Re: objections to QTI
Hal, I agree. It seems clear to me that the urge of nature to increase the entropy of the universe is the engine behind everything we see happening, including life and evolution. Why did life occur? Why, to increase the entropy of the universe! How did life occur? Well, you mix some chemicals together and cook them and proteins appear. Then the proteins assemble themselves into RNA, which starts replicating. It sounds so simple - why, I wonder, haven't we been able to do it ourselves? Maybe if you did this a million times, varying the recipe slightly each time, one of them WOULD work - in a sterile environment which no longer exists on earth. The entropy of the universe was zero or close to it at the moment of the Big Bang, and approaches infinity as expansion makes the universe ever larger and colder. If the universe started contracting, its entropy would get smaller, which nature doesn't allow in large-scale systems. This seems to me an argument in support of perpetual expansion. And where did this mysterious Big Bang come from? A quantum fluctuation of virtual particles I'm told. What, exactly, does that mean? Why? How can 10^119 particles at an extremely hot temperature originate from nothing? So many questions - so little time. Norman - Original Message - From: Hal Ruhl [EMAIL PROTECTED] To: everything-list@eskimo.com Sent: Wednesday, June 01, 2005 11:46 AM Subject: Re: objections to QTI Hi All: In my view life is a component of the fastest path to heat death (equilibrium) in universes that have suitable thermodynamics. Thus there would be a built in pressure for such universes to contain life. Further I like Stephen Gould's idea that complex life arises because evolution is a random walk with a lower bound and no upper bound. The above pressure will always quickly jump start life at the lower bound in such universes by rolling the dice so to speak as much as necessary to do so. Hal Ruhl
Re: objections to QTI
Norman Samish wrote: If the universe started contracting, its entropy would get smaller, which nature doesn't allow in large-scale systems. This seems to me an argument in support of perpetual expansion. From what I've read, if the universe began contracting this would not necessarily cause entropy to decrease, in fact most physicists would consider that scenario (which would mean the 'arrow of time' would reverse during the contraction) pretty unlikely, although since we don't know exactly why the Big Bang started out in a low-entropy state we can't completely rule out a low-entropy boundary condition on the Big Crunch. And where did this mysterious Big Bang come from? A quantum fluctuation of virtual particles I'm told. Whoever told you that was passing off speculation as fact--in fact there is no agreed-upon answer to the question of what, if anything, came before the Big Bang or caused it. Jesse
Re: objections to QTI
On Mon, 6 Jun 2005, Jesse Mazer wrote: Norman Samish wrote: If the universe started contracting, its entropy would get smaller, which nature doesn't allow in large-scale systems. This seems to me an argument in support of perpetual expansion. From what I've read, if the universe began contracting this would not necessarily cause entropy to decrease, in fact most physicists would consider that scenario (which would mean the 'arrow of time' would reverse during the contraction) pretty unlikely, although since we don't know exactly why the Big Bang started out in a low-entropy state we can't completely rule out a low-entropy boundary condition on the Big Crunch. This is quite correct. The idea that there are future as well as past boundary conditions is an extreme minority one. And where did this mysterious Big Bang come from? A quantum fluctuation of virtual particles I'm told. Whoever told you that was passing off speculation as fact--in fact there is no agreed-upon answer to the question of what, if anything, came before the Big Bang or caused it. Jesse Maybe Norman is confusing the rather more legit idea that the *fluctuations* in the Big Bang, that explain why the universe is not completely uniform, come from quantum fluctuations amplified by inflation. This is currently the leading theory for the origin of structure, in that it has quite a lot of successful predictions to its credit. Paddy Leahy
Re: Julian Barbour (was: Re: objections to QTI)
Le 01-juin-05, à 18:49, Patrick Leahy a écrit : I read his book a year or so ago, so may be a bit hazy, but: Pour Bruno: he definitely does not want to talk about space-time capsules. Partly this is motivated by his metaphysical ideas about time, partly by the technicalities of the 3+1 (i.e. space+time, not persons!) approach to GR and the Wheeler-De Witt equation which he advocates. This leads him into severe difficulties, and he has not successfully described how this can be reconciled with the relativity of simultaneity, which he also wants to assert. Barbour regards this as an open question within his theory; others regard it as a fatal objection. Thanks. Very clear. Of course when Barbour says that time is an illusion he really means that the *flow* of time is an illusion, or rather a category error, which is a pretty standard position (e.g. forcefully argued by Deutch in his book). I agree with Deutsch. Note that I don't like to much the word illusion. A more relevant word would be phenomenological (but then that's ugly). Perhaps appearance or first person appearance would be more precise and less misleading than illusion. Although he sometimes speaks as though he denies it, I think if push came to shove he would have to admit that there is an identifiable, objective, structural feature in his (or anybody's) theory of physics which corresponds to time. I hope for him! Bruno http://iridia.ulb.ac.be/~marchal/
Re: objections to QTI
Hi Saibal, Hi Bruno, Patric has already explained Barbour's position (I didn't read his book). Separating space from time is not very natural... I agree. If only because of special relativity. But the very notion of space is quite complex. It is a reason why I find loop gravity more convincing than string theory. In loop gravity a natural quantum theory of space-time is given. In string theory, it looks like we still need a classical space-time background. (With comp there is an appearance of purely subjective (1-person) time with S4Grz, but space doesn't yet appear, although Goldblatt gives a modal analysis of Minkowski space-time which provides some hope it can be done. It is also possible that space is eventually generated by a sort of abstract theory of knots which could emerge from the computations statistics. This is not in my thesis and I'm speculating a little bit. Perhaps one can use a similar method as presented here: http://arxiv.org/abs/math-ph/0008018 to derive the notion of space-time as a first person phenomena. Thanks for the reference. I will take a look on it (when I will be less buzy: those who asked me a paper are so glad with it that they ask me to rewrite the second part making it less technical for a wider audience, but that's work, and new deadline :() Bruno http://iridia.ulb.ac.be/~marchal/
Re: objections to QTI
