Quantum theory of measurement
statistical correlation between the screen and the contents of the CC, via transitive correlations such as CC -- printer -- George Washington -- Bob -- screen I don't like this argument because it seems to me that these correlations should be too small to make any difference, but I recognize it as an apparent mathematical loophole, according to which my variant scenarios may be considered as different from the original quantum eraser experiment. Comments? -- Ben Goertzel
RE: Quantum theory of measurement
Hi, Oops, I gave the wrong link I said Specifically, I'll refer to the quantum eraser thought experiment summarized at http://grad.physics.sunysb.edu/~amarch/ but I meant http://www.dhushara.com/book/quantcos/qnonloc/eraser.htm Anyway, the essential idea of the two experiments is the same. -- Ben
RE: Quantum theory of measurement
Hal, What will the outcome be in these experiments? It won't make any difference, because the CC is not used in the way you imagine. It doesn't have to produce a record and it doesn't have to erase any records. OK, mea culpa, maybe I misunderstood the apparatus and it was not the CC that records things, but still the records could be kept somewhere, and one can ask what would happen if the records were kept somewhere else (e.g. in a macroscopic medium). No? The point is, there is no change to the s photon when we put the polarizer over by p. Its results do not visibly change from non-interference to interference, as the web page might imply. (If that did happen, we'd have the basis for a faster than light communicator.) No, all that is happening is that we are choosing to throw out half the data, and the half we keep does show interference. Yes but we are choosing which half to throw out in a very peculiar way -- i.e. we are throwing it out by un-happening it after it happened, by destroying some records that were only gathered after the events recorded in the data already happened... Ben
RE: Quantum theory of measurement
What if instead of throwing out the information you shoot it into a black hole? Then presumably the information is really gone so the result should be as if the information were quantum erased?? Unless there are white holes of course!! ;-) Yes but we are choosing which half to throw out in a very peculiar way -- i.e. we are throwing it out by un-happening it after it happened, by destroying some records that were only gathered after the events recorded in the data already happened... Ben
RE: Quantum theory of measurement
Thanks very much Jesse! You answered the question I *would have* asked had I rememberd my quantum physics better ;-) I think your answer is related to a paradox a friend mentioned to me. The paradox is as follows: One does the EPR thing of creating two particles with opposite spin. Send one far away to Alpha Centauri and send the other through a Stern-Gerlach magnet and let the spin up and spin down outputs interfere to form a double slit. If the far away particle is measured up vs. down, our local particle must definitely go through the up hole or the down hole and we get no interference pattern. If he measures the far away particle sideways we get a superposition of states and we get interference. Thus by rotating his measurement he should be able to communicate to us faster than the speed of light. We should see our pattern blinking between interference and not. What's wrong with that argument? Along the lines of your solution to my other, related puzzle, I'll try to analogize a solution to this puzzle. I guess the idea must be: there is no change to what a particular particle does when you observe its faraway coupled pair in a certain way. Its individual results do not visibly change from non-interference to interference. (If that did happen, you'd have the basis for a faster than light communicator, as you say.) Instead, when you observe some of the particles sideways and some vertically, you must be creating correlational information that exists only statistically as a correlation between that's happening in Alpha Centauri and what's happening locally. So, maybe there is some weird cancellation here, like in the case you described in your email. Perhaps, if one restricts attention to the cases where the faraway particle is measured right then interference is seen, and if one restricts attention to the cases where the faraway particle is measured left then interference is seen; but if one looks across all cases where the faraway particle is measured sideways, then the peaks and troughs of the different cases might cancel out and you'd get no interference? -- Ben I think Ben's question here does make sense. See below... The point is, there is no change to the s photon when we put the polarizer over by p. Its results do not visibly change from non-interference to interference, as the web page might imply. (If that did happen, we'd have the basis for a faster than light communicator.) No, all that is happening is that we are choosing to throw out half the data, and the half we keep does show interference. Yes but we are choosing which half to throw out in a very peculiar way -- i.e. we are throwing it out by un-happening it after it happened, by destroying some records that were only gathered after the events recorded in the data already happened... You have to try to stop thinking of this in mystical terms. IMO people present a rather prosaic phenomenon in a misleading and confusing way, and this is giving you an incorrect idea. Nothing is un-happening. No records are destroyed after they were gathered. Although it may be true that no records are destroyed after they're gathered, what is true is that an *opportunity* to find out retroactively which path the signal photon took is eliminated when you choose to combine the paths of the idler photons instead of measuring them. For reference, look at the diagram of the setup in fig. 1 of this paper: http://xxx.lanl.gov/PS_cache/quant-ph/pdf/9903/9903047.pdf In this figure, pairs of entangled photons are emitted by one of two atoms at different positions, A and B. The signal photons move to the right on the diagram, and are detected at D0--you can think of the two atoms as corresponding to the two slits in the double-slit experiment, while D0 corresponds to the screen. Meanwhile, the idler photons move to the left on the diagram. If the idler is detected at D3, then you know that it came from atom A, and thus that the signal photon came from there also; so when you look at the subset of trials where the idler was detected at D3, you will not see any interference in the distribution of positions where the signal photon was detected at D0, just as you see no interference on the screen in the double-slit experiment when you measure which slit the particle went through. Likewise, if the idler is detected at D4, then you know both it and the signal photon came from atom B, and you won't see any interference in the signal photon's distribution. But if the idler is detected at either D1 or D2, then this is equally consistent with a path where it came from atom A and was reflected by the beam-splitter BSA or a path where it came from atom B and was reflected from beam-splitter BSB, thus you have no information about which atom the signal photon came from and will get interference in the signal photon's distribution, just like in the double-slit experiment
