postulate at the heart of Laplace's argument: that it's possible to know the precise initial conditions of any phenomenon in the universe. From inevitable large or small inaccuracies of the initial conditions, and the extreme sensitivity of certain systems to the initial conditions, any attempt to predict the future evolution of these systems is doomed to failure.
This is a central tenet of chaos theory, which has become an important component to physics in the attempt to understand the world. I've often wondered why Newton failed to discover chaos. Uncertainty was lurking at the heart of his equations. Potential unpredictability lay in his theory of gravitation because it was using that very theory to study lunar motion that Henri Poincaré discovered chaos. Recently, it has been shown that a slight change in the position or initial speed of a planet such as Pluto could make a slip out of its regular orbit into a chaotic one. The solar which was consideredto be a well-oiled cosmic mchine running on rigid, deterministic laws, is also chaotic. Chaos lurks in the regular, and the unpredictable is never far from the predictable. This chance and indetermination affect not only the planets, stars and galaxies, but also everyday life. A simplistic conception of the laws of cause and effectis no longer defendable. That said, the fact that Newton failed to notice chaos takes nothing away from his genius. On the contrary, his intellectual brilliance in singling out and studying the systems in naturethat do evolve in a linear and nonchaotic way allowed him to formulate his monumental theory of gravitation.
In scientific terms, chaos isn't lack of order, as in the general use of the word. It has more to do with long term unpredictability. For example, it's impossible to forecast next week's weather, because weather events are extremely sensitive to initial environment conditions. In order to predict long term weather, we would need to know these initial conditions with infinite precision, which is impossible. Even if we were to acquire that perfect knowledge, it would not be possible to communicateit to our computers because of their fitite memory.Chaos represents an ineluctable limit to our knowledge. The seeds of ignorance have been planted in the very workings of nature. It would be vain, in any attempt to understand the weather's moods, to set up meteorological stations everywhere. There would still be undetectably tiny atmospheric variations. As they become amplified, the fluctuations can lead to a storm or a beautiful blue sky. That's why chaos is often explained by what physicists call the "butterfly effect": the flapping of a butterfly's wings in Guiana can trigger a rainstorm in New York. Newton and Laplace's deterministic dream has faded away.
MATTHIEU: The butterfly effect is even clearer when it comes to mental events. A simple thought can lead to planetary convultions. A feeling of hatred or ambition can set off a world war. Tiny differences in the motivations behind our actionscreate radically different courses of events, which lead to a vast range of misunderstandings and conflict.
THUAN: Chaos is at work all the time in our daily lives. You must have experienced occations where apparently innocent events led to dramatic consequences. An alarm clock fails to go off, so a man misses his interview and the job he wanted. A speck of dust in the gas tank makes a car break down, so a woman misses her plane and escapes death when it crashes into the ocean a few hours later. Insignificant events and imperceptible differences in circumstances can thus radically alter someone's life.
MATTHIEU: A determinist might reply that if it were possible to know the initial conditions perfectly, no matter how subtle they were, and if we had the necessary computing power, we could predict how a series of events would develop.
THUAN: But it's our very inability to know perfectly the initial conditions that makes it impossible to predict the future.
pp 156-159: Buddhism and causality
THUAN: When I mentioned an underlying creative nature in the world that chaos theory and quantum uncertainty have freed from the straitjacket of determinism, I wasn't necessarilyimplying that there is consciousness of some kind governing this creativity. I believe that nature evolves and acquires emergent properties according to the laws of organization and the principles of complexity. Can you clearify Buddhism's views on determinism and cause and effect?
MATTHIEU: First, Buddhism rejects the idea that anything can be causeless. If a result could happen without any cause, absolutely anything could lead to absolutely anything else, since what is causeless depends on nothing. So an effect must depend on its causes and conditions. This seems simple, but things become more complicated when we remember that Buddhism also rejects the notion of "objective" reality. The reductionist way of looking at causality supposes that an inherently existing entity with intrinsic properties act on other entities by altering their properties. But Buddhist logic points out the insurmountable problems that arise when we consider phenomena as concrete, independent entities. So our view of causality is more complicated. In order to truly understand the Buddhist view, we shoulgd go through the traditional Buddhist analysis of this problem of causality.
