Even if you remove the size restriction and the physical limitations of manufactured circuitry, we're lacking the perfectly defined model of how a neuron actually works. We have plenty of knowledge about neurons, but nowhere near enough to simulate them realistically. You'd need to be able to account for every possible state a neuron could ever be in.
But a neuron is more than just an input-output state machine, it's affected by levels of oxygen, glucose, and any number of hormones, proteins, and other chemicals in the bloodstream. An adult human's neurons are each individually shaped by their entire existence up to that point. Alcohol consumption, sun exposure, antidepressant medication, hydration levels, exercise levels. It all affects how they work.
And that's just one neuron. Simulating the brain as a solution to this problem is, I think, out of the question.
It wasn't necessary to simulate a feather in bird's wing in order to fly. In fact, practical flight really only happened once people started taking away features observed in nature.
>An adult human's neurons are each individually shaped by their entire existence up to that point. Alcohol consumption, sun exposure, antidepressant medication, hydration levels, exercise levels. It all affects how they work.
Possibly, but why on Earth would you want to simulate that? Just simulate what the neuron is supposed to be doing or would be doing under ideal circumstances.
But a neuron is more than just an input-output state machine, it's affected by levels of oxygen, glucose, and any number of hormones, proteins, and other chemicals in the bloodstream. An adult human's neurons are each individually shaped by their entire existence up to that point. Alcohol consumption, sun exposure, antidepressant medication, hydration levels, exercise levels. It all affects how they work.
And that's just one neuron. Simulating the brain as a solution to this problem is, I think, out of the question.