Re: another puzzzle
On 6/17/05, Stathis Papaioannou [EMAIL PROTECTED] wrote: You find yourself in a locked room with no windows, and no memory of how you got there. (...) a light (...) alternates between red and green every 10 minutes. (...) Every 10 minutes, the system alternates between two states. One state consists of you alone in your room. The other state consists of 10^100 exact copies of you, their minds perfectly synchronised with your mind, each copy isolated from all the others in a room just like yours. Your task is to guess which colour of the light corresponds with which state and write it down. Then God will send you home. (...) But just as you are about to write down your conclusion, the light changes to green... What's wrong with the reasoning here? To make the story more visualisable, imagine that God throws a coin (since he doesn't play dice) to decide whether he will initialise the system in state A (one person) or B (many). We can imagine that at this point the universe is split in two, and in universe 1 there are many people in the room, while in universe 2 there is only one. After ten minutes, God switches the state of *both* universes. In universe 1 there is now one person in the room, while in universe 2 there are many, most of which with a false memory of being there for more than 10 minutes. This happens for a while before the people in the rooms start to learn about the experiment and God's game. But you can convince yourself that it doesn't matter much what was the initial state and how many times the light has switched; if you believe God's story, the most likely is that you have just been created after the last switch, and you have a false memory of being there for a while. Eric.
Re: another puzzzle
On 6/23/05, Stathis Papaioannou [EMAIL PROTECTED] wrote: Eric Cavalcanti writes: I don't think it is that good an analogy for the following reason: I don't believe that pushing a button to create a copy of me in New York will increase my expectation of experiencing New York, while I believe that flipping a coin to decide whether I'll take a plane to New York does. The latter case you could describe in terms of a splitting of the muiltiverse in two universes: one in which I go to New York and one in which I don't. The former I would represent in terms of a single universe where I will not experience New York, but only a copy of me will. I think there is something fundamental about the fact that the copies can meet *in principle*. It doesn't matter how hard it is, how far away you put them, or how controlled you do it. All it matters for me is that they could, in principle, communicate. In this case I don't believe I could have a first person expectation of being in New York. Eric2 finds himself in New York: E2- Wow! It worked after all! I really am in New York! E1- You might be in New York, but I haven't gone anywhere, and I'm the original. E2- How can you demonstrate that you have any more claim to being Eric than I have? I know everything Eric knows, I look like Eric, I certainly feel 100% certain that I'm Eric; what else could I possibly do to convince you than that? E1- But you materialised out of thin air [or whatever copies materialise out of], whereas nothing happened to me, I'm still here where I was. So obviously I'm the original! E2- None of that proves that you have any more claim to being Eric than I am, even if you could somehow show you were the original and I a copy. However, I have some information that might interest you. The people who set up this duplication procedure have not been entirely honest with you. When the original Eric pushed that button, a copy was created, but locally rather than in New York. In fact, the copy was created in a room exactly like the one you are in now. Then, the original Eric flew to New York in the normal way. So you see, I'm the original and you are the copy! E1- But that's ridiculous! I feel *exactly* the same as I did before pressing that button; nothing at all happened to *me*, so I have to be the original! E2- So how do you think you should have felt if you were the copy? That's the whole idea of a functionally identical copy: no-one, neither the copy nor anyone else, can tell that there is any difference. And anyway, it happens to us all the time even without duplicating machines. Almost all the atoms in our body are replaced over the course of months or years. It happens gradually, but if it happened quickly, the effect would be that you would completely disintegrate and be replaced by a near-identical copy who thinks he is you, remembers everything you remember, etc. How is that any different to what has just happened to us? E1- For one thing, that would be different because there is only one Eric extant at any one time. E2- Which would have been the case if we were using destructive teleportation, where the original is destroyed in the process of scanning it. But you're being a bit inconsistent, aren't you? You're saying that if the original were destroyed and replaced with a copy, as happens in the course of life over time, then the copy would have the right to call himself the original; whereas if the original were not destroyed, the copy would not be the original. And yet in both cases the copy would be exactly the same. E1- I don't know about the same; I might feel more at ease if you weren't around... E2- Oh! So now you admit that you're the copy! [and we could go on like this for quite a while, with no resolution to the problem...] Yep, it's a hard problem, and I heard that line of argumentation hundreds of times. But I am still not convinced that the mere fact that someone scans me would increase my expectation of having a discontinuity of experience. I agree that the dialogue above would happen (or not exactly, because Eric wouldn't believe that destructive teleportation is teleportation at all. He would say that it is homicide followed by duplication. In fact, I believe that in your example Eric the copy would probably agree that he is a copy after seing evidence of that, and would live with his life without claiming the rights of the original. That would make him very unhappy and confused, of course, and then Eric the original would pity him and help him as he would help a twin brother. Furthermore, there is always some way to tell the difference between the copy and the original, in principle, even if that infomation is not epistemologically available to the subjects themselves. If the original flew to New York, then he would have interacted with the environment in a completely different way than if he stayed in the room
More about identity (was Re: Torture yet again)
I can see an interesting new problem in this thread. Let me put it in a thought experiment as the praxis in this list requires. You are in the same torture room as before, but now the guy is going to torture you to death. You have three options: A: you flip a coin to decide whether you are going to be tortured; B: you press the copy button 100 times; C: you press the copy button once. What do the people in this list choose? For some people, creating copies increases their 1st person probability of escaping torture. So that at each time they press the button they can associate with that a 50% probability of escape. These would choose B, since then they would have a very near certainty of escaping torture. For others, creating copies does not increase any such probability, and there is ultimately no meaning in talking about 1st person probability. But for some reason they seem to feel a strong connection with the copies, as if they are all the same person. They think it is just as good to offer a good meal to the copies as it is to offer it for themselves. These people should choose C, since in this case they will be comforted by the fact that a copy of themselves would survive and have a good life. They don't really need more than one. Actually, one is much better than many, since they wouldn't have the legal and financial problems associated with having lots of copies around. For others, as myself, creating copies does not increase my 1st person probability of escaping torture. And differently from Lee, I think it is just as good to offer a good meal to my copy as it is to offer it to my family and friends. But it is definitely different from offering it to me. These people would choose A. I cannot really understand choice B. Would anyone really choose that or am I just grossly misunderstanding some opinions in this list? About choice B, it raises other interesting questions: suppose you know that the copies are going to undergo some sort of plastic surgery a week or so after the experiment, and will look very different from yourself now. They could also undergo some type of slow personality modification (as education), such that they would at any moment agree that they are experiencing a continuity of identity. Would you still choose B? What if this change really isn't slow, but sudden, at the time of creation of the copy? Does it make a difference? Then what is the difference between doing a copy of yourself or a copy of someone else, since any two people could be connected by a series of continuous transformations? Would you still be comforted by the fact that someone, even if very different from you, would be created to replace you? Eric
Fwd: another puzzzle
On 6/27/05, Stathis Papaioannou [EMAIL PROTECTED] wrote: Sorry for going on about this, but I'm still trying to understand: what possible difference could it make to anyone - you or your copy - if you suddenly disintegrated and were replaced a microsecond later with an exact copy? To understand my point of view you need to stop thinking in pure physicalist terms. Imagine that your consciousness is fundamental. You are defined by your experiences, not by the pattern of matter that your body is composed of. Your experiences seem to obey a given set of restrictions, such as those that we identify as laws of physics. Apart from the fact that you have experiences, be agnostic to any other proposition, including the one that there is a physical objective world. Note that I didn't say deny any proposition. The best analogy is to imagine that you are in a game, as the example I used before. The game feeds experiences into your brain, if you like. These experiences obey certain rules that were defined by the programmer. In the case of the thought experiment described before, where you press the button to create a copy, your next experience will be whatever the programmer decided it would be. He could have made the program in such a way that you would experience one of the two with 50% probability, or he could have made the program such that you always experience being in the same place. The only way to know is to try it. I believe that in this particular case I will always experience to be the same, but of course that is just my intuition. Now imagine that other people are playing the game , and they watch you doing the experiment. They can never know whether you are now experiencing to be the copy or still the original, since that information is not available within the game. Of course, that is a dualist view of the world, which takes consciousness as something fundamental. If you don't believe that consciousness plays any fundamental role in the universe, then to be consistent you should say that there is no meaning to attach a probability to what is your next experience at all, since the question is meaningless from a physicalist perspective. Lee Corbin, for example, has a consistent set of beliefs about this (even though I don't agree with him). How would this in any way be different if you didn't disintegrate, but passed from one moment to the next as per usual? My view is that, as a matter of fact, we do die every moment only to be replaced by a copy, since to be one and the same at different times is physically impossible; at the very least, the atoms comprising our body have different spacetime coordinates. Suppose that this were actually scientifically confirmed: every microsecond, every human being disintegrates and is replaced within a femtosecond by an exact copy, and this has been occurring for as long as the human species has been around, and will continue to occur. If you still felt in the light of this knowledge that copies are not the same as the original in some important but ineffable sense, would you go about your life any differently, or even worry about it, given that the creation/destruction cycle is far shorter than the time it would take to even form a worry in your mind? Surely not. As I tried to argue before, there is a huge difference between making a copy without in any way affecting the original, and continuously changing the original. In the former case, there are two asymmetrical copies. One is a continuous evolution of the original, while the other has been created moments ago from raw materials. The copy will have a discontinuity of experience. There is no a priori reason to assign a 50/50 probability in this case. In fact, consider the following problems; 1. You are scanned to be copied, but no copy is made. Your data is saved in a hard drive, and it could be used to create copies of you in any time during the next millions of years. If you believe MWI, if it can be used, it will. So the measure of being a copy could be much larger than the measure of being the original, and simply because you were scanned you have a negligible probability to experience to be in the same place anymore. Of course, this invokes the problem of how to measure the thickness of each copy's world, which I didn't see any satisfactory answer yet. 2. When you are scanned, how fast does the scan need to be to count as a copy? The scan cannot be instantaneous. The final copy will then be a rough smeared-out description of my body during a certain interval of time. Will I experience to be the copy (if that is possible) soon after the scan is started or soon after it is finished? What if the scan is made long enough to take more than a moment of thought so that I can experience the slow process of being copied? At which point will I stop experiencing this process and start experincing to be the copy? 3. Of course, the copy is never perfectly identical to the original. How is the
Re: QM formalist wanted
On 7/5/05, [EMAIL PROTECTED] [EMAIL PROTECTED] wrote: hi all. I am posting a want ad for a QM formalist who is very conversant in the mathematical formalism. here is the proposal: over the last few years I have developed an ad hoc theory that I believe comes very close to the QM formalism. this theory is classical local. it is very easily visualized the mathematics How do you overcome the fact that local realistic theories are shown not to be able to reproduce the predictions of QM? Or is this what you mean by very close? Without entanglement, I'd say that it's not close enough. In fact, it has been shown already that one can derive many of the counterintuitive features of QM from a classical description. Eric.
