Tom Ray wrote a very nice essay critiquing Ray Kurzweil’s argument that machines will soon be smarter than we are.
The first point is plain logic. Kurzweil observes that following Moore’s law, computers will have more processing power than the human brain within a couple of decades. Ray points out that the power of software is not improving at anywhere near the same rate. There’s plenty of evidence that complicated software is outstripping our ability to design and maintain it effectively.
The second point is more subtle. Kurzweil argues that it will be possible to implement human intelligence in silicon, simply by reverse engineering the brain and mapping its neural connections into software. Ray notes that there are many aspects of human intelligence that depend on subtle properties of chemistry, for example, the delicate balance of hormones that influences temperament and mood, shaping our decisions, communication, and art.
It may be possible to create AI. Ray, who created the “Tierra” artificial life ecosystem, believes that the most promising method is to create digital a-life systems and let them evolve on their own. If such intelligence evolved, it would be different than human intelligence, depending on the very different properties of its technology and environment.
At any rate, the mechanisms to create artificial intelligence aren’t obvious, and there isn’t any reason to believe that it will happen any time soon.