Thanks for the reference - but I had a problem with it. It shut down my Internet Explorer for some reason. I found this article, which may be the same thing, at http://xxx.lanl.gov/abs/gr-qc/9903045 Norman ~~~ General Relativity and Quantum Cosmology, abstract gr-qc/9903045 From: Carlo Rovelli [view email] Date: Fri, 12 Mar 1999 15:05:25 GMT (40kb) Quantum spacetime: what do we know? Authors: Carlo Rovelli Comments: To appear on: Physics Meets Philosophy at the Planck scale, C Callender N Hugget eds, Cambridge University Press This is a contribution to a book on quantum gravity and philosophy. I discuss nature and origin of the problem of quantum gravity. I examine the knowledge that may guide us in addressing this problem, and the reliability of such knowledge. In particular, I discuss the subtle modification of the notions of space and time engendered by general relativity, and how these might merge into quantum theory. I also present some reflections on methodological questions, and on some general issues in philosophy of science which are are raised by, or a relevant for, the research on quantum gravity. - Original Message - From: scerir [EMAIL PROTECTED] To: everything-list@eskimo.com Sent: Wednesday, June 01, 2005 12:55 PM Subject: Re: objections to QTI Norman Samish wrote: This scenario that you are discussing reminds me of this interview with Julian Barbour where he proposes that time is an illusion. This reminds me of a good paper by Carlo Rovelli (about quantum gravity, GR, space-time, etc.) http://ws5.com/copy/time2.pdf in which he suggests that the temporal aspects of our world have a statistical (thermodynamical) origin, rather than dynamical. Time is our incomplete knoweldge of (the state of) the world. Not sure, though, whether the motto Time is ignorance can solve the question, by SPK, about the quantum, or indeterministic, block universe. s. ~
Julian Barbour (was: Re: objections to QTI)
I read his book a year or so ago, so may be a bit hazy, but: Pour Bruno: he definitely does not want to talk about space-time capsules. Partly this is motivated by his metaphysical ideas about time, partly by the technicalities of the 3+1 (i.e. space+time, not persons!) approach to GR and the Wheeler-De Witt equation which he advocates. This leads him into severe difficulties, and he has not successfully described how this can be reconciled with the relativity of simultaneity, which he also wants to assert. Barbour regards this as an open question within his theory; others regard it as a fatal objection. Of course when Barbour says that time is an illusion he really means that the *flow* of time is an illusion, or rather a category error, which is a pretty standard position (e.g. forcefully argued by Deutch in his book). Although he sometimes speaks as though he denies it, I think if push came to shove he would have to admit that there is an identifiable, objective, structural feature in his (or anybody's) theory of physics which corresponds to time. Reminds me of the opening of a history book: There was no such thing as the Scientific Revolution, and this is a book about it. Paddy Leahy == Dr J. P. Leahy, University of Manchester, Jodrell Bank Observatory, School of Physics Astronomy, Macclesfield, Cheshire SK11 9DL, UK Tel - +44 1477 572636, Fax - +44 1477 571618
Re: objections to QTI
Hi All: In my view life is a component of the fastest path to heat death (equilibrium) in universes that have suitable thermodynamics. Thus there would be a built in pressure for such universes to contain life. Further I like Stephen Gould's idea that complex life arises because evolution is a random walk with a lower bound and no upper bound. The above pressure will always quickly jump start life at the lower bound in such universes by rolling the dice so to speak as much as necessary to do so. Hal Ruhl At 10:13 PM 5/31/2005, you wrote: Norman Samish wrote: [Responding to Russell Standish] This article, as you point out, asserts that the rapidity of biogenesis on Earth suggests that life is common in the Universe. This assertion is shown to be probably correct with some reasonable assumptions. One of the assumptions is that if life occurs here, it must also occur on other terrestrial planets. However, the part that I have trouble with is figuring out exactly how that first living organism was created. (Living means it has the ability to take in energy from the environment and transform the energy for growth and reproduction.) Living requires a highly organized and complex mechanism - that humans, so far, have not been able to create. I can't imagine how such an organism could occur accidentally. I would call that first living organism a miraculous circumstance. I don't see how anyone could say that life is or isn't common in the Universe on the basis of current evidence. It taxes astronomers to the limit at present to discover the existence of enormous gas giants orbiting stars relatively close to Earth. Even in our own solar system, how could we possibly know whether simple or even relatively complex lifeforms are not living in, for example, the huge and hugely complex atmosphere of Jupiter? --Stathis Papaioannou _ SEEK: Over 80,000 jobs across all industries at Australia's #1 job site. http://ninemsn.seek.com.au?hotmail
Re: objections to QTI
Norman Samish This scenario that you are discussing reminds me of this interview with Julian Barbour where he proposes that time is an illusion. This reminds me of a good paper by Carlo Rovelli (about quantum gravity, GR, space-time, etc.) http://ws5.com/copy/time2.pdf in which he suggests that the temporal aspects of our world have a statistical (thermodynamical) origin, rather than dynamical. Time is our incomplete knoweldge of (the state of) the world. Not sure, though, whether the motto Time is ignorance can solve the question, by SPK, about the quantum, or indeterministic, block universe. s.
Re: objections to QTI
- Original Message - From: Bruno Marchal To: Saibal Mitra Subject: Re: objections to QTI Date: Wed, 1 Jun 2005 15:24:56 +0200 Le 01-juin-05, à 15:00, Saibal Mitra a écrit : Hi Norman, I entirely agree with Julian Barbour. A fundamental notion of time would act as a pointer indicating what is real (things that are happening now) and what was real and what will be real. Most of us here on the everything list believe that in a certain sense 'everything exists', so the notion of a fundamental time would be contrary to this idea. I think that that most here on the list would consider time as a first person phenomena Barbour doesn't believe in time at all, let alone fundamental time. Barbour doesn't talk about space-time capsules because he doesn't believe that time exists. Indeed. (SGrz pour those who knows). I would like to know if Norman and Saibal and others agree that there is nothing special with time. Why does not Julian Barbour talk about space-time capsule? (Or does he?) I think space is also a first person phenomena. OK? Bruno http://iridia.ulb.ac.be/~marchal/ I completely disagree with Barbour. Just for the record. -- ___ Sign-up for Ads Free at Mail.com http://promo.mail.com/adsfreejump.htm
Re: objections to QTI
Hi Bruno, Patric has already explained Barbour's position (I didn't read his book). Separating space from time is not very natural... Perhaps one can use a similar method as presented here: http://arxiv.org/abs/math-ph/0008018 to derive the notion of space-time as a first person phenomena. Saibal - Original Message - From: Bruno Marchal [EMAIL PROTECTED] To: Saibal Mitra [EMAIL PROTECTED] Cc: Norman Samish [EMAIL PROTECTED]; everything-list@eskimo.com Sent: Wednesday, June 01, 2005 03:24 PM Subject: Re: objections to QTI Le 01-juin-05, à 15:00, Saibal Mitra a écrit : Hi Norman, I entirely agree with Julian Barbour. A fundamental notion of time would act as a pointer indicating what is real (things that are happening now) and what was real and what will be real. Most of us here on the everything list believe that in a certain sense 'everything exists', so the notion of a fundamental time would be contrary to this idea. I think that that most here on the list would consider time as a first person phenomena Indeed. (SGrz pour those who knows). I would like to know if Norman and Saibal and others agree that there is nothing special with time. Why does not Julian Barbour talk about space-time capsule? (Or does he?) I think space is also a first person phenomena. OK? Bruno http://iridia.ulb.ac.be/~marchal/
Re: objections to QTI
