Consciousness

[helene_t]

how can "x is something physical" be tautological? it sounds as if you are saying that there has been a change in thinking re: things metaphysical, for example logic or kindness... or maybe you and i are missing a connection, maybe you are equating the results of physicality with the results of spirituality... or maybe you are saying there is a difference between a thing being physical and a thing being material... are those words synonymous (to you)?

This is very difficult to discuss since it's so difficult to provide concise definitions of all these concepts. I have never been exposed to a concise definition of "physical", "material" etc. Rather, I have formed my own concepts by inference from the way people around me used such words. Unconsciously, I rely on the assumption that people around me have formed the same concepts because they have been exposed to the same language. This assumption clearly breaks down when I encounter someone like you who seem to have been raised in a different culture than mine. Maybe some of these words have been used in a slightly different way when they were told to you than when they were told to me. More importantly (but also more tricky) the concepts you need to form when raised in a (say) materialistic culture may be different from the concepts you need to form when you are raised in a (say) spiritual culture.

 

Consider this analogy: you and I discuss the color of some object. If you say it's "red", would that make the provoke the same mental image in me as it does in you? Who knows. Even if an MRI scan could prove that you think about the color "red" in exactly the same way as I do, it would not prove that we "feel" the same when thinking about "redness".

 

Some would say that this doesn't matter (or isn't even meaningful) as long as we both agree that tomatoes are usually red: the important thing, in a social context, about "redness" is that it is the color of tomatoes, not the way it feels to think about red things.

 

But if I come from a planet where tomatoes have the same color as cucumbers while strawberries have the same color as aubergines, we must be very careful how to use the labels "red", "green" and "violet" when talking to each other. (Of course this could be resolved by reference to some light source the color of which can be predicted from the laws of physics, such as a sodium lamp. But I hope you see what I mean ....)

 

Anyway, let me try:

 

"Physics" is a/the science that aims at constructing a single, coherent model that can explain and predict empiric evidence. As such it differs from biology, psychology, sociology etc. which aim at a ratatouille of shallow models that make biased predictions including "noise", the nature of which is beyond the scientific discipline. In the time of Descartes, physics was seen as limited to simple objects like planets and snooker balls. Very few philosophers imagined that such a single model would also apply to life, let alone mental states.

 

Today, virtually all biologists agree that biology is in principle just physics plus complexity. The reason why we haven't closed down the biological labs and transfer their tasks to the dpt. of applied physics is that the gap between physics and biology still exist at the practical level: our data are still too sparse and inaccurate, the reasoning to complex, our computers too slow.

 

What about the gap between physics and psychology? Memory, perception, emotions and mental images are just in these decades getting understood as physical phenomena. But somehow it "feels" as there is more to consciousness than the movements of the electrons in the synapses in my brain. That is the hard problem of consciousness. Some dismiss consciousness as a non-phenomena, but I have a number of problems with that. Conscious behavior seems to be different from unconscious behavior - blindisighted people who can perceive images but aren't conscious about them respond differently to the images than normal people do.

 

It is logically possible that there is something "out there" beyond physics. But I don't see much reason to assume that. You mention logic. That is not something "out there", as I see it, merely the common ground that all reasoning must build on, regardless of the kind of empiric it relies on. Kindness? May depend how you define it but I think it's a down-to-Earth psychological phenomena that can be explained without invoking consciousness or other problematic things.

 

In the days of Freud, the science of the mind (as opposed to merely behavioral psychology) relied almost exclusively on introspection. Maybe one could argue that as long as that was the case, psychology should, at least partly, be regarded a metaphysical rather than physical theory. But today psychology is becoming more and more of a natural science.

[luke warm]

will you accept as a working definition "that which is suspended in space and time" for either/both 'physical' and 'material'?

[helene_t]

will you accept as a working definition "that which is suspended in space and time" for either/both 'physical' and 'material'?

hmmmm .... information has a time dimension, yet it's not quite clear if information should be considered something physical. It probably is in modern physics, but the classical way of looking at it is more like that the paper and the ink are physical things while the information written with the ink is more like something we humans attribute to it.

