Re: Quantum Suicide without suicide
On Thursday, January 9, 2003, at 08:22 PM, George Levy wrote: OK. Let's consider the case of the guy dying of cancer and playing the stock market simultaneously.. In real life, the hard part is to get meaningful probability data. For the sake of the argument let's assume the following scenario: ..scenario elided, not to mislead, but because I will not be using any details of the calculation... As we can see, the rate of return for Alice is 4.8 times that of Bob. Alice will make a profit, but not Bob. Conclusions: All this involves really basic probability theory. The first person perspective probability is identical to the probability conditional to the person staying alive. The probability of the event in question (stock going up) must be tied to the person staying alive ( a cure for cancer). In the case of a conventional QS suicide to world conditions matching the requested state: ie. winning one million dollars. In the deathrow case one could imagine a scenario in which the event in question (DNA test discovery) is tied to a reprieve from the governor coming because of a DNA test exhonerating the prisoner. The prisoner could bet on DNA testing as a good investment. The airline case is similar. The hard part is figuring the probability of very unlikely saving events such as a scientific discovery, ET landing on earth or the coming of the messiah :-) How is this different from standard life insurance arguments, where buying a policy is betting one will die and not buying a policy is betting one will live? If one has no heirs to worry about, no concern about the world if and after one dies, then it has been known for a long time that the smart thing to do is not to buy life insurance. If one dies, the policy payoff is worthless (to the dead person), but if one lives, the money has been saved. Similar calculations are very simple for going into a dangerous situation: take a bet, at nearly any odds, that one will live. If the odds of survival in going into a combat situation are one in a hundred, and betting odds reflect this, bet everything one can on survival. If one dies, the $10,000 lost is immaterial. If one lives, one has a payout of roughly a million dollars. The scenario with cancer cures and doctors and quackery and all just makes this standard calculation more complicated. And instead of couching this in terms of bets (or stock investments), one can phrase it in standard terms for high risk jobs: Your chance of succeeding is one in a hundred. But if you succeed, one million dollars awaits you. (I doubt many would take on such a job. But with varying payouts, we all take on similar sorts of jobs. For example, flying on business.) It's a reason some people take on very risky jobs. They figure if they succeed, they'll be rich. If they fail, they'll be dead and won't care. (Certainly not many people think this way, but some do. But betting on yourself is not quantum suicide in any way I can see. It's just a straightforward calculation of odds and values of things like money (of no value if dead, for example) in the main outcomes. Lastly, like most many worlds views, the same calculations apply whether one thinks in terms of actual other worlds or just as possible worlds in the standard probability way (having nothing to do with quantum mechanics per se). Or so I believe. I would be interested in any arguments that the quantum view of possible worlds gives any different measures of probability than non-quantum views give. (If there is no movement between such worlds, the quantum possible worlds are identical to the possible worlds of Aristotle, Leibniz, Borges, C.I. Lewis, David Lewis, Stalnaker, Kripke, and others.) --Tim May How we burned in the prison camps later thinking: What would things have been like if every security operative, when he went out at night to make an arrest, had been uncertain whether he would return alive? --Alexander Solzhenitzyn, Gulag Archipelago
Re: Quantum Suicide without suicide
This is a reply to Eric Hawthorne and Tim May. Eric Hawthorne wrote: George Levy wrote: Conclusions: All this involves really basic probability theory. The first person perspective probability is identical to the probability conditional to the person staying alive. But that first-person probability is not objective, true. It is a first person point of view. and not valid, and not useful. not true as the example demonstrates Consider this from a purely pragmatic point of view. (Not a formal argument per say.) A person must consider the (non-zero) objective probability that they will die (and be then non-existent) (if they do this or that action). If people did not account for the probability that they will die if they do a foolish act, then they will probably die. Their subjective 1st person sense of probability is naively optimistic and not a survival trait. If a person acts with that kind of probability belief in every possible world, they will reduce their measure beyond measure. Surely there is something incorrect about a probability view which has that detrimental effect on one's measure. Reread the example. The way