Modal Logic
Hi Bruno, On 8/11/05, Bruno Marchal [EMAIL PROTECTED] wrote: I am having a problem understanding this axiom: (...) Lob formula (B(Bp-p)-Bp), the main axiom of the modal logic of self-reference (G) can be interpreted as showing that some form of honest placebo effect works! But this is something I am still taking with some grain of salt. See the book Forever Undecided to see Smullyan exploiting the working of some self-fulfilling beliefs. Suppose p = it is raining today B(Bp-p) is true because I believe that if I believe it is raining today it IS raining today, since If I believe it is raining today it is because I have gone outside and seen that it is raining today, or I believe my source of information for that matter. But it doesn't follow from that that I do believe that it is raining today. It happens by the way that I don't believe it is raining today, because I can see a beutiful sun outside. What's wrong? Eric.
Fwd: Modal Logic
-- Forwarded message -- From: Eric Cavalcanti [EMAIL PROTECTED] Date: Aug 13, 2005 4:38 PM Subject: Re: Modal Logic To: Bruno Marchal [EMAIL PROTECTED] Hi Bruno, On 8/13/05, Bruno Marchal [EMAIL PROTECTED] wrote: Hi Eric, I am having a problem understanding this axiom: (...) Lob formula (B(Bp-p)-Bp), the main axiom of the modal logic Suppose p = it is raining today B(Bp-p) is true because I believe that if I believe it is raining today it IS raining today, since If I believe it is raining today it is because I have gone outside and seen that it is raining today, or I believe my source of information for that matter. But it doesn't follow from that that I do believe that it is raining today. It happens by the way that I don't believe it is raining today, because I can see a beutiful sun outside. What's wrong? Literaly, it means you are less modest than a Lobian machine! If B(Bp - p) was true, it would mean that whatever the poof you have that p is true, then p is true. What about dreaming that you have look through the window and see it rains? OK, I grant that I might have false beliefs. In fact, I strongly believe that I do have many false beliefs. (Remember B is not the incorrigible first person. B is really for a scientific third person sharable justification). Of course it makes things still more unbelievable, given that you will tell me that in case you have a proof, it is even more amazing you can be wrong. But then it is like that by incompleteness. OK, so we shouldn't read Bx as I believe x, but as It is believable that x. Is that right? But B(Bp - p) is very different from Bp - p. The first is It is believable that p is believable only if p is true. The second is It is believable that p only if p is true. But if we are talking about third person justifiable beliefs, how can we ever say B(Bp-p) is true? Couldn't we always be sceptical about the truth of any belief? Can you give a particular example of a sentence p such that B(Bp-p) is true? Eric.
Re: Modal Logic
Hi Bruno, Can you give a particular example of a sentence p such that B(Bp-p) is true? Take any proposition you can prove, for example the tautology (p - p), or t. (...) So once you have prove t, all the proposition of the shape anyproposition - t is easily deducible, by applying modus ponens and the a fortiori axiom. In particular Bt - t is justified. And thus B(Bt - t) is true. (or, by necessitation B(Bt - t) follows). So an example of such a p making B(Bp - p) true, is p = t. But then any proposition of the form B(q-p)-Bp would be true as well. Why is that not an axiom? Further, by your explanation above it seems that the axiom should be more like Bp-B(q-p). Since as I understood it, if you can justify p, then you can justify any sentence of the form q-p. On the other direction, suppose it is justifiable that ~p. That is, B(~p) and I suppose ~Bp with the excluded middle. So it is true that Bp-q for any q, and in particular for q=p. So B(Bp-p). But Bp is false by assumption so B(Bp-p)-Bp is false. What's wrong? Eric.
JOINING post
Hi, My name is Eric Cavalcanti, and I am joining this list. As was solicited in the website, I am sending this Joining post with details of my background. I am a physicist, recently received my MSc in atomic physics. I have been participating in the Fabric of Reality list for some time, so I have some familiarity (but no extensive knowledge) with some of the topics discussed in this list... Seems the discussions here are also very interesting. Regards, -Eric.
Re: Quantum accident survivor
Hi, Sorry for the late reply to this: From: Hal Finney [EMAIL PROTECTED] You can assume anything you like! Seriously, we have had extensive and occasionally acrimonious debates on this topic in the past, without much success or resolution. I think that we have no good foundation for establishing the truth or falsehood of any theory of identity in absolute terms. Instead, these issues must be considered matters of taste. You can indeed choose to believe that as long as any version of yourself continues in any universe, then you will consider yourself to still be alive. You could also choose the contrary, that if the total measure (ie. probability) of your survival is extremely small, that you are dead. Hal Finney - Original Message - From: Frank [EMAIL PROTECTED] Hi there, Hal, one nitpick about your comments: In the case of Quantum Immortality, I don't think it's a matter of taste, or interpretation. It is a theory that every one of us can and ultimately will test. Granted, we will only be aware of a positive result, but, nevertheless... cheers, Frank I agree with you. The QTI is after all experimentally testable, and of direct importance for all of us. But I guess the problems in this discussion is the lack of precise definition of the terms and of the philosophical framework. First, in this discussion I am always assuming MWI. In a materialistic framework - with nothing external to the physical world - it is hard to define personal identity if we take the MWI in account. But in this case there is clearly no 'soul' or anything other than the configuration of atoms to describe what we call 'ourselves'. In any branching of the multiverse there are multiple copies of my body being produced. Nevertheless, I only experience one of those states. Therefore, I guess the best I could say is that ' I ' is one of the instances of this configuration. Let me stress this point: *I am, for all practical purposes, one and only one specific configuration of atoms in a specific universe. I could never say that ' I ' is ALL the copies, since I NEVER experience what the other copies experience. The other copies are just similar configurations of atoms in other universes, which shared the same history, prior to a given point in time.* In some of these branching universes, this configuration of atoms that I call 'me' will not show signs of what we call life anymore. Notice that death is no different from any other branching in the multiverse in a materialistic point of view. There is no 'soul' being detached from the body or anything else. So there is no reason to suppose that my personal experiences will not be, as before, one of any of the future configurations of these atoms that I call 'me', including those where this configuration is a 'dead' state. In particular, after a severe car crash, most of these will be dead. Notice again that 'dead' has, in this paradigm, no supernatural meaning, it means nothing more than 'that body does not show vital functions anymore'. In particular, that body has no sensorial experiences anymore. But there is yet no reason to suppose that I cannot be one of those bodies. Therefore, in this framework, in the case of a severe car crash, the probability that I have no more future sensorial experiences - i.e., that I am dead for good (or bad?) - is simply the measure of universes where my body is dead. When some people suppose that our next experience is necessarily one of the alive ones, they are tacitly assuming a dualistic position. But if we decide to accept a dualistic framework QTI would probably be the least probable scenario. We could as well say that the next experience would be of many other kinds: in other bodies, reincarnation, or any transcedental experience like going to heaven - there is no reason to decide between these. For instance, QTI poses a difficulty for the dualist: at each moment, if QTI and is true, an infinity of 'souls' is merging into one single body, since this body is dying at an infinity of other universes. How does this square with the common definition of a 'soul' as an immaterial *individuality*? -Eric.
Re: Quantum accident survivor
What do you mean by *entirely equal*? - Original Message - From: David Kwinter [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Thursday, November 06, 2003 5:19 AM Subject: Re: Quantum accident survivor On Tuesday, November 4, 2003, at 10:47 AM, Eric Cavalcanti wrote: Let me stress this point: *I am, for all practical purposes, one and only one specific configuration of atoms in a specific universe. I could never say that ' I ' is ALL the copies, since I NEVER experience what the other copies experience. The other copies are just similar configurations of atoms in other universes, which shared the same history, prior to a given point in time.* I would consider these other copies entirely equal to myself IF AND ONLY IF they are succeeding RSSA observer-moments. Glossary references : ) RSSA - The Relative Self-Sampling Assumption, which says that you should consider your next observer-moment to be randomly sampled from among all observer-moments which come immediately after your current observer-moment and belong to the same observer.
Re: Request for a glossary of acronyms
Also, what about a weighted version of the ASSA? I believe other animals are conscious and thus would qualify as observers/observer-moments, which would suggest I am extraordinarily lucky to find myself as an observer-moment of what seems like the most intelligent species on the planet...but could there be an element of the anthropic principle here? Perhaps some kind of theory of consciousness would assign something like a mental complexity to different observer-moments, and the self-sampling assumption could be biased in favor of more complex minds. I think the anthropic principle could be used quite well to account for that, since if you were an animal other than a human being, you could not be asking that question. But I don't see the need nor the basis to assign any sort of weight to the 'selection' of different observers, just as there is no weight (other than the anthropic principle) to account for the fact that we live in this particular universe which allows for human beings. -Eric.
Fw: Quantum accident survivor
Hi, - Original Message - From: David Kwinter [EMAIL PROTECTED] I mean the absolutely exact same David Kwinter or Eric Cavalcanti as was the moment before. I agree that a moment from now there will be a number of exactly equal copies. Nevertheless, I am sure I will only experience being one of them, so this is what I mean by ' me ' - the actual experiences I will have. Maybe some copy of me will win the lottery every time I play, but that does not give me reason to spend my money on it. I still believe that the probability that 'I' win is 1/10^6, even if on a multiverse sense, the probability that at least one copy of me wins is 1. The same should be the case with death if we assume a materialistic position. What do you mean by *entirely equal*? - Original Message - From: David Kwinter [EMAIL PROTECTED] To: Sent: Thursday, November 06, 2003 5:19 AM Subject: Re: Quantum accident survivor On Tuesday, November 4, 2003, at 10:47 AM, Eric Cavalcanti wrote: Let me stress this point: *I am, for all practical purposes, one and only one specific configuration of atoms in a specific universe. I could never say that ' I ' is ALL the copies, since I NEVER experience what the other copies experience. The other copies are just similar configurations of atoms in other universes, which shared the same history, prior to a given point in time.* I would consider these other copies entirely equal to myself IF AND ONLY IF they are succeeding RSSA observer-moments. Glossary references : ) RSSA - The Relative Self-Sampling Assumption, which says that you should consider your next observer-moment to be randomly sampled from among all observer-moments which come immediately after your current observer-moment and belong to the same observer. In a materialistic framework, ' I ' am a bunch of atoms. These atoms happen to constitute a system that has self-referential qualities that we call consciousness. If it happened that these atoms temporarily (like in a coma or anesthesy) or permanently (death) lose this quality, so will ' I '. I respectfully disagree - parallel universes are equally REAL- you will still be you! Quantum branches stem from the same exact atoms in the versions of us that die in tons of possible accidents everyday. I believe that they do in fact exist, and that they do stem from the same atoms. But they are not 'me', in the sense that I don't see through their eyes. That's what matters when talking about Immortality. We want to know if WE are immortal - i.e., if our first-person experience is eternal - not if SOME copy of us will survive. What QTI assumes is that ' I ' cannot be one of the dead copies - i.e., that the dead copies should be excluded from the sampling pool. But that is a too strong assumption, which I haven't seen any justification for. Surely my next observer-moment should be alive or it would not be an observer. But what makes us believe that 'we' - our first-person individuality - must necessarily have a next observer-moment in the first place? That is the assumption that does not seem well-based. If non-observing states are prohibited, then we should never expect to be in a coma, or anesthesized, for instance. Whenever you would be submitted to a surgery, you would see that the doctor somehow failed to apply the anesthesy correctly, and you would have a *very* conscious experience. -Eric.