RE: Neutrino shield idea
The discussion of John Ross's theory is off-topic. However, I would be happy about it anyway, IF I thought it was a good theory, which I do not. But I don't feel like taking the time to argue about why i don't think it's a good theory, so I will continue to ignore the thread. -- Ben Goertzel -Original Message- From: Jesse Mazer [mailto:[EMAIL PROTECTED] Sent: Tuesday, October 11, 2005 1:56 PM To: [EMAIL PROTECTED]; everything-list@eskimo.com Subject: RE: Neutrino shield idea John Ross wrote: Another solution is for you to ignore my comments, or maybe me yours. This isn't just about me personally not being interested in your posts, it's about the discussion of your alternative physics ideas being *off-topic* on this list, just as much so if you came here and started a discussion about politics or your favorite TV shows. But if the rest of the list members disagree with me I'll go with whatever the consensus is...how about a poll, who here thinks that the discussion of John Ross' theory is off-topic here, and who thinks it's on-topic? (regardless of whether or not you personally find John Ross' ideas to be of interest) Jesse
RE: Memory-prediction framework
I wrote a sort-of-review of this book some time ago... http://www.goertzel.org/dynapsyc/2004/OnBiologicalAndDigitalIntelligence.htm -- Ben Goertzel -Original Message-From: Lennart Nilsson [mailto:[EMAIL PROTECTED]Sent: Friday, August 12, 2005 2:00 PMTo: everything-list@eskimo.comSubject: Memory-prediction framework Thoughts on the Memory-prediction framework in explaining intelligence anyone? Book: Jeff Hawkins On Intelligence
RE: is induction unformalizable?
Wei, Isn't the moral of this story that, to any finite mind with algorithmic information I, "uncomputable" is effectively synonymous with "uncomputable within resources I"? Thus, from the perspective of a finite mind M, A = P( X is uncomputable) should be equal to B = P(X is uncomputable within resources I) since there is no evidence comprehensible by M that can distinguish A from B. Any formalization of induction that says A and B are unequal is not a correct model of induction as experienced by a finite mind. Induction is formalizable, but only using *experience-based semantics*, in which one assigns probabilities to propositions based on actual experienced pieces of evidence in favor of these propositions. Considering induction outside of the context of a particular finite system's experience leads to apparent paradoxes like the one you're suggesting. But if one construes induction experientially, one finds that these paradoxes never occur in any finite system's experience. As an example of experience-based semantics, see Pei Wang's NARS theory of AI. I don't fully accept the NARS theory, I have my own related theory that is probabilistically grounded, unlike NARS. But NARS is an example of what experience-based semantics means in concrete mathematical practice. -- Ben -Original Message-From: Wei Dai [mailto:[EMAIL PROTECTED]Sent: Wednesday, July 13, 2005 11:15 PMTo: everything-list@eskimo.comSubject: is induction unformalizable? One day,Earth is contacted by a highly advanced alien civilization, and they tell us that contrary to what most of us think is likely,not all ofthe fundamental physical laws of our universearecomputable. Furthermore, they claim to be able to manufacture black boxes that work as oracles for the Halting Problem of Turing machines (one query per hour). They give us one free sample, and want to sell us more at a reasonable price. But of course we won't be allowed to open up the boxes and look inside to find out how they work. So our best scientists test the sample black box in every way that they can think of, but can't find any evidence that it isn't exactly what the aliens claim it is. At this point many people are ready to believe the claim andspend their hard earned money to buy these devices for their families. Fortunately, the Artificial Intelligence in charge of protecting Earth from interstellar fraud refuses to allow this. Having been programmed with UD+ASSA (see Hal Finney's 7/10/2005 post for a good explanation of what this means), it proclaims that there is zero probability that Halting Problem oracles can exist, so it must be pure chance that the sample black box has correctly answered all the queriessubmitted to itso far. The moral of this story is that our intuitive notion of induction is not fully captured by the formalization of UD+ASSA. Contrary to UD+ASSA, we will not actually refuse to believe in the non-existence of uncomputable phenomena no matter what evidence we see. What can we do to repair this flaw?Using a variant of UD, basedon a more powerful type of computer (say an oracle TM instead of a plain TM), won't helpbecause that just moves the problem up to a higher level of the computational hierarchy. No matter what type of computer (call it C) we base UD' on, it will always assign zero probability to the existence of even more power types of computer (e.g., ones that can solve the halting problem for C). Intuitively, this doesn't seem like a good feature. Earlier on this mailing list, I had proposed that we skip pass the entire computational hierarchy and jump to the top of the set theoretic hierarchy, by using a measure that is baseda set theoretic notion ofcomplexity instead of a computational one. In this notion, instead of defining the complexity of an object by the length of its shortest algorithmic description, we define its complexityby the length of its shortest description in the language of a formal set theory. The measure would be constructed in a manner analogous to UD, with each set theoretic description of an object contributing n^-l tothe measure of the object, where n is the size of the alphabet of the set theory, and l is the length of the description. Lets call this STUM for set theoretic universal measure. STUM along with ASSA does a much better job of formalizing induction, but I recently realized that it still isn't perfect. The problem is that it still assigns zero probability to some objects that we intuitively think is very unlikely, but not completely impossible. An example would be a device that can decidethe truth value of any set theoretic statement. A universe that contains such a device would exist in the set theoretic hierarchy, but would have no finite description in formal set theory, and would be
RE: is induction unformalizable?
