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On Time and Free Will

What Does Physics Teach Us About Determinism?


Saturday, December 31, 2011

In any attempt to bridge the domains of experience belonging to the spiritual and physical sides of our nature, time occupies the key position.

—Arthur Stanley Eddington, 1928

Everything is determined, the beginning as well as the end, by forces over which we have no control. It is determined for insects as well as for the stars. Human beings, vegetables, or cosmic dust, we all dance to a mysterious tune, intoned in the distance by an invisible piper.

—Albert Einstein

Even very smart people can be wrong. After all, Einstein showed with his theories of relativity that Newton, another very smart guy, didn’t have the whole picture on the nature of space or time. But nor did Einstein, it seems, as I’ll describe. It is becoming increasingly clear that Einstein was wrong about the nature of time and determinism.

What is time? For Einstein and most physicists, time is considered an additional dimension akin to a spatial dimension — sometimes described as “the spatialization of time.” We arrive at a four-dimensional universe in which time is reversible and there is no real difference between past, present, and future. Past, present, and future are all just different coordinates in an unchanging and eternal “block universe.” Einstein made this view explicit in a 1955 letter to a friend; the appearance of past, present, and future as distinct features of our experience, he wrote, is a “stubbornly persistent illusion.”

Sometimes, developments that seem like advances can actually be setbacks. Einstein’s views on time have become prevalent in science and philosophy, but what is far less prevalent is the understanding that in a world where time is an illusion and the universe is deterministic, there is no room for free will.

Free will is an active area of interest in psychology and philosophy. There is an increasing — and disturbing — trend toward a kind of hard-nosed acceptance that we don’t have free will. The attitude is something like: “Science is increasingly showing us that we are not that important. Copernicus showed us that we’re not at the center of the universe, Darwin showed us that we’re just another animal, and physics has shown us that there is nothing special about consciousness and that we suffer from an illusion of free will because past, present, and future all exist at the same time.”

Tam Hunt
Click to enlarge photo

Tam Hunt

This attitude, while increasingly pervasive, goes too far in my view. Much of it is, of course, correct: We are not at the center of the universe, and we have evolved just as all other creatures have evolved on this blue/green planet of ours. But we are also the leading edge of that creative process, with our highly complex consciousness and associated attributes. Even though many things are indeed beyond our conscious control, it is not the case that we are conscious automatons in a deterministic world. New physical ideas support this view, and we are now seeing the dissemination of these ideas slowly but surely, steadily eroding Einsteinian determinism.

Do you really believe you have no free will? Does a physicist who subscribes to Einstein’s “tenseless” theory of time really believe she has no free will? I believe the answer is “no” in both cases. Even those who deny free will certainly act as though they do have free will. And let’s not forget that our criminal justice system, not to mention our entire system of morality and ethics, rests on the notion that we do have free will.

Doesn’t common sense demand some kind of reconciliation with our innate sense of free will and physical conceptions of time?

Ilya Prigogine (1917-2003), a Belgian physicist and Nobel Prize winner, worked for decades to show why Einstein was wrong about his views on time and determinism. Prigogine states in his 1996 book, The End of Certainty, which summed up his life work on the nature of time: “The spatialization of time is incompatible with both the evolving universe, which we observe around us, and our own human experience.”

Indeed, our own human experience is tensed through and through. All we know with any certainty is the fact of our own experience now, now, now. All we know is the now. The past is remembered, and the future imagined. Only the now is real.

How, then, do we reconcile the obvious facts of our experience with the strange physics of tenseless time, with Einstein’s “block universe” in which past, present, and future are all said to exist concurrently?

It is becoming increasingly apparent that we reconcile these competing views by bowing to common sense and embracing new ideas in the area of physics known as thermodynamics — Prigogine’s life-long area of focus. Prigogine describes at length in his work how thermodynamics demonstrates the necessity of an arrow of time. There is no block universe. Prigogine writes, “Nature itself … distinguishes between past and future. There is an arrow of time.” He also states that we need to reformulate the “laws of physics in accordance with the open, evolving universe in which man lives.” Hear hear.

Prigogine’s work is of the highest rigor and provides at least a partial solution to the problems of time and free will. He shows that classical mechanics and the prevailing versions of quantum mechanics can’t describe much of the universe accurately because they consist of time-reversible equations. Irreversibility must be included in the equations in order to accurately model our universe.

Prigogine concludes: “We see that human creativity and innovation can be understood as the amplification of laws of nature already present in physics or chemistry…. Nature is indeed related to the creation of unpredictable novelty where the possible is richer than the real.”

Why did Einstein believe time was an illusion?

I’m going to get a bit more detailed at this point and explain how Einstein arrived at the notion of the block universe, of tenseless time. It’s based on an assumption that is not necessarily true and that I believe is not true.

Einstein developed his theory of special relativity in 1905 by starting with the idea that “time” can best be defined by using light as a tool for establishing the simultaneity of distant events. He further assumed that the speed of light is constant in all directions, regardless of the speed of the observer. I’ve previously written about how strange this assumption is because nothing else in the universe behaves this way. It has nonetheless become the prevailing view of the nature of light, space, and time.