Re: Fw: Quantum accident survivor
- Original Message - From: Jesse Mazer [EMAIL PROTECTED] I agree that a moment from now there will be a number of exactly equal copies. Nevertheless, I am sure I will only experience being one of them, so this is what I mean by ' me ' - the actual experiences I will have. Maybe some copy of me will win the lottery every time I play, but that does not give me reason to spend my money on it. I still believe that the probability that 'I' win is 1/10^6, even if on a multiverse sense, the probability that at least one copy of me wins is 1. The same should be the case with death if we assume a materialistic position. But you should no more expect to end up in a branch where you died than in a branch where you were never born in the first place. Consider, instead of a branching multiverse, a Star-Trek-style transporter/duplicator in a single universe, which can deconstruct you and reconstruct exact copies atom-by-atom in distant locations (assuming the error introduced by the uncertainty principle is too small to make a difference--if you don't want to grant that, you could also assume this is all happening within a deterministic computer simulation and that you are really an A.I.). To use Bruno Marchal's example, suppose this duplicator recreates two identical copies of you, one in Washington and one in Moscow. As you step into the chamber, if you believe continuity of consciousness is real in some sense and that it's meaningful to talk about the probabilities of different possible next experiences, it would probably make sense to predict from a first-person-point of view that you have about a 50% chance of finding yourself in Moscow and a 50% chance of finding yourself in Washington. On the other hand, suppose only a single reconstruction will be performed in Washington--then by the same logic, you would probably predict the probability of finding yourself in Washington is close to 100%, barring a freak accident. OK, so now go back to the scenario where you're supposed to be recreated in both Washington and Moscow, except assume that at the last moment there's a power failure in Moscow and the recreator machine fails to activate. Surely this is no different from the scenario where you were only supposed to be recreated in Washington--the fact that they *intended* to duplicate you in Moscow shouldn't make any difference, all that matters is that they didn't. But now look at another variation on the scenario, where the Moscow machine malfunctions and recreates your body missing the head. I don't think it makes sense to say you have a 50% chance of being killed in this scenario--your brain is where your consciousness comes from, and since it wasn't duplicated this is really no different from the scenario where the Moscow machine failed to activate entirely. In fact, any malfunction in the Moscow machine which leads to a duplicate that permanently lacks consciousness should be treated the same way as a scenario where I was only supposed to be recreated in Washington, in terms of the subjective probabilities. Extending this to the idea of natural duplication due to different branches of a splitting multiverse, the probability should always be 100% that my next experience is one of a universe where I have not been killed. I don't quite agree with that argument, even though I was intrigued in the first read. The reason is similar to those exposed by Hal finney in his reply to this post. These copies are not copies made by the branching of MWI. In fact, I believe that I will never experience being one of those copies. Let me see if I can support that: Suppose you don't destroy the original, but merely make the copies (and this also answers the later post from someone with the address [EMAIL PROTECTED]). If a copy of me is made *in my own universe*, I don't expect to have the experiences of the copies. Suppose I sit on this copy machine in New York, and the information of the position and velocities (within quantum uncertainty) of all particles in my body is copied. Suppose, for the sake of the argument, that the mere retrieval of this information should pose no problem to me. It should me harmless. This information then travels by wire from the reader to the reproducer. An almost perfect copy of me is made in Paris. Should I, in that moment, expect to have the first-person 50% probability of suddenly seeing the eiffel tower? I don't think anyone would support that. And in that case, you shouldn't support the notion that you could ever be a copy of yourself, since you could always NOT destroy the original in your example. Whenever you did, the original would have the first-person experience of dying, i.e., it would never be conscious again. This example is similar to that of the Schwarzenegger movie where he had a clone of himself made. Of course the making of the clone has no implication in the original person's experiences whatsoever. For instance, if
Re: Quantum accident survivor
Hi, I found this post really thoughtful, but I didn't quite agree. Let's see if I can argue on it: Doesn't this part: In a materialistic framework, ' I ' am a bunch of atoms. These atoms happen to constitute a system that has self-referential qualities that we call consciousness. If it happened that these atoms temporarily (like in a coma or anesthesy) or permanently (death) lose this quality, so will ' I '. Contradict this part: It is not useful to talk about 1st person experiences in 3rd person terms, since when we do that we lose the very thing that we want to study. Since surely one can describe a bunch of atoms with self-referential qualities in wholly objective, i.e. 1st person, terms? But I'm getting ahead of myself here.. I think we actually agree on 99% of this issue. I think the only place we disagree is on some very subtle issues regarding how one can refer to I. Let me then explicitly state that I am a materialist and a functionalist with regard to consciousness. Let me stress this point: *I am, for all practical purposes, one and only one specific configuration of atoms in a specific universe. I could never say that ' I ' is ALL the copies, since I NEVER experience what the other copies experience. Here I think you're making an assumption. You are certainly not ALL the copies, but then it doesn't follow that you are only 1. You could be a fuzzy set of copies that have experiences so similar that they cannot be told apart. That is, they cannot be told apart yet. Unnoticeable differences eventually can percolate up and make a noticeable difference, or they can be made noticeable by making more sensitive observations. Yes, I am making an assumption, and working through it. The assumption is that there is nothing external to the physical body to account for consciousness. I totally agree with this assumption. It's the one and only one part that I disagree with, to this extent: You may, if you wish, decide to refer to one and only one universe and to the Eric within that universe. That is, you can stipulate that the Eric you are referring to is a completely specified entity. But to do so meaningfully, you would need to take some sort of god-like view of the plenitude, and *actually specify* the Eric you're talking about. Otherwise how do you know what you are referring to? Just saying I or one and only one does not do the job. (Like Wittgenstein's man who says I know how tall I am! and proves it by putting his hand on top of his head.) Let's say that you were able to completely specify one Eric, by giving a (possibly infinitely) long description. Let's call the entity you have thus specified Eric01. Our point of difference seems to be this: You believe that when Eric01 says I, he is referring precisely to Eric01. I believe that when Eric01 says I, he is referring to the entire ensemble of Erics who are identical to Eric01 in all the ways Eric01 is capable of detecting. Because each member of this ensemble is also saying I, and meaning the same thing by it. Now you would say that since each completely specified Eric is in fact different, each one has a different consciousness. Here is where our disagreement about _reference_ is relevant to QTI. I definitely agree with you that if you mean to completely specify one Eric when you say I, then it is almost certain that that Eric will die in one of these dangerous situations. But let's now specify TWO Erics: Eric01 and Eric02. They are indistinguishable from each other, and indeed their universes are identical, save for a tiny fluctuation which will miraculously save Eric02's life tomorrow, but doom Eric01. If Eric01 and Eric02 mean the same thing when they refer to I the instant before the death-event, then that I is going to survive, even though Eric01 does not. If they refer to different things, then there is no question of I surviving; it is simply the case that Eric01 dies and Eric02 lives. Let me stress that I do not think anything like Eric01 and Eric02 'share' a 'consciousness' that reaches between their universes. It's simply that if there is no way for Eric01 to know that he is Eric01 rather than Eric02, then there is no difference between them with respect to their consciousness. I don't quite agree with your point of view, and the reason is maybe similar to our disagreement in my statement: It is not useful to talk about 1st person experiences in 3rd person terms, since when we do that we lose the very thing that we want to study. You are trying to identify ' me ' by somehowpointing it out from the pool of similar entities in a God's perspective. That may be even impossible, if there is no God, but that is another discussion. The thing is that I find it misleading anyway. I don't need to point out who ' I ' am. I am concerned with my first-person experiences, and that is easy to determine without even
Re: Quantum accident survivor
Hi, I disagreed with some points in your argumentation... - Original Message - From: David Barrett-Lennard [EMAIL PROTECTED] I'm trying to define identity... Let's write x~y if SAS's x and y (possibly in different universes) have the same identity. You did not yet 'define' identity. You just proposed a relation between two entities which is supposed to mean that these two entities have the same 'identity'. I propose that this relation must be reflexive, symmetric and transitive. This is a proposal which seems self-evident, but let us keep in mind that we have no reason to propose it yet, since we don't even know what 'identity' means. I believe, in fact, that this relation '~' is NOT transitive! Let me try to argue why later. This neatly partitions all SAS's into equivalence classes, and we have no ambiguity working out whether any two SAS's across the multi-verse have the same identity. Consider an SAS x that splits into x1, x2 (in child universes under MWI). We assume x~x1 and x~x2. By symmetry and transitivity we deduce x1~x2. So this definition of identity is maintained across independent child universes. This is where the '~' relation shows that it cannot be transitive. I don't know what your definition of identity is, but in other posts I have argued that I am not the copies of me in other universes. Therefore, since you have come to the conclusion that I am, it must be the case that your assumption of the transitivity of '~' is wrong. To support your definition of '~', you must give a better reason to believe that you are the copies of yourself in other worlds. Just defining an arbitrary '~' relation does not do the job. In fact, I believe we should define another relation of personal identity, which is NOT symmetric. I shall use the notation '' meaning that if xy, x is a former state of y. 'x' is unambiguously defined by following down the multiverse branching 'tree'. But we cannot define the '' relation, i.e., the relation by which yx would mean that y is a continuation of x 'uptree'. Since there are multiple choices for the next state of x, it cannot be told in advance what the next subjective moment will be. So you can say that xx1 and xx2, but it does not follow that x1x2 OR x2x1. And since, by my definition, personal identity can be determined only by the relation '', x1 does not have the same 'identity' of x2. This is at odds with the following concept of identity... I am, for all practical purposes, one and only one specific configuration of atoms in a specific universe. I could never say that ' I ' is ALL the copies, since I NEVER experience what the other copies experience It seems necessary to distinguish between a definition of identity and the set of memories within an SAS at a given moment. Is it possible that over long periods of time, the environment can affect an SAS to such an extent that SAS's in different universe that are suppose to have the same identity actually have very little in common? What happens if we splice two SAS's (including their memories)? It seems to me that the concept of identity is not fundamental to physics. It's useful for classification purposes as long as one doesn't stretch it too far and expose its lack of precision. Maybe it is not fundamental to physics, but it surely is fundamental to us, since that may be the difference between immortality or otherwise. Even more importantly, it is the basis for all our daily decisions. It is not merely a classification purpose. When you decide not to spend your money on the lottery, you don't think that doing so is good, because you will be increasing the number of 'yous' who are rich elsewhere. You don't care for the other 'yous' because you truly believe that the probability that you will just lose yor money is too high. And if you don't care for the other 'yous' they are not really 'you', they are other entities. This reminds me of the problem of defining the word species. Although a useful concept for zoologists it is not well defined. For example there are cases where (animals in region) A can mate with B, B can mate with C, but A can't mate with C. Although you can safely ignore those classifications when relating to objects, you cannot deny that defining your identity is too easy. Cut your finger and you will know who is feeling the pain. -Eric.
