Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Why Minds Are Not Like Computers (2009)

thenewatlantis.com

Post reply on HN
Print view View original

31–40 of 49 posts

Re: Why Minds Are Not Like Computers (2009)

#31

Post by justinpaulson »

yew wrote: post #18
justinpaulson wrote: post #10

Earlier quoted context omitted.

Except the author does in fact have a BS in CS. IMO, the brain does far more than performing computation. Sure humans were once "computers," but our ability to perform computation is not a valid argument to that computation, or the inner workings of our mind, being the same as digital computers performing computation. You failed to look up the author's credentials and I feel like you may have also failed to read the…

. . . our ability to perform computation is not a valid argument to that computation, or the inner workings of our mind, being the same as digital computers performing computation. No one [1] thinks that the human brain is likely to be a digital computer performing arithmetic on fixed-width binary integers and IEEE floating-point numbers. The argument for AI is simply that the mind appears to be a material object and…

I think there are far too many assumptions about how the body works and the laws of physics (both of which we are far away from completely understanding) to say that the mind is equivalent to a Turing machine.

Re: Why Minds Are Not Like Computers (2009)

#32

Post by dragonwriter »

wwweston wrote: post #24
yew wrote: post #18

Earlier quoted context omitted.

. . . our ability to perform computation is not a valid argument to that computation, or the inner workings of our mind, being the same as digital computers performing computation. No one [1] thinks that the human brain is likely to be a digital computer performing arithmetic on fixed-width binary integers and IEEE floating-point numbers. The argument for AI is simply that the mind appears to be a material object and…

> The argument for AI is simply that the mind appears to be a material object and the laws of physics appear to be Turing-equivalent. This line of argument does achieve the goal of making it trivially true under the definitions given that the brain is a computer, but it seems to me it robs the assertion of insight -- e.g., the brain is computer because everything is a computer, including the nearest rock, since it's…

> This line of argument does achieve the goal of making it trivially true under the definitions given that the brain is a computer, but it seems to me it robs the assertion of insight

I think, rather, it reveals the fundamental lack of clarity of the contrary position.

> e.g., the brain is computer because everything is a computer, including the nearest rock, since it's also a physics-governed system.

Right. But no one is questioning the ability to build a computer that simulates the behavior of a rock; or most other physics-governed systems. The AI-is-impossible position boils down to the argument that the mind is not like all other physics governed systems, though it tends to waffle and hedge and bob and weave around that point rather than coming right out with it. Pointing to Turing equivalence and the apparent computability of natural phenomena forces the AI-is-impossible-because-the-mind-is-not-the-kind-of-thing-a-computer-can-simulate argument to come straight out and either (1) reject the universal computability of physical systems, or (2) reject the mind as a physical system.

It still, of course, leaves plenty of room for the proposition that AI is possible but really quite hard.

Re: Why Minds Are Not Like Computers (2009)

#33

Post by scarmig »

sullyj3 wrote: post #21
palosanto wrote: post #19

"If we achieve artificial intelligence without really understanding anything about intelligence itself then we will have no idea how to control it." Exactly. It's fascinating/scary to me how people still talk about A.I. or machine consciousness when we basically have no idea how consciousness works in general.

People who say things like that don't understand how to reason using limiting cases. We have artificial intelligence right now. Maybe not artificial general intelligence, but plenty of stuff traditionally thought of as being solely the domain of minds, is now performed by software. I'd say we understand it pretty well, and we certainly have the ability to control it.

The one iron-clad rule of artificial intelligence: any successful attempt at implementing it makes it not artificial intelligence, just something that computers are able to do.

(Though I guess there is the second rule of over-optimistic timelines, to be fair.)

Re: Why Minds Are Not Like Computers (2009)

#34

Post by pjungwir »

tjradcliffe wrote: post #26
Sharlin wrote: post #9

Earlier quoted context omitted.

Such overconfidence. There is no generally accepted evidence that anything physical, whether brain or something else, can compute something a TM cannot compute. Penrose's claims are conjectures at best and pseudoscience at worst.

Since the brain is not just a Turing machine, it would be astonishing if it was limited to the capabilities of a Turning machine. The brain is capable of emulating a Turning machine, but that is just one of its capabilities. The things a Turing machine lacks are interupts and I/O. If you hook sensors up to a Turing machine and make the tape change depending on the state of those sensors, you don't have a Turing machi…

Actually Turing's paper "On Computable Numbers" distinguishes between "automatic machines" (a-machines) and "choice machines" (c-machines), where the latter can pause to ask for input. It seems to me this accounts for your I/O. (I think this is also how you'd add a RNG to a Turing machine.) His paper pretty much only considers a-machines, so I'm curious what is written about c-machines elsewhere. It's unclear to me how much c-machines "change the story." For instance you can't escape Godel's Incompleteness Theorem by adding a finite number of axioms to fill in all the unprovable statements, because there are infinitely many of them.

Re: Why Minds Are Not Like Computers (2009)

#35

Post by Phemist »

tjradcliffe wrote: post #26
Sharlin wrote: post #9

Earlier quoted context omitted.