The problem of establishing simultaneity between distant events was a major inspiration for Einstein’s special theory of relativity. Establishing whether one event is simultaneous with an event elsewhere was a thorny problem in Einstein’s era — and remains so today. In late 19th-century Switzerland (where Einstein lived at the time), the problem of synchronizing the country’s many town clocks became an obsession among physicists, including Einstein, in large part because of the growing network of trains and train schedules.

Einstein proposed in his 1905 paper on special relativity that, rather than making an assertion about whether a given event was “really” simultaneous with other events elsewhere, the problem could be resolved by postulate. Einstein’s postulate was to assume that light travels at a uniform speed at all times for all observers no matter their own speed. Light could be used to synchronize distant clocks under this assumption. With distant synchronized clocks, events occurring at those clocks may be judged as simultaneous or not by noting the readings of the clocks at each location at the time of the events and then adjusting for the speed of light. Einstein wrote in his 1916 popular book on his relativity theories (emphasis in original):

There is only one demand to be made of the definition of simultaneity, namely, that in every real case it must supply us with an empirical decision as to whether or not the conception that has to be defined is fulfilled. That my definition satisfies this demand is indisputable. That light requires the same time to traverse [paths of equal distance, regardless of motion] is in reality neither a supposition nor a hypothesis about the physical nature of light, but a stipulation [postulate] which I can make of my own free will in order to arrive at a definition of simultaneity.”

In other words, to arrive at a way of determining simultaneity, Einstein stipulated (or postulated) that the speed of light is constant for all observers, regardless of their own motion. So, rather than treat the speed of light like any other speed, which does depend on the speed of the observer, light is to be considered the exception to this otherwise universal rule.

Einstein is certainly correct when he stated that he may stipulate what he wishes, but there is, however, more than one demand to be made of a definition of simultaneity: that it help us arrive at an accurate understanding of nature and not conflict with undeniable aspects of human experience, such as the flow of time and evolution of the universe.

There are other interpretations of relativity that don’t require assuming a constant speed of light for any observer — for example that of Hendrik Lorentz, a Dutch Nobel Prize winner who was a mentor to Einstein. Under Lorentz’s theory, the speed of light acts like any other speed in that it changes with respect to the speed of the observer. Lorentz’s theory explains empirical observations just as Einstein’s theory does because both theories use the same mathematical framework known as the Lorentz transformations. Thus, we need not lose the accuracy of the mathematical formalisms of special relativity even if we reject Einstein’s assumptions.

Another well-known Einstein saying, with respect to Niels Bohr’s “Copenhagen interpretation” of quantum mechanics, is that “God does not play dice with the universe.” Indeed, he does not. But nor is the universe deterministic as Einstein believed. Rather, God has given to his creation the ability to choose, the ability to exert free will, at every level of nature, as I have described in a number of columns. Thus, what is thought of as chance is better described as choice. Choice, not chance. This panpsychist expansion of Prigogine’s work brings us full circle.

Reconciling relativity and quantum theory?

Determinism is a common theme in relativity theory (the physics of the very large scale) and quantum mechanics (the very small scale), which conflict in many ways. Resolving the nature of time, free will, and determinism, may well lead us to a reconciliation of these two pillars of modern physics. This reconciliation remains the biggest challenge in modern physics.

There are more than two choices, however, when it comes to the famous debate between Einstein’s determinism and Bohr’s complementarity and indeterminism. Bohr’s view is that the act of measurement and choosing what to measure has a real role in determining the results of measurement. This has given rise to all manner of suggestions that humans literally create their own physical world around them. This goes too far in my view.

There is a third choice: the view that all aspects of the universe enjoy at least a rudimentary free will. In this view, all entities “measure” themselves through their ongoing and necessary interaction with the universe around them. This conclusion follows from the extension of at least a rudimentary consciousness to all matter.

This position seems very strange to most people encountering it for the first time, but it has support from good sources. The well-known British-American physicist Freeman Dyson, with Princeton’s Institute for Advanced Studies for many years, stated in 1979: “[T]he processes of human consciousness differ only in degree but not in kind from the processes of choice between quantum states which we call ‘chance’ when made by electrons.” David Bohm, a highly influential American physicist, wrote similarly in 1987: “Even the electron is informed with a certain level of mind.”

The rudimentary free will that exists in subatomic particles like electrons compounds upward until it reaches the rarefied heights that we humans enjoy. We are not different in kind from the rest of the universe — in terms of free will or consciousness. We human beings, the result of almost four billion years of evolution, are instead different only in degree. The difference seems to be a difference in kind because the gap is very large. But the spectrum of free will is surely grand, and we happen to enjoy a rarefied position at its most advanced terminus.

Under the views on time that I’ve sketched here, we realize that choice — free will — pervades our universe. Each moment is creative and free for each and every entity in our universe. At lower levels of complexity, habit dominates, and the exercise of free will is quite regular — which is why our statistical laws of mechanics work quite well in most situations (with some key exceptions, as Prigogine describes). But as choice complexifies, outcomes become less certain — as befits a creative and evolving universe.

I’ll end with another Prigogine nugget: “[T]he more we know about our universe, the more difficult it becomes to believe in determinism.”

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