Re: Measure, Doomsday argument
Russell, you wrote: ... - ... By contrast a universe that is just big enough (eg a few years old,...=... what 'years'? Terrestrial? some planet's in Oregon? lightyear(!?) or do you have a UTM (Universal Time Schedule) for the Plenitude? Sorry for the bartend to speak into John M - Original Message - From: Russell Standish [EMAIL PROTECTED] To: Jonathan Colvin [EMAIL PROTECTED] Cc: everything-list@eskimo.com Sent: Wednesday, June 22, 2005 12:02 AM Subject: Re: Measure, Doomsday argument
Re: Measure, Doomsday argument
No :) - these arguments do not depend on precise timescales - ROTFL. Big and old just means big and old enough for evolution to take place. Cheers On Wed, Jun 22, 2005 at 07:55:12AM -0400, jamikes wrote: Russell, you wrote: ... - ... By contrast a universe that is just big enough (eg a few years old,...=... what 'years'? Terrestrial? some planet's in Oregon? lightyear(!?) or do you have a UTM (Universal Time Schedule) for the Plenitude? Sorry for the bartend to speak into John M - Original Message - From: Russell Standish [EMAIL PROTECTED] To: Jonathan Colvin [EMAIL PROTECTED] Cc: everything-list@eskimo.com Sent: Wednesday, June 22, 2005 12:02 AM Subject: Re: Measure, Doomsday argument -- *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 pgpp4G31MME6k.pgp Description: PGP signature
Re: Measure, Doomsday argument
Le Lundi 20 Juin 2005 23:12, Hal Finney a écrit : The empirical question presents itself like this. Very simple universes (such as empty universes, or ones made up of simple repeating patterns) would have no life at all. Perhaps sufficiently complex ones would be full of life. So as we move up the scale from simple to complex, at some point we reach universes that just barely allow for advanced life to evolve, and even then it doesn't last very long. The question is, as we move through this transition region from nonliving universes, to just-barely-living ones, to highly-living ones, how long is the transition region? That is, how much more complex is a universe that will be full of life, compared to one which just barely allows for life? We don't know the answer to that, but in principle it can be learned, through study and perhaps experimental simulations. If it takes only a bit more complexity to go from a just-barely-living universe to a highly-living one, then we have a puzzle. Why aren't we in one of the super-living universes, when their complexity penalty is so low? Beside this. I just think about this : Why aren't we blind ? :-) If the measure of an OM come from the information complexity of it, it seems that an OM of a blind person need less information content because there is no complex description of the outside world available to the blind observer. So as they are less complex, they must have an higher measure ... but I'm not blind, so as a lot of people on earth... Quentin
Re: Measure, Doomsday argument
The answer is probably something along the lines of: OM with lots of sighted observers (as well as the odd blind one) will have lower complexity than OMs containing only blind observers (since the latter do not seem all that probable from an evolutionary point of view). Given there are so many sighted observers around, then it is not surprising if we're sighted. This argument is a variation of the argument for why we find so many observers in our world, rather than being alone in the universe, and is similar to why we expect the universe to be so big and old. Of course this argument contains a whole raft of ill-formed assumptions, so I'm expecting Jonathin Colvin to be warming up his keyboard for a critical response! Cheers. On Tue, Jun 21, 2005 at 10:56:48PM +0200, Quentin Anciaux wrote: Beside this. I just think about this : Why aren't we blind ? :-) If the measure of an OM come from the information complexity of it, it seems that an OM of a blind person need less information content because there is no complex description of the outside world available to the blind observer. So as they are less complex, they must have an higher measure ... but I'm not blind, so as a lot of people on earth... Quentin -- *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 pgpPnVEqKU4qp.pgp Description: PGP signature
Re: Measure, Doomsday argument
Quentin Anciaux writes: Why aren't we blind ? :-) If the measure of an OM come from the information complexity of it, it seems that an OM of a blind person need less information content because there is no complex description of the outside world available to the blind observer. So as they are less complex, they must have an higher measure ... but I'm not blind, so as a lot of people on earth... There may be something of a puzzle there... Although I think specifically that blind people don't necessarily have a lower information content in their mental states. It is said that blind people have their other sense become more acute to take over the unused brain capacity (at least people blind from birth). So their mental states may take just as much information as sighted people. Beyond that, the puzzle remains as to why we are as complex as we are, why we are not simpler beings. It would seem that one could imagine conscious beings who would count as observers, as people we might have been, but who would have simpler minds and senses than ours. Certainly the higher animals show signs of consciousness, and their brains are generally smaller than humans, especially the cortex, hence probably with lower information content. Of course there are a lot more people than other reasonably large-brained animals, so perhaps our sheer numbers cancel any penalty due to our larger and more-complex brains. Hal Finney