the example is set up, the probability of Alice's survival is not affected one iota by her investment. It remains constant with a value of 20% whether she buys the stock or not. The issue the example intends to illustrate is her decision with regard her return on investment. Of course one could construct another example where her survival is decreased (as in conventional QS) or increased (Alice's investment has an impact on Charles' research and makes Charles' success more probable). But that is another story. As I mentioned earlier, if measure is infinite, there may not be any sense in talking about increasing or decreasing absolute measure. If absolute measure did have meaning, one's measure should keep decreasing as one ages since the cumulative probability of one's dying increases with age. Yet from a subjective viewpoint an old man and a young man have the same measure. A concept that I discussed a few months ago, was the extension of the Cosmological Principle to the manyworld. The Cosmological Principle asserts that the universe is uniform in the large scale, independently of where the observer is positioned. An extension of this principle that supported the Steady State theory asserted that the universe looked the same at any time in its history. This extension has been discredited by the evidence for an expanding universe. However, one could argue that the reason the Cosmological Principle does not work is that the scope of its application is not large enough. With the Manyworld (or in the limit, the Plenitude) we are bound to have the largest possible scope possible, and therefore the Cosmological Principle should work. The Cosmological Principle is also appealing in that it describes the Manyworld with the smallest amount of information possible. Thus the Cosmological Principle applied to the Manyworld states that measure is independent of the position of the observer. If the Cosmological Principle holds then we should not have to worry about absolute measure. Tim May wrote: On Thursday, January 9, 2003, at 08:22 PM, George Levy wrote: OK. Let's consider the case of the guy dying of cancer and playing the stock market simultaneously.. In real life, the hard part is to get meaningful probability data. For the sake of the argument let's assume the following scenario: ..scenario elided, not to mislead, but because I will not be using any details of the calculation... As we can see, the rate of return for Alice is 4.8 times that of Bob. Alice will make a profit, but not Bob. Conclusions: All this involves really basic probability theory. The first person perspective probability is identical to the probability conditional to the person staying alive. The probability of the event in question (stock going up) must be tied to the person staying alive ( a cure for cancer). In the case of a "conventional" QS suicide to world conditions matching the requested state: ie. winning one million dollars. In the deathrow case one could imagine a scenario in which the event in question (DNA test discovery) is tied to a reprieve from the governor coming because of a DNA test exhonerating the prisoner. The prisoner could bet on DNA testing as a good investment. The airline case is similar. The hard part is figuring the probability of very unlikely saving events such as a scientific discovery, ET landing on earth or the coming of the messiah :-) How is this different from standard life insurance arguments, where buying a policy is betting one will die and not buying a policy is betting one will live? If one has no heirs to worry about, no concern about the world if and after one dies, then it has been known for a long time that the "smart" thing to do is not to buy life insurance. If one
Re: Quantum suicide without suicide
Hi Brent. Brent Meeker wrote: I don't understand the point of this modification. The idea of QS was to arrange that in all possible worlds in which I exist, I'm rich. If it's just a matter of being rich in a few and not rich in the rest, I don't need any QS. Yes but you only want to know those worlds where you are rich. You don't want to be in those worlds where your are poor. In this example I only intended to pinpoint the crux of consciousness in relation to QS experiment and to show how altering a minimum amount in the memory of the observer changes his frame of reference. George
Re: Quantum suicide without suicide