Re: Quantum accident survivor
Hi, - Original Message - From: Hal Finney [EMAIL PROTECTED] Eric Cavalcanti, [EMAIL PROTECTED], writes: In the case of non-destructive-copy experiment, the copy is made in a distinct place/time from the original. They could as well be done 100,000 years in the future and in the Andromeda galaxy, and you should as well expect to have the subjective experience of being that copy with the same probability as being the smooth continuation of yourself on Earth. Yes, that makes sense. But in the multiverse, there are certainly infinite other perfect copies of yourself which are not smooth continuations. We can imagine thousands of ways how these copies could be made. In computer simulations, in a distant Earth in the Tegmark plenitude, or elsewhere. Yes, but keep in mind that there are also infinitely other copies which *are* smooth continuations. And these probably outnumber the ones which are discontinuous (assuming that terms like outnumber can be generalized to infinite sets, or else that the sets involved are merely large and not infinite). I don't think so. Suppose you have at least one other perfect copy of yourself, such that you could expect that your next experience be one of that copies' with the same probability as the smooth continuation. A moment dt from now the original 'you' will have branched into a number N of possible future states. Since the copy is perfectly equal, the copy will also evolve to a number of future states that is of the same order of magnitude of N. According to your view, each of these states is a continuation of yourself with equal probability, so that you should expect to have about 50% probability of being your copy. But, if the Plenitude deserves the name, then we should expect to have at least a Huge number of copies at any moment. Therefore, either there are no other copies - i.e. the plenitude is not real, and there are no simulations of yourself anywhere in the multiverse, etc. - or you cannot experience being one of your copies, and QTI is not real. One of these has to go. But suppose you just stepped outside the Paris duplicator. Unaware of the experiment that is being made, your last memory is sitting in front of your computer, reading this email. Suddenly, you see the Eiffel Tower. That would surely be a psychological experience that we don't have too often. And since there are infinite copies of yourself at any given moment, if you should expect to be any of them at the next moment, you shouldn't expect to ever feel the continuous experience you do. Rather, you should expect to feel both, with some probability. And I think that the multiverse holds a greater proportion of continuations that are continuous than that are discontinuous. Fundamentally this is because the conditions that promote consciousness and therefore the formation of brains like mine will tend to involve continuous chains of experience. Only in a relatively few universes will I be subject to unknowing duplications. Therefore I think it is highly unlikely but not impossible that I will suddenly experience a discontinuity. I have argued above about the proportion of smooth/discontinuous states. Let us suppose, though, that our society evolves to a state where such duplications are routine. Anyone may have their brain scanned at any time, without their knowledge, and new copies of them created. Suppose I am such a copy, in fact, I am a 10th generation copy; that is, 10 times in my life I have found myself having an experience similar to what you described, a discontinuity where I was just walking along or sitting there, and suddenly found myself stepping out of a duplicating machine because someone copied me. I think you will agree that my memories are reasonable; that is, that anyone who has gone through such an experierence as I describe will in fact remember these discontinuities. Given my history, wouldn't it be reasonable for me to expect, at any future moment, to possibly face another such discontinuity? It has happened many times before, both to me and to other people that I know; it is an often-discussed phenomenon of the world, in this scenario. Just like anything else that happens occasionally to everyone, it would be perfectly reasonable and rational to have an expectation that it might happen to you. It would be perfectly normal, in such a society, to expect to BE a clone, if you have some reason to believe you are, such as a long-forgot discontinuity of experience. But one should not expect to ever BECOME a clone, for the reasons I argued above. -Eric.
Re: Quantum accident survivor
Hi, - Original Message - From: Pete Carlton [EMAIL PROTECTED] Greetings; this reply has taken some time... I don't quite agree with your point of view, and the reason is maybe similar to our disagreement in my statement: It is not useful to talk about 1st person experiences in 3rd person terms, since when we do that we lose the very thing that we want to study. I think you're right; this is the central disagreement. To spell it out: I do not believe the 1st person/3rd person distinction is fundamental. That is, I think that once you've explained what a system does (and how it does it), you've explained everything. Consciousness is simply a complicated set of behavioral dispositions, which can in principle be explained from an objective, 3rd-person standpoint; and the 1st person viewpoint is just a description, a way that it naturally occurs to us to put things, because of our psychology (biology). It seems a fundamental disagreement indeed. Let us try to discuss about it a little bit... When you said earlier that: In a materialistic framework, ' I ' am a bunch of atoms. These atoms happen to constitute a system that has self-referential qualities that we call consciousness. I took you to be agreeing with me on my view of consciousness. But I think a difference is highlighted here: I don't need to point out who ' I ' am. I am concerned with my first-person experiences, and that is easy to determine without even gaining acces to the other entities who look like me. What, exactly, are these first-person experiences? Are they really so easy to determine? I would say that whatever they are, they contain no information on whether you are Eric01 or Eric02. We know that these completely specified entities do exist, but since Eric01 has no way of knowing he is in fact Eric01, it does not matter what he experiences; the difference between Eric01 and Eric02 is not a difference for Eric. Suppose I am going to make an experiment to determine the z-component of a spin-1/2 particle. There are two possibilities: 1/2,-1/2. Let us forget about all other particles that are changing in the universe for the sake of the argument. So Eric01 is the one who measured 1/2. Eric 02 measured -1/2. They have had completely different experiences. Each one can say: I could have experienced (-1/2,1/2) but I did not. I actually measured (1/2,-1/2). If he knows about the multiverse, he might wonder that the universe split when he measured this event, and some copy of him measured the other outcome. But that does not change the fact that he can tell what outcome he DID measure. You could now say: But there is no tag or anything telling who is 01 or who is 02. In fact, I could beforehand decide that if I measure 1/2, I will put a tag in my forehead written: 01. And that I would put a tag written 02 otherwise. The difference between Eric01 and Eric02 is now manifest! But we are placing too much emphasis on Eric's actual measurement. Now suppose Eric is sitting in his lab unaware of whatever is going on in the particle beam hitting the detector. A friend of his knows of his wonderings about personality and decides to play a game with him. If he (the friend) measures spin 1/2, he will place a tag on his back written 01 or 02 respectively. The difference between Eric01 and Eric02 is again manifest. Nevertheless, Eric01/02 are unaware of it. Now let's get rid of any conscious awareness. The spin1/2 particle has been detected, but no one knows. Nevertheless, the universe has split, and - in principle - Eric could have detected the particle, and he could get to the same conclusion about how the outcome could have been different. The fact that he did not actually measure it does not imply that his universe is not different from the universe where his copy is. No one can say that Eric01 and Eric02 are indeed the same person just because they do not know which one they are. Even if their universe is different only for the state of a particle! Now suppose Eric placed a bet with his pal Pete. If the measurement comes out 1/2, Eric will pay him a 6-pack of beer. Otherwise Pete will pay for Eric. The particle is measured, the universe split. In one of them, Eric is sad and thirsty. For Eric01, the outcome was not good, and even though Pete comes up and say: Cheer up! In another universe you are drinking beer! that does not represent any relief on his thirst. He can only wish he was the other one. (And this is seeming particularly awful to me right now, since my air-conditioner is broken and it is really hot in Rio today). Now what sense could there be for Eric01 to wish he was the other one if Pete insists that he is both? Is that just Eric's shortmindedness or does it say something about the nature of the self? Hal Finney's thought experiment about the 2 identical computers is right on, I think. You have 2 AI programs running in lockstep. Nothing in the programs' experiences can
Re: Quantum accident survivor
- Original Message - From: Bruno Marchal [EMAIL PROTECTED] When you said earlier that: In a materialistic framework, ' I ' am a bunch of atoms. These atoms happen to constitute a system that has self-referential qualities that we call consciousness. I would say I *own* a bunch of atoms. And we should distinguish third person self-reference like after the self-duplication you will see me at W and at M, say, and first person self-reference like after the self-duplication, if comp is true, I will either feel to be at W, or I will feel to be at M, but I will never feel to be at both place at once. I agree that *own* is a better term. But I still don't agree that I should either feel to be W or M. I believe I would still be the original. I have been discussing this on this list for a while and did not yet see a convincing argument. In fact, I think the people in this list have various different beliefs in this topic. Some say I should somehow expect to be both at the same time; some say personal identity does not exist at all, which is quite nice to be said but hard to make a sense of (if you are not an enlightened buddhist or something); and some, like you, believe I should have equal subjective probabilities of being each. But I don't see a justification for this beyond personal taste. I know I must have lost this argument earlier on this list, but could you refer me to a more complete argument, or give a description of it here? -Eric.