 

Not sure if this response makes sense .....

[luke warm]

will you accept as a working definition "that which is suspended in space and time" for either/both 'physical' and 'material'?

hmmmm .... information has a time dimension, yet it's not quite clear if information should be considered something physical. It probably is in modern physics, but the classical way of looking at it is more like that the paper and the ink are physical things while the information written with the ink is more like something we humans attribute to it.

 

Not sure if this response makes sense .....

of course it makes sense, everything you write does (or would, if i understood half of it - which i don't)... in any case, i'm used to thinking of things in this context as either material or immaterial (and am unsure how 'physical' differs from 'material'), and have had many debates with people who say that only the material exists... they in effect deny the existence of anything metaphysical, and while this stance is intuitively incorrect it can only be disproved on philosophical grounds

 

or it could up to now... now i think even physicists can be considered 'dualists' (at the least)... so if that's true, ie. if the immaterial (or non-physical if that's acceptable) does exist, it can hardly be tautological to refer to the physical (or material) as something that exists

 

but back to the topic, i still maintain that "mindstuff" can interact with the material and vice versa without itself being material (assuming, again, that 'physical' and 'material' can be used interchangeably)... as i said in my first post, wonderful topic

[Al_U_Card]

In an infinite universe EVERYTHING exists. (Yes, Jimmy, there is a Santa God.....;-) ) Therefore reality includes whatever you can conceive of so you need only define things by their appearance and that is totally subjective and depends on your intention when you become aware of their presence.

 

Btw physical refers to.....the empty space that is 9.9x10 exp30 of most things? But space is not "empty" at the quantum effect level. Beyond the Planck length..... Immaterial should only refer to that which is beond your awareness and therefore unable to receive your intention.

 

The universe (ours among the infinite multiverses) exists because of our awareness (our consciousness perceives it). Our intention is to understand our purpose within it and then (hopefully) to fulfill that purpose.

[barmar]

I'm jumping into this thread pretty late, but I'd like to recommend a recent book to the list in the original post: Douglas Hofstadter's I Am a Strange Loop. His basic thesis is that just about everything is conscious, but that there are different levels of consciousness (insects are near the bottom of the scale, mammals and baby humans in the middle, grown humans at the top -- and some humans are more conscious than others). Consciousness comes from the ability of a mind to contain representations of minds -- both itself and of others. The notion of "I" is just a special case of the way we're able to think about the actions and intentions of people -- it just happens to be the case where that person is onself. This is the "strange loop" he refers to in his title.

 

His book is also related to a personal tragedy he suffered. He wrote the book after his wife died, and much of what he came up with is inspired by the way bits of the consciousness of departed loved ones remain in those who survive them. Although she is no longer around to express opinions, often he'll see things and think things like "She would have loved this." These thoughts are probably what inspired our ancestors to create myths about souls, spirits and ghosts -- something about the person seems to persist after the body dies.

[helene_t]

in any case, I'm used to thinking of things in this context as either material or immaterial (and am unsure how 'physical' differs from 'material'), and have had many debates with people who say that only the material exists... they in effect deny the existence of anything metaphysical, and while this stance is intuitively incorrect it can only be disproved on philosophical grounds

As I wrote in response to Quantumcat I think the verb "to exist" means different things in different areas. To a mathematician, things exists if they could conceivably exist - this is because Math is a/the science of the conceivable, and "real" existence is irrelevant. If a mathematical object exists it merely means that it could serve as a model for "real" things that could convceivably exist, but whether those "real" things in fact exist is none of the mathematicians concern. In fact much of math is about sets that are too large to be oberved if translated into physical things - the bandwidth of our sensory inputs as well as to our memory is limited to finite sets of objects and countable sets of states of those objects, but that does not prevent mathematicians from proving the existence of much larger sets.

