Because the brain is about 170 billion cells, half of them interacting chaotically
Note, I do not mean randomly, I mean chaotically. What is chaos? you might wonder.
Chaos, is when you look at something, and realise “I cannot predict how this will come out”. The thing you are looking at may be perfectly deterministic, like — say — this little formula…
z⁰=0
zn+1=z²n+C
and it is still completely unpredictable until you actually feed numbers into it and see how it turns out.
Because looking at this formula, could you predict that it will produce this picture?
A Mandelbrot fractalNo, you cannot, because that is a chaotic formula, the smallest change in input will lead to vastly different outcomes.
And this is what the brain is like, it is chaotic. Neurons — the active part of the brain — are like little analog computer elements that…
- we do not know how they operate
- we do not know how they are connected to each other
- we do not know how they form systems together
and there are 85 billion of them in an average human brain.
So, how could we get around this? Well, we would have to create a good model of what neurons are and how they operate. Then we would need to implement that model of them, and especially of how they are interconnected, and then we would need to run a simulation.
Even if each neuron was only byte each, it would take 85 gigabytes of memory just for that. And to then run the simulation, and model the chemical reaction that trigger electrical impulses to fly between the neurons correctly, it will take ages.
Today, we are — when it comes to simulating a working brain — about here, at the level of Babbage’s “Analytical engine”.
Analytical engineWe have a very long way to go before we have a good understanding of how the human brain makes consciousness, simply because we do not have the knowledge of how its constituent parts operate, and interconnect, and we have nowhere near the required computing power to run a proper simulation of a brain.