(De)coherence
I think this discussion might have already took place here, but I will post this to take your opinions on the topic. How do we define (de)coherence? What makes interference happen or be lost? Taking the double-slit experiment in mind, with paths A and B, the first answer that comes to the mind is that the particle should not be detected while passing through the slits in a way that we can tell which path the particle went through. I like to understand this as if the universes A and B have changed enough, in the state of a macroscopic number of particles, in order for us to have access to that information. So we could postulate that different universes do not interfere. But is that detection merely the interaction of the particle with anything? I don't think so. For instance, suppose we use electrons in a double-path experiment. They take the two paths by being steered with magnetic fields, and then meet again to interfere in a screen. I believe this experiment would also produce interference, but correct me if I'm wrong. Well, the electrons surely interacted with photons of the magnetic field, or in last analysis with the electrons that are producing the magnetic field. Or we could use an arrangement of electric fields - before anyone argues that 'magnetic fields do no work' or something - in such a way that the interaction with some massive particle would be evident. On the other hand, a photon being deflected by a mirror is also interacting with something, but still that does not prevent interference from happening. If these experiments produce the interference pattern, then the mere interaction of the particle with anything does not by itself cause decoherence. What then does? Is it only when a large enough number of particles change their states? But what would be the threshold? Or is it the 'information'? But then how do we define 'information'? -Eric.
(De)coherence
I think this discussion might have already took place here, but I would like to take you opinions on this. How do we define (de)coherence? What makes interference happen or be lost? Take the a double-slit-like experiment. A particle can take two paths, A and B. We can in principle detect which path the particle went through. Suppose we can make the detecting apparatus 'non-interfering' enough so that the particle is not grossly deflected by the detection, but can still reach the screen. We know that the result of this thought-experiment is that interference does not happen. The first answer is that the paths have 'decohered'. But what exactly does that mean? In a MWI perspective, I like the explanation that the two universes A and B are different by a large number of particles: the electrons in a wire, which carry the amplified pulse of the detector, which then reach a computer, and such and such. Something of the order of 10^23 particles have changed state. Now suppose we use some kind of very slow detector. The detection is made by, say, a very slow process such that not many particles (suppose only one particle, even though I don't know how to make that detector) change their state before the interfering particle reaches the screen. After that, we can amplify this information and know which path the particle went through. Again, I believe interference would not be possible. But it is a little harder to say why. Before anyone says that *some* other particle has changed state, and that should be enough for the decoherence, suppose now an experiment with a charged particle, say, an electron. We make it go through paths A and B by steering it with magnetic fields. Certainly, it has interacted with *something*, ot it could not be steered. It interacted with the photons of the EM field, or in last analysis, with the electrons that are generating it. We could use electric fields, so that the interaction is more evident. On the other hand, a photon being reflected by a mirror is also interacting with something, but that does not prevent the interference from happening, as is well known. Therefore interaction by itself does not cause decoherence. And if it is just a large number of particles changing state that does, then what is the threshold? Would an experiment with a few-particle-delayed-detector as described above allow interference? Or is it the 'information' that causes decoherence? If that is the case, how does one define 'information'? -Eric.
Re: (De)coherence
Hi Matt, - Original Message - From: Matt King [EMAIL PROTECTED] Just my tuppenceworth... Eric Cavalcanti wrote: I think this discussion might have already took place here, but I would like to take you opinions on this. How do we define (de)coherence? What makes interference happen or be lost? First, these are two separate questions. (...) This is also how the MWI preserves locality in the EPR paradox/Aspect experiments, which I think is an important experimental vindication of MWI. Thanks for this first part. Some stuff could clarify my thoughts. (...) Now suppose we use some kind of very slow detector. The detection is made by, say, a very slow process such that not many particles (suppose only one particle, even though I don't know how to make that detector) change their state before the interfering particle reaches the screen. After that, we can amplify this information and know which path the particle went through. Again, I believe interference would not be possible. But it is a little harder to say why. I'm not sure I can answer this question with certainty. I think it depends on how many possible internal states the recording particle/system may have; the more states, the more decoherence, and the less likely it is that interference will be seen by the second observer. If the detector had only two possible internal states, I think it is indeed possible for the screen observer to see some interference if the experiment were repeated many times. I don't think the Copenhagen Interpretation was designed to include single particles as observers; rather one would include them in the wavefunction of the total system. Consider as an example Helium. You could think of one electron as being the observer of the other electron; under CI both are included in the wavefunction nonetheless. I think that the CI would therefore make different predictions whether or not one assumes that the recording particle qualifies as an observer. I'm not aware of anything in the CI framework which would help you choose which assumption to make; rather you'd do this retroactively depending on which results you got. I know that the logical inconsistencies in the CI when more than one observer are included are exactly what led Everett to develop MWI in the first place; if anyone has any specific information about what these inconsistencies were, I'd be very excited to hear about it. In the MWI, there is no distinction between observers and other systems, even single particles, and I'm pretty sure that it would predict that the second observer would see some interference in this case, with the amount of interference smoothly (and exponentially rapidly) decreasing with increasing number of internal states of the first observing system (due to decoherence). How do you express that mathematically? On another thought, wouldn't that lead to an inconsistency? No matter how small the detector is, if in principle we could read the result and know what path the particle went through, how could the other path have interfered? Hope this helps, Yes, it did. Thanks. -Eric.
Re: Re:Is the universe computable?
- Original Message - From: David Barrett-Lennard [EMAIL PROTECTED] 0xf2f75022aa10b5ef6c69f2f59f34b03e26cb5bdb467eec82780 didn't exist in this universe (with a very high probability, it being a 512 bit number, generated from physical system noise) before I've generated it. Now it exists (currently, as a hex string (not necessarily ASCII) on many systems (...) You admit a base 16 notation for numbers - which means you allow numbers to be written down that aren't physically realized by the corresponding number of pebbles etc. So much for talking about pebbles in your previous emails! I think that it doesn't matter what base you choose to write down the number. It is an integer, therefore it is physically realizable *in principle*. If you write '1aa3' in base 16, it means '6893' in base 10, which corresponds to a given number of pebbles. We may think that there is somehow more reality in 6893 in comparison to 1aa3, but they are both in the same footing, except that we are more used to the first representation. Why would one claim that the corresponding decimal representation of Eugen's 512-bit number has any more reality that the hexadecimal one? This shows well how we take for granted the connection between a number's representation in digits and the physical representation in pebbles. But to take from any representation to any other, some operation is necessary. What 6893 means is take 3 pebbles, sum those with 9x10 pebbles, then sum 8x100, then 6x1000 and you will have the number of pebbles represented by 6893 This operation uses implicitly the concepts of sum and multiplication, and of the physical representation of the first 10 digits (or maybe we could argue that even those are actually the representation of successive sums of units). It tooks us years in primary school to master these concepts and operations until we thought they are natural. An interesting fact is that it is very easy to represent integer numbers that cannot be physically realizable in pebbles or in atoms, not even using all of the atoms in the universe. 10^(56^579), for example. I believe that this representation is as good as the corresponding decimal or hexadecimal one, since any of them requires some operation to be converted in pebbles. But before one argues that this is an argument for arithmetical realism, it is not *necessarily* the case that 10^(56^579) exists independently of *this* representation either. I have no formed opinion on arithmetical realism, even though I tend to accept that there is some external reality to the integers. But is the reality that is assigned to numbers of the same kind that is assigned to their physical representation? Are we not discussing just words without any meaning? -Eric.
Re: More on qualia of consciousness and occam's razor
Entering the discussion here... - Original Message - From: Pete Carlton [EMAIL PROTECTED] 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? And why assume that we are not? I prefer not to have my right to ask waived. If I cannot ask it, then I should understand why not, and that would be an answer in a way. To borrow a bit from Wittgenstein -- imagine you have completely translated these aliens' language, and they tell you that each of them has a box with something inside it. Although they talk a lot in rather vague terms about what's in their box, they insist you can't really know what is inside it. Now what is the logical conclusion here: a) There may or may not be something in the box. b) There's definitely something in the box, and I have absolutely no idea what it is. What on earth could possibly make someone conclude (b) here? It's not logical at all. Yet this is what people conclude when they bend over backwards talking about qualia and how ineffable they are. And you seem to conclude a (c) hypothesis: there is definitely nothing inside the box. I stay with (a). And to try to find out if there is something there or not, we need to talk about it, and qualia is the word for the hypothetical contents of the box. So, in addition to the empirical data, there is this extra bit of information, neither contained in the data nor able to be derived from it using the laws of physics: what it actually feels like to be the one experiencing the subjective sensation. If someone can think of a better way to describe it than extra bit of information or can come up with a way to formalise it, I would be happy to hear about it. A better way to describe what, exactly? What it actually feels like? But why do you first commit yourself to the view that this question makes any sense? Suppose a blind man did understand all the chain of events that lead from the light reaching the eyes to the retina, then to the brain and finally to the qualia of red. Would he see the red? Why not? I can imagine that I have my vision scrambled in such a way that red is exchanged with blue. Red is the color that I associate with an apple, and blue to the sky. I can imagine that the sky appeared to have the color of an apple and an apple appeared to have the sky's color. But if that happened, from then on, I could change the names of the colors in such a way that I still called the apple 'red' and the sky 'blue'. If there is no such a thing as 'qualia', then nothing really happened. But I could tell that things are different. In what sense could they be different? I suppose there will still be some who insist that if you know all about the physiology etc. behind the alien response to gamma rays, then you know all there is to know. I think this response is analogous to the shut up and calculate attitude to the interpretation of quantum mechanics. Yes, I am one of these people. You say if you know all about, and you must be taken seriously here: you would really have to know all about it. But if you did, you would be able to entirely trace the causal pathway from the receipt of the gamma rays, to whatever internal responses go on inside the alien's body, to the subsequent report of I feel that pleasant, odd-multiple feeling. Let's say you had that entire explanation written out. And subjective experience doesn't appear anywhere on this list. So what reason on earth do you have to assert that it exists? When the alien says I feel that pleasant feeling, he is just saying that he knows that chain of events is happening in his body right now. Suppose you are watching him with equipments that let you know that same thing. Could you also say I feel that pleasant feeling too? Why not, if there is nothing beyond the chain of events? What could make the alien's knowledge different from yours? One obvious answer is that he is the organism where those events are happening. But this means that each organism is entitled to feel something about himself , an experience that is inaccesible to others, no matter how comprehensive their knowledge is. But that is something that you are claiming that does not exist. How can we explain this without something as qualia? Sorry for making so many questions. I don't intend to be pedantic, but I really don't know the answers. Of course subjective experience exists in a way -- but it's just a way of talking about things. It isn't a primitive. When I see red, I have a subjective experience of red, sure -- but all this means is just that my brain has responded to a certain stimulus in the way it normally does. And maybe it is not all that this means... Eric.
