So, about that Albert Einstein quote from which this blog gets its title – it is an interesting story about probability, determinism, fate and physics.
You can find different versions, of varying provenance, where Einstein is quoted as saying something like, “God doesn’t play dice with the world.”  This quote is cited often by some religious writers to indicate that Einstein was a theist in some conventional sense. This is not the case; Einstein was of Jewish heritage but followed no religious practice. But we will put off Einstein’s own peculiar use of “God language” to Part Two of this post. This post looks at the scientific context to his claim.
Einstein was not so much using this mental model of dice to be talking theology as he was using “God language” to talk to a broader audience about his disagreements with then-emerging theories of quantum physics, and in particular Werner Heisenberg’s Uncertainty Principle (1927), with which he disagreed for many years.
Einstein was a determinist. He saw his revolutionary mathematical descriptions of the relationships between energy, matter and time, as well as the other “rules” of the larger cosmos, as setting the universe in a “one way” direction. Everything that happens is determined by everything that happened before. If we can completely describe the “antecedent” (what just happened a moment ago), then we can completely predict what will happen next. 
“Everything is determined, the beginning as well as the end, by forces over which we have no control. It is determined 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.” 
From the larger perspective of the cosmos, this certainly appears to be true. We can now walk cosmological events back billions of years to see evidence of the past that brought us to this particular time and place. And already there is likely an asteroid on an unfailing and predictable path that will intersect the Earth at some time in the future to cause some havoc.
Werner Heisenberg instead saw the nature of matter at the subatomic level, and he saw there something probabilistic, rather than discretely measurable, which did not mesh well with Einstein’s more cosmic-level theories of relativity. Indeed, physicists still seek a “Grand Unified Theory” of physics which explains both the “macro” world of the cosmos, which Einstein’s math defined, and the “micro” world of subatomic quantum physics coming from a younger generation of physicists.
But in asserting that “God does not play dice,” Einstein was saying that the future was pretty much set, with no unpredictable, probability-based wiggle room. And in this particular point Einstein was very likely wrong, and Heisenberg remains apparently correct, at least at the level of quantum physics.
When physicists speak of electrons as “particles,” for instance, they mean something other than the discrete little balls of matter orbiting the atom’s nucleus, as we conventionally and incorrectly drew them in high school. At the atom’s smallest level, electrons are better described by their “orbital,” a probability distribution of where the electron ought to be, rather than an “orbit.” 
That is far too brief a simplification of the determinism argument, and this as deep as I likely will get into the language of quantum mechanics. Mixing quantum mechanics and “God language” is generally dangerous from either side, even if you are Albert Einstein, and certainly if you write blog posts. I will leave it by suggesting that the lesson here is that some sort of probabilistic randomness (or stochastic process) appears to be at the very heart of our universe, at the very core of reality.
That said, the farther away you get from the core of the atom, the universe more often does appear pretty deterministic, more than we normally assume.
Einstein’s persistent and unique use of “God language,” which infuriated even many of his closest friends, is the subject of Part Two of this post, which is in the queue.
Part Two is now posted.
- The easiest-to-verify version of this quote comes from physicist Max Born’s own annotated correspondence between himself and Einstein. This quote is on page 91 from a letter dated December 4, 1926, relating to the ongoing disagreement over quantum mechanics: “I, at any rate, am convinced that the He is not playing at dice.”
- While he did conjecture later in life about the time effects of black holes, his consistent view of “this universe” in which he was living was quite linear and deterministic.
- Clark, Ronald W. Einstein: the Life and Times. Avon Books, 1972, p. 422.
- For an extended discussion of this debate, a good source is Lindley, David. Uncertainty: Einstein, Heisenberg, Bohr, and the Struggle for the Soul of Science. Anchor Books/Random House, 2008.