Free Will by Wayne Radinsky

When you observe an event involving subatomic particles, such as electrons or photons, you can't predict exactly what will happen, but only a probability. For example, if you run electrons through a spin measuring device called a Stern-Gerlach Magnet, it will tell you that half of your electrons are "spin up" and the other half are "spin down". Spin is either "up" or "down", never anything in between, because subatomic particles behave in a discrete, quantized way like this. The important point here is that we cannot predict which way any particular electron will go. All we can do is predict that if you make many thousands of observations, about half of them will be "spin up", and about half will be "spin down" -- i.e. we can predict the probability is 50/50. And there are clever experiments you can do where the probability deviates from 50/50 (which I will skip for purposes of simplicity), but in no case can we predict the behavior of an individual electron.

Seth Lloyd, the physicist who builds quantum computers at MIT, has a philosophical theory about this. He says, whenever one of these "quantum events" occurs, new information is created out of nothing. That is, when you measure the spin of an electron, the universe introduces a new bit of information, that did not exist before -- and furthermore this new bit of information is completely random.

Now, this isn't the only possibility. It is possible that something determines whether the electron is "spin up" or "spin down", but that we human beings simply haven't figured out what it is yet. If you look back at the history of science, there were many times when phenomena was observed, but it was a long time before people understood what the cause was. People observed the motions of the planets for thousands of years before Newton came up with an explanation for their movement, for example. So, the fact that we cannot predict an individual electron's behavior could just be a sign of human ignorance.

Seth Lloyd is well aware of this. The universe "creating" new information, at each quantum event, is how he thinks the universe works. But it's just his theory, and he knows he can't prove it. I know this because I discussed it with him when he visited Boulder in 2006. And by the way, if you ever have a chance to go to a Seth Lloyd talk, you should -- they're great!

Anyway, maybe at this point you can see where I'm about to go with this. Basically, there are 2 possibilities. One is, that the universe introduces new random bits of information continuously. The other possibility is that it doesn't -- that these quantum events have some precise, deterministic cause, but we human beings simply don't know what it is.

Let's explore the deterministic idea for a moment. If every event in the universe has a deterministic cause, that means the entire universe is deterministic. It means all the apparent randomness is just that -- apparent randomness, the product of non-linear discrete mathematics. Stephen Wolfram, in his "Big Book" (A New Kind Of Science), demonstrates how an extremely simple mathematical function (which he calls a cellular automata), can generate an unlimited amount of apparent randomness -- that is, a never-ending stream of bits of information, which never repeat, and never have any discernible patterns whatsoever. It looks completely random. But it isn't -- every time you run the computer program, you get exactly the same sequence of bits of information in the output. It is totally "random", yet at the same time, totally "deterministic" -- because there are no discernible patterns, yet you get exactly the same output every time.

Now, those of you who know some mathematics know this is called a "pseudo-random number generator". And you may have learned that a "pseudo-random number generator" always repeats -- it has "cycles", as they are called, and the cycles may have an exceptionally long "period", as the length of the cycles are called, but it never generates a truly unlimited amount of apparently random output. So, you're probably wondering how Wolfram got around this. The answer is that a pseudo-random number generator on a computer has a fixed amount of internal data (which is "seeded" with some initial value to get the pseudo-random number generator started). In a computer, this could be, for example, a 32-bit number, or a 64-bit number, or maybe several. Wolfram's pseudo-random number generator, by contrast, expands its memory usage (by 2 bits, in fact), on each step. This is how it is able to avoid getting cycles, and generate an unlimited amount of "apparent randomness" in a precisely deterministic manner.

Now, the universe can store bits of data in the quantum states of every subatomic particle. So the amount of "memory" available to the universe to use as a pseudo-random number generator, is unfathomably large. So large, in fact, that there would be no hope in us humans seeing any recognizable patterns. So, if the universe is generating the behavior of each electron in our spin-measuring experiment in a completely deterministic, pseudo-random manner, there is no way we humans (not knowing the real cause of what determines the electron's behavior) could possibly see the patterns.

Now, I titled this piece "free will", so you're probably wondering what all this has to do with "free will". Or maybe it is obvious by now. You see, our brains are made of atoms. Those atoms are made of subatomic particles -- protons, neutrons, and, yes, electrons. Those subatomic particles have "quantum events", exactly of the nature I described here, every time they interact. Our eyes have quantum events every time photons, another subatomic particle, arrive. In short, we have an unfathomable number of these "quantum events" happening inside our brains and bodies every second. If they are truly random -- the universe introducing new bits of information as Seth Lloyd described -- then our illusion of "free will" is really just the product of randomness -- the random thoughts that pop into our heads are the ultimate result of the universe continuously generating this new random information. If, on the other hand, these "quantum events" are pseudo-random, then it means the universe is deterministic, and everything in the world today is the result of information that existed at the moment of the Big Bang -- the universe is essentially a giant decompression algorithm. It would mean that the entire history of the universe was pre-determined. It would mean, at the moment of the Big Bang, that it was already predetermined, not just that the Milky Way galaxy would form and earth would form and humans would evolve, but that Bill Gates would become the richest person in the world. And that millions in Africa would starve to death.

Either conclusion is rather unsettling when it comes to the notion of "free will" -- because what we are saying is that everything that happens is due to either luck or fate. You could say that Bill Gates became the world's richest person simply by dumb luck. The answer to the question "is his success due to luck or smarts" is that his smarts came from luck -- he was lucky enough to have the right series of genetic mutations -- random information created by the universe, in "quantum events" culled by the laws of physics in a process we call evolution by natural selection -- going back to the beginning of life 3.5 billion years ago, to give him the necessary intelligence. Plus he had the good luck to be in the right place at the right time when IBM came knocking. In other words -- if you believe the universe creates new information as it goes along, then it's ALL luck.

So, there you are. Life is either all luck or all fate. Free will is an illusion. "Quantum events" are either caused by nothing (truly random) or caused by something (pseudo-random). But -- and here is the interesting point -- it's impossible to tell which it is. Maybe someday, scientists will figure out which it is, but right now, at this point in history, it's impossible to know.