“You’ve already made the choice. Now you have to understand it.”

Yesterday I watched Stephen Hawking’s Grand Design episode ‘The Meaning of Life’, and I have to admit that I became extraordinarily surprised. In this episode, Hawking talks about the intrinsic significance of the free will, developing a thinking line which ends up with surprising conclusions.

A neuron network.

What would you answer if I asked you whether you’re free to choose or not? I know, obviously you think you’re free to choose, don’t you? What if I told you you may not be as free as you think? What if the free will is a false impression of consciousness? Our brain, as any other entity of the universe, is bound to work according to some laws, the laws of science, and here is where our reasoning begins. As we all know, our brain is made of neurons, a type of cell which is capable of transmitting electrical pulses  (yes, I’m using the terminology ‘transmitting’ instead of ‘generating’), something around 40 mV owing to the action potential of the synapse, which means, in the end, information. This process might seem quite complex, but, in a nutshell, this electrical signals are diffused throughout the brain according to the Maxwell equations of electromagnetism, which, by the way, we know fairly well. Given a circuit and some initial conditions, we are able to find the solution. Then, what happens if we apply these rules to the brain?

John Conway, a British mathematician, came across a significant development for our discussion in 1970. Imagine an infinite plane divided into squares (so every square has 8 neighbours), and every square has to be in one of two states: live (filled) / dead (blank). Now let’s consider four simple rules:

1. Any live square with fewer than two live neighbours dies, as if caused by underpopulation.
2. Any live square with two or three live neighbours lives on to the next generation.
3. Any live square with more than three live neighbours dies, as if caused by overcrowding.
4. Any dead square with exactly three live neighbours becomes a live square, as if by reproduction.

Possible evolution for Conway’s algorithm.

Now imagine an initial state, for example, the one in the figure aside, with three live squares at the bottom on the right, forming an inverted L. What is relevant about this algorithm is that it is a Universal Turing Machine (UTM), an important concept within Computer Science and Artificial Intelligence, which means that anything that can be computed algorithmically can be computed using this algorithm (By the way, you can play and get used to this algorithm in this website if you feel like).

Now let’s assume that every former square is a neuron, and ‘live’ means ‘transmitting’. What we see is that the former simple rules forge a unique map, which defines the state of the neurons and thus the consequences of its ‘transmitting’ state. In other words, a sensitive neuron is turned on (‘live’ state) and the process starts, the signal reaches a motor neuron, which conducts to a consequence. The sensation, however, is not forgotten with the consequence, as the algorithm carries on. Some time goes by and the next stimulus arrives to the system, this stimulus definitely interacts with the remaining memory of the latter, and so its consequence is given owing to the past states. This algorithm is so alike to living processes that Conway named it the ‘Game of life’.

Therefore, what if the rules and the initial state are given? The consequences are unique. Imagine yourself making a decision at a certain point of your life, for example when you decided your degree. The connection rules between your neurons are given and your life has led you to a given state: the next state is unique. Where is the free will then? Following Hawking’s conclusion, maybe I’m an engineer because of my initial state and these rules, and the free will is only an impression of consciousness. Maybe fate has a scientific base after all.