I agree that " As Sgoes toinfinity, the AI's probability would converge to 0, whereas the human's would converge to some positive constant. " but this doesn't mean induction is unformalizable, it just means that the formalization of cognitive-science induction in terms of algorithmic information theory (rather than experience-grounded semantics) is flawed... ben -Original Message-From: Wei Dai [mailto:[EMAIL PROTECTED]Sent: Thursday, July 14, 2005 1:05 AMTo: Ben Goertzel; everything-list@eskimo.comSubject: Re: is induction unformalizable? Correct me if wrong, but isn't the halting problem only undecidable when the length of the program is unbounded? Wouldn't the AI assign non-zero probability to a machine that solved the halting problem for programs up to size S? (S is the number of stars in the sky, grains of sand, atoms in the universe, etc...) As an aside, this would actually be my best guess as to what was really going on if I were presented with such a box (and I'm not even programmed with UD+ASSA, AFAIK). Any sufficiently advanced technology is indistinguishable form magic (but not actual magic) and all that ;-... Moshe The AI would assign approximately 2^-S to this probability. A human being would intuitively assign a significantly greater a priori probability, especially for larger values of S. As Sgoes toinfinity, the AI's probability would converge to 0, whereas the human's would converge to some positive constant. Why 2^-S? Being able to solve the halting problem for programs up to size S is equivalent to knowing the first S bits of the halting probability (Chaitin's Omega). SinceOmega is incompressible by a Turing machine, the length of the shortest algorithmic description of the first S bits of Omega isjust S (plus a small constant). See http://www.umcs.maine.edu/~chaitin/xxx.pdf. Here's another way to see why the AI's method of induction does not capture our intuitive notion. Supposed we've determined empirically that the black box can solve the halting problem for programs up to some S. No matter how large S is, the AI would still only assign a probability of2^-100 to the black box being able to solve halting problems for programs of size S+100.
Time travel in multiple universes
Hi, I recently wrote a blog entry on time travel http://www.goertzel.org/blog/blog.htm and Tom Buckner followed up with an interesting comment on the potential for time travel in Tegmarkian multiple universes. (You can see it by going to the bottom of the page and clicking where it says "1 Comments.") I am curious for any reactions to Buckner's comment by you multiple-universe experts ;-) thanks Ben Goertzel
RE: Many worlds theory of immortality
Saibal, Does your conclusion about conditional probability also apply to complex-valued probabilities a la Youssef? http://physics.bu.edu/~youssef/quantum/quantum_refs.html http://www.goertzel.org/papers/ChaoQM.htm -- Ben Goertzel -Original Message-From: Bruno Marchal [mailto:[EMAIL PROTECTED]Sent: Tuesday, May 03, 2005 4:20 AMTo: Saibal MitraCc: everything-list@eskimo.comSubject: Re: Many worlds theory of immortalityLe 16-avr.-05, à 02:45, Saibal Mitra a écrit : Both the suicide and copying thought experiments have convinced me that thenotion of a conditional probability is fundamentally flawed. It can bedefined under ''normal'' circumstances but it will break down precisely whenconsidering copying or suicide.This is a quite remarkable remark. I can related it to the COMBINATORS thread.In a nutshell: in the *empirical* FOREST there are no kestrels (no eliminators at all),nor Mockingbird, warblers or any duplicators. Quantum information behaveslike incompressible fluid. Universes differentiate, they never multiplies. Deutsch is right on that point. I use Hardegree (ref in my thesis(*)) He did show thatquantum logic can be seen as a conditional probability logic. We will come back on this (it's necessarily a little bit technical). I am finishing atechnical paper on that. The COMBINATORS can help to simplify considerablythe mathematical conjectures of my thesis.Bruno(*) Hardegree, G.M. (1976). The Conditional in Quantum Logic. In Suppes, P., editor, Logic and Probability in Quantum Mechanics, volume78 of Synthese Library, pages 55-72. D. Reidel Publishing Company, Dordrecht-Holland.http://iridia.ulb.ac.be/~marchal/
RE: Afshar and ...the idea of a photon is dead