Tim May wrote On Wednesday, January 8, 2003, at 10:58 AM, George Levy wrote: In the original verision of Quantum Suicide (QS), as understood in this list, the experimenter sets up a suicide machine that kills him if the world does not conform to his wishes. Hence, in the branching many-worlds, his consciousness is erased in those worlds, and remains intact in the worlds that do satisfy him. Is it possible to perform such a feat without suicide? What is the minimum attrition that is required and still get the effect of suicide? Hawking had a good line: When I hear about Schrodinger's Cat, I reach for my gun. Good line? I would say it is rather stupid (with all my respect for Hawking). Come on. The Schroedinger's Cat paper is one of the deepest early paper on QM conceptual issues. The notion of entanglement appears in it. It prepares both EPR and quantum computing, which arises from taking seriously the QM superpositions. You can only mock Schroedinger's Cat by taking a purely instrumentalist view of QM, and with such a view quantum computing would not have appear. Slightly modify the QS conditions in another direction: instead of dying immediately, one goes onto death row to await execution. Or one is locked in a box with the air running out. And so on. This removes the security blanket of saying Suicide is painless, and in all the worlds you have not died in, you are rich! In 99....99% of all worlds, you sit in the box waiting for the air to run out. It reminds me a novel I wrote (a long time ago) where computationalist practitioners always wait for complete reconstitution before annihilating the original. It can be consider as a fair practice letting imagine the risk of such immortality use. I don't know if there are other worlds in the DeWitt/Graham sense (there is no reason to believe Everett ever thought in these terms), but if they exist they appear to be either unreachable by us, or inaccessible beyond short times and distances (coherence issues). I disagree. It is only by playing with word that you can suppress the many worlds in Everett. Some of Everett's footnote are rather explicit. See the Michael Clive Price FAQ for more on this. http://www.hedweb.com/everett/everett.htm People like Roland Omnes which agree with pure QM (QM without collapse) and still postulate a unique world acknowledge their irrationality. In particular, it seems to me there's a causal decision theory argument which says that one should make decisions based on the maximization of the payout. And based on everything we observe in the world around us, which is overwhelmingly classical at the scales we interact in, this means the QS outlook is deprecated. You confuse first and third person point of view. If you put yourself at the place of Schroedinger Cat you will survive in company of people which will *necessarily* be more and more astonished, and which should continue to bet you will not survive. Although *where* you will survive they will lose their bets. Consider this thought experiment: Alice is facing her quantum mechanics exam at Berkeley. She sees two main approaches to take. First, study hard and try to answer all of the questions as if they mattered. Second, take the lessons of her QS readings and simply _guess_, or write gibberish, killing herself if she fails to get an A. (Or, as above, facing execution, torture, running out of air, etc., just to repudiate the suicide is painless aspect of some people's argument.) From rationality, or causal decision theory, which option should she pick? It depends of Alice's goal. If she just want the diplom (and not the knowledge corresponding to the field she studies) then QS is ok, but quite egoist and vain at some other level. If she want the knowledge, she will be unable to find a working criteria for her quantum suicide. By the Benacerraf principle we cannot know our own level of implementation code. (I use comp here). All indications are that there are virtually no worlds in which random guessers do well. Of course! From a 3-person point of view quantum suicide is ordinary suicide. Tegmark (and myself before in french) made this completely clear. Also, it is an open problem if some feature in the apparition of life or even matter-appearance does not rely on some quantum guess. (The odds are readily calcuable, given the type of exam, grading details, etc. We can fairly easily see that a random guesser in the SATs will score around 550-600 combined, but that a random guesser in a non-multiple-choice QM exam will flunk with ovewhelming likelihood.) What should one do? What did all of you actually do? What did Moravec do, what did I do, what did Tegmark do? I think the QS point is not practical, and it is highly unethical. It is the most egoist act possible. But QS just illustrate well conceptual nuances in the possible interpretation of QM and MWI. Bruno
Re: Quantum suicide without suicide
Thanks Bruno, for your comments, I fully agree with you. Let me add a few comments for Tim and Scerir Tim May wrote: Consider this thought experiment: Alice is facing her quantum mechanics exam at Berkeley. She sees two main approaches to take. First, study hard and try to answer all of the questions as if they mattered. Second, take the lessons of her QS readings and simply _guess_, or write gibberish, killing herself if she fails to get an "A." (Or, as above, facing execution, torture, running out of air, etc., just to repudiate the "suicide is painless" aspect of some people's argument.) What should one do? What did all of you actually do? What did Moravec do, what did I do, what did Tegmark do? Tim, this example is completely inapplicable to the case of QS just like you would not set up a relativistic experiment to measure the slowing of a clock in which the clock travels one mile per hour. To get significant results you must travel a significant fraction of the speed of light. QS