 

One can see physics as the science of the "real", but I think a deeper (which not necessarily means "better") way of seeing it is as the science of particular models for commonly accepted empirics. We cannot logically prove commonly accepted empirics is "real", and there are also an infinity of models that could fit our empirics and we cannot logically prove that the model we have chosen will be consistent with future empirics. That is why physics, unlike mathematics, is open to debate and revision. However, there are some pretty well established philosophical principles that help us choose among possible models so that physics will tend to produce the most useful insight given our limited knowledge and reasoning capabilities, and so that scientific "facts" rarely get revised. (When a theory has reached undergraduates' textbooks, it is unlikely to get refuted. Of course, merely getting its way into a few peer-reviewed articles doesn't necessarily make a theory a "fact").

 

One of these principles is Occam's razor which forces us to choose the simplest model among several candidates. Now it is sometimes disputable what "simpler" means (is it simpler to assume the free will to exist or to be an illusion?) but in general, it is simpler to assume that things don't exist. So in physics, things tend not to exist unless it is inconceivable (or at least leads to awkward thinking) that they don't exist. This is almost the opposite of the math criteria.

 

Example: There is a model for cosmology that says that whenever something happens that might not have happened, the universe has branched in two (think of the way Internet Explorer behaves when you open a new window: it loads a new copy of the document you were already reading so you get two identical windows. If the windows show random animation, they may be slightly different due to the randomness). So after trillions of random events have happened, there are 2^{trillions} parallel universes. Is this a "simple" model? Since it solves the otherwise tricky question of accounting for why random events turn out as they do, one could say so. More to the point: suppose we accept the model. Do the other universes "exist", then? Some would say no, since the model prevents us from observing them (even indirectly) and therefore by definition, they don't exist.

 

As I see it, the existence of the other universes (assuming that we accepting the multiple universe model) is not a physics question but rather a question related to the meaning of the verb "to exist", which is a philosophical one.

 

Consciousness comes from the ability of a mind to contain representations of minds -- both itself and of others.

This is interesting. The "mirror test" is seen as a test for consciousness. I never really understood this, to me sentience (consciousness?) is intuitively something very different from self-awareness and empathy. I see self-awareness and empathy as rather mundane things that could easily be programmed into a "stupid" computer. But maybe I'm seeing things completely wrong.

 

Anyway, if consciousness can really be reduced to self-awareness and empathy, then progress could speed up a lot since a lot is becoming known about the neurophysiology of those phenomena.

[Al_U_Card]

Example: There is a model for cosmology that says that whenever something happens that might not have happened, the universe has branched in two (think of the way Internet Explorer behaves when you open a new window: it loads a new copy of the document you were already reading so you get two identical windows. If the windows show random animation, they may be slightly different due to the randomness). So after trillions of random events have happened, there are 2^{trillions} parallel universes. Is this a "simple" model? Since it solves the otherwise tricky question of accounting for why random events turn out as they do, one could say so. More to the point: suppose we accept the model. Do the other universes "exist", then? Some would say no, since the model prevents us from observing them (even indirectly) and therefore by definition, they don't exist.

Hi Helene

 

As a mathematician, you are better placed to know about what is simpler, (ie more likely) a single unique event or a continuing series of events to even infinite series.......

 

All of these "parallels", like the virtual nature of quantum dynamical particles, only exist if they need to. They only need to if they are to be perceived and the superposition of the wave-function collapses (coalesces is perhaps more adroit) resulting in their existence.

 

No need to sweat it, as we have "created" quite a few since this thread began...lol

[helene_t]

Came to think of something:

 

Denett's model is this: Consciousness is required to ask the questions to which the "lower-level" mental modules provide answers. For example, a blindsighted patient cannot on his own initiative discover an object in his visual field because he lacks the fantasy to ask himself about the existence of the object. But if someone else asks the blindsighted patient if the object exists, the patient can verify it. Presumably, without consciousness the patient has insufficient bandwidth to scan his own visual field and requires some "inspired guess" as to what to look for - somehow the consciousness can provide those guesses.

