Hi Quentin,

concerning "finite/infinite" number of steps, it seems to me that it is always possible to have a computation that will take an infinite number of steps to arrive at a particular state, since for any state, thereexists an infinity of computational histories which go through it, soitseems to me that some of them needs infinite steps... Do I miss something ?

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`Yes. My fault. I was not clear enough. First it is obvious that any`

`states in the execution of the DU has only a finite 3-computations.`

`But, as you say, any states belong to an infinite set of computations,`

`and this justifies that from the first person point of view we can have`

`infinite past. I should have mention the 1-3 difference. Apology. (But`

`I would not say that some state *needs* an infinite 3-computation, that`

`one would not even be generated by the DU.`

Regards, Bruno

Sincerely, Quentin Anciaux Le lundi 13 juin 2005 à 15:37 +0200, Bruno Marchal a écrit :I agree with everything you say in this post, but I am not sure that settles the issue. It does not change my mind on the preceding post where we were disagreeing; which was that IF I must choose between A) splitted between 10000 finite hells and 1 infinite paradise B) Splitted between 1 infinite hell and 10000 finite paradises where "finite" and "infinite" refer to the number of computational steps simulating the stories of thoise hells and paradises, THEN I should choose A. This is because all finite stories have a measure "0". Infinitestories, by their "natural" DU multiplications will have a measureone.But we are on the verge of inconsistency, because in practice there is no way to garantie anything like the finiteness of any computation going through our states (this is akin to the insolubility of the self-stopping problem by sufficiently rich (lobian) turing machine). The idea that I try to convey is that if I am in state S1, the probability of some next state S2 depends on the proportion, among the infinite stories going through S1 of those *infinite* stories going also through S2. And all finite stories must be discounted. (It is not necessary I remain "personally" immortal in those infinite stories, the measure is given by the stories going through my states even if I have a finite 3-life-time in all of those stories).(btw, this entails also that comp implies at least infinite pastand/orfuture for any universes supporting our present story). [Note that here I am going far ahead of what I can ask to the lobian machine, because our talk involves quantifiers on stories and that'svery complex to handle. Well, to be sure I have till now only beenableto translate the case of "probability one", in machine term; but it is enough to extract non trivial information on the logic of "observable" proposition.] Bruno Le 13-juin-05, à 13:00, Stathis Papaioannou a écrit :I have been arguing in recent posts that the absolute measure of an observer moment (or observer, if you prefer) makes no possibledifference at the first person level. A counterargument has beenthat,even if an observer cannot know how many instantiations of him are being run, it is still important in principle to take the absolutemeasure into account, for example when considering the total amountofsuffering in the world. The following thought experiment shows how, counterintuitively, sticking to this principle may actually be doing the victims a disservice: You are one of 10 copies who are being tortured. The copies are all being run in lockstep with each other, as would occur if 10 identicalcomputers were running 10 identical sentient programs. Assume thatthetorture is so bad that death is preferable, and so bad that escaping it with your life is only marginally preferable to escaping it by dying (eg., given the option of a 50% chance of dying or a 49% chance of escaping the torture and living, you would take the 50%). Thetorture will continue for a year, but you are allowed one of 3choicesas to how things will proceed:(a) 9 of the 10 copies will be chosen at random and painlesslykilled,while the remaining copy will continue to be tortured. (b) For one minute, the torture will cease and the number of copies will increase to 10^100. Once the minute is up, the number of copies will be reduced to 10 again and the torture will resume as before. (c) the torture will be stopped for 8 randomly chosen copies, and continue for the other 2. Which would you choose? To me, it seems clear that there is an 80% chance of escaping the torture if you pick (c), while with (a) it is certain that the torture will continue, and with (b) it is certain that the torture will continue with only one minute of respite. Are there other ways to look at the choices? It might be argued thatin (a) there is a 90% chance that you will be one of the copies whoiskilled, and thus a 90% chance that you will escape the torture,betterthan your chances in (c). However, even if you are one of the ones killed, this does not help you at all. If there is a successor observer moment at the moment of death, subjectively, your consciousness will continue. The successor OM in this case comes from the one remaining copy who is being tortured, hence guaranteeing that you will continue to suffer. What about looking at it from an altruistic rather than selfish viewpoint: isn't it is better to decrease the total suffering in the world by 90% as in (a) rather than by 80% as in (c)? Before makingplans to decrease suffering, ask the victims. All 10 copies willpleadwith you to choose (c).What about (b)? ASSA enthusiasts might argue that with this choice,anOM sampled randomly from the set of all possible OM's will almost certainly be from the one minute torture-free interval. What would this mean for the victims? If you interview each of the 10 copies before the minute starts, they will tell you that they are currently being tortured and they expect that they will get one minute respite, then start suffering again, so they wish the choice had been (c). Next, if you interview each of the 10^100 copies they will tell you that the torture has stopped for exactly one minute by the torture chambre's clock, but they know that it is going to start again andthey wish you had chosen (c). Finally, if you interview each of the10copies for whom the torture has recommenced, they will report that they remember the minute of respite, but that's no good to them now, and they wish you had chosen (c). --Stathis Papaioannou _________________________________________________________________ Express yourself instantly with MSN Messenger! Download today - it's FREE! http://messenger.msn.click-url.com/go/onm00200471ave/direct/01/http://iridia.ulb.ac.be/~marchal/

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