I don't know anything about Afshar, but I do know that variable-speed-of-light (VSL) theories of quantum gravity are now being considered seriously by physics journals and by some leading physicists. Joao Maguiejo (sp?) has a popular book on the topic entitled Faster than the Speed of Light. The first half of the book will be too elementary for members of this list, but the second half is a good read -- though it leaves one eager for the mathematical details, which are found in the author's and others' technical papers. Lee Smolin, who is well-respected for his role in creating loop quantum gravity, is now taking VSL theories seriously. -- Ben Goertzel -Original Message- From: Saibal Mitra [mailto:[EMAIL PROTECTED] Sent: Sunday, August 01, 2004 8:03 AM To: [EMAIL PROTECTED] Cc: everything; [EMAIL PROTECTED] Subject: Re: Afshar and ...the idea of a photon is dead Unfortunately, sensationalists articles that are completely baloney appear in most scientific journals from time to time. Nature published an article claiming that if the fine structure conswtant is changing, as suggested by some astronomical observations, then this change must be due to a change in the speed of light. Now, this must be nonsense, because the value of the speed of light, being a dimensional constant, is determined by our choice of units. In fact, that there are dimensional constants at all, is an artefact of using inconsistent units at the same time. Michael Duff has explained this in the articles: http://arxiv.org/abs/hep-th/0208093 and: http://arxiv.org/abs/physics/0110060 - Oorspronkelijk bericht - Van: Nicole Barberis [EMAIL PROTECTED] Aan: [EMAIL PROTECTED] Verzonden: Friday, July 30, 2004 06:15 PM Onderwerp: Afshar and ...the idea of a photon is dead I was stunned to read Quantum Rebel in July 24th's New Scientist. Shahriar Afshar, an American, comes to the conclusion that we have no other choice but to declare the idea of Einstein's photon dead (page 35). His work has been tested and is now being peer reviewed. How trustworthy is New Scientist as a news source? Is it prone to sensationalists articles. I'm a fairly new reader of this magazine, but it seemed to me to be a good source of science news until last week's rushed Hawking article and this week's no-such-thing-as-a-photon showcase article. Of course, if it is repeatedly proved true than I would welcome the new finding but for now I'm just a bit stunned by the news. -Nicole __ Do you Yahoo!? New and Improved Yahoo! Mail - 100MB free storage! http://promotions.yahoo.com/new_mail Yahoo! Groups Sponsor ~-- Yahoo! Domains - Claim yours for only $14.70 http://us.click.yahoo.com/Z1wmxD/DREIAA/yQLSAA/pyIolB/TM ~- Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Fabric-of-Reality/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/ --- Incoming mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.732 / Virus Database: 486 - Release Date: 7/29/2004 --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.732 / Virus Database: 486 - Release Date: 7/29/2004
RE: Many Worlds invalidated?
A powerpoint reviewing these ideas is at John Cramer's website: http://faculty.washington.edu/jcramer/PowerPoint/43 I suspect that advocates of the Copenhagen and MW Interpretations will give different applications of their interpretations to the Afshar experiment than Cramer does. His applications of these rival interpretations to the experiment have a straw man flavor to them. -- Ben -Original Message- From: Jeff Bone [mailto:[EMAIL PROTECTED] Sent: Monday, April 26, 2004 2:27 PM To: [EMAIL PROTECTED] Cc: [EMAIL PROTECTED] Subject: Many Worlds invalidated? Hot off the press, via Boingsters: http://www.boingboing.net/2004/04/26/many_worlds_theory_i.html Many Worlds theory invalidated Kathryn Cramer breaks the story on a to-be-presented Harvard talk on an experiment that appears to invalidate both the Many Worlds and Copenhagen theories of quantum mechanics. Kathryn is the daughter of John Cramer, a physicist whose Transactional Interpretetation hypothesis is the only one left intact by the experiment's findings. It has been widely accepted that the rival interpretations of quantum mechanics, e.g., the Copenhagen Interpretation, the Many-Worlds Interpretation, and my father John Cramer's Transactional Interpretation, cannot be distinguished or falsified by experiment, because the experimental predictions come from the formalism that all such interpretations describe. However, the Afshar Experiment demonstrates in an interaction-free way that there is a loophole in this logic: if the interpretation is inconsistent with the formalism, then it can be falsified. In particular, the Afshar Experiment falsifies the Copenhagen Interpretation, which requires the absence of interference in a particle-type measurement. It also falsifies the Many-Worlds Interpretation which tells us to expect no interference between worlds that are physically distinguishable, e.g., that correspond to the photon's passage through one pinhole or the other. Link (Thanks, Kathryn!) http://www.kathryncramer.com/wblog/archives/000530.html
RE: Are we simulated by some massive computer?