Hi Brent, There's no doubt that my imagination is not up to the task of coming up with reasonable explanations of all that I see. I could never imagine relativity, quantum mechanics, black holes, singularities, the Big Bang, infinite space, the multiverse, and Günter Wächtershäuser's recipe for life. (Boil water. Stir in the minerals iron sulfide and nickel sulfide. Bubble in carbon monoxide and hydrogen sulfide. Wait for proteins to form. - from http://www.resa.net/nasa/links_origins_life.htm#common%20origin). These explanations are too far-fetched for me to ever dream up. Yet if I'm asked to provide answers, these are the only ones I can offer. I think they all qualify as marvelous circumstances. Norman Samish ~~ (Norman writes) However, the part that I have trouble with is figuring out exactly how that first living organism was created. (Living means it has the ability to take in energy from the environment and transform the energy for growth and reproduction.) Living requires a highly organized and complex mechanism - that humans, so far, have not been able to create. I can't imagine how such an organism could occur accidentally. I would call that first living organism a miraculous circumstance. (Brent writes) Maybe it's just a failure of imagination. Could you have imagined quantum mechanics? There are several good theories of how life may have originated on Earth. See The Origins of Life by Maynard Smith and Szathmary and Origins of Life by Freeman Dyson for two of them. Brent Meeker
Re: objections to QTI
Hal, It is possible that miracles will be as uncommon and surprising in your QTI-guaranteed future as they seem to be today. If you live to 1000, unlikely as it sounds at present, shouldn't you expect it to happen in the *least* unlikely way? This may involve advances in medicine initially, then when you are, say, 200 and terminally ill, mind uploading may finally become possible. Your best chance of these things happening is to live in a world where life-prolonging technology becomes generally available (or at least available to the wealthy, which is nothing new), so you are probably *not* going to be unique in living to a very advanced age. So, in answer to your question, finding yourself miraculously alive at 1000 while everyone else dies young would be something extremely unlikely and surprising, no less so if QTI is true, and therefore not evidence in its favour. --Stathis Papaioannou Let me pose the puzzle like this, which is a form we have discussed before: Suppose you found yourself extremely old, due to a near-miraculous set of circumstances that had kept you alive. Time after time when you were about to die of old age or some other cause, something happened and you were able to continue living. Now you are 1000 years old in a world where no one else lives past 120. (We will ignore medical progress for the purposes of this thought experiment.) Now, one of the predictions of QTI is that in fact you will experience much this state, eventually. But the question is this: given that you find yourself in this circumstances, is this fact *evidence* for the truth of the QTI? In other words, should people who find themselves extremely old through miraculous circumstances take it as more likely that the QTI is true? Hal Finney _ REALESTATE: biggest buy/rent/share listings http://ninemsn.realestate.com.au
Re: objections to QTI
Hi Norman, I entirely agree with Julian Barbour. A fundamental notion of time would act as a pointer indicating what is real (things that are happening now) and what was real and what will be real. Most of us here on the everything list believe that in a certain sense 'everything exists', so the notion of a fundamental time would be contrary to this idea. I think that that most here on the list would consider time as a first person phenomena. Saibal -Defeat Spammers by launching DDoS attacks on Spam-Websites: http://www.hillscapital.com/antispam/ - Oorspronkelijk bericht - Van: Norman Samish Aan: everything-list@eskimo.com Verzonden: Monday, May 30, 2005 06:04 PM Onderwerp: Re: objections to QTI Hi Saibal and Stathis, This scenariothat you are discussing reminds me of this interview with Julian Barbour where he proposes that "time" is an illusion. If you agree or disagree with Barbour,I'd like to hear why. http://www.science-spirit.org/article_detail.php?article_id=183 Norman Samish - Original Message - From: "Saibal Mitra" [EMAIL PROTECTED]To: "Stathis Papaioannou" [EMAIL PROTECTED]; everything-list@eskimo.comSent: Monday, May 30, 2005 8:28 AMSubject: Re: objections to QTIHi Stathis,I think that your example below was helpful to clarify the disagreement. You say that randomly sampling from all the files is not 'how real life works'. However, if you did randomly sample from all the files the result would not be different from the selective time ordered sampling you suggest, as long as the effect of dying (reducing the absolute measure) can be ignored. If I'm sampled by the computer, I'll have the recollection of having been a continuum of previous states, even though these states may not have been sampled for quite some while. I'll subjectively experience a linear time evolution. The order in which the computer chooses to generate me at various instances doesn't matter. There are a few reasons why I believe in the ''random sampling''. First of all, random sampling seems to be necessary to avoid the Doomsday Paradox. See this article written by Ken Olum: http://arxiv.org/abs/gr-qc/0009081He explains here why you need the Self Indicating Assumption. The self indicating assumption amounts to adopting an absolute measure that is proportional to the number of observers. Another reason has to do with the notion of time. I don't believe that events that have happened or will happen are not real while events that are happening now are real. They have to be treated in the same way. The fact that I experience time evolution is a first person phenomena. Finally, QTI (which more or less follows if you adopt the time ordered picture), implies that for the most part of your life you should find yourself in an a-typical state (e.g. very old while almost everyone else is very young). -Saibal-- Oorspronkelijk bericht - Van: "Stathis Papaioannou" [EMAIL PROTECTED]Aan: everything-list@eskimo.comVerzonden: Monday, May 30, 2005 04:02 PMOnderwerp: objections to QTI I thought the following analogy might clarify the point I was trying to makein recent posts to the "Many Pasts? Not according to QM" thread, addressingone objection to QTI.You are a player in the computer game called the Files of Life. In this gamethe computer generates consecutively numbered folders which each containmultiple text files, representing the multiple potential histories of theplayer at that time point. Each folder F_i contains N_i files. The firstfolder, F_0, contains N_0 files each describing possible events soon afteryour birth. You choose one of the files in this folder at random, and fromthis the computer generates the next folder, F_1, and places in it N filesrepresenting N possible continuations of the story. If you die going fromF_0 to F_1, that file in F_1 corresponding to this event is blank, andblank files are deleted; so for the first folder N_0=N, but for the nextone N_1=N, allowing for deaths. The game then continues: you choose a fileat random from F_1, from this file the computer generates the next folderF_2 containing N_2 files, then you choose a file at random from F_2, and soon.It should be obvious that if the game is realistic, N_i should decrease withincreasing i, due to death from accidents (fairly constant) + death fromage related disease. The earlier folders will therefore on average containmany more files than the later folders. Now, it is argued that QTI isimpossible because a randomly sampled observer moment from your life is veryunlikely to be from a version of you who is 1000 years old, wh
Re: objections to QTI
