Hi John, On 15 Jun 2010, at 13:41, John Mikes wrote:

Bruno, I don't claim to follow your discussion with Colin in 'good'understanding, but there was a sentence to which I ask someexplanation:"I study just the hypothesis that the brain is Turing emulable."Do you mean 'brain' as the physical tissue-mass (not likely), or thebrainfunction as 'mentality' into the summation of what we try to use?

`The brain is whatever is needed to be Turing emulated for my`

`consciousness to persist. It may be the whole Milky galaxy, described`

`at the level of the Heisenberg matrix or Schroedinger wave with a fine`

`graining up to the superstring, quantum fields or elementary particles`

`(if that exist). I just don't know.`

`If digital mechanism is true, not only I cannot know that, but such a`

`fine graining hides a finer graining ad infinitum, which play a role`

`in matter, but no more in consciousness (below that level).`

`If I am dying, and that my doctor believes that my brain is`

`constituted of some wet machinery (glials cells and neurons), and that`

`an emulation at the level of molecules is enough, I may as well trust`

`him, like doing some Pascal Gambit.`

`I will cross my fingers, and assuming mechanism, I 'know' why I have`

`to cross my fingers.`

Do you mean 'Turing' as the presently used embryonic binary addingmachine, or the universal machine - what we (us) try to emulate?

`It is the same. Roughly speaking Turing discovered that Universal`

`Computability, although non trivial at all, is very cheap. To be sure`

`binary adding machine are not universal, but if they can add *and*`

`multiply, they become universal. This is not obvious at all, but we`

`know this since Gödel, Church, Kleene's works around 1930.`

`The universality of addition and multiplication is the main reason we`

`can say today, about arithmetical truth: we know almost nothing.`

`Assuming comp, we can add, and we will never know. It is too big, too`

`complex, too much transcendental.`

I do not think the 1st part of the 1st Q gets a yes, just as the2nd Q is also likely to be anchored in the 2nd part.In which case instead of saying something, like "AI is digitallycomputable" I may paraphrase the idea in my primitive wording:"We may suppose to be able to compute (~understand) whatever is instore to be understood"

`Computing is quite different from understanding. There is more in`

`(just) the computing store than what we can ever understand.`

`When a universal machine begins to try to understand herself, she`

`grows indefinitely, and her ignorance grows indefinitely, and even`

`more quickly than herself.`

`There is a threshold, though, at which point she will *understand*`

`that very phenomenon. She will understand she will never understand,`

`even just herself, still less any of her possible universal`

`neighborhoods. She may become wise, or modest, (Löbian) at that point.`

What I would hold a bit exaggerated considering that our 'universaldatabase' (the wholeness of the existence (~nature) ) MAY(?) includelots of domains so far not absorbed into our working personal mentalcapabilities (beyond Colin's mini solipsism, D.Bohm's explicate, R.Rosen's system-model?) and so our 'computing' is far from being ableto match the universal machine's.

`May be. I make explicit that I identify "our computing" with the`

`computing power of the universal machine. This statement is equivalent`

`with Church's thesis. Church's thesis is very plausible, both`

`empirically and conceptually. I recall that the universal "Turing"`

`machine, or the set of what such a machine can compute, is close for`

`the Cantor Diagonal procedure. This is an utterly incredible fact,`

`that Gödel disbelieved until his reading of Turing, and then called a`

`'miracle'.`

Unless, of course, you may include into the 'emulable' theacceptance of such hiatus.

Absolutely.

`Like Hofstadter illustrated, anyone can emulate the brain of Einstein,`

`for example when doing an oral presentation on GR, even without the`

`knowledge of German, or of general relativity (and without`

`understanding anything).`

`For the same reason we will probably copy brains well before`

`understanding the brain, and when we will understand brains, it will`

`be too late, we will be more complex than brain.`

`Computing, or emulating, IS not equivalent with understanding, or even`

`just with proving-in-a-theory.`

`The ultra-weak theory ROBINSON-ARITHMETIC is already universal (in the`

`sense of computer science), yet quite dumb and without capacity to`

`prove any non trivial generalizations. Yet ROBINSON-ARITHMETIC, by`

`computing universality, can already emulate all the richer, and`

`Löbian, effective theories or machines.`

`ROBINSON-ARITHMETIC cannot prove the consistency of ROBINSON-`

`ARITHMETIC, still less of the consistency of the richer ZERMELO-`

`FRAENKEL set theory-machine. But ROBINSON-ARITHMETIC *can* prove that`

`ZERMELO-FRAENKEL set theory proves the consistency of ROBINSON-`

`ARITHMETIC. This will not really help ROBINSON-ARITHMETIC!`

Or: if you apply the words "theoretically" : WE (~universalmachines) have - theoretically- the capability of applyingomniscience.

`I don't think so. WE (universal machine), as far as we are self-`

`referentially correct (and thus Löbian), are cured from the idea of`

`omniscience. We cannot be omniscient, still less apply that concept to`

`anything.`

`In the frame of the digital mechanist hypothesis, even "God" is NOT`

`omniscient, nor omnipotent.`

Excuse my asking into what you say you ARE still studying.

`The subject is infinite and infinitely fascinating. Here I try more to`

`share my enthusiasm and befuddling than to convince anyone of any`

`truth. It is always a pleasure to answer (or to try to answer)`

`questions. Feel always free to ask any questions, I love *all*`

`questions.`

Best, Bruno http://iridia.ulb.ac.be/~marchal/ -- You received this message because you are subscribed to the Google Groups "Everything List" group. To post to this group, send email to everything-l...@googlegroups.com. To unsubscribe from this group, send email to everything-list+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/everything-list?hl=en.