Penrose and his book have been debunked. http://www.mth.kcl.ac.uk/~llandau/Homepage/Math/penrose.html

"The question of whether a computer can think is no more interesting than the question of whether a submarine can swim."

E. Dijkstra

He's a Platonist, so he believes in the existence of a real world that is neither material nor mental.

His central claim that conscious acts are in some sense noncomputational is prima facie false.

And his concrete solution to problem collects together several other very difficult problems and essentially says, solve one, solve them all. (Great news for his publishers btw.)

For those reasons, it's hard to take seriously because it's outrageously speculative.

I was annoyed at how the article just blithely asserted that wavefunctions collapse, as if that wasn't a matter of ongoing debate. In fact, Penrose is remarkable among big name physicists for being sure that wavefrom collapse occurs. http://www.hedweb.com/manworld.htm#believes

Patricia Smith Churchland has famously remarked about Penrose's theories that "Pixie dust in the synapses is about as explanatorily powerful as quantum coherence in the microtubules."

http://en.wikipedia.org/wiki/Hard_problem_of_consciousness#S...

The argument that computers can't think derives from the idea that there are noncomputational processes at work in the brain. Essentially, we don't know how certain thoughts arrive in our mind. We can't create an algorithm to mimic our chain-of-thought generator.

But that doesn't mean we can't create a computer that can have similar noncomputational "thoughts".

People must choose, when a computer need not choose. What I mean is, a computer can shut down. A human mind cannot -- and continue to live. When a computer "observes" -- so to speak -- stimuli it cannot handle or are beyond its capacity, it does not make random choices about what to do now. We do not trust randomness. Sometimes, however, humans have no option but randomness. This is why in a crowd of 100 each one will react differently to the same stimulus. If it suddenly gets very cold, some will shiver, some will leave, some will get up and jump around.

In most cases, Computer systems aren't even allowed to accept input that isn't known to be valid. Minds have to all the time.

When you begin to predict the future and that's largely what the human mind is -- a future prediction machine, then it becomes even more complex. It requires memory. Concoctions from memory or assumptions. We don't let computers assume.

In many ways, we are holding computers back. Because we are afraid. We are afraid of what they will decide for us. We are afraid of random. We need control. We haven't subjected computers to survival of the fittest.

If we did, then by the law of large numbers, eventually, like I suppose is true with many humans, one will survive that we can't explain how. We won't know how that computer made all the right decisions the whole time.

We don't know how to program computers to accept any input. White is the maximum color. Black is the darkest. But computers could see much darker than black and much brighter than white. How can we control something like that? We can't. We won't be able to. It will see and know thinks we can't imagine.

It's silly to think computers can't.

This is a classic Dunning-Kruger situation. Penrose is out of domain of expertise here. He has not bothered to study the theory of mind (eg see the lack of relevant references in his book).

His arguments do not stack up, as extensively documented elsewhere.

This is not the first time that a famous physicist/mathematician has got it drastically. Neils Bohr was an animist - he believed along with many people at the time that there was some magic hidden essence to life that went beyond material things. When told about the discovery of DNA he said "Yes, but where is the life?".

Check out the awesome Gödel CAPTCHA (linked from the article): http://www.scottaaronson.com/writings/captcha.html

Yay! No more spam.

Thus, Penrose notes, they are true because of their meaning, not because of their syntax relation to an axiomatic system. This reinforces the thesis of Jerrold Katz, that syntactic simples are not semantic simples, and so some truths will depend on semantic contents that cannot be exhaustively expressed as syntax

If this were true, would it mean that there are aspects in physics which are not mere abstractions of math?

I bought and read "The Emperor's New Mind" in the early 90s, mostly for "knowing your enemy." I have slowly but surely come to mostly agree with Penrose: I think there is something magical and "quantum mechanical" about brain consciousness (including animals).

I believe in eventual real AI, but I would guess that it will not be on current computer hardware.

because he's wrong and confused

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