Thursday, 23 October 2008

Playing Dice with God

An article published in the Autumn 2008 edition of the Jewish Quarterly

Playing Dice with God

The Large Hadron Collider has been switched on. Somewhere between France and Switzerland protons are colliding with a force unknown since the first moment of creation. It’s a good time to look back at one of the most important scientific and religious debates of the last century – the question of whether or not God plays dice with the Universe. Einstein’s expression is more than a neat turn of phrase; understanding what he meant provides a key to the physicist’s world view. Indeed understanding what Einstein meant when he disregarded a dice-playing deity unlocks not only a central obsession of one of the greatest minds of all time, but also offers a way out of the, largely weary, tit-for-tat that passes for the contemporary debate between religion and science.

Until the 1900s, physicists believed it would be possible to reach a precise understanding of the relationship between cause and effect. If you dropped a weight from a certain height it would take a certain amount of time to reach the ground — that sort of thing. As long as a physicist had enough information about a system they expected to be able to work out precisely how any part of that system would respond at any given time. Einstein was an archetypal classical physicist in that he believed in this type of approach. He was a self-defined ‘determinist;’ a passionate believer in strict rules of cause and effect. He didn’t have the arrogance to believe he understood all these rules, indeed his humility when confronted by the majesty of the world was the prime source of his special kind of religiosity — but he believed such rules did exist and that they applied to every element of the Universe, ‘for the insect as well as for the star. Human beings, vegetables, or cosmic dust, we all dance to a mysterious tune, intoned in the distance by an invisible player.’ 

Einstein’s determinism seeped into his understanding of the workings of the brain and soul, ‘Human beings in their thinking, feeling and acting… are as bound by causation as the stars in their motions,’ he wrote. And that meant, for Einstein, that there was no such thing as free-will. A person might be able to decide what to do, thought Einstein (following Schopenhauer), but they couldn’t decide what they chose to decide – that higher decision was determined by the same universal, if unknown, rules as govern everything else in the world. 

Then came quantum mechanics. The discovery of quantum mechanics in the 1920s was built on the foundations of Einstein’s own discoveries, but Einstein never fully accepted the single most provocative truth of the field of studies his own work begat.

It is possible to ‘charge up’ a cloud of atoms by pumping electricity into it. This results in some of the atoms in the gas absorbing energy and emitting photons. As long as one doesn’t wish to look too closely it is possible to use these emitted photons in a very focussed manner — this, after all, is how lasers work. But while an applied physicist might be content working out how to focus a laser beam to perform any particular task a theoretical physicist, like Einstein, has to grapple with how this stream of photons is produced. And this is where the science becomes murky.

The problem is that atoms in a gas do not emit photons according to precise laws of cause and effect. There is no way to determine which atoms in the gas will emit a photon at any given time and there is no way to determine which direction any particular emitted photon would travel. In general terms the majority of atoms will behave in a particular way, and that is fine for practical applications, but on an individual basis no amount of information about the system of gas and charge can allow a physicist to predict which atom will behave in which way under any given set of circumstances. Three identical atoms could go through identical experiences and two could emit photons in totally different directions while the third atom would emit nothing. While classical theoretical physics speaks in terms of ‘causality’ and predicts certainty, quantum theoretical physics speaks in terms of ‘indeterminacy’ and predicts only probability. Quantum mechanics is not nihilism. It doesn’t reject order, but rather the attempt to pin down the precise nature of this order. As long as one is content to generalize, a certain order can be predicted, it is only when the individual explanations are sought that clear-cut answers are impossible.

Einstein doggedly refused to accept what experiment after experiment seemed to prove — that, on an individual level sub-atomic matter failed to behave according to laws of cause and effect. ‘I find the idea quite intolerable that an electron exposed to radiation should choose of its own free will not only its moment to jump off but also its direction’ he wrote to his colleague Max Born. ‘In that case, I would rather be a cobbler, or even an employee of a gaming house, than a physicist.’  Indeed it is another letter to Born that contains the first appearance of the now-famous aphorism. ‘Quantum mechanics is certainly imposing,’ wrote Einstein, ‘but an inner voice tells me that it is not yet the real thing. The theory says a lot, but it does not really bring us any closer to the secrets of the Old One. I, at any rate, am convinced that He does not play dice.’ 

Does the world operate according to strict causality or is there another ordering power? This is the essence of the argument between Einstein and the school of quantum mechanics led by Niels Bohr. It is no minor detail; it threatens not only the determinist position of classical physics but also the philosophical/theological framework of determinism’s greatest advocate — Einstein himself. Indeed physicist John Wheeler suggested, ‘in all the history of human thought, there is no greater dialogue than that which took place over the years between Niels Bohr and Albert Einstein.’ Turning the clock forward some seventy years Bohr seems to have won. Despite the best efforts of Einstein, and classical and quantum physicists since, physics – at a quantum level – has abandoned the absolute ordered determinism that was the marker of Einstein’s world view.