 

Let's try to combine this with Penrose's idea. The blindsighted person is just a stupid Turing machine so he cannot prove Godel's theorem. Yet if someone presents a candidate Godel-proof for him he can verify if that particular proof is correct. Now this inspired guess of what a Godel-proof might look like has to come from some "super-Turing" source, such as the patient's own consciousness.

 

Of course this is somewhat sloppy since Denett talks about bandwidth and Penrose talks about computability, but maybe that could be reconciled. Denett is not too specific about his "bandwidth problem" anyway, maybe it is in fact a computability problem.

[helene_t]

As a mathematician, you are better placed to know about what is simpler, (ie more likely) a single unique event or a continuing series of events to even infinite series.......

 

All of these "parallels", like the virtual nature of quantum dynamical particles, only exist if they need to. They only need to if they are to be perceived and the superposition of the wave-function collapses (coalesces is perhaps more adroit) resulting in their existence.

Hmmmm .... there is a mathematical concept called "Kolmogorov Complexity" which is roughly the size of a document after it has been compressed by TAR or ZIP or such software. So maybe I can just take all the documents that claim to provide a coherent interpretation of quantum mechanics, ZIP all of them, and then pick the smallest one. Pretty cool, I could become one of the few people who have a qualified opinion about the interpretation of quantum mechanics and I don't even have to read anything about quantum mechanics, let alone understand it :)

[Al_U_Card]

Quantum dynamical philosophy 101

 

Reality is what you make of it.

[helene_t]

Quantum dynamical philosophy 101

 

Reality is what you make of it.

I think that the "constructed reality" is a general philosophical principle that is not related to quantum mechanics. I might have missed something, though.

 

Even if one subscribes to the interpretation of quantum mechanics that a conscious observer influences the observed, it does not necesarilly follow that the the observer excercises conscious control on the object. The observed state may be completely random. After all, if you could decide if Schroedinger's cat is dead or alive, there's no reason to observe it since you already know that it is whatever you want it to be.

 

Constructed realities are at a different level. In the multiversum theory, you can define the other universes as existing or not, according to your taste. Just like in mathematics you can chose the axioms that appeal to you.

[Al_U_Card]

After all, if you could decide if Schroedinger's cat is dead or alive, there's no reason to observe it since you already know that it is whatever you want it to be........you can define the other universes as existing or not, according to your taste.

Well, now that we have elucidated the meaning of life, we can all sleep better. QED :P

[mikeh]

I am way, way late to this thread.. I stopped reading the watercooler a while ago.

 

But, touching upon the free will issue, I have been trying to recall where I read of a study that monitored brain activity in connection with the timing of a so-called conscious decision to manipulate an object and the start of the electrical impulse that actuated the movement. The details are vague, but I seem to recall that the authors of the study had found that the electrical impulse, triggering the movement of a limb (or finger) actually started before the conscious decision was made. So our conscious brain is retroactively rationalizing a response that began automatically, and creating the illusion, within our minds, that 'it' (or "I") chose to intitiate the action.

[goobers]

I am way, way late to this thread.. I stopped reading the watercooler a while ago.

 

But, touching upon the free will issue, I have been trying to recall where I read of a study that monitored brain activity in connection with the timing of a so-called conscious decision to manipulate an object and the start of the electrical impulse that actuated the movement. The details are vague, but I seem to recall that the authors of the study had found that the electrical impulse, triggering the movement of a limb (or finger) actually started before the conscious decision was made. So our conscious brain is retroactively rationalizing a response that began automatically, and creating the illusion, within our minds, that 'it' (or "I") chose to intitiate the action.

Hume! David Hume I say!

[DrTodd13]

I am way, way late to this thread.. I stopped reading the watercooler a while ago.

 

But, touching upon the free will issue, I have been trying to recall where I read of a study that monitored brain activity in connection with the timing of a so-called conscious decision to manipulate an object and the start of the electrical impulse that actuated the movement. The details are vague, but I seem to recall that the authors of the study had found that the electrical impulse, triggering the movement of a limb (or finger) actually started before the conscious decision was made. So our conscious brain is retroactively rationalizing a response that began automatically, and creating the illusion, within our minds, that 'it' (or "I") chose to intitiate the action.