Re: More on qualia of consciousness and occam's razor
Pete, I hope you don't mind my replying to the list. - Original Message - From: Pete Carlton [EMAIL PROTECTED] 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? And why assume that we are not? I prefer not to have my right to ask waived. If I cannot ask it, then I should understand why not, and that would be an answer in a way. At first it seems like a normal question to ask, because we have a way of talking about our experiences that takes them to be simple entities, and why not ask what it is like for other beings? But you're asking the question in the same manner (using the same logical form) as when one asks what's inside a box, and expecting the same kind of answer. But the two cases are conceptually distinct. We are well acquainted with boxes and their contents, and thus have every right to ask what's inside when we see a box. But we have no such acquaintance with minds. I have only followed the analogy. But of course I am aware that the analogy is loose and that we cannot ask about qualia in the same manner as about the contents of a box. I may have overstated a bit -- of course anyone has the right to ask any question they want! =) But when we explore the consequences of consciousness in a multiverse, as this list often does, we shouldn't overlook the fact that there are many views of consciousness and some may lead to fewer problems than others. Earlier there were posts about whether SAS-like patterns in a cellular automaton would really be conscious or not. It seems like this question is asking, I can see how the thing behaves, but what I want to know is, are the lights 'turned on inside' or not?. But we already know that there are no lights -- so what is the question really asking? Maybe we can get away with ignoring questions like this, and have a better universe model as a result. I don't agree that we already know that there are no lights. The thing is that we know what it feels like to be conscious. We know what is the difference between red and blue, and we know we cannot communicate that to someone who cannot see. It is not as if we were unconscious beings asking if there was something like 'qualia' (which we would have no idea about) in the cellular automata. We are not merely inventing concepts which have no correspondence in the real world. Each of us knows exactly what it means, and talk about these things using the assumption that other similar beings have experiences similar to our own. The fact that we try to ask this question in the first place implies that there is something there to be explained, at least. snip know what is inside it. Now what is the logical conclusion here: a) There may or may not be something in the box. b) There's definitely something in the box, and I have absolutely no idea what it is. What on earth could possibly make someone conclude (b) here? It's not logical at all. Yet this is what people conclude when they bend over backwards talking about qualia and how ineffable they are. And you seem to conclude a (c) hypothesis: there is definitely nothing inside the box. I stay with (a). And to try to find out if there is something there or not, we need to talk about it, and qualia is the word for the hypothetical contents of the box. That would be correct if the analogy between boxes and minds were sound, but I don't think it is, and that's the point of bringing it up. About the only thing you can conclude is that something strange is going on because these people insist you can't know what's inside a box. You're right, though, I don't exactly embrace (a), I question the entire setup. Neither do I think the analogy is sound, as I said above. Suppose a blind man did understand all the chain of events that lead from the light reaching the eyes to the retina, then to the brain and finally to the qualia of red. Would he see the red? Why not? Where is the path from the brain to the qualia of red? You're saying that the blind man is aware of trillions of neural changes occurring over time, and that at some point he can say, Now, here's where things leave the brain and start to become qualia... Is this before or after the neural changes that modify behavior, i.e., to cause someone to say, I'm seeing red now? I have no idea. I don't claim to understand how qualia arises. In any case, I grant that the blind man's experience would be quite different from someone who's actually looking at the color red. This is just because the functional states of someone who is seeing red are different than those of someone who just understands what it's like-- you can't stimulate your optic nerve just by will alone. It isn't clear that someone could drive
Re: More on qualia of consciousness and occam's razor
- Original Message - From: Stathis Papaioannou [EMAIL PROTECTED] Pete Carlton wrote: In any case, I grant that the blind man's experience would be quite different from someone who's actually looking at the color red. This is just because the functional states of someone who is seeing red are different than those of someone who just understands what it's like-- you can't stimulate your optic nerve just by will alone. It isn't clear that someone could drive their brain into the state of someone who had seen red merely by understanding everything about the process of seeing red. This is also how I respond to Frank Jackson's colorblind Mary experiment.. So you agree that you cannot drive someone's brain into the state of someone who had seen red merely by understanding everything about the process of seeing red.. That is, you agree that you cannot see red unless you do physically see red. Isn't that somehow in contradiction with your claim below, i.e., that there is nothing else to know beyond the explanation of the physiological response? One thing you seem to agree: you cannot know how red looks like unless you see red. A blind man cannot possibly know that. Now I am aware that know may not be the correct term. Maybe experience would be better. -ENDQUOTE Actually, you probably _could_ drive your brain into seeing red if you knew exactly what physical processes occur in the brain in response to a red stimulus, and if you had appropriate neural interface equipment. Such capabilities do not currently exist - not even close - but the idea is the basis of many SF stories (eg. William Gibson, Greg Egan). The same sort of thing frequently occurs naturally: the definition of a hallucination is a perception without the stimulus that would normally give rise to that perception. The point is, even if you knew in perfect detail what happens in your brain when you see red, you would not actually know/feel/experience the qualia unless you ran the software on your own hardware. You are right. You could in principle (and it indeed happens in hallucination) experience red without the normal physical stimulus. But the argument holds in that you cannot experience red merely by understanding the process. As you say, you have to run it in your own hardware. -Eric.
Re: More on qualia of consciousness and occam's razor
Hi Bruno, - Original Message - From: Bruno Marchal [EMAIL PROTECTED] You take the box/brain analogy to literally. If I rephrase the question as I can see how the thing behaves, but what I want to know is 'is there consciousness there?' . Would you still say But we already know that there are no consciousness -- so what the question is really asking?. Well my remark adds nothing in the sense that Eric Cavalcanti succeeds apparently to pinpoint the contradiction in Pete's post (through the use of Frank Jackson's colorblind Mary experiment). Nice piece of dialog. Actually I do think that the box/brain analogy is not so bad, once we agree to choose another topology for the information space, but for this I need the modal theory of knowledge S4 ... I would love to read more about that. Where can I find a good reference? Of course I mainly agree with Stathis here, and with Eric's assessment, but Stathis formulates it in just the way which makes people abusing the box analogy. Indeed, the only way to actually know/feel/experience the qualia is to run the right software, which really *defines* the owner. The choice of hardware makes no difference. The owner of the hardware makes no difference. This is because the owner is really defined by the (running) software. To be even more exact, there is eventually no need for running the software, because eventually the box itself is a construction of the mind, and is defined by the (possible) software/owner. That illustrates also that you cannot see blue as someone else sees blue by running the [someone else's software] on your hardware, because if you run [someone else's software] on your hardware, you will just duplicate that someone-else, and your hardware will become [someone else's hardware!] And *you* will just disappear (locally). Well, that's just where I guess we come to disagree... :) I am still not sure I believe comp, so I am not yet sure I agree that the hardware doesn't matter at all... Or at least not in that strong sense that one can expect to experience a copy of oneself elsewhere. I am not even sure what 'one' means here... So many doubts... :) -Eric.
OT Ban on scientific publications
Dear colleagues, this email is to draw your attention to a ban on scientific publications for authors of countries for which the USA declared a trade embargo. Under the terms of the trade embargo, a publisher of a journal that accepts a scientific paper from an author residing in Libya, Iran, Iraq, Sudan or Cuba can be fined US$50,000 per case and be sent to jail for up to 10 years. Some professional organizations, amongst others the American Chemical Society, IEEE and AAAS, have in the past declared that they will ignore the ruling. The American Chemical Society alone received 195 papers from the banned countries. But the current policy under President Bush is going towards enforcement of the trade bans. As a result there has been a meeting of science publishers in Washington recently to discuss how to resolve the situation and guarantee freedom of scientific publication. If you want to support the publishers in their effort you can sign a petition at http://www.PetitionOnline.com/PWC/ The site has a more detailed explanation of the situation and links to further editorials, for example http://pubs.acs.org/isubscribe/journals/cen/82/i04/html/8204edit.html and comments on the issue and allows you to see who else has signed.
Fw: Gravity Carrier - could gravity be push with shadows not pull?
Hi there, Well, it is a good try, but it has been proven wrong already indeed. To see a better refutal, see Feynman's popular book 'QED'. For instance, that theory seems even better once you realize that it also acounts for the inverse-square law. But the main flaw, if I recall it, is that objects moving around in space would feel a larger flux of 'iGravitons' coming against the direction of movement, causing a decrease in velocity. So much for inertia... -Eric. - Original Message - From: Eric Hawthorne [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Thursday, February 26, 2004 6:46 AM Subject: Re: Gravity Carrier - could gravity be push with shadows not pull? Caveat: This post will likely demonstrate my complete lack of advanced physics education. But here goes anyway. Is it possible to model gravity as space being filled with an all-directional flux of inverse gravitons? These would be particles which: 1. Zoom around EVERYWHERE with a uniform distribution of velocities (up to C in any direction). 2. Interact weakly with matter, imparting a small momentum to matter (in the direction that the iGraviton was moving) should they collide with a matter particle. The momentum comes at the cost that the iGraviton which collided with mass either disappears or at least reduces its velocity relative to the mass's velocity. So note that: 1. If there was just a single mass, it would not receive any net momentum by collisions from iGravitons because iGravitons with an even distribution of velocities impact it from all sides with equal probability, no matter what the mass's velocity. (This is true because C is the same for each mass no matter how it's travelling, so even distribution of velocities up to C is also the same from the perspective of each mass regardless of its velocity. 2. If two masses are near each other, they shadow each other from the flux of iGravitons which would otherwise be impacting them from the direction in between them. This shadowing would be proportional to the inverse square of the distances between the masses, and would be proportional to the probability of each mass colliding with (i.e. absorbing) iGravitons, and this probability would be proportional to the amount of each mass. (So the iGraviton shadow between the masses would have properties like a gravitational field). 3. The mutual shadowing from momentum-imparting flux from all directions means that net momentum would be imparted on the masses toward each other (by nothing other than the usual collisions with iGravitons from all other directions.) 4. The deficit of iGravitons (or deficit in velocity of them) in between absorbtive masses could be viewed as inward curvature of space-time in that region. Amount or velocity distribution of iGraviton flux in a region could correspond in some way with the dimensionality of space in that region. I find this theory appealing because 1. it's fundamental assumption for causation of gravity is simple (a uniformly-distributed-in-velocity-and-density flux of space-involved (i.e. space-defining) particles.) 2. The paucity of iGravitons (or high iGraviton velocities) in a region corresponding to inward-curving space is an appealingly direct analogy. You can visualize iGravitons as puffing up space and a lack of them causing space there to sag in on itself. I'd be willing to bet that someone has thought of this long before and that it's been proven that the math doesn't work out for it. Has anyone heard of anything like this? Is it proven silly already? Cheers, Eric
Re: Gravity Carrier - could gravity be push with shadows not pull?