Re: Measure, Doomsday argument
On Tue, Jun 21, 2005 at 06:13:53PM -0700, Hal Finney wrote: Quentin Anciaux writes: Why aren't we blind ? :-) If the measure of an OM come from the information complexity of it, it seems that an OM of a blind person need less information content because there is no complex description of the outside world available to the blind observer. So as they are less complex, they must have an higher measure ... but I'm not blind, so as a lot of people on earth... There may be something of a puzzle there... Although I think specifically that blind people don't necessarily have a lower information content in their mental states. It is said that blind people have their other sense become more acute to take over the unused brain capacity (at least people blind from birth). So their mental states may take just as much information as sighted people. Beyond that, the puzzle remains as to why we are as complex as we are, why we are not simpler beings. It would seem that one could imagine conscious beings who would count as observers, as people we might have been, but who would have simpler minds and senses than ours. Certainly the higher animals show signs of consciousness, and their brains are generally smaller than humans, especially the cortex, hence probably with lower information content. Of course there are a lot more people than other reasonably large-brained animals, so perhaps our sheer numbers cancel any penalty due to our larger and more-complex brains. Hal Finney I take from this argument that the Anthropic Principle is a necessary requirement on conscious experience. In other words - self-awareness is a requirement. I cannot say why this should be so, as we do not have an acceptable theory of consciousnes, only that it must be so, otherwise we would expect to live in a too simple environment. And this is an interesting constraint on acceptable theories of consciousness. Cheers PS: only a few species have been shown to be self-aware: Homo Sapiens (older than 18 months), both Chimpanzees, one of the Gibbons (IIRC) and some species of Dolphin. Naturally, I'd expect a few more to come to light, but self-awareness does appear to be rare in the animal kingdom. Of course homo sapiens outnumbers all these species by many orders of magnitude. -- *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 pgp3mLF0FpoKW.pgp Description: PGP signature
RE: Measure, Doomsday argument
Russell Standish wrote: This argument is a variation of the argument for why we find so many observers in our world, rather than being alone in the universe, and is similar to why we expect the universe to be so big and old. Of course this argument contains a whole raft of ill-formed assumptions, so I'm expecting Jonathin Colvin to be warming up his keyboard for a critical response! Ok, if you insist :) I think the above are two disparate arguments. It is simpler by Occam to assume that there should be many observers rather than only one (similar argument to favouring the multiverse over only one big-bang). Once you admit the possibility of one observer, it takes extra argument to say why there should be *only* one. But we expect the universe to be old for cosmological reasons (takes stars a long time to cook up the needed elements, observer take a long time to evolve). Simplicity does not seem to be a factor here. A big universe does not seem much simpler either. Jonathan Colvin
Measure, Doomsday argument
Hi everyone, I have some questions about measure... As I understand the DA, it is based on conditionnal probabilities. To somehow calculate the chance on doom soon or doom late. An observer should reason as if he is a random observer from the class of observer. The conditionnal probabilities come from the fact, that the observer find that he is the sixty billions and something observer to be born. Discover this fact, this increase the probability of doom soon. The probability is increased because if doom late is the case, the probability to find myself in a universe where billions of billions of observer are present is greater but I know that I'm the sixty billions and something observer. Now I come to the measure of observer moment : It has been said on this list, to justify we are living in this reality and not in an Harry Potter like world that somehow our reality is simpler, has higher measure than Whitte rabbit universe. But if I correlate this assumption with the DA, I also should assume that it is more probable to be in a universe with billions of billions of observer instead of this one. How are these two cases different ? Quentin
