You are reading a blog post on a blog that you chanced upon on a list that contains over a thousand such blogs. You clicked on the link, maybe because you love science or maybe because you’re just a nice person who wants to make new friends. In any case, you are now reading a blog post. My question to you is, did you choose to read this blog or were you already destined to read this blog on this particular day, on this particular time since the Big Bang? This summarises the Free Will Debate. And though questions such as these fall under the purview of Philosophy, as always Physics has something to say.Before the formulation of quantum Mechanics, our physical laws were based on Newtonian Mechanics. Which says that knowing the state of a particle at one instant, we can predict with 100% certainty the state of the system in the future. So essentially, free will was an illusion. Since if we could map a human brain accurately, we could, hypothetically, predict the decisions that this human brain would make.
And then came quantum mechanics. Since quantum physics states that’s it’s impossible to completely know the state of a system, we can’t predict the future with a 100% accuracy and so there is free will. People said that because of this uncertainty, free will can exist.
The problem with this argument- and the reason many prominent quantum physicists dismiss it- is that free will is distinct from randomness.
Brian Green explains this wonderfully. He says:
I find this unconvincing because my conception of ‘free will’ is radically distinct from ‘randomness’. To make the point, take quantum mechanics out of the discussion for a moment and imagine instead a comparison between a deterministic Newtonian universe and one in which there’s a wizard throwing dice, with reality unfolding according to the results the wizard obtains. If the wizard throws a 2, for example, I order pizza but if the wizard throws a 7, I order tofu. Although there’s (classical) probabilistic randomness at work here, I would not describe this world as offering me any greater degree of free will than I have in the usual Newtonian one. Free will, in the usual sense of the term, requires that I control my actions. Whether my actions are determined by Newtonian rigidity or probabilistic flexibility, I still am not in control, and so I still lack free will.”
The Free Will debate is fascinating both from a physics standpoint and a philosophy standpoint. I might do an even longer post on it in the future. For now, that’s all. If you have any thoughts, comment below. Or just say “Hi” and leave a link to your blog!