That's not the only interpretation. You could just as easily say that your free will made the decision and your consciousness only became aware of it 500ms later. There was also a recent report about the study of some insect. They were put in a completely white room with no visible landmarks...no edges, nothing to tell one direction from another. Then their movements were monitored. The idea was that if you remove all sensory clues then there would be nothing in a deterministic insect "mind" to cause a change of direction. Therefore, if we remove determinism then one might think all that is left is randomness. However, they determined that the insects' movements were not random either. Thus, they conclude that this insects' brains were neither wholly deterministic or random. What else is there? Free will? I don't know that much about the experiment but it is intriguing.

[helene_t]

But, touching upon the free will issue, I have been trying to recall where I read of a study that monitored brain activity in connection with the timing of a so-called conscious decision to manipulate an object and the start of the electrical impulse that actuated the movement. The details are vague, but I seem to recall that the authors of the study had found that the electrical impulse, triggering the movement of a limb (or finger) actually started before the conscious decision was made. So our conscious brain is retroactively rationalizing a response that began automatically, and creating the illusion, within our minds, that 'it' (or "I") chose to intitiate the action.

Yes, those experiments were discussed in Denett's book as well. His main conclusion was that there seems to be no unique time point at which information reaches the "consciousness" - consciousness is spread out over a distributed system, and the time it takes form information to travel from one module to another can be as much as 0.4 secs.

 

I'll have to agree with Todd that this does not necesarily settle the "free will" dispute. But maybe that depends on ones definition of the free will. If your "true" free will must necesarilly be identical to your own perceived (in effect, reported) free will then your interpretation sounds correct. I don't think that is a reasonable model when it comes to "tough" decisions inviolving ethical dillemas and such - the well-known psychological phenomena of sublimation, i.e. people make up justifications of their decisions in retrospect (and actually believe in those justifications) in order to feel good about what they have decided, contradicts that as I see it. But for the less value-loaded decisions studied in the experiment you mention (it was about pushinh buttons in response to sound signals) maybe the researchers who conducted the experiments would say that they can trust the subjects' reports and therefore disproved free will.

 

The idea was that if you remove all sensory clues then there would be nothing in a deterministic insect "mind" to cause a change of direction. Therefore, if we remove determinism then one might think all that is left is randomness. However, they determined that the insects' movements were not random either. Thus, they conclude that this insects' brains were neither wholly deterministic or random. What else is there? Free will? I don't know that much about the experiment but it is intriguing.

I wonder what "not random" means in this context. Sounds to me more of a case for either a very complex model for what is going on (different self-organized patterns in the insects' behaviour arise purely due to differences in random seeds) or some initial information stored in each insects' memory prior to the experiment. Then again, I don't know about this experiment. Certainly sounds interesting.

[DrTodd13]

Fruit fly free will.

 

Link to the story I mentioned.

[Al_U_Card]

Thus, they conclude that this insects' brains were neither wholly deterministic or random. What else is there? Free will?

Instinct.

 

Consciousness replaced it to allow the extension of ourselves into our environment in an intentional fashion.

 

If you need groceries, how you get to the store depends on what method of transportation is available, how you choose to use it to get to the store and even what you decide to buy.

 

But don't get the victuals and you will not succeed with the rest of the plan...

[joshs]

I almost launched into a discussion in the quantum mechanics thread because I do think it ties in.  Helene...there is a reason to believe physics may play a role in the brain.  Penrose's argument is that the human brain can do things that are provably un-doable for a classic computer/turing machine.  This statement is so important I should say it again.  Humans have performed mental tasks that it has been proven that a turing machine could never complete, no matter how complex it was.

Actually what you should say is that Penrose claims that Humans have performed mental tasks that a Turing machine could never complete.

 

You should probably also note that very few scientists accept Penrose's claim...