6) This shows that if we are in a massive computer running in a universe, then (supposing we know it or believe it) to predict the future of any experiment we decide to carry one (for example testing A or B) we need to take into account all reconstitutions at any time of the computer (in the relevant state) in that universe, and actually also in any other universes (from our first person perspective we could not be aware of the difference of universes from inside the computer). Yes, but this is just a fancy version of the good old-fashioned Humean problem of induction, isn't it? Indeed, predicting the future on a sound a priori basis is not possible. One must make arbitrary assumptions in order to guide predictions. This is a limitation, not of the comp hypothesis specifically, but of the notion of prediction itself. You cannot solve the problem of induction with or without comp, so I don't think you should use problem-of-induction related difficulties as an argument against comp. In fact, comp comes with a kind of workaround to the problem of induction, which is: To justify induction, make an arbitrary assumption of a certain universal computer, use this to gauge simplicity, and then judge predictions based on their simplicity (to use a verbal shorthand for a lot of math a la Solomonoff, Levin, Hutter, etc.). This is not a solution to the problem of induction (which is that one must make arbitrary assumptions to do induction), just an elegant way of introducing the arbitrary assumptions. So, in my view, we are faced with a couple different ways of introducing the arbitrary assumptions needed to justify induction: 1) make an arbitrary assumption that the apparently real physical universe is real 2) make an arbitrary assumption that simpler hypotheses are better, where simplicity is judged by some fixed universal computing system There is no scientific (i.e. inductive or deductive) way to choose between these. From a human perspective, the choice lies outside the domain of science and math; it's a metaphysical or even ethical choice. -- Ben Goertzel
RE: More on qualia of consciousness and occam's razor
; you might even be able to read the brain, scanning for neuronal activity and deducing correctly that the subject sees a red flash. However, it is impossible to know what it feels like to see a red flash unless you have the actual experience yourself. So I maintain that there is this extra bit of information -subjective experience or qualia - that you do not automatically have even if you know everything about the brain to an arbitrary level of precision. In what sense is a quale information? formalizing this might help me to understand your hypothesis better ben
RE: probabilities measures computable universes
The notion of complex-valued or even quaternionic or octonionic probabilities has been considered; see http://physics.bu.edu/~youssef/quantum/quantum_refs.html for some pointers into the literature. -- Ben Goertzel -Original Message- From: scerir [mailto:[EMAIL PROTECTED] Sent: Friday, January 23, 2004 9:23 AM To: [EMAIL PROTECTED] Subject: Re: probabilities measures computable universes Are probabilities always and necessarily positive-definite? I'm asking this because there is a thread, started by Dirac and Feynman, saying the only difference between the classical and quantum cases is that in the former we assume the probabilities are positive-definite. Thus, speaking of MWI, we could also ask: what is the joint probability of finding ourselves in a universe alpha and of finding ourselves in a universe beta, which is 180 degrees out of phase with the first one (whatever that could mean)? s.
RE: I the mirror
Hi, Onar Aam wrote some nice essays on mirrors and awareness, a few years back. He had a quite elaborate theory. Unfortunately, his website seems not to be up anymore. However, if you e-mail him, he will probably send them to you. A year ago his e-mail was [EMAIL PROTECTED], but I'm not 100% sure it's current. -- Ben -Original Message- From: Colin Hales [mailto:[EMAIL PROTECTED]] Sent: Monday, January 20, 2003 7:59 PM To: [EMAIL PROTECTED] Subject: I the mirror Dear Everythingers, This is a query placed as a result of failing to succeed to find answers when googling my way around the place for a very long time (2 years). I am about to conclude that a) no such discourse exists or b) that it is disguised in a form of physics/math that my searching has not uncovered. I know it is off-topic but I thought I'd run it by you folk as the most eclectic agglomerators of knowledge in the multiverse. Off-list replies welcome - keep the noise down and all that. Q. What branch of science has ascertained the role and status of the image in a first person perspective of a mirror? .ie. 'be' the mirror. The answer 'there ain't one as far as I know' is as acceptable as anything. I just need to know what's out there. If there's nothing there then I take it I'm in that breezy lonely spot past the front lines of epistemology and trundle on assuming (a) above. Thanks in advance. Cheers, Colin Hales
RE: I am not meant for your religion
Tim, if you're leaving the list it's a shame; as a lurker I've particularly enjoyed your posts... -- Ben Goertzel I'll miss some tidbits of math I discussed with some of you, but I won't miss the rest. Until we meet in another reality, --Tim May
RE: Science
Extraordinary claims require extraordinary proof. --Tim May One frustrating thing is that it seems almost arbitrary *which* unproven extraordinary claims are celebrated with attention and funding. The amount of attention paid to string theory perplexes me, for example. Yes, it's interesting. But very speculative -- certainly there is no extraordinary proof. Yet string theory is well respected and well funded, whereas other equally speculative theories are not. Now, this probably just means that the current community of physicists has its own collective intuition, and string theory happens to agree with it. But to me this is a clue to worry that the collective intuition may be way wrong... Which is why I think a list like this, with open discussion of speculations *besides* the conventionally-sanctioned speculations, is such a good thing. -- Ben Goertzel
RE: Quantum Probability and Decision Theory