We start with the realization that there can be only four sorts of causality, or means of production, in the world. A thing can be born
(1) from itself;
(2) from something else;
(3) from itself and something else; or
(4) neither from itself nor from something else.
Then we work our way through the possibilities.
The first step is to acknowledge that a thing can't be born of itself. If it contained all of its own causes, it would multiply indefinitely without being able to stop. When all of the necessary causes are present, the event in question must occur. What's more, if a thing was born of itself, this would mean that it already existed. Production would then be unnecessary. If what had already been born was born again, then the process would never stop.
THUAN: And what about the second possibility, which is more similar to our usual ideas of causality and those of science? Can a thing be produced by "something else"?
MATTHIEU: Buddhism accept this sort of causality in terms of relative truth. In absolute terms, however, it affirms that if the cause and effect were totally distinct, then causality couldn't operate. The reasoning goes like this: at the moment when the cause is about to vanisk and the effect is about to appear, do the cause and effect, considered as real, separate entities have a "point of contact", even for a fleeting instant?
If yes, the cause and effect exist simultaneously when they are in contact. The effect thus doesn't need to be produced, given that it already exist and the cause is unnecessary. What's more, two simultaneous entities can't act on each other in caual terms, because they can't act on each other in the present instant (This goes back to what Heisenberg said: "Two simultaneous phenomena cannot be connected by any direct causal action"). On the other hand, if the cause and effect have no point of contact and are totally unconnected, causality breaks down. The two entities have nothing to do with each other and so can't be in a cause-and-effect relationship. What's more, if the cause has nothing to do with its product, anything could be born from anything else. In the words of Chandrakirti:
If something could be produced by something intrinsically "other",
The darkness could be born of fire
And anything could be born from anything.
Anything could be born from anything, because if the "cause" entity is "other" in terms of the "effect" entity, all phenomena are equivalent in the sense that they are all "other" in terms of the effect. In that case, any phenomenon could have the cause. If the cause has already disappeared when the effect appears, then this comes down to saying that the effect happened with no cause and is an ex nihilo creation. In other words, if the cause vaniskes before the result arrives, then the result will never arrive. A seed can't vanish before giving birth to a shoot Nor can the cause remain unchanged when the result arrives, just like a seed can't give birth to a shoot without vanishing. To sum up, a concrete, autonomous entity can't produce another one. If the "result" entity already exists at the same time as the "cause" entity, either it doesn't need to be produced, or it takes part in its own production, which is meaningless. If it doesn't exist, its production is impossible, given that a billion causes can never produce something from nothing. Nagarjuna summed up this argument in the following quattrain:
If the entity of the effect already exists
What does a cause have to produce?
If the entity of the effect does not exist
How could a cause produce it?
And Atisha added, in the Torch of the Path to Enlightenment:
Something that exist already cannot, logically, be born.
Just like nonexistent things—which are like flowers in the sky.
So is the Buddhism's conclusion: What seems to us to be a cause-and-effect relationship can only be possible if neither the cause nor the effect exists independently and permanently. We thus come back to the phrase "because everything is emptiness, everything can exist". The nonreality of phenomena is the precondition for their appearance. These "simple appearances" then evolve according to a law of causality based on interdependent phenomena with no inherent existence. To quote Nagarjuna once more:
There is not the slightest thing
That does not come from a dependent origin.
And therefore there is not the slightest thing
That is not emptiness.
Modifications of these interactions bring about the chain of cause and effect, without its being necessary to postulate the existence of separate entities, each containing its own properties—what physicista call "local" properties.
THUAN: That's right. Einstein, who rejected any idea of a global, interdependent reality, called them "hidden local variables". But experiments on the EPR phenomenon have shown that these local variables don't exist.