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same. There are quite a few changes that each of us undergo from day to day, we don\'t examine the assumption that we are the same person closely.

\"We gradually change our pattern of atoms and neurons but we very rapidly change the particles the pattern is made up of. We used to think that in the brain -- the physical part of us most closely associated with our identity -- cells change very slowly, but it turns out that the components of the neurons, the tubules and so forth, turn over in only days. I\'m a completely different set of particles from what I was a week ago.

\"Consciousness is a difficult subject, and I\'m always surprised by how many people talk about consciousness routinely as if it could be easily and readily tested scientifically. But we can\'t postulate a consciousness detector that does not have some assumptions about consciousness built into it.

\"Science is about objective third party observations and logical deductions from them. Consciousness is about first-person, subjective experience, and there\'s a fundamental gap there. We live in a world of assumptions about consciousness. We share the assumption that other human beings are conscious, for example. But that breaks down when we go outside of humans, when we consider, for example, animals. Some say only humans are conscious and animals are instinctive and machinelike. Others see humanlike behavior in an animal and consider the animal conscious, but even these observers don\'t generally attribute consciousness to animals that aren\'t humanlike.

\"When machines are complex enough to have responses recognizable as emotions, those machines will be more humanlike than animals.\"

The Kurzweil Singularity goes like this: computers get better and smaller. Our ability to measure the world gains precision and grows ever cheaper. Eventually, we can measure the world inside the brain and make a copy of it in a computer that\'s as fast and complex as a brain, and voila, intelligence.

Here in the twenty-first century we like to view ourselves as ambulatory brains, plugged into meat-puppets that lug our precious grey matter from place to place. We tend to think of that grey matter as transcendently complex, and we think of it as being the bit that makes us us.

But brains aren\'t that complex, Kurzweil says. Already, we\'re starting to unravel their mysteries.

\"We seem to have found one area of the brain closely associated with higher-level emotions, the spindle cells, deeply embedded in the brain. There are tens of thousands of them, spanning the whole brain (maybe eighty thousand in total), which is an incredibly small number. Babies don\'t have any, most animals don\'t have any, and they likely only evolved over the last million years or so. Some of the high-level emotions that are deeply human come from these.

\"Turing had the right insight: base the test for intelligence on written language. Turing Tests really work. A novel is based on language: with language you can conjure up any reality, much more so than with images. Turing almost lived to see computers doing a good job of performing in fields like math, medical diagnosis and so on, but those tasks were easier for a machine than demonstrating even a child\'s mastery of language. Language is the true embodiment of human intelligence.\"

If we\'re not so complex, then it\'s only a matter of time until computers are more complex than us. When that comes, our brains will be model-able in a computer and that\'s when the fun begins. That\'s the thesis of Spiritual Machines, which even includes a (Heinlein-style) timeline leading up to this day.

Now, it may be that a human brain contains n logic-gates and runs at x cycles per second and stores z petabytes, and that n and x and z are all within reach. It may be that we can take a brain apart and record the position and relationships of all the neurons and sub-neuronal elements that constitute a brain.

But
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