jjewett@math.lsa.umich.edu (Jim Jewett) (10/12/90)
In article <3617@media-lab.MEDIA.MIT.EDU>, minsky@media-lab.MEDIA.MIT.EDU (Marvin Minsky) writes: |> In article <1990Oct7.192212.24550@math.lsa.umich.edu> jjewett@math.lsa.umich.edu (Jim Jewett) writes: |> |> >|> In article <3549@media-lab.MEDIA.MIT.EDU> |> >minsky@media-lab.media.mit.edu (Marvin Minsky) writes: |> |> >>(Minsky) ...in an essay of mine --- "Communication with Alien |> Intelligence," (is) a cute theory based on some experiments |> with very small Turing machines. It turned out that many of them |> performed operations that could be interpreted as elementary |> addition -- while none of them did anything that was "similar" to |> addition but not exactly addition! |> |> >How do you define "similar" to? Do you mean any associative property |> >with inverses and an identity? Any accumlator? It seems that there |> >will be no woman similar to Mom because we know Mom so well ... but |> >someone for whom she isn't the point of reference may very well see |> >her as similar to her sister. |> |> Consider reading the paper. By "similar" I meant commonsensical things |> -- like could there be anything like the integers except skipping the |> number 5? Or could there be a number system with the symmetry laws |> holding usually but not always. Or integers with tree signs, instead |> of two, etc. OK ... I may still be missing some of the nuances, but ... I can see that merely elimating the number 5 and setting 2+3=6, so that 3+3=7, etc. is just a renaming. But then you mentioned trying to figure out a way that you *could* come up with a different arithmetic. You were unable to find a number system with three signs, though you acknowledged that you weren't able to find one with four either. (At least not in the time devoted, without just starting from the Complex numbers.) And so I wonder how much of your time was, in effect, just refinding what you had already been trained in. You did find some systems with only one sign, and modular arithmetic. While you didn't find them useful, I think that they are different ... at least as different as a third sign. and so I count three "simple" sets of artithmetic ... each with different uses. Modular arithmetic would be more useful for a view based largely on cycles, and we don't use negative distances. Perhaps a three-signed system would also have uses, but we haven't looked for them yet. The experiment that you mentioned in this group was examining simple Turing machines, which meant those with a small set of rules. I still question their simplicity. To you, they look simple. They will look very simple to me as well ... but we do have more in common with each other than with members of another species. (For those a bit lost by this point, remember that the paper was in a book on the Search for Extraterrestrial Life, with Artificial Intelligence assumed to similarly alien. It was also (the version I read) in the April '85 Byte.) For instance, we are genetically based on DNA ... RNA would seem to work similarly ... but not identically. Replacing Carbon with Silicon might also be possible. On another planet, the distribution of "critical" chemicals might be different. I don't *think* that that should alter the rules of simplicity ... but it might have very profound effects on which sorts of chemical reactions occurred most frequently. It is possible that on another world, life would use a standard method that we consider much more difficult, because it would be more common naturally, and therefore have more chances to become useful. (Just as we have found more uses for water than for Einsteinium, so would nature.) On this world, for instance, most people do not understand 1's or 2's complement arithmetic. Yet to a computer, that may seem the most natural, or simple method. Computers then translate the results into the sort of answers that humans like. If, however, there were no humans, what would motivate this? Would 2's complement develop to the point that we could no longer comprehend it? And would this be so basic to any "intelligent" life form that they didn't think to question the assumption? As has been pointed out, (most recently by jmc@Gang-of-Four.usenet (John McCarthy) in <JMC.90Oct9152336@Gang-of-Four.usenet>), we don't use the "simplest" methods (logic) ourselves in all cases. So either complicated methods are sometimes used (and might be by aliens as well), or we don't really understand simple. And after all this ... I'm not even sure that the "simple" concepts are that useful. You mentioned several that you suspect would have to be universal. Even if they are, I wonder whether they are sufficient for intelligence, if computers aren't already there. The most basic concepts were Object-Symbols: Things, ideas, processes (mostly nouns) Difference-symbols: Differences ... including changes Cause-symbols: Active agent - that which is responsible. (For us, usually a noun, typically the subject of an active sentence.) Clause-structures: Allows embedding, so that we can analyze. (eg, "The car that I saw at the the theatre is going by.", or understanding psychology without reference to neurochemistry.) So perhaps a for a computer: object: data structure differnece: comparisons, or parameters and returns of a function. cause: function call (we ourselves don't always find deep causes) Or maybe the result of a test. clause: recursion, or even the concept of calling other functions. And I'm not willing to concede that every program with those constructs is intelligent. -jJ jjewett@math.lsa.umich.edu Take only memories. Jewett@ub.cc.umich.edu Leave not even footprints.