Re: Request for a glossary of acronyms
At 20:17 03/02/04 -0500, Jesse Mazer wrote: Personally, I would prefer to assign a deeper significance to the notion of absolute probability, since for me the fact that I find myself to be a human rather than one of the vastly more numerous but less intelligent other animals seems like an observation that cries out for some kind of explanation. I am not sure about that. Suppose a teacher has 10^1000 students. Today he says to the students that he will, tomorrow, interrogate one student of the class and he will chooses it randomly. Each student thinks that there is only 1/(10^1000) chance that he will be interrogated. That's quite negligible, and (assuming that all student are lazy) none of the students prepare the interrogation. But then the day after the teacher says: Smith, come on to the board, I will interrogate you. I hope you agree there has been no miracle here, even if for the student, being the one interrogated is a sort of (1-person) miracle. No doubt that this student could cry out for an explanation, but we know there is no explanations... Suppose the teacher and the student are immortal and the teacher interrogates one student each day. Eternity is very long, and there will be arbitrarily large period where poor student Smith will be interrogated each days of that period. Obviously Smith will believe that the teacher has something special against him/her. But still we know it is not the case ... So I don't think apparent low probability forces us to search for an explanation especially in an everything context, only the relative probability of continuation could make sense, or ab initio absolute probabilities could perhaps be given for the entire histories. But I think this is more of a philosophical difference, so that even if an ultimate TOE was discovered that gave unique absolute and conditional probabilities to each observer-moment, people could still differ on the interpretation of those absolute probabilities. I am not yet sure I can make sense of them. I think also that your view on RSSA is not only compatible with the sort of approach I have developed, but is coherent with Saibal Mitra backtracking, which, at first I have taken as wishful thinking. What is the backtracking idea you're referring to here? That if you put the probabilities on the infinite stories, any finite story will be of measure null, so that if an accident happens to you, and make you dead (in some absolute sense), you will never live that accident, nor the events leading to that accident: from a 3-person pov it is like there has been some backtracking, but it's seems linear from a 1-pov. (pov = point of view) OK you make me feel COMP could be a little less frightening I'm use to think. Well, if I've spared you some sleepless nights I'm glad! ;) Thanks. Concerning consciousness theory and its use to isolate a similarity relation on the computational histories---as seen from some first person point of view, I will try to answer asap in a common answer to Stephen and Stathis (and you) who asked very related questions. Alas I have not really the time now---I would also like to find a way to explain the consciousness theory without relying too much on mathematical logic, but the similarity between 1-histories *has* been derived technically in the part of the theory which is the most counter-intuitive ... mmh I will try soon ... Yes, I definitely hope to understand the details of your theory someday, I think I will need to learn some more math to really follow it well though. My current self-study project is to try to learn the basic mathematical details of quantum computation and the many-worlds interpretation, It seems a good plan. but after that maybe I'll try to study up a bit on mathematical logic and recursive function theory. And even if I do, there's the little problem of my not knowing French, but I'll cross that bridge when I come to it... Nice, you will be able to read the long version of my thesis ... It's almost self-contained. In logic it is only the beginning which is hard, really. Nevertheless I will try to explain the consciousness theory and the minimal amount of logic needed. The fact is that it is easy to be wrong with self-applied probability, and using logic, it is possible to derive the logic of [probability one] quasi-directly from the (counter-intuitive) godelian logic of self-reference. There are already evidence that we get sort of quantum logic for those probability one. I'm really searching how to justify the wavy aspect of nature. Bruno
Re: Request for a glossary of acronyms
- Original Message - From: Jesse Mazer [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Thursday, February 05, 2004 12:19 AM Subject: Re: Request for a glossary of acronyms Saibal Mitra wrote: This means that the relative measure is completely fixed by the absolute measure. Also the relative measure is no longer defined when probabilities are not conserved (e.g. when the observer may not survive an experiment as in quantum suicide). I don't see why you need a theory of consciousness. The theory of consciousness is needed because I think the conditional probability of observer-moment A experiencing observer-moment B next should be based on something like the similarity of the two, along with the absolute probability of B. This would provide reason to expect that my next moment will probably have most of the same memories, personality, etc. as my current one, instead of having my subjective experience flit about between radically different observer-moments. Such questions can also be addressed using only an absolute measure. So, why doesn't my subjective experience ''flit about between radically different observer-moments''? Could I tell if it did? No! All I can know about are memories stored in my brain about my ''previous'' experiences. Those memories of ''previous'' experiences are part of the current experience. An observer-moment thus contains other ''previous'' observer moments that are consistent with it. Therefore all one needs to show is that the absolute measure assigns a low probability to observer-moments that contain inconsistent observer-moments. As for probabilities not being conserved, what do you mean by that? I am assuming that the sum of all the conditional probabilities between A and all possible next observer-moments is 1, which is based on the quantum immortality idea that my experience will never completely end, that I will always have some kind of next experience (although there is some small probability it will be very different from my current one). I don't believe in the quantum immortality idea. In fact, this idea arises if one assumes a fundamental conditional probability. I believe that everything should follow from an absolute measure. From this quantity one should derive an effective conditional probability. This probability will no longer be well defined in some extreme cases, like in case of quantum suicide experiments. By probabilities being conserved, I mean your condition that ''the sum of all the conditional probabilities between A and all possible next observer-moments is 1'' should hold for the effective conditional probability. In case of quantum suicide or amnesia (see below) this does not hold. Finally, as for your statement that the relative measure is completely fixed by the absolute measure I think you're wrong on that, or maybe you were misunderstanding the condition I was describing in that post. I agree with you. I was wrong to say that it is completely fixed. There is some freedom left to define it. However, in a theory in which everything follows from the absolute measure, I would say that it can't be anything else than P(S'|S)=P(S')/P(S) Imagine the multiverse contained only three distinct possible observer-moments, A, B, and C. Let's represent the absolute probability of A as P(A), and the conditional probability of A's next experience being B as P(B|A). In that case, the condition I was describing would amount to the following: P(A|A)*P(A) + P(A|B)*P(B) + P(A|C)*P(C) = P(A) P(B|A)*P(A) + P(B|B)*P(B) + P(B|C)*P(C) = P(B) P(C|A)*P(A) + P(C|B)*P(B) + P(C|C)*P(C) = P(C) And of course, since these are supposed to be probabilities we should also have the condition P(A) + P(B) + P(C) = 1, P(A|A) + P(B|A) + P(C|A) = 1 (A must have *some* next experience with probability 1), P(A|B) + P(B|B) + P(C|B) = 1 (same goes for B), P(A|C) + P(B|C) + P(C|C) = 1 (same goes for C). These last 3 conditions allow you to reduce the number of unknown conditional probabilities (for example, P(A|A) can be replaced by (1 - P(B|A) - P(C|A)), but you're still left with only three equations and six distinct conditional probabilities which are unknown, so knowing the values of the absolute probabilities should not uniquely determine the conditional probabilities. Agreed. The reverse is true. From the above equations, interpreting the conditional probabilities P(i|j) as a matrix, the absolute probability is the right eigenvector corresponding to eigenvalue 1. Let P(S) denote the probability that an observer finds itself in state S. Now S has to contain everything that the observer knows, including who he is and all previous observations he remembers making. The ''conditional'' probability that ''this'' observer will finds himself in state S' given that he was in state S an hour ago is simply P(S')/P(S). This won't work--plugging into the first equation above, you'd get (P(A)/P(A)) * P(A) + (P(B)/P(A)) * P(B)
Re: More on qualia of consciousness and occam's razor
On Tue, Feb 03, 2004 at 02:55:53PM -0800, Pete Carlton wrote: But even this goes way out in front of what we can possibly know. You say we have no idea what these feelings are like to experience--but why should we assume we even are entitled to ask this question? Here's my basic philosophy: we're entitled to ask any question whose answer is relevant to making a decision. As far as qualia is concerned, consider this thought experiment: Two subjects labeled A and B and placed in separate rooms. They're each given a button and told to choose between pushing it and not pushing it. If subject A pushes the button, he is rewarded. If subject B doesn't push the button, he is rewarded. While they consider their choices, they're both given a real-time high-resolution brain scan of subject A. So if they can answer the question is the person being scanned having the same subjective experiences that I am having? then they can both obtain the rewards for sure, otherwise they can only choose blindly. Does this convince you that it makes sense to ask what other people experience?
Fw: NKSwire -- News about A New Kind of Science
February 2004 The complete NKS book is now available online, with full text, images, 30,000+ links and more... http://www.wolframscience.com/nksonline
Re: More on qualia of consciousness and occam's razor
Wei Dai asks: Does this convince you that it makes sense to ask what other people experience? Nobody KNOWS what other people experience. We can KNOW only what other people communicate about their experience. Just as: our experience is a first person secret, even we ourselves don't 'know' it, only in an 'adjusted' (interpreted) format of our mindwork, which we may communicate(?) to others. Such communication can be quite straightforward, or adjusted to our communicational purposes, as the case may be. My answer to your question (to Pete): Yes, it makes sense to ask, prepared for a thorough re-thinking for such (multiple?) transmutations. So the reasonable question may be: to ask what other people may communicate about their experience. That stands also for computersG. Regards John Mikes - Original Message - From: Wei Dai [EMAIL PROTECTED] To: Pete Carlton [EMAIL PROTECTED] Cc: Stathis Papaioannou [EMAIL PROTECTED]; [EMAIL PROTECTED]; [EMAIL PROTECTED] Sent: Friday, February 06, 2004 9:57 AM Subject: Re: More on qualia of consciousness and occam's razor On Tue, Feb 03, 2004 at 02:55:53PM -0800, Pete Carlton wrote: But even this goes way out in front of what we can possibly know. You say we have no idea what these feelings are like to experience--but why should we assume we even are entitled to ask this question? Here's my basic philosophy: we're entitled to ask any question whose answer is relevant to making a decision. As far as qualia is concerned, consider this thought experiment: Two subjects labeled A and B and placed in separate rooms. They're each given a button and told to choose between pushing it and not pushing it. If subject A pushes the button, he is rewarded. If subject B doesn't push the button, he is rewarded. While they consider their choices, they're both given a real-time high-resolution brain scan of subject A. So if they can answer the question is the person being scanned having the same subjective experiences that I am having? then they can both obtain the rewards for sure, otherwise they can only choose blindly. Does this convince you that it makes sense to ask what other people experience?