decisions are significantly different from "classical" decisions when the life of the experimenter is at stake, (or as I pointed out earlier the memory of the quantum suicide machine in the mind of the experimenter must be at stake). The amount "at stake" does not have to be 100% as I shall explain below. Even intentional death (suicide) is not necessary. The incoming death may be entirely unintentional! This reminds me of a science fiction story I read about 30 years ago in which the end of the world was forecasted for midnight. A zealous journalist was faced with preparing a story to be published the next day (after the world ended.) He accomplished the task by stating in the story that the forecast was in fact in error and that the world had not ended. In the branch of the manyworld, in which he remained alive, his story was right, and he therefore, astonished the public with his prescience. He made the right QS decision. As you can see, suicide is not necessary. One could be on death row - in other words have a high probability of dying - and make decisions based on the probability of remaining alive. Being on death row, dying of cancer, travelling on an airline, or sleeping in our bed involve different probability of death... These situations only differ in degrees. We are all in the same boat so to speak. We are all likely to die sooner or later. The closer the probability of death, the more important QS decision becomes. The guy on death row must include in his QS decision making the factor that will save his life: probably a successful appeal or a reprieve by the state governor. The person flying in an airline should include in his QS decision process the fact that the plane will not have a mechanical failure or be hijacked. The person dying of cancer must include the possibility of finding a cure to cancer, or of being successfully preserved somehow by cryogenic means. As you see, suicide is not necessary for QS decisions. In addition the whole issue of "measure" is in my opinion suspect as I have already extensively stated on this list. See below. Scerir wrote Lev Vaidman wrote that we must care about all our 'successive' worlds in proportion to their measures of existence [Behavior Principle]. He does not agree to play the 'quantum Russian roulette' because the measure of existence of worlds with himself dead is be much larger than the measure of existence of the worlds with himself alive and rich! I agree that QS is unethical. Yet, the reasons given by Vaidman could be unjustified because maximizing measure may not be possible if measure is already infinite - a clue that measure is infinite is that the manyworld seem to vary according to a continuum since schroedinger function is continuous. George
Re: Quantum suicide without suicide
From: Tim May [EMAIL PROTECTED] Date: Thu Jan 9, 2003 1:22:32 PM US/Pacific To: [EMAIL PROTECTED] Subject: Re: Quantum suicide without suicide On Thursday, January 9, 2003, at 12:32 PM, George Levy wrote: As you can see, suicide is not necessary. One could be on death row - in other words have a high probability of dying - and make decisions based on the probability of remaining alive. Being on death row, dying of cancer, travelling on an airline, or sleeping in our bed involve different probability of death... These situations only differ in degrees. We are all in the same boat so to speak. We are all likely to die sooner or later. The closer the probability of death, the more important QS decision becomes. The guy on death row must include in his QS decision making the factor that will save his life: probably a successful appeal or a reprieve by the state governor. No, this is the good news fallacy of evidential decision theory, as discussed by Joyce in his book on Causal Decision Theory. The good news fallacy is noncausally hoping for good news, e.g., standing in a long line to vote when the expected benefit of voting is nearly nil. (But if everyone thought that way, imagine what would happen! Indeed.) The guy on death row should be looking for ways to causally influence his own survival, not consoling himself with good news fallacy notions that he will be alive in other realities in which the governor issues a reprieve. The quantum suicide strategy is without content. As you see, suicide is not necessary for QS decisions. No, I don't see this. I don't see _any_ of this. Whether one supports Savage or Jefferys or Joyce or Pearl, I see no particular importance of quantum suicide to the theory of decision-making. It would help if you gave some concrete examples of what a belief in quantum suicide means for several obvious examples: -- the death row case you cited -- the airplane example you also cited -- Newcomb's Paradox (discussed in Pearl, Joyce, Nozick, etc.) -- stock market investments/speculations --Tim May
Quantum suicide without suicide