When a finite quantum computer can break the Turing barrier, that will prove something. But when your first step is to prepare an infinite superposition, that has no applicability to the physical universe. Hal Finney Precisely. Deutsch's arguments make a lot of assumptions about things being finitely given; Calude's theory makes very different assumptions. If you take Calude's assumptions and replace them with finite-precision assumptions, the non-Turing stuff goes away. Less formally: you need to put noncomputable information into QM to get noncomputable information out of QM. If you don't explicitly put noncomputable information into it, you won't get any out. ben
RE: Funding AI
Tim May wrote: Except I'll add that I don't agree physics is stumped by most complex systems. Physics doesn't try to explain messy and grungy situations, nor should it. Turbulence is a special case, and I expect progress will be made, especially using math (which is why Navier-Stokes issues are on the same list with other math problems for the prize money). I guess this comes down to the semantics of the word physics. If you want to define physics to exclude all complex systems besides turbulent fluids, that's your right. But I don't like your definition, personally. What about protein folding? What about potential quantum effects in water macromolecules in the brain? What about bioelectromagnetic fields, as studied by Russian researchers extensively over the last 50 years? Etc. etc. etc. I feel like you're taking a whole lot of things that contemporary physics can't deal with because of its conceptual shortcomings, and classifying them as not physics, in order to make physics look more successful than it is. Of course, physics has been dramatically successful in some areas, but let's not overlook its weaknesses. Quantum gravity is not the only area it's tried and failed to touch. And I have a suspicion that the same mathematical/conceptual breakthrough that allows complex systems to be rigorously studied, will also help with the quantum gravity problem. This suspicion is in line with the intuition of plenty of smart physicists, including John Wheeler with his whole It From Bit concept (which portrays physical law itself as the result of complex self-organization). Funding is the key issue. Someday I'll write a thing for this list about successes vs. failures in terms of auto-funding each successive stage of a complex technological path. In a nutshell, the electronics/computer industry was essentially self-funding for the past 50 years, with the products of 1962, for example, paying for the work that led to the 1965 products. Same thing with aviation. ... It is unlikely that the path to AI will be successful if there are not numerous intermediate successes and ways to make a _lot_ of money. My tip to all AI workers is to look for those things. (This is more than just banal advice about try to make money, I am hoping. I have seen too many tech enthusiasts clamoring for moon shots to fund what they think is needed...)) The AGI may come from the distant great-great grandchild of financial AI systems. I've worked on financial AI systems myself. It's hard to argue with a statement as loose as distant great-great grandchild ... but I think financial AI is not on the shortest path to AGI right now. I agree that it's important for incremental progress toward AGI to be financially viable, and in fact my own current work involves building toward real AGI, partly via building bioinformatics applications (which ARE financially viable in the short run). However, I also would point out that AGI research is different from many other kinds of research, in that the primary research tools are very inexpensively available. All you need are computers. yeah, you may need a shitload of RAM, but it's a very different situation from other sciences: you don't need a cyclotron, a chip fabrication plant, a microarrayer, a PCR machine, etc. etc. There is real potential for real progress to be made on a shoestring. Funding is valuable, but less critical than in a lot of other areas. Fundamental physics has the same inexpensiveness, to an extent -- a theoretical breakthrough could be made by a guy sitting alone in his attic unfunded. But to verify the currently fashionable theories requires insanely expensive equipment, which is a real obstacle to progress -- a type of obstacle that's not nearly so severe in AI right now. ben
RE: Applied vs. Theoretical
Tim May wrote: As I hope I had made clear in some of my earlier posts on this, mostly this past summer, I'm not making any grandiose claims for category theory and topos theory as being the sine qua non for understanding the nature of reality. Rather, they are things I heard about a decade or so ago and didn't look into at the time; now that I have, I am finding them fascinating. Some engineering/programming efforts already make good use of the notions [see next paragraph] and some quantum cosmologists believe topos theory is the best framework for partial truths. The lambda calculus is identical in form to cartesian closed categories, program refinement forms a Heyting lattice and algebra, much work on the fundamentals of computation by Dana Scott, Solovay, Martin Hyland, and others is centered around this area, etc. FWIW, I studied category theory carefully years ago, and studied topos theory a little... and my view is that they are both very unlikely to do more than serve as a general conceptual guide for any useful undertaking. (Where by useful undertaking I include any practical software project, or any physics theory hoping to make empirical predictions). My complaint is that these branches of math are very, very shallow, in spite of their extreme abstractness. There are no deep theorems there. There are no surprises. There are abstract structures that may help to guide thought, but the theory doesn't tell you much besides the fact that these structures exist and have some agreeable properties. The universe is a lot deeper than that Division algebras like quaternions and octonions are not shallow in this sense; nor are the complex numbers, or linear operators on Hilbert space Anyway, I'm just giving one mathematician's intuitive reaction to these branches of math and their possible applicability in the TOE domain. They *may* be applicable but if so, only for setting the stage... and what the main actors will be, we don't have any idea... -- Ben Goertzel
RE: Re: The number 8. A TOE?