"Scientists" shouldn't really get a vote in this matter. A climatologist would be quite unqualified to voice an opinion. Same for physicists and biologists. They can say they don't believe it all they want. They can say they don't see how it could possibly work. What they need to do is show the flaw in his argument based on computer science. I've yet to see a convincing refutation.

Ooh, I am going to have a field day with this. Penrose is a Mathematical Physisist. He important work is in Differential Geometry and the Structure of Space Time. He is most famous for his work on Black Holes. Now while some people's brains do in fact remind me of Black Holes, I have to remark that he has no special expertese in Cognitive Science, although one of his students did change fields and do work on AI and on a bridge playign program (GIB). I in fact, did my thesis research in a similar area to much of Penrose's work (his work on twister's and on minkowski space)- I certainly don't think that that qualifies me as an expert on the brain (any more than it qualifies him). In fact most people I have read who do work in the field of Cognetive science (For instance Richard Hofstader, Daniel Dennet, etc.) don't agree with Penrose at all. I personally think penrose's argument is poppycock. Why can't a turing machine prove Godel's theorem? That penrose asserts that there are things that a computer can't do, doesn't make it true. Where you don't see a conclusive refutation, I don't even see a claim. As far as I am concered this is like my claiming that God is a Blue guy from a planet orbiting Riga, and saying we should accept God is Blue and from Riga unless you can prove otherwise.

 

Anyway Godel's Theorem a very formal theorem that can be stated and proven in a very formal system. It just happens to have meta system conclusions. We proved it in a finite number of steps in my theory of computation class, probably a monkey could get this one right eventually with a little luck...

 

Anyway, what the heck is this argument Todd? WHo exactly are you claiming is qualified to make an argument about conciousness.

[DrTodd13]

I'm saying that computer scientists are qualified. Cognitive scientists are not qualified to refute an argument based on computability. I think you miss the point here. You can't say a turing machine can prove Godel just because you did it because the supposition here is that humans can do things that turing machines can't.

[mikeh]

But, touching upon the free will issue, I have been trying to recall where I read of a study that monitored brain activity in connection with the timing of a so-called conscious decision to manipulate an object and the start of the electrical impulse that actuated the movement. The details are vague, but I seem to recall that the authors of the study had found that the electrical impulse, triggering the movement of a limb (or finger) actually started before the conscious decision was made. So our conscious brain is retroactively rationalizing a response that began automatically, and creating the illusion, within our minds, that 'it' (or "I") chose to intitiate the action.

Yes, those experiments were discussed in Denett's book as well. His main conclusion was that there seems to be no unique time point at which information reaches the "consciousness" - consciousness is spread out over a distributed system, and the time it takes form information to travel from one module to another can be as much as 0.4 secs.

 

I'll have to agree with Todd that this does not necesarily settle the "free will" dispute. But maybe that depends on ones definition of the free will. If your "true" free will must necesarilly be identical to your own perceived (in effect, reported) free will then your interpretation sounds correct. I don't think that is a reasonable model when it comes to "tough" decisions inviolving ethical dillemas and such - the well-known psychological phenomena of sublimation, i.e. people make up justifications of their decisions in retrospect (and actually believe in those justifications) in order to feel good about what they have decided, contradicts that as I see it. But for the less value-loaded decisions studied in the experiment you mention (it was about pushinh buttons in response to sound signals) maybe the researchers who conducted the experiments would say that they can trust the subjects' reports and therefore disproved free will.

 

Intriguing issue: can there be 'free will' that operates on a level of which we are not aware? Is it even meaningful to define free will in this fashion?

 

To the 'me' who read your post, the answer has to be NO.

 

If I am a puppet whose strings are being pulled by some hidden and inaccessible puppet master.. then 'I' certainly don' t have free will.

 

And there seems to be no plausible reason why the puppet master has to have free will. Occam's Razor suggests, to me anyway, that the puppet master is more plausibly reacting due to a combination of randomness coupled with hard-wired responses that have evolved in our life-forms over time... the startle response, for one.... i.e. instinct. We know that there are such hard-wired behaviours... even if we refuse to see it in ourselves, we surely see it in other creatures... and we know that there is an element of randomness to physical activities if we descend deeply enough in scale. So why superimpose, on these known and sufficient explanations, the added and inexplicable element of 'free will' on the part of the puppet master?