Le 01-juin-05, à 15:00, Saibal Mitra a écrit : Hi Norman, I entirely agree with Julian Barbour. A fundamental notion of time would act as a pointer indicating what is real (things that are happening now) and what was real and what will be real. Most of us here on the everything list believe that in a certain sense 'everything exists', so the notion of a fundamental time would be contrary to this idea. I think that that most here on the list would consider time as a first person phenomena Indeed. (SGrz pour those who knows). I would like to know if Norman and Saibal and others agree that there is nothing special with time. Why does not Julian Barbour talk about space-time capsule? (Or does he?) I think space is also a first person phenomena. OK? Bruno http://iridia.ulb.ac.be/~marchal/
Re: objections to QTI - erratum
I should have said, you could *not* just take any files from any folder and cobble together an individual history... For example, the version of me that got this sentence right the first time has split off and spawned a whole new set of files/OM's, none of which can be incorporated into the history of the version writing this erratum, unless purely by chance they happen to fit in. --Stathis Papaioannou I think that your example below was helpful to clarify the disagreement. You say that randomly sampling from all the files is not 'how real life works'. However, if you did randomly sample from all the files the result would not be different from the selective time ordered sampling you suggest, as long as the effect of dying (reducing the absolute measure) can be ignored. You would have to follow the branching pattern as defined by the program. I suggested that one file is chosen at random from each folder and a new folder generated from this file. It would be very resource-hungry, but it is simple enough to imagine the computer generating the entire multiverse, i.e. each file branching out to a new folder, each file in each new folder branching out to another new folder, and so on. This would generate all the OM's associated with an individual. However, you could *not* just take any files from any folder and cobble together an individual history, which is what would happen if you sample files at random. To create an individual history, you have to trace a single path through the (perhaps infinitely) branching tree, which is a very different matter. This is true even if you ignore the effect of dying, so each folder/time slice has the same number of files/same measure. _ Express yourself instantly with MSN Messenger! Download today - it's FREE! http://messenger.msn.click-url.com/go/onm00200471ave/direct/01/
Re: objections to QTI
Dear Prof. Standish, Thanks for the quibbles, which sound reasonable. However, I'm going to stand my ground. You gave this reference about life's origins. (I found it at http://arxiv.org/PS_cache/astro-ph/pdf/0209/0209385.pdf) This article, as you point out, asserts that the rapidity of biogenesis on Earth suggests that life is common in the Universe. This assertion is shown to be probably correct with some reasonable assumptions. One of the assumptions is that if life occurs here, it must also occur on other terrestrial planets. However, the part that I have trouble with is figuring out exactly how that first living organism was created. (Living means it has the ability to take in energy from the environment and transform the energy for growth and reproduction.) Living requires a highly organized and complex mechanism - that humans, so far, have not been able to create. I can't imagine how such an organism could occur accidentally. I would call that first living organism a miraculous circumstance. As for all of today's humans coming from 2000 breeders 70,000 years ago, you point out that this may merely mean that natural selection caused other, inferior, Neanderthal lines to disappear. This does not necessarily mean that some disaster had reduced the numbers of our breeding ancestors to 2,000, as I assumed. However, a natural disaster did occur approximately 70,000 years ago, according to http://www.olympus.net/personal/ptmaccon/pif/time_lines/time_lines_4.html This source says, Largest volcanic eruption in 400 million years, producing 2500-3000 kilometers of ash, and 1 trillion tons of aerosols. Cloud was more than 34 kilometers high. Ash covers India between 1 and 6 meters deep. (May have started folllowing cooling period). 6 year period during which the largest amount of volcanic sulphur was deposited in the past 110,000 years, followed by 1000 years of the lowest ice core oxygen isotope ratios, temperatures were colder than during the Last Glacial Maximum at 18 - 21,000 years ago. Sea level was 160 feet below current. Global temperature drops average of 21 degrees. Volcanic Winter lasted about six years. It was followed by 1,000 years of the coldest Ice Age on record. Warming begins again 1,000 years later. Believed that the 1% human genetic variation stems from this time. No other species shows such a small variation. Genetic evidence suggests only 1,000 adults survived world wide. May be event which caused rise in modern racial differences - Professor Stanley Ambrose of the University of Illinois. This article suggests that near-extinction of humans did occur. Norman Samish Minor quibbles, which don't actually detract from your argument: On Mon, May 30, 2005 at 01:19:28PM -0700, Norman Samish wrote: 1) How did life originate if not through a miraculous circumstance? In other branches of the multiverse, perhaps most of them, there is no life. There is evidence that life might arise fairly easily, given the right conditions. This is the so-called early appearance of life argument. See arXiv:astro-ph/0209385. 2) An article at http://news-service.stanford.edu/news/2003/may28/humans-528.html suggests that all of earth's present human inhabitants originated from about 2,000 breeders, about 70,000 years ago. Humans were then very close to extinction. In many other branches of the multiverse extinction did, in fact, occur. Endangerment of a species does not follow from a genetic bottleneck. Consider a beneficial mutation arising 70,000 years ago, and rapidly increasing to 100% fixation within the human population. The genetic data would point to us all being descended from a single Adam or Eve at the time, and the number of individuals whose descendants ultimately breed with Adam or Eve's descendents. All other germ lines are eliminated from the population by natural selection. Thus a genetic bottleneck. However, the breeding population may have been any number - eg 1 million, hardly an endangered species. A/Prof Russell Standish Phone 8308 3119 (mobile) Mathematics 0425 253119 () UNSW SYDNEY 2052 [EMAIL PROTECTED] Australiahttp://parallel.hpc.unsw.edu.au/rks International prefix +612, Interstate prefix 02
Re: objections to QTI
On Mon, May 30, 2005 at 11:46:08PM -0700, Norman Samish wrote: Dear Prof. Standish, Thanks for the quibbles, which sound reasonable. However, I'm going to stand my ground. You gave this reference about life's origins. (I found it at http://arxiv.org/PS_cache/astro-ph/pdf/0209/0209385.pdf) This article, as you point out, asserts that the rapidity of biogenesis on Earth suggests that life is common in the Universe. This assertion is shown to be probably correct with some reasonable assumptions. One of the assumptions is that if life occurs here, it must also occur on other terrestrial planets. This is not really assumed, but shown to be a more likely occurance given the rapidity of biogenesis, than not. However, the part that I have trouble with is figuring out exactly how that first living organism was created. (Living means it has the ability to take in energy from the environment and transform the energy for growth and reproduction.) Living requires a highly organized and complex mechanism - that humans, so far, have not been able to create. I can't imagine how such an organism could occur accidentally. I would call that first living organism a miraculous circumstance. The origin