Perhaps a million years after a particle is produced by a quantum event, it will reach a distant galaxy where alien scientists perform a measurement on it discovering its 'spin'. Until a measurement is made, a particle has both spin up and spin down at the same time.
Credit: Tim Wetherell
Quantum mechanics is inherently statistical in that it can tell you the probability of something like a nucleus emitting an alpha particle in a given time, but it can’t tell you exactly when or how.
In the early days of quantum mechanics this caused great consternation for many scientists, including Einstein whose dislike of this apparent randomness prompted him to protest “God does not play dice!”
Einstein and others proposed what’s now known as hidden variable theory, to get some causality back into the quantum world.
In essence this says that there are mechanisms within the nucleus that lead to the emission of the alpha particle in a deterministic way, but we can’t see them so they appear random to us.
However in 1964, the physicist John Bell published a famous paper in which he argued that no hidden variable theory can reproduce all of the observed quantum phenomena.
A well-known and intriguing aspect of Bell’s work are what’s known as Bell inequalities. Bell considered a situation in which something like the decay of a nucleus emits two particles simultaneously that move in opposite directions.
One of the key features of quantum mechanics is that each such emitted particle exists in a superposition of every possible state until a measurement is made, at which point they condense into a single real state. In this way, it’s the actual process of making measurements that in effect “creates” reality – strange but true.
Conservation rules also dictate that if the spin of one such emitted particle is up, then that of its twin must be down. But of course until a measurement is actually made, each particle has both spin up and down at the same time.
Physicists call this quantum entanglement - two particles whose states depend on each other but where both particles still exist in all possible states because no measurement has yet been made on them.
In a Bell inequality scenario, a measurement made on one such entangled particle causes both it and its twin to instantly condense into a single real state, even if the two are separated by vast distance. This notion was also intensely disliked by Einstein, who termed it “spooky interaction at a distance.”
However, Bell showed Einstein could not have his cake and eat it too. His “Bell inequality” paper proved that any hidden variable theory for quantum systems, in which observers had free will to choose what they measured, was forced to have such spooky interactions!
Of course people immediately began to ask if a Bell inequality scenario, or something like it, could be used to create faster than light communication?
The basic idea is that a pair of quantum entangled particles are sent in opposite directions from a location midway between two distant observers.
If a measurement is made on one, perhaps by an alien civilisation in a distant galaxy, that would instantly affect the state of its twin here on Earth so surely that’s faster than light communication right?
Unfortunately the universe doesn’t work that way. The problem is, that although the effect may be instant, if we measure the spin of our particle as up, we don’t know if the aliens caused that by measuring theirs as down, or if it was our own measurement that condensed the sate.
There are exactly as many ups as downs so there’s no way to tell. To find out you’d have to send a message to the aliens and ask them what they did and of course that would have to be at sub-light speed.
Mechanism of free will is mental feedback
The problem with free will, as I see it, is that people have the wrong impression of what it means. Free will is not all it’s cracked up to be but there’s no doubt we have a modest form of it. I prefer to call it “self-determinism”. This self-determinism is empirically proven every time we conceive and execute a plan. I’ve found this is hard to explain because so many people assume that any free will must contradict causality and, thus, determinism. I claim that the only free will we have is actually self-determinism and that it isn’t in conflict with causality: in fact, it’s a product of human intelligence interacting with causality. I’ll try to explain . . .
I maintain that “free will” is an awful term to express the independent agency humans possess to define purpose for themselves and pursue it. Our choices aren’t free in a libertarian sense: they’re free within the constraints of our heredity and experience (which are both products of causality). Perhaps Arthur Schopenhauer summed it up best: “Man can do what he wills but he can not will what he wills.” We can do, in the present, whatever our experience has prepared us for.
Experience represents the past. Experience — what we’ve learned — is all we know. With the exception of instinct and reflex, I believe it’s virtually impossible to think or act beyond our experience. Even inspiration comes from experience. Where the rubber meets the road is in the present. This is where our human brains interact with the world around us to form the conceptual continuity of consciousness: our identity. Experience influences us so much because it’s been layered into our identity just as the present will be. THAT is the self in self-determinism.
Don’t get me wrong . . . causality rules. We might think we’re in control until that fire or disease or earthquake or tsunami or accident or economic crash changes our lives. Causality is the ultimate big dog. We can make choices to maximize security but we can never be sure we’re secure. We can’t anticipate everything.
So how do you explain the fact that, despite the pervasiveness of causality, we can still map out our own futures and achieve our plans (if they’re any good)? How do you explain how we, for the most part, hack our own paths into the future?
Feedback.
Mental feedback is the key. It doesn't matter how the brain produces mental feedback as long as it does. Without it, we could not have memories or analyze problems or learn or make plans. Without it, we could not understand causality or anticipate it. Intelligence and consciousness itself hinge on mental feedback. Mental feedback gives us a temporal advantage over causality by allowing us to anticipate it and plan for the future accordingly. THAT is the determinism in self-determinism.
It lacks the flourish and romanticism of unbridled, libertarian, free will but self-determinism has its own beauty revealed in the paradox of independent agency in a clockwork universe. Causality determines the scope of our abilities and actions and we use those abilities and actions to hack our own paths into the future. We’re so good at it, we’re getting cocky. But we’re not masters of causality . . . merely expressions of it.