 

Anyway, I appreciate that I should shut up and read those authors who have thought longer, harder, and better than my sophomoric meanderings :) Thanks to those, such as yourself, who have posted more meaningful comments :)

[Al_U_Card]

Intriguing issue: can there be 'free will' that operates on a level of which we are not aware? Is it even meaningful to define free will in this fashion?

 

To the 'me' who read your post, the answer has to be NO.

 

If I am a puppet whose strings are being pulled by some hidden and inaccessible puppet master.. then 'I' certainly don' t have free will.

 

And there seems to be no plausible reason why the puppet master has to have free will. Occam's Razor suggests, to me anyway, that the puppet master is more plausibly reacting due to a combination of randomness coupled with hard-wired responses that have evolved in our life-forms over time... the startle response, for one.... i.e. instinct. We know that there are such hard-wired behaviours... even if we refuse to see it in ourselves, we surely see it in other creatures... and we know that there is an element of randomness to physical activities if we descend deeply enough in scale. So why superimpose, on these known and sufficient explanations, the added and inexplicable element of 'free will' on the part of the puppet master?

 

Anyway, I appreciate that I should shut up and read those authors who have thought longer, harder, and better than my sophomoric meanderings :) Thanks to those, such as yourself, who have posted more meaningful comments :)

I usually regret not agreeing with you Mike, but your opinion is more valuable to me than all of those other ones combined.

[joshs]

I'm saying that computer scientists are qualified. Cognitive scientists are not qualified to refute an argument based on computability. I think you miss the point here. You can't say a turing machine can prove Godel just because you did it because the supposition here is that humans can do things that turing machines can't.

OK, so you are

1. clearly saying that Penrose in NOT qualified, since he is not a computer scientist. Its very interesting that you are praising his argument, and then saying other people with similiar background do not have the background to make an argument about the subject.

 

2. Further, you are saying that someone who studies computers is capable of making a statement that compares computers and brains, but someone who studies brains is not qualified. Facenating.

 

3. What supposition? You are making a supposistion that humans can do things that turning machines can't. I have never seen any proof of this statement. Hence your argument is based on a premise without any foundation. Why exactly can't a turing machine prove godel's theorem? Or some other interesting statement starting from the same axioms. As a mathematician, with some expertise into what constitutes proofs, I would dispute that a sequence of statements that are not translatable into something tha can be described in a formal language, and proven sequentially, was a proof to begin with. So almost by definition, a proof is a sequence of statements that a computer can devlop. So the main question is "does the brain have to use something from outside the formal system, to realize what the correct sequence of steps was?" Further, is that extra thing the brain is using from outside the formal system its self just part of a slightly largely formal system (and hence can be part of a turing machine) or does the key ingrediant come magically from someplace other than the formal physics rules that govern the neurons in the brain.

[hrothgar]

3. What supposition? You are making a supposition that humans can do things that turning machines can't. I have never seen any proof of this statement. Hence your argument is based on a premise without any foundation. Why exactly can't a turing machine prove godel's theorem? Or some other interesting statement starting from the same axioms. As a mathematician, with some expertise into what constitutes proofs, I would dispute that a sequence of statements that are not translatable into something that can be described in a formal language, and proven sequentially, was a proof to begin with. So almost by definition, a proof is a sequence of statements that a computer can develop.

Hi Josh

 

Couple quick comments:

 

1. I very much agree with your statement that Penrose is asserting that humans can do things that a Turing machine can't. I am still waiting for anyone to provide some kind of proof of this assertion.

 

2. There is a lot of documentation regarding Turing machines and incompleteness. Back in the 1930s, Turing proved that there isn't a general solution to the "halting problem". This was one of the "big" results in the field. There is a decent write up available at

 

http://en.wikipedia.org/wiki/Halting_problem