It is a dialogue and an outcome that fascinates me, as a Masorti Rabbi, in two ways. Firstly it is an argument predicated on a belief in the essential unity of truth. One sometimes hears the claim that religion and science are interested in two entirely different spheres; science explains how things happen and religion explains what a person should try and do. That feels fuzzy and wrong. It certainly runs counter to Einstein’s claim, accepted by Bohr, that what applies to apples falling from trees must also hold true for the innermost secrets of the heart. If religion and science aspire to revealing truths, they have to overlap. If science predicts only pure causality and I choose to believe in free-will or Divine intervention I cannot claim to be able to accept the truths of science in one sphere, while holding tight to religious dogma in another. As the Kabbalists point out kula chada — it’s all one. This is a significant challenge to the contemporary religious truth seeker. Scientists are trained to reject superseded truth claims (with every new scientific discovery textbooks are re-written, old editions are dumped into the recycling), but religions in general and traditional forms of Judaism in particular don’t like being superseded. We don’t throw out the Code of Jewish Law just because, contrary to the Talmudic claim that fish and meat consumed together are dangerous, we subsequently discover no such pathology. But there has to be a line.

Solomon Schechter, the first President of the Jewish Theological Seminary wrote about the rabbinic tale in which the Biblical patriarch Abraham smashes the wares of his father, a seller of idols. It must have been tempting for Abraham, wrote Schechter to continue the life of dishonesty of an idol salesman, but the Jew, ‘being the first and fiercest Noncomformist of the East’ is called upon to ‘boldly denounce’ superseded truth claims.  As Jews we have to be in search of truth, wherever it may be found, and we need to prepare ourselves for the consequences of what we might find. At the very least if we find certain truth claims of our faith superseded by science we should admit that, if we do persist in following various religious doctrines, we are not doing so in pursuit of some grand universal truth, but rather, to borrow language from Mordechai Kaplan, we are performing ‘customs’ and travelling on ‘folkways.’  As such the rejection of determinism at a foundational, albeit sub-atomic, level is important. It may well be that the world in general behaves according to predictable rules of cause and effect, but this, according to the laws of quantum mechanics, does not exclude the possibility that on an individual basis strict causality takes second place behind some other unknowable, unpredictable force.

Secondly the argument about the behaviour of the quantum can also be understood as an argument about whether, at the heart of the universe, the world is a paradigm of order (per Einstein), or, if not chaotic as such, then a good deal less straightforward (per Bohr). This, in turn, feeds two totally different ways of understanding suffering. If we suffer but feel the world is ultimately ordered along determinist principles (Einstein), we will, consciously or otherwise, acknowledge our own pain fits into this mechanistic system. This, in turn, often leads to a search for causation; why did this happen to me? On the other hand if we perceive the world as less clear; with layers of order and complexity folded one on top of the other like a giant fractal (Bohr), another response beckons. It might be possible that there is no reason why one small baby died, and another lived; maybe there is no reason for the triumph of the wicked and the destruction of the good. As a Rabbi I am often grateful for this latter response (of Bohr) when confronted by suffering that defies determinist causation.

Many Jews (especially those who are distant from religious study) assume that, on the question of causation of suffering, Judaism sides wholeheartedly with the determinist Einstein, but that is incorrect. A more nuanced and accurate representation of the tradition should acknowledge precisely what Bohr suggests – at a certain level we can predict order but when it comes to individuals we need to acknowledge an absence of causation. Nowhere is this common fallacy and accurate reality better expressed than in the first verse of the Hebrew Bible. The opening of the Bible as translated in the Christian King James Version reads ‘In the beginning God created the heaven and earth.’ It’s a beautifully balanced, ordered reading of Genesis 1:1. It’s a translation that might make a person think the Hebrew Bible believes that everything in the world is in order, determined, but as a translation it is wrong. It fails to communicate a clear element of the original Hebrew. The Hebrew suggests a far less ordered creation and the Jewish JPS translation is more accurate when it translates, ‘When God began to create heaven and earth — the earth being unformed and void, with darkness over the surface of the deep and a wind from God sweeping over the water — God said, “Let there be light.”’ In other words at the first moment of creation there is a void — tohu vavohu.                

Mystics from Isaac Luria to Nahman of Braslav have understood this emptiness — also referred to as a place of tzimtzum or the hallal hapanui — as the primordial location of indeterminism  In the beginning chaos and order stood side by side, each competing for the upper hand, just as we find in the argument between Bohr and Einstein.

There are, in these encounters between Judaism and physics different ways of framing very similar perspectives on the Universe and everything in it. The science acts as a testing ground for the religious claims — if it fails the test of science it cannot be claimed as ‘true,’ while the religion provides a broader framework for the claims of science — a way of setting scientific claims against a broader canvas. At the very least engaging seriously with Einstein’s dice playing (or otherwise) deity has to be an improvement on arguments about whether God does or doesn’t exist and, if he does, whether he gave dictation on Sinai all those years ago.

Jeremy Gordon is Rabbi of New London Synagogue.
The author is grateful to Prof. Louis Lyons (University of Oxford) for looking over the physics discussed in this paper.
Citations from Einstein’s work are taken from Walter Isaacson’s 2008 biography Einstein.

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