of replicators has been demonstrated in a number of computational system, the first, and probably most famous is Andy Pargellis's Amoeba system. I'd have to do some digging, but I recall having seen one or two other examples. Origin of metabolic cellular structures seems to on the verge of being demonstrated also in artificial media - there is a big push with Norm Packard and Steen Rasmussen in Venice, of all places to do this in chemical milieu. Digital examples might include Ono's artificial chemistry model, and the original model of Autopoeiesis by Francisco Varela. Taking these two steps together, origin of life is within reach. I think this tells us life is perhaps not too hard, but complex multicellular life on the other hand is. As for all of today's humans coming from 2000 breeders 70,000 years ago, you point out that this may merely mean that natural selection caused other, inferior, Neanderthal lines to disappear. This does not necessarily mean that some disaster had reduced the numbers of our breeding ancestors to 2,000, as I assumed. However, a natural disaster did occur approximately 70,000 years ago, according to http://www.olympus.net/personal/ptmaccon/pif/time_lines/time_lines_4.html This source says, Largest volcanic eruption in 400 million years, producing 2500-3000 kilometers of ash, and 1 trillion tons of aerosols. That would be larger than the Deccan Traps then, that occured during the K-T transition approx 65 million years ago. I don't think so. That volcano dumped around half a million cubic kilometres of lava on the Earth according to http://volcano.und.nodak.edu/vwdocs/volc_images/europe_west_asia/india/deccan.html. According to other articles on the 'net, Mt Toba produced about 800 km^3 of material - a bit of a squib compared with the Deccan Traps. Anyway, disredarding the initial hyperbole, it is interesting that there was such a significant environmental impact at the time of this genetic bottleneck. We're not completely out of the woods though. 60-70,000 years ago corresponds the the accepted time for Homo Sapiens to leave Africa - such an event is bound to have a genetic fingerprint also (most of the genetic variation would remain within Africa for example). Also I'm thinking to myself - how come I've never heard of Mt Toba before? Is this some conspiracy on behalf of the Out of Africa theorists, or is the Mt Toba theory somewhat of an exageration. Anyway, cheers. Its always nice to hear a new angle on things. -- *PS: A number of people ask me about the attachment to my email, which is of type application/pgp-signature. Don't worry, it is not a virus. It is an electronic signature, that may be used to verify this email came from me if you have PGP or GPG installed. Otherwise, you may safely ignore this attachment. A/Prof Russell Standish Phone 8308 3119 (mobile) Mathematics0425 253119 () UNSW SYDNEY 2052 [EMAIL PROTECTED] Australiahttp://parallel.hpc.unsw.edu.au/rks International prefix +612, Interstate prefix 02 pgpu7XGz35jja.pgp Description: PGP signature
Re: objections to QTI
Hi Hal, Remember that the chain of events that must lead you to be 1000 years old must be perfectly logical and consistent. A good science fiction writer would have no problem weaving a plot that could bring you to such a situation. One could evoke living in a simulator, or the appearance of aliens capable of prolonging life, etc... This plot would be extremely unlikely but so is our present situation right here and now. So your scenario differs only in degrees from the one we are experiencing right now. Your age depends how you look at it. Our life as a continuous chain from cell to cell has lasted possibly more than 4 billion years. (happy birthday :-) ) So it appears that our existence does justify QTI George Hal Finney wrote: Let me pose the puzzle like this, which is a form we have discussed before: Suppose you found yourself extremely old, due to a near-miraculous set of circumstances that had kept you alive. Time after time when you were about to die of old age or some other cause, something happened and you were able to continue living. Now you are 1000 years old in a world where no one else lives past 120. (We will ignore medical progress for the purposes of this thought experiment.) Now, one of the predictions of QTI is that in fact you will experience much this state, eventually. But the question is this: given that you find yourself in this circumstances, is this fact *evidence* for the truth of the QTI? In other words, should people who find themselves extremely old through miraculous circumstances take it as more likely that the QTI is true? Hal Finney
RE: objections to QTI
-Original Message- From: Norman Samish [mailto:[EMAIL PROTECTED] Sent: Tuesday, May 31, 2005 6:46 AM To: everything-list@eskimo.com Subject: Re: objections to QTI Dear Prof. Standish, Thanks for the quibbles, which sound reasonable. However, I'm going to stand my ground. You gave this reference about life's origins. (I found it at http://arxiv.org/PS_cache/astro-ph/pdf/0209/0209385.pdf) This article, as you point out, asserts that the rapidity of biogenesis on Earth suggests that life is common in the Universe. This assertion is shown to be probably correct with some reasonable assumptions. One of the assumptions is that if life occurs here, it must also occur on other terrestrial planets. However, the part that I have trouble with is figuring out exactly how that first living organism was created. (Living means it has the ability to take in energy from the environment and transform the energy for growth and reproduction.) Living requires a highly organized and complex mechanism - that humans, so far, have not been able to create. I can't imagine how such an organism could occur accidentally. I would call that first living organism a miraculous circumstance. Maybe it's just a failure of imagination. Could you have imagined quantum mechanics? There are several good theories of how life may have originated on Earth. See The Origins of Life by Maynard Smith and Szathmary and Origins of Life by Freeman Dyson for two of them. Brent Meeker
Re: objections to QTI
Norman Samish wrote: [Responding to Russell Standish] This article, as you point out, asserts that the rapidity of biogenesis on Earth suggests that life is common in the Universe. This assertion is shown to be probably correct with some reasonable assumptions. One of the assumptions is that if life occurs here, it must also occur on other terrestrial planets. However, the part that I have trouble with is figuring out exactly how that first living organism was created. (Living means it has the ability to take in energy from the environment and transform the energy for growth and reproduction.) Living requires a highly organized and complex mechanism - that humans, so far, have not been able to create. I can't imagine how such an organism could occur accidentally. I would call that first living organism a miraculous circumstance. I don't see how anyone could say that life is or isn't common in the Universe on the basis of current evidence. It taxes astronomers to the limit at present to discover the existence of enormous gas giants orbiting stars relatively close to Earth. Even in our own solar system, how could we possibly know whether simple or even relatively complex lifeforms are not living in, for example, the huge and hugely complex atmosphere of Jupiter? --Stathis Papaioannou _ SEEK: Over 80,000 jobs across all industries at Australia's #1 job site. http://ninemsn.seek.com.au?hotmail
Re: objections to QTI
