There's a huge philosophical difference between the idea that there is something going on in a brain that can't be computed (what the article suggests, and what you seem to suggest here) and the idea that a brain is hard to simulate (which is what you suggest in the next paragraph). As the posters above you have pointed out, the former is a fringe opinion unsupported by current evidence. The latter is a skeptical viewpoint to which many neuroscientists subscribe. Personally, I'm in the "I want to believe" camp.

> My intuition is that it would require a leap on the order of vacuum tube ENIAC -> Intel Core i7. Meanwhile consumer demand for faster and faster chips is giving way to demand for slower but more energy efficient chips for mobile devices, which is subtracting from the economic incentive to continue Moore's Law.

To a first approximation, speed, power consumption, and performance per dollar are all linear functions of transistor size. If you can make smaller transistors, you can make a more power-efficient chip with the same performance, or you can make a more powerful chip with the same energy consumption. I don't think people will stop innovating on this front until we hit a physical wall. There may only be one major desktop CPU maker, but there are plenty of competing fabrication plants. Since the brain is embarrassingly parallel, we only need to get within a few orders of magnitude of simulating a brain on a single chip, at which point we can just string a bunch of processors together.

> Personally I'm much more optimistic about "wet" transhumanism-- life extension, augmentation, brain hacking, etc., than I am about "real" AI in the near term or mind uploading.

If by "near term" you mean within the next 20 years or so, I agree. Beyond that, it's really hard to tell. If faster computers actually let us make scientific discoveries faster, the singularity people may well be right.

1) Be sufficiently large that quantum effects are irrelevant, like a billiard ball, and thus it can be modeled deterministically inside of a computer. The Tegmark paper proposes this is how the brain works.

2) Rely on quantum mechanical effects (which are non-deterministic, but can still be simulated inside a computer if you trust a computer's opinion of "random"). Penrose, Searle, etc. would argue otherwise, that there's a method to the madness, and that there's something "special" about the quantum mechanical effect on microtubules. We still don't understand quantum mechanics very well, so if human consciousness really relies on quantum mechanics, there is arguably a bit of wiggle room here, especially if you're a physicist of the same caliber as Penrose.

Microtubules are specifically of interest because they're one of the few brain structures small enough to arguably be subject to quantum mechanical events.

Tegmark argues that they're not small enough and that it's irrelevant.

The real question is:

Is it possible to simulate a brain within a computer?

- not -

Is it really hard? Is it too hard for modern technology? Is this problem simply too complex for us to understand? Do we lack the technology to build sufficient understanding today? Etc. Etc.

This article is claiming it's IMPOSSIBLE to simulate a brain within a computer. Proving that is a tall order.