Such overconfidence. There is no generally accepted evidence that anything physical, whether brain or something else, can compute something a TM cannot compute. Penrose's claims are conjectures at best and pseudoscience at worst.

Since the brain is not just a Turing machine, it would be astonishing if it was limited to the capabilities of a Turning machine. The brain is capable of emulating a Turning machine, but that is just one of its capabilities. The things a Turing machine lacks are interupts and I/O. If you hook sensors up to a Turing machine and make the tape change depending on the state of those sensors, you don't have a Turing machi…

Unless interrupts and the Input portion of I/O are generated by an oracle (A machine of a computational class more powerful than UTMs) of some sort, a Turing Machine with I/O and interrupts is equivalent to a UTM. I remember the proof being trivial, ie some guys did it during my CS undergrad for a short (2-week) research introduction course, but I can't find a proper paper about it atm. Granted, if the brain was an oracle, this would be true, but you would have to presume that the brain was an oracle in order to prove that it is stronger than a UTM.

In regards to your last statement, the other way works as well. There are statements that can't be proved by any human brain, but can be proved by non-brain logical systems. For example: "The brain cannot consistently assert this statement". One can then create instances of types of problems that are equivalent (when put through some bijective transformation) to the beforementioned statement.

Re: Why Minds Are Not Like Computers (2009)

#36

Post by wwweston »

dragonwriter wrote: post #32
wwweston wrote: post #24

Earlier quoted context omitted.

> The argument for AI is simply that the mind appears to be a material object and the laws of physics appear to be Turing-equivalent. This line of argument does achieve the goal of making it trivially true under the definitions given that the brain is a computer, but it seems to me it robs the assertion of insight -- e.g., the brain is computer because everything is a computer, including the nearest rock, since it's…

> This line of argument does achieve the goal of making it trivially true under the definitions given that the brain is a computer, but it seems to me it robs the assertion of insight I think, rather, it reveals the fundamental lack of clarity of the contrary position. > e.g., the brain is computer because everything is a computer, including the nearest rock, since it's also a physics-governed system. Right. But no o…

> But no one is questioning the ability to build a computer that simulates the behavior of a rock; or most other physics-governed systems.

I'm willing to make that challenge: a complete simulation of rock sounds like a formidable problem to me, one I'm not at all certain is within state of the art.

Particularly if (as we're generally imagining when we're talking about simulating brains) we're asking the simulation to be able to stand in for its analog as part of a process-chain connected to a non-simulated situation.

Re: Why Minds Are Not Like Computers (2009)

#37

Post by coldtea »

sudo_free_cake wrote: post #2

This is why people not trained in CS shouldn't speculate on it, when they do you get garbage like this. The brain performs computation, it is by definition a computer. Before modern computers there was a human job, called, computer. One who performs computations. The analogy of the brain to a computer is perfect, because the brain is a computer.

>The brain performs computation, it is by definition a computer.

Citation needed.

Actually that's the standard motto of any era -- the brain was like god (soul), then like gears in the early mechanical era, and so on to the computer analogy.

Re: Why Minds Are Not Like Computers (2009)

#38

Post by pjungwir »

cgio wrote: post #25
innguest wrote: post #7

Earlier quoted context omitted.

Thank you for the straight-shot no-nonsense clarification. :)

I would not discount Penrose with the ease the GP does. These themes are quite philosophical, therefore all sides are making some big assumptions. I would read Penrose, Dennett, Chalmers, Tononi, Searle, Putnam and many others. In philosophy the trick is to disagree with everyone.

Agreed. I am very intrigued by Penrose but not convinced. In Scott Aaronson's online lectures for Quantum Computing since Democritus he is pretty dismissive of Penrose, but in the book he asks why a renowned Oxford scholar would insist on such a position, and that's a good question! In these arguments people are too willing to clamp shut their opinion and shut down wonder.

Re: Why Minds Are Not Like Computers (2009)

#39

Post by coldtea »

dragonwriter wrote: post #32
wwweston wrote: post #24

Earlier quoted context omitted.

> The argument for AI is simply that the mind appears to be a material object and the laws of physics appear to be Turing-equivalent. This line of argument does achieve the goal of making it trivially true under the definitions given that the brain is a computer, but it seems to me it robs the assertion of insight -- e.g., the brain is computer because everything is a computer, including the nearest rock, since it's…

> This line of argument does achieve the goal of making it trivially true under the definitions given that the brain is a computer, but it seems to me it robs the assertion of insight I think, rather, it reveals the fundamental lack of clarity of the contrary position. > e.g., the brain is computer because everything is a computer, including the nearest rock, since it's also a physics-governed system. Right. But no o…

>But no one is questioning the ability to build a computer that simulates the behavior of a rock; or most other physics-governed systems.

Actually it sounds especially difficult.

A crude approximation (simulation) at best.

Nothing like a full rock, with its full interactions with its full environment (that might need simulating the whole universe), and with oversimplifying most of its properties (molecular interactions, heat dynamics, etc).

Now make it a "wet rock" and we're even further away (and I wont even dare ask for mold on it or anything, much less living micro-organisms)...

Post reply on HN