Hi Stathis, I think that your example below was helpful to clarify the disagreement. You say that randomly sampling from all the files is not 'how real life works'. However, if you did randomly sample from all the files the result would not be different from the selective time ordered sampling you suggest, as long as the effect of dying (reducing the absolute measure) can be ignored. If I'm sampled by the computer, I'll have the recollection of having been a continuum of previous states, even though these states may not have been sampled for quite some while. I'll subjectively experience a linear time evolution. The order in which the computer chooses to generate me at various instances doesn't matter. There are a few reasons why I believe in the ''random sampling''. First of all, random sampling seems to be necessary to avoid the Doomsday Paradox. See this article written by Ken Olum: http://arxiv.org/abs/gr-qc/0009081 He explains here why you need the Self Indicating Assumption. The self indicating assumption amounts to adopting an absolute measure that is proportional to the number of observers. Another reason has to do with the notion of time. I don't believe that events that have happened or will happen are not real while events that are happening now are real. They have to be treated in the same way. The fact that I experience time evolution is a first person phenomena. Finally, QTI (which more or less follows if you adopt the time ordered picture), implies that for the most part of your life you should find yourself in an a-typical state (e.g. very old while almost everyone else is very young). Saibal - Defeat Spammers by launching DDoS attacks on Spam-Websites: http://www.hillscapital.com/antispam/ - Oorspronkelijk bericht - Van: Stathis Papaioannou [EMAIL PROTECTED] Aan: everything-list@eskimo.com Verzonden: Monday, May 30, 2005 04:02 PM Onderwerp: objections to QTI I thought the following analogy might clarify the point I was trying to make in recent posts to the Many Pasts? Not according to QM thread, addressing one objection to QTI. You are a player in the computer game called the Files of Life. In this game the computer generates consecutively numbered folders which each contain multiple text files, representing the multiple potential histories of the player at that time point. Each folder F_i contains N_i files. The first folder, F_0, contains N_0 files each describing possible events soon after your birth. You choose one of the files in this folder at random, and from this the computer generates the next folder, F_1, and places in it N files representing N possible continuations of the story. If you die going from F_0 to F_1, that file in F_1 corresponding to this event is blank, and blank files are deleted; so for the first folder N_0=N, but for the next one N_1=N, allowing for deaths. The game then continues: you choose a file at random from F_1, from this file the computer generates the next folder F_2 containing N_2 files, then you choose a file at random from F_2, and so on. It should be obvious that if the game is realistic, N_i should decrease with increasing i, due to death from accidents (fairly constant) + death from age related disease. The earlier folders will therefore on average contain many more files than the later folders. Now, it is argued that QTI is impossible because a randomly sampled observer moment from your life is very unlikely to be from a version of you who is 1000 years old, which has very low measure compared with a younger version. The equivalent argument for the Files of Life would be that since the earlier files are much more numerous than the later files, a randomly sampled file from your life (as created by playing the game) is very unlikely to represent a 1000 year old version of you, as compared with a younger version. This reasoning would be sound if the random sampling were done by mixing up all the files, or all the OM's, and pulling one out at random. But this is not how the game works and it is not how real life works. From the first person viewpoint, it doesn't matter how many files are in the folder because you only choose one at each step, spend the same time at each step, and are no more likely to find yourself at one step rather than another. As long as there is at least *one* file in the next folder, it is guaranteed that you will continue living. Similarly, as long as there is at least *one* OM in your future which represents a continuation from your present OM, you will continue living. --Stathis Papaioannou _ Meet 1000s of Aussie singles today at Lavalife! http://lavalife9.ninemsn.com.au/
Re: objections to QTI
Hi Saibal and Stathis, This scenariothat you are discussing reminds me of this interview with Julian Barbour where he proposes that "time" is an illusion. If you agree or disagree with Barbour,I'd like to hear why. http://www.science-spirit.org/article_detail.php?article_id=183 Norman Samish - Original Message - From: "Saibal Mitra" [EMAIL PROTECTED]To: "Stathis Papaioannou" [EMAIL PROTECTED]; everything-list@eskimo.comSent: Monday, May 30, 2005 8:28 AMSubject: Re: objections to QTIHi Stathis,I think that your example below was helpful to clarify the disagreement. You say that randomly sampling from all the files is not 'how real life works'. However, if you did randomly sample from all the files the result would not be different from the selective time ordered sampling you suggest, as long as the effect of dying (reducing the absolute measure) can be ignored. If I'm sampled by the computer, I'll have the recollection of having been a continuum of previous states, even though these states may not have been sampled for quite some while. I'll subjectively experience a linear time evolution. The order in which the computer chooses to generate me at various instances doesn't matter. There are a few reasons why I believe in the ''random sampling''. First of all, random sampling seems to be necessary to avoid the Doomsday Paradox. See this article written by Ken Olum: http://arxiv.org/abs/gr-qc/0009081He explains here why you need the Self Indicating Assumption. The self indicating assumption amounts to adopting an absolute measure that is proportional to the number of observers. Another reason has to do with the notion of time. I don't believe that events that have happened or will happen are not real while events that are happening now are real. They have to be treated in the same way. The fact that I experience time evolution is a first person phenomena. Finally, QTI (which more or less follows if you adopt the time ordered picture), implies that for the most part of your life you should find yourself in an a-typical state (e.g. very old while almost everyone else is very young). -Saibal-- Oorspronkelijk bericht - Van: "Stathis Papaioannou" [EMAIL PROTECTED]Aan: everything-list@eskimo.comVerzonden: Monday, May 30, 2005 04:02 PMOnderwerp: objections to QTI I thought the following analogy might clarify the point I was trying to makein recent posts to the "Many Pasts? Not according to QM" thread, addressingone objection to QTI.You are a player in the computer game called the Files of Life. In this gamethe computer generates consecutively numbered folders which each containmultiple text files, representing the multiple potential histories of theplayer at that time point. Each folder F_i contains N_i files. The firstfolder, F_0, contains N_0 files each describing possible events soon afteryour birth. You choose one of the files in this folder at random, and fromthis the computer generates the next folder, F_1, and places in it N filesrepresenting N possible continuations of the story. If you die going fromF_0 to F_1, that file in F_1 corresponding to this event is blank, andblank files are deleted; so for the first folder N_0=N, but for the nextone N_1=N, allowing for deaths. The game then continues: you choose a fileat random from F_1, from this file the computer generates the next folderF_2 containing N_2 files, then you choose a file at random from F_2, and soon.It should be obvious that if the game is realistic, N_i should decrease withincreasing i, due to death from accidents (fairly constant) + death fromage related disease. The earlier folders will therefore on average containmany more files than the later folders. Now, it is argued that QTI isimpossible because a randomly sampled observer moment from your life is veryunlikely to be from a version of you who is 1000 years old, which has verylow measure compared with a younger version. The equivalent argument forthe Files of Life would be that since the earlier files are much morenumerous than the later files, a randomly sampled file from your life (ascreated by playing the game) is very unlikely to represent a 1000 year oldversion of you, as compared with a younger version. This reasoning would besound if the "random sampling" were done by mixing up all the files, or allthe OM's, and pulling one out at random. But this is not how the game worksand it is not how real life works. >From the first person viewpoint, itdoesn't matter how many files are in the folder because you only choose oneat each step, spend the same time at each step, and are no more likely tofind yourself at one step rather than another. As long as there is at least*one* file in the next folder, it is guaranteed that you will continueliving. Similarly, as long as there is at least *one* OM in your futurewhich
