Let me go through the section of Kaku's book where he talks about reverse engineering the brain. I'll summarize it by points and you tell me if it sounds crazy:
From pages 87-95 of Physics of the Impossible:
Future of AI: Reverse Engineering the Brain:
1. By midcentury, we should be able to complete the next milestone in the history of AI: reverse engineering the human brain.
2. Optogenics is a first, modest step. The next step is to actually model the entire brain, using the latest in technology. There are at least two ways to solve this colossal problem, which will take many decades of hard work. The first is by using supercomputers to simulate the behavior of billions of neurons, each one connected to thousands of other neurons. The other way is to actually locate every neuron in the brain.
3. The key to the first approach, simulating the brain, is simple: raw computer power. The bigger the computer, the better. Brute force, and inelegant theories, may be the key to cracking this gigantic problem. And the computer that might accomplish this herculean task is called Blue Gene, one of the most powerful computers on earth, built by IBM [...] which is capable of 500 trillion operations per second.
4. What I was interested in was the fact that Blue Gene was simulating the thinking process of a mouse brain, which has about 2 million neurons (compared to the 100 billion neurons that we have). Simulating the thinking process of a mouse brain is harder than you think, because each neuron is connected to many other neurons, making a dense web of neurons. But while I was walking among rack after rack of consoles making up Blue Gene, I could not help but be amazed that this astounding computer power could simulating only the brain of a mouse, and then only for a few seconds. This does not mean that Blue Gene can simulate the behavior of a mouse. At present, scientists can barely simulate the behavior of a cockroach. Rather, this means that Blue Gene can simulate the firing of neurons found in a mouse, not its behavior.
5. Henry Markram [...] began in 2005 when he was able to obtain a small version of Blue Gene, with only 16,000 processors, but within a year he was successful in modeling the rat's neocortical column, part of the neocortex, which contains 10,000 neurons and 100 million connections. That was a landmark study because it meant that it was biologically possible to completely analyze the structure of an important component of the brain, neuron for neuron.
6. In 2009, Markram said optimistically, "It is not impossible to build a human brain and we can do it in ten years. If we build it correctly, it should speak and have an intelligence and behave very much as a human does." He cautions, however, that it would take a supercomputer 20,000 times more powerful than present supercomputers, with a memory storage 500 times the entire size of the current Internet, to achieve this.
7. So what is the roadblock preventing this colossal goal? To him, it's simple: money. [...] "It's not a question of years, it's one of dollars... it's a matter of if society wants this. If they want it in ten years, they'll have it in ten years. If they want it in a thousand years, they can wait."
8. A rival group [...] called Dawn [...] is truly a sight, with 147,456 processors with 150,000 gigabytes of memory. It is roughly 100,000 times more powerful than the computer sitting on your desk. [...] In 2006, it was able to simulate 40 percent of a mouse's brain. In 2007, it could simulate 100 percent of a rat's brain (which contains 55 million neurons, much more than the mouse brain). And in 2009, the group broke yet another world record. It succeeded in simulating 1 percent of the human cerebral cortex, or roughly the cerebral cortex of a cat, containing 1.6 billion neurons with 9 trillion connections. However, the simulation was slow, about 1/600th the speed of the human brain. If it simulated only a billion neurons, it went much faster, about 1/83rd the speed of the human brain.
9. We might be able to reverse engineer the brain within ten years, but only if we had a massive Manhattan Project-style crash program and dumped billions of dollars into it. However, this is not likely to happen any time soon, given the current economic climate. Crash programs like the Human Genome Project, which cost nearly $3 billion, were supported by the US government because of their obvious health and scientific benefits. However, the benefits of reverse engineering the brain are less urgent, and hence will take much longer. More realistically, we will approach this goal in smaller steps, and it may take decades to fully accomplish this historic feat.
10. It will take many decades, even after the human brain is finally reverse engineered, to understand how all the parts work and fit together.
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