Re: Measure, Doomsday argument
Quentin Anciaux writes: It has been said on this list, to justify we are living in this reality and not in an Harry Potter like world that somehow our reality is simpler, has higher measure than Whitte rabbit universe. But if I correlate this assumption with the DA, I also should assume that it is more probable to be in a universe with billions of billions of observer instead of this one. How are these two cases different ? I would answer this by predicting that any universe which allows for a substantial chance of billions of billions of observers would have to be much more complex. It would have a larger description, either in terms of its natural laws or of the initial conditions. Aside from the DA, we have another argument against the fact that our universe is well suited for advanced civilizations, namely the Fermi paradox: that we have not been visited by aliens. These two are somewhat similar arguments, the DA limiting civilization in time, and Fermi limiting it in space. In both cases it appears that our universe is not particularly friendly to advanced forms of life. The empirical question presents itself like this. Very simple universes (such as empty universes, or ones made up of simple repeating patterns) would have no life at all. Perhaps sufficiently complex ones would be full of life. So as we move up the scale from simple to complex, at some point we reach universes that just barely allow for advanced life to evolve, and even then it doesn't last very long. The question is, as we move through this transition region from nonliving universes, to just-barely-living ones, to highly-living ones, how long is the transition region? That is, how much more complex is a universe that will be full of life, compared to one which just barely allows for life? We don't know the answer to that, but in principle it can be learned, through study and perhaps experimental simulations. If it takes only a bit more complexity to go from a just-barely-living universe to a highly-living one, then we have a puzzle. Why aren't we in one of the super-living universes, when their complexity penalty is so low? OTOH if it turns out that the transition region is wide, and that you need a much more complex universe to be super-living than to be just-barely-living, then that is consistent with what we see. We are in one of the universes in the transition region, and in fact so are most advanced life forms. The relative complexity of super-living universes means that their measures are low, so even though they are full of life, it is more likely for a random advanced life form to be in one of the marginal universes like our own. In this way the DA is consistent with the fact that we don't live in a magical universe, but it implies some mathematical properties of the nature of computation which we are not yet in a position to verify. Hal Finney
Re: Measure, Doomsday argument
- Original Message - From: Quentin Anciaux [EMAIL PROTECTED] To: everything-list@eskimo.com Sent: Monday, June 20, 2005 11:37 PM Subject: Measure, Doomsday argument Hi everyone, I have some questions about measure... As I understand the DA, it is based on conditionnal probabilities. To somehow calculate the chance on doom soon or doom late. An observer should reason as if he is a random observer from the class of observer. The conditionnal probabilities come from the fact, that the observer find that he is the sixty billions and something observer to be born. Discover this fact, this increase the probability of doom soon. The probability is increased because if doom late is the case, the probability to find myself in a universe where billions of billions of observer are present is greater but I know that I'm the sixty billions and something observer. This is a false argument see here: http://arxiv.org/abs/gr-qc/0009081 To calculate the conditional probability given the birthrank you have you must use Bayes' theorem. You then have to take into account the a priori probability for a given birthrank. If you could have been anyone of all the people that will ever live, then you must include this informaton in the a-priori probability, and as a result of that the Doomsday Paradox is canceled. Now I come to the measure of observer moment : It has been said on this list, to justify we are living in this reality and not in an Harry Potter like world that somehow our reality is simpler, has higher measure than Whitte rabbit universe. But if I correlate this assumption with the DA, I also should assume that it is more probable to be in a universe with billions of billions of observer instead of this one. How are these two cases different ? Olum also stumbles on this point in his article. I also agree with Hall's earlier reply that (artificially) increasing the number of universes will lead to a decrease in intrinsic measure. One way to see this is as follows (this argument was also given by Hall a few years ago, if I remember correctly): According to the Self Sampling Asumption you have to include an ''anthropic'' factor in the measure. The more observers there are the more likely the universe is, but you do have to multiply the number of observers by the intrinsic measure. For any given universe U you can consider an universe U(n) that runs U n times, So, the anthropic factor of U(n) is n times that of U. This means that the intrinsic measure of U(n) should go to zero faster than 1/n, or else you wouldn't be able to normalize probabilities for observers. U(n) contains Log(n)/Log(2) bits more than U (you need to specify the number n). So, assuming that the intrinsic measure only depends on program size, it should decay faster than 2^(-program length). Saibal - Defeat Spammers by launching DDoS attacks on Spam-Websites: http://www.hillscapital.com/antispam/