Re: objections to QTI
Let me pose the puzzle like this, which is a form we have discussed before: Suppose you found yourself extremely old, due to a near-miraculous set of circumstances that had kept you alive. Time after time when you were about to die of old age or some other cause, something happened and you were able to continue living. Now you are 1000 years old in a world where no one else lives past 120. (We will ignore medical progress for the purposes of this thought experiment.) Now, one of the predictions of QTI is that in fact you will experience much this state, eventually. But the question is this: given that you find yourself in this circumstances, is this fact *evidence* for the truth of the QTI? In other words, should people who find themselves extremely old through miraculous circumstances take it as more likely that the QTI is true? Hal Finney
Re: objections to QTI
Hal, I believe that many miraculous circumstances have already occurred. This comes about because of Tegmark's hypothesis that space is infinite and that any universe that is mathematically describable must exist. (I particularly love the part where he computes the distance to a universe identical to this one.) 1) How did life originate if not through a miraculous circumstance? In other branches of the multiverse, perhaps most of them, there is no life. 2) An article at http://news-service.stanford.edu/news/2003/may28/humans-528.html suggests that all of earth's present human inhabitants originated from about 2,000 breeders, about 70,000 years ago. Humans were then very close to extinction. In many other branches of the multiverse extinction did, in fact, occur. 3) Would humans have survived if the cold war had erupted into a nuclear exchange? In other branches of the multiverse, humans did self-destruct (and may do so in this one). 4) In my personal history, there are several close calls where I could easily have been killed. In some branches of the multiverse I was, in fact, killed. In this branch I survive. Norman Samish - Original Message - From: Hal Finney [EMAIL PROTECTED] To: everything-list@eskimo.com Sent: Monday, May 30, 2005 9:23 AM Subject: Re: objections to QTI Let me pose the puzzle like this, which is a form we have discussed before: Suppose you found yourself extremely old, due to a near-miraculous set of circumstances that had kept you alive. Time after time when you were about to die of old age or some other cause, something happened and you were able to continue living. Now you are 1000 years old in a world where no one else lives past 120. (We will ignore medical progress for the purposes of this thought experiment.) Now, one of the predictions of QTI is that in fact you will experience much this state, eventually. But the question is this: given that you find yourself in this circumstances, is this fact *evidence* for the truth of the QTI? In other words, should people who find themselves extremely old through miraculous circumstances take it as more likely that the QTI is true? Hal Finney
Re: objections to QTI
Hi Norman, I don't think it makes much difference whether time is real or not as far as the game I have described is concerned. Each consecutive folder corresponds to a time step, but you could as easily consider the whole ensemble of folders and files as a mathematical object existing timelessly in Platonia; similarly with the multiverse. --Stathis Papaioannou Hi Saibal and Stathis, This scenario that you are discussing reminds me of this interview with Julian Barbour where he proposes that time is an illusion. If you agree or disagree with Barbour, I'd like to hear why. http://www.science-spirit.org/article_detail.php?article_id=183 Norman Samish - Original Message - From: Saibal Mitra [EMAIL PROTECTED] To: Stathis Papaioannou [EMAIL PROTECTED]; everything-list@eskimo.com Sent: Monday, May 30, 2005 8:28 AM Subject: Re: objections to QTI Hi Stathis, I think that your example below was helpful to clarify the disagreement. You say that randomly sampling from all the files is not 'how real life works'. However, if you did randomly sample from all the files the result would not be different from the selective time ordered sampling you suggest, as long as the effect of dying (reducing the absolute measure) can be ignored. If I'm sampled by the computer, I'll have the recollection of having been a continuum of previous states, even though these states may not have been sampled for quite some while. I'll subjectively experience a linear time evolution. The order in which the computer chooses to generate me at various instances doesn't matter. There are a few reasons why I believe in the ''random sampling''. First of all, random sampling seems to be necessary to avoid the Doomsday Paradox. See this article written by Ken Olum: http://arxiv.org/abs/gr-qc/0009081 He explains here why you need the Self Indicating Assumption. The self indicating assumption amounts to adopting an absolute measure that is proportional to the number of observers. Another reason has to do with the notion of time. I don't believe that events that have happened or will happen are not real while events that are happening now are real. They have to be treated in the same way. The fact that I experience time evolution is a first person phenomena. Finally, QTI (which more or less follows if you adopt the time ordered picture), implies that for the most part of your life you should find yourself in an a-typical state (e.g. very old while almost everyone else is very young).-Saibal - - Oorspronkelijk bericht - Van: Stathis Papaioannou [EMAIL PROTECTED] Aan: everything-list@eskimo.com Verzonden: Monday, May 30, 2005 04:02 PM Onderwerp: objections to QTI I thought the following analogy might clarify the point I was trying to make in recent posts to the Many Pasts? Not according to QM thread, addressing one objection to QTI. You are a player in the computer game called the Files of Life. In this game the computer generates consecutively numbered folders which each contain multiple text files, representing the multiple potential histories of the player at that time point. Each folder F_i contains N_i files. The first folder, F_0, contains N_0 files each describing possible events soon after your birth. You choose one of the files in this folder at random, and from this the computer generates the next folder, F_1, and places in it N files representing N possible continuations of the story. If you die going from F_0 to F_1, that file in F_1 corresponding to this event is blank, and blank files are deleted; so for the first folder N_0=N, but for the next one N_1=N, allowing for deaths. The game then continues: you choose a file at random from F_1, from this file the computer generates the next folder F_2 containing N_2 files, then you choose a file at random from F_2, and so on. It should be obvious that if the game is realistic, N_i should decrease with increasing i, due to death from accidents (fairly constant) + death from age related disease. The earlier folders will therefore on average contain many more files than the later folders. Now, it is argued that QTI is impossible because a randomly sampled observer moment from your life is very unlikely to be from a version of you who is 1000 years old, which has very low measure compared with a younger version. The equivalent argument for the Files of Life would be that since the earlier files are much more numerous than the later files, a randomly sampled file from your life (as created by playing the game) is very unlikely to represent a 1000 year old version of you, as compared with a younger version. This reasoning would be sound if the random sampling were done by mixing up all the files, or all the OM's, and pulling one out at random. But this is not how the game works and it is not how