Oops, I realize that it wasn't in 'QED' but in the 'Lectures' that I read that... - Original Message - From: Eric Cavalcanti [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Thursday, February 26, 2004 10:18 AM Subject: Fw: Gravity Carrier - could gravity be push with shadows not pull? Hi there, Well, it is a good try, but it has been proven wrong already indeed. To see a better refutal, see Feynman's popular book 'QED'. For instance, that theory seems even better once you realize that it also acounts for the inverse-square law. But the main flaw, if I recall it, is that objects moving around in space would feel a larger flux of 'iGravitons' coming against the direction of movement, causing a decrease in velocity. So much for inertia... -Eric. - Original Message - From: Eric Hawthorne [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Thursday, February 26, 2004 6:46 AM Subject: Re: Gravity Carrier - could gravity be push with shadows not pull? Caveat: This post will likely demonstrate my complete lack of advanced physics education. But here goes anyway. Is it possible to model gravity as space being filled with an all-directional flux of inverse gravitons? These would be particles which: 1. Zoom around EVERYWHERE with a uniform distribution of velocities (up to C in any direction). 2. Interact weakly with matter, imparting a small momentum to matter (in the direction that the iGraviton was moving) should they collide with a matter particle. The momentum comes at the cost that the iGraviton which collided with mass either disappears or at least reduces its velocity relative to the mass's velocity. So note that: 1. If there was just a single mass, it would not receive any net momentum by collisions from iGravitons because iGravitons with an even distribution of velocities impact it from all sides with equal probability, no matter what the mass's velocity. (This is true because C is the same for each mass no matter how it's travelling, so even distribution of velocities up to C is also the same from the perspective of each mass regardless of its velocity. 2. If two masses are near each other, they shadow each other from the flux of iGravitons which would otherwise be impacting them from the direction in between them. This shadowing would be proportional to the inverse square of the distances between the masses, and would be proportional to the probability of each mass colliding with (i.e. absorbing) iGravitons, and this probability would be proportional to the amount of each mass. (So the iGraviton shadow between the masses would have properties like a gravitational field). 3. The mutual shadowing from momentum-imparting flux from all directions means that net momentum would be imparted on the masses toward each other (by nothing other than the usual collisions with iGravitons from all other directions.) 4. The deficit of iGravitons (or deficit in velocity of them) in between absorbtive masses could be viewed as inward curvature of space-time in that region. Amount or velocity distribution of iGraviton flux in a region could correspond in some way with the dimensionality of space in that region. I find this theory appealing because 1. it's fundamental assumption for causation of gravity is simple (a uniformly-distributed-in-velocity-and-density flux of space-involved (i.e. space-defining) particles.) 2. The paucity of iGravitons (or high iGraviton velocities) in a region corresponding to inward-curving space is an appealingly direct analogy. You can visualize iGravitons as puffing up space and a lack of them causing space there to sag in on itself. I'd be willing to bet that someone has thought of this long before and that it's been proven that the math doesn't work out for it. Has anyone heard of anything like this? Is it proven silly already? Cheers, Eric
Re: The FLip Flop Game
AAAghhh!!! I didn't read it carefully again!!! Yes, it is not even-money. In the infinite players case, even though you are equally likely to win or lose, you win money in the long run. I am going to sleep... :) Eric. On Mon, 2004-10-11 at 17:52, Kory Heath wrote: At 12:20 AM 10/11/2004, Norman Samish wrote: For example, if there are 3 players then the long-term odds are that each game costs each player 25 cents. If there are 5 players, the average cost goes down to 6.3 cents per game. If there are 7 players, they make on the average 3.1 cents per game. If there are 9 players they make about 9 cents per game. It isn't clear to me why this should be so. The issue is in the payout structure you suggest, which is that if you win you get $2, and if you lose, you pay $1. This is not an even-money proposition. If your chances of winning are exactly 1/3, then for every three times you play you will (on average) pay $1 twice and win $2 once, which is break-even. Therefore, you have a positive expectation if your winning chances are any greater than 1/3. In three-player Flip-Flop, your winning chances are only 1/4, so the three-player game is a bad bet even given this generous payout structure. However, as you add players, your chances of winning tend towards 50% (but never quite reach it). Very quickly, your winning chances will become greater than 1/3, and the game will suddenly have a positive expectation for you, and a negative one for the house. If the casino wants to guarantee profits, it must adjust its payout structure to an even-money proposition. In other words, losers pay $1, and winners get $1. As you add more players, your winning chances improve, but they're still always slightly less than 50%, so the game will always have a negative expectation for the players. As a side note, the common parlance in betting is that you pay a certain amount up front (the bet), and then if you win you get a certain amount back, while if you lose you get nothing. In this way of speaking, an even-money proposition would be to bet $1 and get $2 back if you win. The bet that you proposed was equivalent to betting $1 and getting $3 back when you win, which is better than even-money. -- Kory
Re: S, B, and a puzzle by Boolos, Smullyan, McCarthy
On Mon, 2004-10-11 at 22:51, Bruno Marchal wrote: As a Price, I give you the (known?) Smullyan McCarthy As a Price, or a Prize? :) puzzle. You are in front of three Gods: the God of Knights, the God of Knaves, and the God of Knives. The God of Knight always tells the truth. The God of Knaves always lies, and the God of Knives always answers by yes or no randomly. You must find which is which, through some questions. You can ask no more than three yes-no (answerable) questions. (Each question must be asked to one God, but you can ask more than one question to a God; only then there will be a God you can no more ask a question). And (added McCarthy) I let you know that all the Gods, although they understand English, will answer the yes-know question by either JA or DA, and you are not supposed to know which means yes and which means no. Wow, that was a hard one! I have been thinking about it all day, but I think I got to the solution. Let's see... I developed a whole method for solving this kind of problem. :) Labelling the Knights' God as T, the Knaves' God as F, and the Knives' God as R, we have 6 possible 'states' we want to distinguish, which are all the permutations of them. I'll make 3 questions, which can have two possible outcomes each, JA(J) or DA(D). This means that in the end my experiment has 8 possible outcomes. From this initial analysis it is clear that I cannot aim to ask questions which would give me information about the statements JA=YES or JA=NO, because for that I would need to distinguish between 12 states. But since I have 2 outcomes more than states, it is possible that I might in some cases get this last answer, but only as a bonus. So I make a table where I try to fit a set of 3 questions whose outcomes are going to distinguish these states. One possible table is the following: State 1st J DJJ JD DJ DD Final --- TRF J J J JJJ TFR D JJ DJJ FRT J D J JDJ FTR D DJ DDJ RTF J/D J DD D JJD/DDD RFT J/D D JD D JDD/DJD --- The blank spaces mean that we don't care what would be the answer in those cases, because they have been already ruled out. It's important to leave blank spaces in at least two lines which correspond to 'R's in the same column, because we can always make the question to the the God in that column so that we can arrange the random answers to fall in those places. The columns 'J', 'JJ' and so on indicate the outcomes that I wish the next question to have given outcome 'J', 'JJ' and so on for the previous questions. Some more thought shows that you can always come up with *some* question that fits whatever choice of outcomes you want, given the constraints above. So we have a lot of freedom to choose the outcomes in the above table, the only problem will be to think of the corresponding verbal questions. So the first problem is to come up with some question which would be answered as in the '1st' column. This question could be, using the idea of Jesse Mazer, but with an extra trick: If I asked you Is the 2nd God the 'R', would you say 'JA'? The interesting thing is that this question does not tell us if JA is YES or NO, but a minute of thought shows that the outcomes are the same whatever JA means. After some thought, the other questions can be: Column'J': 3rd god, if I asked you 'Are you the 'F'', would you say 'JA'?; Column'D': 2nd god, if I asked you 'Are you the 'F'', would you say 'JA'?; Columns 'JJ' and 'JD': 3rd god, if I asked you 'Is the 2nd god 'R'', would you say 'JA'?; Columns 'DJ' and 'DD': 2nd god, if I asked you 'Is the 3rd god 'R'', would you say 'JA'?. So I think these would solve the problem. It was a lot of fun! Let me see what you guys think. As an extra challenge, can you think of a way to find out if JA=YES in some of the outcomes? It would involve different questions, but I think it should be possible in principle. Eric.
Observation selection effects
I have read some stuff on Nick Bostrom's page (http://nickbostrom.com/) and while in general I agree with his conclusions about observation-selection effects, there is one example which I am not sure I understand. It is the one about cars in the next lane going faster: (http://plus.maths.org/issue17/features/traffic/index.html) I agree with the general conclusion: when we randomly select a driver and ask her whether she thinks the next lane is faster, more often than not we will have selected a driver from the lane which is in fact slower and more densely packed. And in a sense I agree with: If you are driving on the motorway and think of your present observation as a random sample from all the observations made by all the drivers, then chances are that your observation will be made from the viewpoint that most drivers have, which is the viewpoint of the slow-moving lane. That is, IF I think of my present observation as a random sample from all the observations, THEN chances are that my observation is from the slow lane. But I am not sure I agree that we can always think of our observation as being from such a sample. For example: suppose I just arrived at a 2-lane road. I took lane A. One of them is slower than the other, in the sense that for the next couple of miles after my initial positioWhere is the flaw? n the average velocities of the cars in lane S is lower than on lane F. But it is not clear which (A or B) is faster from my point-of-view (POV), so that, in trying to decide which lane to go, I need to think of a statistical argument to decide wether or not I should change lanes. From Bostrom's argument, I should think of my observation as being selected from a sample of the drivers on the road, so that it is more likely that I am on the slower road. Therefore, I should change to lane B. From another perspective, I have just arrived at the road and there was no particular reason for me to initially choose lane A or lane B, so that I could just as well have started on the faster lane, and changing would be undesirable. From this perspective, there is no gain in changing lanes, on average. Extending the argument, suppose I drive for a couple of miles, and get to another point where I want to decide if I should change lanes. Since I had no reason to change lanes a couple of miles ago, I still have no reason to do so now. Unless, of course, I can clearly see that the next lane is faster, but adding that assumption changes the problem completely. Where is the flaw? Eric.