See my web page for links to papers, and archive addresses with more explanations, including the basic results of my thesis. (Mainly the Universal Dovetailer Argument UDA and its Arithmetical version AUDA). I read your argument for the UDA, and there's nothing there that particularly worries me. You seem to be making points about the limitations of the folk-psychology notion of identity, rather than about the actual nature of the universe... When you say sum over all computational histories, what if we just fix a bound N, and then say sum over all computational histories of algorithmic info. content = N. Finite-information-content-universe, no Godel problems. So what's the issue? The main reason is that, once we postulate that we are turing emulable, (i.e. the computationalist hypothesis comp), then there is a form of indeterminacy which occurs and which force us to take into account the incompleteness phenomenon. ?? I'm sorry, but I don't get it. Could you please elaborate? thanks Ben
RE: turing machines = boolean algebras ?
Essentially, you can consider a classic Turing machine to consist of a data/input/output tape, and a program consisting of -- elementary tape operations -- boolean operations I.e. a Turing machine program is a tape plus a program expressed in a Boolean algebra that includes some tape-control primitives. -- Ben G -Original Message- From: Stephen Paul King [mailto:[EMAIL PROTECTED]] Sent: Tuesday, November 26, 2002 9:25 AM To: [EMAIL PROTECTED] Subject: Re: turing machines = boolean algebras ? Dear Ben and Bruno, Your discussions are fascinating! I have one related and pehaps even trivial question: What is the relationship between the class of Turing Machines and the class of Boolean Algebras? Is one a subset of the other? Kindest regards, Stephen
RE: The class of Boolean Algebras are a subset of the class of Turing Machines?
The statement Boolean Algebras are a subset of the class of Turing Machines doesn't seem quite right to me, I guess there's some kind of logical typing involved there. A Turing machine is a kind of machine [albeit mathematically modeled], whereas a boolean algebra is an algebra. Boolean algebra is a mathematical framework that is sufficient to model/design the internals of Turing machines... In a conceptual sense, they're equivalent ... -- Ben -Original Message- From: Stephen Paul King [mailto:[EMAIL PROTECTED]] Sent: Tuesday, November 26, 2002 12:29 PM To: Ben Goertzel; [EMAIL PROTECTED] Subject: The class of Boolean Algebras are a subset of the class of Turing Machines? Dear Ben, So you are writing that the class of Boolean Algebras are a subset of the class of Turing Machines? Kindest regards, Stephen - Original Message - From: Ben Goertzel [EMAIL PROTECTED] To: Stephen Paul King [EMAIL PROTECTED]; [EMAIL PROTECTED] Sent: Tuesday, November 26, 2002 9:58 AM Subject: RE: turing machines = boolean algebras ? Essentially, you can consider a classic Turing machine to consist of a data/input/output tape, and a program consisting of -- elementary tape operations -- boolean operations I.e. a Turing machine program is a tape plus a program expressed in a Boolean algebra that includes some tape-control primitives. -- Ben G -Original Message- From: Stephen Paul King [mailto:[EMAIL PROTECTED]] Sent: Tuesday, November 26, 2002 9:25 AM To: [EMAIL PROTECTED] Subject: Re: turing machines = boolean algebras ? Dear Ben and Bruno, Your discussions are fascinating! I have one related and pehaps even trivial question: What is the relationship between the class of Turing Machines and the class of Boolean Algebras? Is one a subset of the other? Kindest regards, Stephen
RE: The class of Boolean Algebras are a subset of the class of Turing Machines?
Among other things, Bruno is pointing out that if we assume everything in the universe consists of patterns of arrangement of 0's and 1's, the distinction btw subjective and objective reality is lost, and there's no way to distinguish simulated physics in a virtual reality from real physics. I accept this -- there is no way to make such a distinction. Tough luck for those who want to make one!! ;-) -- Ben G -Original Message- From: Stephen Paul King [mailto:[EMAIL PROTECTED]] Sent: Tuesday, November 26, 2002 1:38 PM To: [EMAIL PROTECTED] Subject: Re: The class of Boolean Algebras are a subset of the class of Turing Machines? Dear Ben, So then it is: Boolean Algebras /equivalent Turing Machines in the mathematical sense. I am asking this to try to understand how Bruno has a problem with BOTH comp AND the existence of a stuffy substancial universe. It seems to me that the term machine very much requires some kind of stuffy substancial universe to exist in, even one that is in thermodynamic equilibrium. I fail to see how we can reduce physicality to psychology all the while ignoring the need to actually implement the abstract notion of Comp. I really would like to understand this! Sets of zero information fail to explain how we have actual experiences of worlds that are stuffy substancial ones. It might help if we had a COMP version of inertia! Kindest regards, Stephen - Original Message - From: Ben Goertzel [EMAIL PROTECTED] To: Stephen Paul King [EMAIL PROTECTED]; [EMAIL PROTECTED] Sent: Tuesday, November 26, 2002 12:49 PM Subject: RE: The class of Boolean Algebras are a subset of the class of Turing Machines? The statement Boolean Algebras are a subset of the class of Turing Machines doesn't seem quite right to me, I guess there's some kind of logical typing involved there. A Turing machine is a kind of machine [albeit mathematically