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Why Roger Penrose thinks computers can't

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Re: Why Roger Penrose thinks computers can't

#31

Post by Symmetry »

mark_l_watson wrote: post #29
ugh wrote: post #22

Earlier quoted context omitted.

Why is quantum physics magical? Or is that not what you wanted to say? As far as I know we have a pretty clear understanding of quantum physics.

I only have a BS in Physics (UCSB) so this may be rough: about 10 years ago I went to a Quantum Mechanics and Consciousness conference and the gist is that there is a quantum effect that is required consciousness. My dad taught physics at Berkeley and his friend from Berkeley Henry Stapp presented an interesting paper on this theory. The philosopher David Chalmers was also there and he talked about the difficult ques…

There are several obvious explanations like that we evolved conciousness in order to be able to explain ourselves to other humans. But I thought Chalmers believe that the physical world was "causally closed" and that therefore a purely material feedback process like evolution couldn't select for qualia?

Re: Why Roger Penrose thinks computers can't

#32

Post by zephjc »

varjag wrote: post #17

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...

Pretty much. Penrose, despite being generally brilliant, is not an expert in neuroscience. QM explanations seem like hand waving or saying "we don't really know, and since I know a lot about QM, that must be the reason". It's almost avoiding investigation into the hard problems of neurobiology to find the real, physical processes that bring about human cognition.

Re: Why Roger Penrose thinks computers can't

#33

Post by yequalsx »

Symmetry wrote: post #30
yequalsx wrote: post #23

Earlier quoted context omitted.

I'll try to give an overview of what's going on. In the late 1800s Peano came up with his set of axioms for the integers. This set is second order which means it isn't computable. Hilbert and others wanted a computable set of axioms so that one could, in theory, remove humans from the discovery of mathematical truth. So the first order axioms were invented. Godel showed that the first order axioms are not strong enou…

Ok, I'll confess that I'm not sure what you're talking about when you mention second order systems. However, Godel's incompleteness theorems (plural) were a lot more general than you're suggesting. First Theorem: "Any effectively generated theory capable of expressing elementary arithmetic cannot be both consistent and complete. In particular, for any consistent, effectively generated formal theory that proves certai…

Definitely his Incompleteness Theorem (I there are two of them and also a Completeness Theorem) was more general than what I mentioned but the shock was its application to arithmetic. The second order axioms are not recursively enumerable (think computable). It was the goal of Hilbert to find a computable system capable of proving (in theory) all true statements. There is no such computable system.

One can find complete axiomatic systems of the integers. It's quite easy. Just take all true statements as the axiom system. The problem is that there is no computable method for determining in such a system whether or not a given statement is an axiom.

Again, we humans can work in the second order axiom system but computers can't. So it appears there's a difference between human intelligence and computer intelligence.

Re: Why Roger Penrose thinks computers can't

#34

Post by jacksoncarter »

Symmetry wrote: post #26
jacksoncarter wrote: post #14

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. Wha…

"People must choose, when a computer need not choose." Perhaps I'm not understanding something, but that seems to be obviously false. A human always has the option of being unsure in the face of non-computable statements like "You can't know that this sentence is true" or such.

Imagine a dataset where the inputs are to be in a range from 1-100, but for some reason unknown to the programmers when the program was written, there is a value of 4,000.

In the real world, a human must decide what to do with that 4,000. A computer would crash or throw an error or something like that even though the data may actually be valid.

Re: Why Roger Penrose thinks computers can't

#35

Post by waveman »

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?".

Re: Why Roger Penrose thinks computers can't

#36

Post by gruseom »

waveman wrote: post #35

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 tim…

Personally my sympathies are with Penrose and Bohr.

Re: Why Roger Penrose thinks computers can't

#37

Post by wlievens »

yequalsx wrote: post #33
Symmetry wrote: post #30

Earlier quoted context omitted.

Ok, I'll confess that I'm not sure what you're talking about when you mention second order systems. However, Godel's incompleteness theorems (plural) were a lot more general than you're suggesting. First Theorem: "Any effectively generated theory capable of expressing elementary arithmetic cannot be both consistent and complete. In particular, for any consistent, effectively generated formal theory that proves certai…

Definitely his Incompleteness Theorem (I there are two of them and also a Completeness Theorem) was more general than what I mentioned but the shock was its application to arithmetic. The second order axioms are not recursively enumerable (think computable). It was the goal of Hilbert to find a computable system capable of proving (in theory) all true statements. There is no such computable system. One can find compl…

I still don't understand what you mean by the "second order axiom system" that is somehow the domain only of humans...
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