RE: Observation selection effects
On Mon, 2004-10-04 at 10:42, Stathis Papaioannou wrote: Eric Cavalcanti writes: QUOTE- And this is the case where this problem is most paradoxical. We are very likely to have one of the lanes more crowded than the other; most of the drivers reasoning would thus, by chance, be in the more crowded lane, such that they would benefit from changing lanes; even though, NO PARTICULAR DRIVER would benefit from changing lanes, on average. No particular driver has basis for infering in which lane he is. In this case you cannot reason as a random sample from the population. -ENDQUOTE I find this paradox a little disturbing, on further reflection. You enter the traffic by tossing a coin, so you are no more likely to end up in one lane than the other, and you would not, on average, benefit from changing lanes. Given that you are in every respect a typical driver, what applies to you should apply to everyone else as well. This SHOULD be equivalent to saying that if every driver decided to change lanes, on average no particular driver would benefit - as Eric states. However, this is not so: the majority of drivers WOULD benefit from changing. (The fact that nobody would benefit if everyone changed does not resolve the paradox. We can restrict the problem to the case where each driver individually changes, and the paradox remains.) It seems that this problem is an assault on the foundations of probability and statistics, and I would really like to see it resolved. I found the answer of why you should be more likely to enter in the crowded lane in this case. The answer came after I tried to think about an example for few people (which turned out not to work as I thought it would) Suppose a coin is toss for N people, which enter one of two rooms according to the result. Suppose first N=3. Then it is more likely that I will be in the crowded room, even though there was no particular bias in each coin toss. But still, if I am given the option to change, and if I am in the crowded room, I'll probably still be in the crowded room after I change! Now as N grows large, it is still more likely that I will be in the crowded room, only it is less so. I was neglecting the effect that you make yourself when you enter the room/lane. When N is large and even, it is equally likely that the lane I enter is slower/faster. But it may be that both lanes have same numbers, so my entering will make that lane be the slower, and that's where the effect comes from. If it is odd, and I enter the fast lane, it is possible that they become equal. If I enter the slower lane, it will become even slower. A minute of thought shows that my changing lanes does not affect the result, though, as much as changing rooms does not make me more likely to be in the less crowded when N=3. Therefore it is not a good advice for people to change lanes in this case, even though it is more likely that they are in the slower lane! Eric.
[Fwd: RE: Observation selection effects]
I always forget to reply-to-all in this list. So below goes my reply which went only to Hal Finney. -Forwarded Message- From: Eric Cavalcanti [EMAIL PROTECTED] To: Hal Finney [EMAIL PROTECTED] Subject: RE: Observation selection effects Date: Tue, 05 Oct 2004 12:57:14 +1000 On Tue, 2004-10-05 at 10:20, Hal Finney wrote: Stathis Papaioannou writes: In the new casino game Flip-Flop, an odd number of players pays $1 each to individually flip a coin, so that no player can see what another player is doing. The game organisers then tally up the results, and the result in the minority is called the Winning Flip, while the majority result is called the Losing Flip. Before the Winning Flip is announced, each player has the opportunity to either keep their initial result, or to Switch; this is then called the player's Final Flip. When the Winning Flip is announced, players whose Final Flip corresponds with this are paid $2 by the casino, while the rest are paid nothing. Think about if the odd number of players was exactly one. You're guaranteed to have the Winning Flip before you switch. Then think about what would happen if the odd number of players was three. Then you have a 3/4 chance of having the Winning Flip before you switch. Only if the other two players' flips both disagree with yours will you not have the Winnning Flip, and there is only a 1/4 chance of that happening. Exactly. It is interesting to note that, even though you are more likely to be in the Winning Flip, there is no disadvantage in Switching. To understand that, we can look at the N=3 case, and see that if I am in the Winning Flip with someone else, then if I change I will still be in the Winnig Flip with the other person. As opposed to Stathis initial thought, even though the Winning Flip is indeed as likely to be Heads as Tails, each individual is more likely to be in the Winning Flip as in the Losing Flip in any given run. So that this would never make it into a Casino game, because the house would lose money in the long run. Eric.
RE: [Fwd: RE: Observation selection effects]
On Tue, 2004-10-05 at 19:31, Brent Meeker wrote: I always forget to reply-to-all in this list. So below goes my reply which went only to Hal Finney. -Forwarded Message- From: Eric Cavalcanti [EMAIL PROTECTED] Think about if the odd number of players was exactly one. You're guaranteed to have the Winning Flip before you switch. No, you're guranteed NOT to be in the winning flip. Then think about what would happen if the odd number of players was three. Then you have a 3/4 chance of having the Winning Flip before you switch. Only if the other two players' flips both disagree with yours will you not have the Winnning Flip, and there is only a 1/4 chance of that happening. Exactly. It is interesting to note that, even though you are more likely to be in the Winning Flip, there is no disadvantage in Switching. To understand that, we can look at the N=3 case, and see that if I am in the Winning Flip with someone else, then if I change I will still be in the Winnig Flip with the other person. As opposed to Stathis initial thought, even though the Winning Flip is indeed as likely to be Heads as Tails, each individual is more likely to be in the Winning Flip as in the Losing Flip in any given run. So that this would never make it into a Casino game, because the house would lose money in the long run. I think you've confused the definitions of winning flip and losing flip. The winning flip is the *minority at the time of the flip* For N=3 you can't be in the winning flip with someone else at the time of the flip - but you can switch to it. Yes, you're right. Hal and I have confused the definitions. It is still not a paradox, though. You are more likely to be in the Losing Flip. So that this could indeed be a Casino game. Eric.
Re: An All/Nothing multiverse model
On Wed, 2004-11-17 at 08:39, Georges Quenot wrote: Hal Ruhl wrote: [...] The idea that defining a thing actually defines two things seems self evident [once you notice it]. At least one case of unavoidable definition also seems self evident [once you notice it]. The problem with evidence is that on one side there is no other known basis to build certainties and on the other it appears to be very relative [once you notice it]. :-) But that's inevitable, or isn't it? Can we have any certainty other than those logically derived from assumed principles? And in this case, isn't it desirable that at least the assumed principles are self-evident? Could we have something better? Also, (self) evidence that seems so sounds like a pleonasm to me. Yes, I think I agree with you, but that's the common usage. A'self-evident' means evident without proof. But can something be 'evident' only after proof? It seems to me that an 'evident' proposition doesn't need proof either. Eric.
where is the harmonic oscillatorness?
I think some of the discussions about COMP and simulating people
could be better understood if we can first understand a (much)
simpler problem: a harmonic oscillator.
The relevance of this is that ultimately there might be no meaning
in saying that a string in Platonia or wherever represents anything,
without the mapping that gives the semantics for it. If it means
something, then we should be able to explicit show how to objectively
find this meaning for a simple case of a harmonic oscillator.
Let's define a turing machine M with a set of internal states Q,
an initial state s, a binary alphabet G={0,1}. The transition
function is f: Q X G - Q X G X {L,R} , i.e., the function
determines from the internal state and the symbol at the pointer
which symbol to write and which direction (left or right) to
move.
Write a program in M that calculates the evolution of a harmonic
oscillator (HO). The solutions are to be N pairs of position and
momentum of a HO, with time step T and d decimal digits. Let this
set of pairs be P.
The program will eventually halt and the tape will display a string
S.
The programmer knows (of course) how to read S and find P. The
programmer uses for that (unconsciously or not) a mapping A that
takes from strings to pairs of real numbers. This mapping depends
ultimately on the particular way the programmer chose to write the
program and is by no means trivial.
Suppose you didn't write this program. Can you look at the output
and know that it represents a harmonic oscillator, given that you
know all the details of M? This is a problem of reverse engineering
which could be feasible in principle for a simple enough program.
It would help particularly if M is reversible, since you could from
the output work out the program and with enough time and luck, work
out what the program is supposed to do. In this way you would be
finding the mapping A.
But is there anything objective about the string S and the machine
M that makes that program represent a harmonic oscillator, or is
that interpretation ultimately dependent on the mapping A?
Is there some harmonic oscillatorness in S?
Eric.
Re: where is the harmonic oscillatorness?
On Wed, 2005-05-11 at 11:46, Hal Finney wrote:
Eric Cavalcanti writes:
Let's define a turing machine M with a set of internal states Q,
an initial state s, a binary alphabet G={0,1}. The transition
function is f: Q X G - Q X G X {L,R} , i.e., the function
determines from the internal state and the symbol at the pointer
which symbol to write and which direction (left or right) to
move.
Write a program in M that calculates the evolution of a harmonic
oscillator (HO). The solutions are to be N pairs of position and
momentum of a HO, with time step T and d decimal digits. Let this
set of pairs be P.
The program will eventually halt and the tape will display a string
S.
...
Is there some harmonic oscillatorness in S?
Yes, potentially there is. The first thing you need to do is to
define a harmonic oscillator. Obviously you can't ask whether there
is X-ness in something if you don't have a definition of X.
Sure.
So let us write a definition of a harmonic oscillator. Express it as a
program which, when given some input that claims to describe a harmonic
oscillator, returns true if it is one, and false if it is not. This
input can be required to be in some canonical form.
Agreed.
For example, I can write a program for which the input is a sequence
of N k-digit numbers, where each k-digit number encodes a pair (x,p)
in a given way. And then I can go and write a program to check if these
numbers behave closely like a harmonic oscillator.
Now, if string S truly contains a harmonic oscillator, we should be
able to write a simple program which translates S into the form needed
for input to our test program, and which will then cause the test
program to return true.
This is the hard part. If we don't know how the pairs are coded in the
string, which ultimately depends on the programmer's design, how can we
do that in general? And in the end that just amounts to finding
the mapping A that I defined before, the existence of which seems to be
utterly dependent on a programmer/cracker.
Further, given some complex enough string, you could always find SOME
mapping from that string into the set P of coordinates of a harmonic
oscillator, which uses SOME code. Right? I guess that's along the lines
of what you say below:
The key is that the translation program must be simple. The simpler it
is, the greater the degree to which we can say that S contains a harmonic
oscillator. The more complex it is, then the harmonic oscillator is as
much in the mapping as in S.
But is there some natural objective way of making this translation? Can
we say that these translation programs exist out there independent of
people to make them and that they make some objective sense out of
dead strings in Platonia?
Further, these mappings are completely arbitrary, since they not only
depend on the coding in the input, which isn't known a-priori, but on
the design of the program that's testing the harmonic oscilatorness
of the string. It could happen that by accident, a string which is
the output of a program that simulates a dancing Santa could pass the
harmonic oscillatorness test.
This argument gains strength when we are dealing with an object more
complex than a harmonic oscillator. If the object we are testing for
is so complex that it takes billions of bits to specify, then as long
as the mapping program is substantially smaller than that size, we have
an excellent reason to believe that the object is really in S.
Hmm... I vaguely see your point but remain unconvinced that there is
something objective about the mapping.
Now, I have cheated in one regard. I don't know of an objective way of
judging whether the mapping program is simple. There are some results
in algorithmic information theory which go part way in this direction,
but there seem to be loopholes that are hard to avoid. So things are not
quite as simple as I have said, but I think the thrust of the argument
shows the direction to pursue.
I don't have as much problem with the simplicity of the mapping as
with the objective existence of it. I could provisionally accept that
there is some objective meaning to simplicity but I wouldn't be
yet satisfied.
Eric.