modeled], whereas a boolean algebra is an algebra. Boolean algebra is a mathematical framework that is sufficient to model/design the internals of Turing machines... In a conceptual sense, they're equivalent ... -- Ben -Original Message- From: Stephen Paul King [mailto:[EMAIL PROTECTED]] Sent: Tuesday, November 26, 2002 12:29 PM To: Ben Goertzel; [EMAIL PROTECTED] Subject: The class of Boolean Algebras are a subset of the class of Turing Machines? Dear Ben, So you are writing that the class of Boolean Algebras are a subset of the class of Turing Machines? Kindest regards, Stephen - Original Message - From: Ben Goertzel [EMAIL PROTECTED] To: Stephen Paul King [EMAIL PROTECTED]; [EMAIL PROTECTED] Sent: Tuesday, November 26, 2002 9:58 AM Subject: RE: turing machines = boolean algebras ? Essentially, you can consider a classic Turing machine to consist of a data/input/output tape, and a program consisting of -- elementary tape operations -- boolean operations I.e. a Turing machine program is a tape plus a program expressed in a Boolean algebra that includes some tape-control primitives. -- Ben G -Original Message- From: Stephen Paul King [mailto:[EMAIL PROTECTED]] Sent: Tuesday, November 26, 2002 9:25 AM To: [EMAIL PROTECTED] Subject: Re: turing machines = boolean algebras ? Dear Ben and Bruno, Your discussions are fascinating! I have one related and pehaps even trivial question: What is the relationship between the class of Turing Machines and the class of Boolean Algebras? Is one a subset of the other? Kindest regards, Stephen
RE: Re: The number 8. A TOE?
Bruno wrote: *** Let me insist because some people seem not yet grasping fully that idea. In fact that 1/3-distinction makes COMP incompatible with the thesis that the universe is a machine. If I am a machine then the universe cannot be a machine. No machine can simulate the comp first person indeterminacy. This shows that the Wolfram-Petrov-Suze-... thesis is just inconsistent. If the universe is a (digital) machine then there is level of description of myself such that I am a machine (= I am turing-emulable, = comp), but then my most probable neighborhood is given by a sum over all computational histories going through my possible states, and by godel (but see also the thought experiments) that leads to extract the probable neighborhood from a non computable domain, in a non computable way. In short WOLFRAM implies COMP, but COMP implies NOT WOLFRAM(*). So WOLFRAM implies NOT WOLFRAM, so NOT WOLFRAM. Eventually physics will be reduced into machine's machine psychology. If octonion play a fundamental role in physics, it means, with comp, that octonions will play a fundamental role in psychology. *** Unfortunately, I do not follow your argument in spite of some significant effort. When you say sum over all computational histories, what if we just fix a bound N, and then say sum over all computational histories of algorithmic info. content = N. Finite-information-content-universe, no Godel problems. So what's the issue? *** And, dear Ben, I should still read how you link octonions and the deep aspect, as you say, of the mind. BTW, I would be also glad if you could explain or give a rough idea how quaternions play a role in the mondane aspect of the mind, as you pretend in one of your paper, if you have the time. *** I'll address this in a later post, unfortunately I have to catch a plane and don't have time at the moment ben
RE: Re: The number 8. A TOE?
Regarding octonions, sedenions and physics Tony Smith has a huge amount of pertinent ideas on his website, e.g. http://www.innerx.net/personal/tsmith/QOphys.html http://www.innerx.net/personal/tsmith/d4d5e6hist.html His ideas are colorful and speculative, but also deep and interesting. One could spend a very long time soaking up all the ideas on the site. By the way, Tony is a very nice guy, who did a postdoc under Finkelstein (of quantum set theory fame) and earns his living as a criminal-law attorney. I spent some time a few years back trying to create a novel physics theory based on discrete Clifford algebras, which relate closely to quaternions and octonions. My effort was unfinished, and I turned my attention to other types of science, but some of my notes are at: http://www.goertzel.org/papers/main.htm (scroll to the bottom to see a list of documents under the heading Some Incomplete Speculations on the Foundations of Physics -- Ben Goertzel
JOINING post
Hi all, I'm Ben Goertzel. This is my initial joining post I'm a math PhD originally, spent 8 years as an academic in math, CS and psych departments. Have been in the software industry for the last 5 years. My primary research is in Artificial General Intelligence (see www.realai.net) -- my friends and I are building a genuinely intelligent software program, a multi-year project that's been going on for some time. Am also working in bioinformatics, analyzing gene expression data Before building a thinking machine became an almost all-consuming obsession, I spent some time trying to create a unified physics theory. It was to be a discrete theory based on the discrete Clifford algebra the Cayley algebra. I'm also interested in the physics applications of the notion of mind creating reality while reality creates mind (John Wheeler and all that...). I studied quantum gravity, chromodynamics, string theory and lots of other fun stuff in the late 80's and early 90's, but haven't really kept current with technical physics, and all that stuff is pretty rusty for me now, but I still find it fascinating... Ben Goertzel www.goertzel.org/work.html