Re: objections to QTI
Minor quibbles, which don't actually detract from your argument: On Mon, May 30, 2005 at 01:19:28PM -0700, Norman Samish wrote: 1) How did life originate if not through a miraculous circumstance? In other branches of the multiverse, perhaps most of them, there is no life. There is evidence that life might arise fairly easily, given the right conditions. This is the so-called early appearance of life argument. See arXiv:astro-ph/0209385. 2) An article at http://news-service.stanford.edu/news/2003/may28/humans-528.html suggests that all of earth's present human inhabitants originated from about 2,000 breeders, about 70,000 years ago. Humans were then very close to extinction. In many other branches of the multiverse extinction did, in fact, occur. Endangerment of a species does not follow from a genetic bottleneck. Consider a beneficial mutation arising 70,000 years ago, and rapidly increasing to 100% fixation within the human population. The genetic data would point to us all being descended from a single Adam or Eve at the time, and the number of individuals whose descendants ultimately breed with Adam or Eve's descendents. All other germ lines are eliminated from the population by natural selection. Thus a genetic bottleneck. However, the breeding population may have been any number - eg 1 million, hardly an endangered species. -- *PS: A number of people ask me about the attachment to my email, which is of type application/pgp-signature. Don't worry, it is not a virus. It is an electronic signature, that may be used to verify this email came from me if you have PGP or GPG installed. Otherwise, you may safely ignore this attachment. A/Prof Russell Standish Phone 8308 3119 (mobile) Mathematics0425 253119 () UNSW SYDNEY 2052 [EMAIL PROTECTED] Australiahttp://parallel.hpc.unsw.edu.au/rks International prefix +612, Interstate prefix 02 pgp9cD8ufXyCZ.pgp Description: PGP signature
Re: objections to QTI
Saibal Mitra wrote: I think that your example below was helpful to clarify the disagreement. You say that randomly sampling from all the files is not 'how real life works'. However, if you did randomly sample from all the files the result would not be different from the selective time ordered sampling you suggest, as long as the effect of dying (reducing the absolute measure) can be ignored. You would have to follow the branching pattern as defined by the program. I suggested that one file is chosen at random from each folder and a new folder generated from this file. It would be very resource-hungry, but it is simple enough to imagine the computer generating the entire multiverse, i.e. each file branching out to a new folder, each file in each new folder branching out to another new folder, and so on. This would generate all the OM's associated with an individual. However, you could just take any files from any folder and cobble together an individual history, which is what would happen if you sample files at random. To create an individual history, you have to trace a single path through the (perhaps infinitely) branching tree, which is a very different matter. This is true even if you ignore the effect of dying, so each folder/time slice has the same number of files/same measure. If I'm sampled by the computer, I'll have the recollection of having been a continuum of previous states, even though these states may not have been sampled for quite some while. I'll subjectively experience a linear time evolution. The order in which the computer chooses to generate me at various instances doesn't matter. It does matter in that the tree structure described above, and the path of an individual history through the tree structure, is dependent on doing the computations in order. In a trivial sense you could say that the order does not matter in that if the computation were predetermined in some way, then the computer could generate the folders and files in any order. There are a few reasons why I believe in the ''random sampling''. First of all, random sampling seems to be necessary to avoid the Doomsday Paradox. See this article written by Ken Olum: http://arxiv.org/abs/gr-qc/0009081 He explains here why you need the Self Indicating Assumption. The self indicating assumption amounts to adopting an absolute measure that is proportional to the number of observers. I'll look that up eventually. The SSA, anthropic principle, Doomsday Paradox, etc., I admit give me headaches. I think there is something basically wrong or confused with these ideas and am hoping that one morning I will wake up and realise what it is. Until that happy day arrives I will have to confine myself to answering that if random sampling saves us from the Doomsday Paradox, then maybe we are all doomed, because random sampling across all possible OM's in the multiverse cannot possibly give a coherent individual history. Another reason has to do with the notion of time. I don't believe that events that have happened or will happen are not real while events that are happening now are real. They have to be treated in the same way. The fact that I experience time evolution is a first person phenomena. Fair enough. You can consider the tree as described above drawn timelessly on the fabric of reality. You still have to take a subset of files/OM's from the tree in such a way as to define a single path through each node in order to give the first person impression (you could say: illusion) of a single individual history in time. Finally, QTI (which more or less follows if you adopt the time ordered picture), implies that for the most part of your life you should find yourself in an a-typical state (e.g. very old while almost everyone else is very young). That's perhaps right, although it is not without problems, when you consider that being 30 or 40 years old is no more atypical when you expect to live to infinity than being millions or trillions of years old. If it is right, at least in the prediction of your age relative to everyone else, then maybe it is an argument against MWI? --Stathis Papaioannou Van: Stathis Papaioannou [EMAIL PROTECTED] Aan: everything-list@eskimo.com Verzonden: Monday, May 30, 2005 04:02 PM Onderwerp: objections to QTI I thought the following analogy might clarify the point I was trying to make in recent posts to the Many Pasts? Not according to QM thread, addressing one objection to QTI. You are a player in the computer game called the Files of Life. In this game the computer generates consecutively numbered folders which each contain multiple text files, representing the multiple potential histories of the player at that time point. Each folder F_i contains N_i files. The first folder, F_0, contains N_0 files each describing possible events soon after your birth. You choose one of the files in this folder at random, and from this the