RE: Measure, Doomsday argument
From: Quentin Anciaux [EMAIL PROTECTED] To: everything-list@eskimo.com Subject: Measure, Doomsday argument Date: Mon, 20 Jun 2005 23:37:45 +0200 Hi everyone, I have some questions about measure... As I understand the DA, it is based on conditionnal probabilities. To somehow calculate the chance on doom soon or doom late. An observer should reason as if he is a random observer from the class of observer. The conditionnal probabilities come from the fact, that the observer find that he is the sixty billions and something observer to be born. Discover this fact, this increase the probability of doom soon. The probability is increased because if doom late is the case, the probability to find myself in a universe where billions of billions of observer are present is greater but I know that I'm the sixty billions and something observer. I always thought the DA was understood in terms of absolute probability, not conditional probability. Conditional probability is supposed to tell you, given your current observer-moment, what the probability of various possible next experiences is for you; absolute probability is supposed to give the probability of experiencing one observer-moment vs. another *now*. The DA is based on assuming my current observer-moment is randomly sampled from the set of all observer-moments (possibly weighted by their absolute probability, although some people reason as if each observer-moment is equally likely for the purposes of the random-sampling assumption), and noting that if civilization were to be very long-lasting, it'd be unlikely to randomly choose an observer-moment of a person so close to the beginning of civilization. Jesse
Re: Measure, Doomsday argument
Saibal Mitra wrote: - Original Message - From: Quentin Anciaux [EMAIL PROTECTED] To: everything-list@eskimo.com Sent: Monday, June 20, 2005 11:37 PM Subject: Measure, Doomsday argument Hi everyone, I have some questions about measure... As I understand the DA, it is based on conditionnal probabilities. To somehow calculate the chance on doom soon or doom late. An observer should reason as if he is a random observer from the class of observer. The conditionnal probabilities come from the fact, that the observer find that he is the sixty billions and something observer to be born. Discover this fact, this increase the probability of doom soon. The probability is increased because if doom late is the case, the probability to find myself in a universe where billions of billions of observer are present is greater but I know that I'm the sixty billions and something observer. This is a false argument see here: http://arxiv.org/abs/gr-qc/0009081 To calculate the conditional probability given the birthrank you have you must use Bayes' theorem. You then have to take into account the a priori probability for a given birthrank. If you could have been anyone of all the people that will ever live, then you must include this informaton in the a-priori probability, and as a result of that the Doomsday Paradox is canceled. I don't think the cancellation argument in that paper works, unless you already *know* the final measure of one type of civilization vs. another from the perspective of the multiverse as a whole. For example, if I know for sure that 50% of civilizations end after 200 billion people have been born while 50% end after 200 trillion have been born, then it's true that observing my current birthrank to be the 100 billionth person born, I should not expect my civilization is any more likely to end soon, since 50% of all observers who find themselves to have the same birthrank are part of 200-billion-person civilizations and 50% of all observers who find themselves to have the same birthrank are part of 200-trillion person civilizations. But if I don't know for sure what the measure of different civilizations is, suppose I am considering two alternate hypotheses: one which says 50% of all civilizations end after 200 billion people and 50% end after 200 trillion, vs. a second hypothesis which says 99% of all civilizations end after 200 billion people and 1% end after 200 trillion. In that case, observing myself to have a birthrank of 100 million should lead me, by Bayesian reasoning, to increase my subjective estimate that the 99/1 hypothesis is correct, and decrease my subjective estimate that the 50/50 hypothesis is correct. Jesse