Re: measure and observer moments
Given temporal proximity of two states (e.g. observer-moments), increasing difference between the states will lead to dramatically lower measure/probability for the co-occurrence as observer-moments of the same observer (or co-occurrence in the same universe, is that maybe equivalent?) . When I say two states S1, S4 are more different from each other whereas states S1,S2 are less different from each other, I mean that a complete (and yet fully abstracted i.e. fully informationally compressed) informational representation of the state (e.g. RS1) shares more identical (equivalent) information with RS2 than it does with RS4. This tells us something about what time IS. It's a dimension in which more (non-time) difference between co-universe-inhabiting states can occur with a particular probability (absolute measure) as the states get further from each other in the time of their occurrence. Things (states) which were (nearly) the same can only become more different from each other (or their follow-on most-similar states can anyway) with the passage of time (OR with lower probability in a shorter time.) Maybe? Eric Saibal Mitra wrote: - Original Message - From: Jesse Mazer [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Thursday, February 05, 2004 12:19 AM Subject: Re: Request for a glossary of acronyms Saibal Mitra wrote: This means that the relative measure is completely fixed by the absolute measure. Also the relative measure is no longer defined when probabilities are not conserved (e.g. when the observer may not survive an experiment as in quantum suicide). I don't see why you need a theory of consciousness. The theory of consciousness is needed because I think the conditional probability of observer-moment A experiencing observer-moment B next should be based on something like the "similarity" of the two, along with the absolute probability of B. This would provide reason to expect that my next moment will probably have most of the same memories, personality, etc. as my current one, instead of having my subjective experience flit about between radically different observer-moments. Such questions can also be addressed using only an absolute measure. So, why doesn't my subjective experience ''flit about between radically different observer-moments''? Could I tell if it did? No! All I can know about are memories stored in my brain about my ''previous'' experiences. Those memories of ''previous'' experiences are part of the current experience. An observer-moment thus contains other ''previous'' observer moments that are consistent with it. Therefore all one needs to show is that the absolute measure assigns a low probability to observer-moments that contain inconsistent observer-moments. As for probabilities not being conserved, what do you mean by that? I am assuming that the sum of all the conditional probabilities between A and all possible "next" observer-moments is 1, which is based on the quantum immortality idea that my experience will never completely end, that I will always have some kind of next experience (although there is some small probability it will be very different from my current one). I don't believe in the quantum immortality idea. In fact, this idea arises if one assumes a fundamental conditional probability. I believe that everything should follow from an absolute measure. From this quantity one should derive an effective conditional probability. This probability will no longer be well defined in some extreme cases, like in case of quantum suicide experiments. By probabilities being conserved, I mean your condition that ''the sum of all the conditional probabilities between A and all possible "next" observer-moments is 1'' should hold for the effective conditional probability. In case of quantum suicide or amnesia (see below) this does not hold. Finally, as for your statement that "the relative measure is completely fixed by the absolute measure" I think you're wrong on that, or maybe you were misunderstanding the condition I was describing in that post. I agree with you. I was wrong to say that it is completely fixed. There is some freedom left to define it. However, in a theory in which everything follows from the absolute measure, I would say that it can't be anything else than P(S'|S)=P(S')/P(S) Imagine the multiverse contained only three distinct possible observer-moments, A, B, and C. Let's represent the absolute probability of A as P(A), and the conditional probability of A's next experience being B as P(B|A). In that case, the condition I was describing would amount to the following: P(A|A)*P(A) + P(A|B)*P(B) + P(A|C)*P(C) = P(A) P(B|A)*P(A) + P(B|B)*P(B) + P(B|C)*P(C) = P(B) P(C|A)*P(A) +
Physicists attack cosmological model
-- News Physicists attack cosmological model (Feb 6) http://physicsweb.org/article/news/8/2/4 Many astronomers believe that the universe is dominated by cold 'dark matter' and 'dark energy' - a view that has been confirmed by recent measurements on the cosmic background radiation. Now, however, a group of astrophysicists in the UK has found that this radiation - the microwave 'echo' of the big bang - may in fact have been modified or `corrupted' as it passed through galaxy clusters on its way to Earth. The result could undermine previous evidence for both dark matter and energy (Monthly Notices of the Royal Astronomical Society 347 L67; arxiv.org/abs/astro-ph/0306180)