In the original verision of Quantum Suicide (QS), as understood in this list, the experimenter sets up a suicide machine that kills him if the world does not conform to his wishes. Hence, in the branching many-worlds, his consciousness is erased in those worlds, and remains intact in the worlds that do satisfy him. Is it possible to perform such a feat without suicide? What is the minimum attrition that is required and still get the effect of suicide? Here is a thought experiment that illustrates that this may be possible. There is a cost - it is not death - just a tiny weeny lobotomy. :-) All the experimenter has to do is set up his machine to erase the portion of his memory that stores the information dealing with the machine erasing from his mind the information about the machine erasing from his mind the information about the machine erasing from his mind the portion of his memory dealing with the experiment, (phew! I thought I was going into infinite regress!) and then have the machine erase (or destroy) itself without a trace (this is important to maintain consistency). The outcome of the experiment in the many-world branches is as follows: 1) in some branches the experimenter's wishes are satisfied and he remembers the experiment. His world is consistent. 2) in the other branches the experimenter's wishes are not satisfied, and he does not recall performing the experiment. Whether he as done the experiment or not is not subjectively material to him. His world is consistent. What can we deduce from this? I don't really know for sure but I 'd like to discuss it. 1) The erasing of the memory of the quantum suicide machine seems to be the minimum required in terms of information deletion. Why? What does the memory of the quantum suicide machine have to do with consciousness? Is the infinite regress relevent? - this infinite regress describing this machine erasing from his mind the information about the machine erasing from his mind the information about the machine erasing from his mind the information about the machine erasing from his mind the information about the machine... ? 2) The other worlds in which the experimenter's wishes are not satisfied are of two kinds. A) those worlds where he did not perform the experiment, and of course have no memory of performing the experiment B) those worlds where he did perform the experiment but does not remember performing the experiment because of the lobotomy. In my opinion those worlds are equivalent because I believe in a subjective reality. But of course, many of you will disagree. 3) The lobotomy was a way to shift the experimenter subjective frame of reference. How does the knowledge of the machine affect the frame of reference? What is the essence of the frame of reference? George Levy
Re: Quantum suicide without suicide
On Wednesday, January 8, 2003, at 10:58 AM, George Levy wrote: In the original verision of Quantum Suicide (QS), as understood in this list, the experimenter sets up a suicide machine that kills him if the world does not conform to his wishes. Hence, in the branching many-worlds, his consciousness is erased in those worlds, and remains intact in the worlds that do satisfy him. Is it possible to perform such a feat without suicide? What is the minimum attrition that is required and still get the effect of suicide? Hawking had a good line: When I hear about Schrodinger's Cat, I reach for my gun. Slightly modify the QS conditions in another direction: instead of dying immediately, one goes onto death row to await execution. Or one is locked in a box with the air running out. And so on. This removes the security blanket of saying Suicide is painless, and in all the worlds you have not died in, you are rich! In 99....99% of all worlds, you sit in the box waiting for the air to run out. I don't know if there are other worlds in the DeWitt/Graham sense (there is no reason to believe Everett ever thought in these terms), but if they exist they appear to be either unreachable by us, or inaccessible beyond short times and distances (coherence issues). In particular, it seems to me there's a causal decision theory argument which says that one should make decisions based on the maximization of the payout. And based on everything we observe in the world around us, which is overwhelmingly classical at the scales we interact in, this means the QS outlook is deprecated. Consider this thought experiment: Alice is facing her quantum mechanics exam at Berkeley. She sees two main approaches to take. First, study hard and try to answer all of the questions as if they mattered. Second, take the lessons of her QS readings and simply _guess_, or write gibberish, killing herself if she fails to get an A. (Or, as above, facing execution, torture, running out of air, etc., just to repudiate the suicide is painless aspect of some people's argument.) From rationality, or causal decision theory, which option should she pick? All indications are that there are virtually no worlds in which random guessers do well. (The odds are readily calcuable, given the type of exam, grading details, etc. We can fairly easily see that a random guesser in the SATs will score around 550-600 combined, but that a random guesser in a non-multiple-choice QM exam will flunk with ovewhelming likelihood.) What should one do? What did all of you actually do? What did Moravec do, what did I do, what did Tegmark do? --Tim May
