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Friday, January 24, 2014

What is consciousness?

As I sit typing, I am aware of many things. I see, hear, and touch. I know where each part of my body is and can move. I am aware of the thoughts forming in my head and the words that symbolize them. All of this is made possible by billions of interconnected neurons trading chemicals. That and nothing more. 

The individual atoms that make up the brain cannot do any of these things. Nor can the more complex molecules or neurons. Nor can even a large group of neurons. So the question is, if none of those simpler things can think or feel, how is it that a brain can? 

A partial answer to this question is to say that thought is an emergent property of the brain. All that means is that the brain as a whole can do things none of its parts can do alone. A brain is like a machine that only works when all the parts are combined in the right way. This is a good enough explanation for me.

This isn't the end of the mystery though. The really great question is why am I aware as this particularly arrangement of neurons and not some other? Before I was born, all the atoms that would become my body already existed. And as I grew, I eventually gained awareness. But why is my awareness tied to this particular brain? Couldn't I have just as easily been born another person or an animal? Why are there many minds instead of just one big one? 

I doubt we will ever know the answer. The human brain is finite, so it follows there are limits to what it can do. Every brain is a kind of miniature universe. We don't interact with world. We interact with the model our brains have built to represent it. The brain has about 100 billion neurons, with each being connected on average to 1,000 others. A neuron can have only two states: it is either firing or not firing. So the lower limit to the number of possible brain states is 2 to the power of 100 billion, which is about 127 followed by 208 zeroes. Given the human life span, no one will ever live long enough to experience ever possible brain state. 
Even if you had been around since the beginning of the universe, you'd still have only scratched the surface. 

"There is a theory which states that if ever anyone discovers exactly what the Universe is for and why it is here, it will instantly disappear and be replaced by something even more bizarre and inexplicable.
There is another theory, which states that this has already happened"

-The Hitchhiker's Guide to the Galaxy

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