Re: The Nature of Time
Hi Stephen, My point is that time as a pointer that points to what exists and what not (anymore or yet), cannot exist. You can indeed map the set of all such pointers to the real line. I agree that relativity is inconsistent with such an idea of time. Saibal Hi Saibal Are you defining time as isomorphic to the Real number line? Could it be that all of these proofs of the nonexistence of time are really just proofs that time is *not* that but something else entirely? It seems to me that we are thinking of the way that we can chronometrize events in our past with real number values and concluding that this labeling scheme extends into the future in a unique way, the problem is that if we take General Relativity seriously this is a non-started of an idea. The relativity of simultaneity coupled with general covariance does not permit any form of unique labeling events. We really need to stop assuming a Newtonian Absolute chronometrization of events. Time is a local measure of change, nothing more. Onward! Stephen *** -Original Message- From: smi...@zonnet.nl Sent: Saturday, April 02, 2011 8:27 PM To: everything-list@googlegroups.com Subject: Re: QTI is trivially false I think we are now making hidden assumptions about the nature of time, namely that it really exists, and then we are trying to argue that you can still have immortality (in different senses). However, it is far more natural to assume that time does not exist and then you get immortality (in the sense of my conscious states that have a finite memory always existing) in a far more straightforward way. That time does not exist is a quite natural assumption. To see this, assume that it does exist. But then, since time evolution is given by a unitary transform, the past still exists in a scrambled way in the present (when taking into account parallel universes). E.g. your past brain state of ten years ago can still be described in terms of the physical variables as they exist today. Of course such a description is extremely complicated involving the physical state of today's multiverse within a sphere of ten lightyears. Then assuming that the details of implementation does not affect consciousness (as long as the right program is being run), one has to conclude that your past state of coinsciousess exists also today. You could therefore just as well assume that time does not exist, as the two possibilities are operationally equivalent. Saibal -- You received this message because you are subscribed to the Google Groups Everything List group. To post to this group, send email to everything-list@googlegroups.com. To unsubscribe from this group, send email to everything-list+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/everything-list?hl=en. -- You received this message because you are subscribed to the Google Groups Everything List group. To post to this group, send email to everything-list@googlegroups.com. To unsubscribe from this group, send email to everything-list+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/everything-list?hl=en.
Re: Changing the past by forgetting
Yes, I agree, and that's then why we cannot do this in practice. The verification of the MWI would have to wait untilk we have artificially intelligent observers implemented by quantum computers. However, ass uming that the MWI is indeed correct, it doesn't matter if you undo the measurement. If you just dump your memory in the nvironment in an irreversible way, you end up in a superposition like: |you[ |universe_1| + |universe_2 ] As far as |you are concerned, it doesn't matter if |universe_1 and |universe_2 differ by one electron state or the state of 10^23 particles: the result of a new measurement is not pre-determined in either case. - Original Message - From: Brent Meeker meeke...@dslextreme.com To: everything-list@googlegroups.com Sent: Sunday, March 15, 2009 08:06 PM Subject: Re: Changing the past by forgetting Saibal Mitra wrote: If we consider measuring the spin of a particle, you could also say that the two possible outcomes just exist and thatthere are two possible future versions of me. There is no meaningful way to associate myself with either of the two outcomes. But then, precisely this implies that after a measurement and forgetting about the result will yield a version of me who is in a similar position as that earlier version of me who had yet to make the measurement. If one could perform measurements in a reversible way, this would be possible to experimentally confirm, as David Deutsch pointed out. You can start with a spin polarized in the x direction. Then you measure the z-component. There then exists a unitary transformation which leads to the observer forgetting about the outcome of the measurement and to the spin to be restored in the original state. The observer does remember having measured the z-component of the spin. Then, measuring the x-component again will yield spin-up with 100% probability, confirming that both branches in which the observer measured spin up and spin down have coherently recombined. This then proves that had the observer measured the z-component, the outcome would not be a priori determined, despite the observer having measured it earlier. So, both branches are real. But then this is true in general, also if the quantum state is of the form: |You[|spin up|rest of the world knows the spin is up + |spin down|rest of the world knows spin is down] You're contemplating reversing three different things: 1) Your knowledge, by forgetting a measurement result. Something that's easy to do. 2) The spin state of a particle. 3) The state of what the rest of the world knows. Because of the entanglement, I don't think you can, in general, reverse the spin state of the particle without reversing what is known about it by the rest of the world. If it was a known state (to someone) the particle can easily be put back in that state. But to do so for a general, unknown state, after a measurement would require invoking time-reversal invariance of the state of whole universe (or at least all of it entangled with the particle spin via the measuring apparatus). Brent Meeker although you cannot directly verify it here. But that means that you cannot rule out an alternative theory in which only one of the branches is real when performing a measurement in this case. But if the reality of both branches is accepted, then each time you make a measurement and you don't know the outcome, the outcome is not fixed (proovided, of course, there is indeed more than one branch). - Original Message - From: Jack Mallah jackmal...@yahoo.com To: everything-list@googlegroups.com Sent: Thursday, March 12, 2009 03:47 AM Subject: Re: Changing the past by forgetting --- On Tue, 3/10/09, Saibal Mitra smi...@zeelandnet.nl wrote: http://arxiv.org/abs/0902.3825 I've written up a small article about the idea that you could end up in a different sector of the multiverse by selective memory erasure. I had written about that possibility a long time ago on this list, but now I've made the argument more rigorous. Saibal, I have to say that I disagree. As you acknowledge, erasing memory doesn't recohere the branches. There is no meaningful sense in which you could end up in a different branch due to memory erasure. You admit the 'effect' has no observable consequences. But it has no unobservable meaning either. In fact, other than what I call 'causal differentiation', which clearly will track the already-decohered branches (so you don't get to reshuffle the deck), there is no meaningful sense in which you will end up in one particular future branch at all. Other than causal differentiation tracking, either 'you' are all of your future branches, or 'you' are just here for the moment and are none of them. --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google
Extra explanation
I just send a posting to the FOR list about my article. I did not have the time to reply to everyone on this list previously. Reading the old discussion again, I think that it was suggested that the exact quantum states matter, but they don't. It was only used to illustrate the thought experiment by Deutsch which would allow one to prove that the MWI is correct. This is what I sent to the FOR list: Some time ago I wrote a small article: http://arxiv.org/abs/0902.3825 This was recently featured in New Scientist: http://www.newscientist.com/article/mg20227044.200-avoid-a-future-cataclysm-forget-the-past.html The idea is that an observer can undo things that have already happened by resetting its memory, because when you reset your memory to a previous state, that previous state you are evolving into will be the same in a sector of the multiverse which evolved from that previous state and then was reset for any reason. So, if the reseting is triggered for reason A or reason B, it would lead to the observer ending up in the same state. The outcome of a new measuremnt to find out why the mempory was reset is then not pre-determined. Some details: The word state here refers to the classically describable state of an observer. In the article, I focus on machine observers. The subjective state of the observer is then exactly specified by specifying the ones and zeroes of the bits of the memory. So, I assume that whatever the observer can be aware of is encoded by the classical state of the bits of the computer and not the exact quantum state of the computer. The exact state of the computer has to be specified using a wavefunction of the computer (in fact, the state of the computer will be entangled with the rest of the universe). Then, one can write down any generic quantum state of the universe containing the observer by supplementing the (classical) information stored in the bits by the extra information you need to fully specify the wavefunction of the computer and everything else in the universe. One can then consider the unitary transformations that would represent a memory backup, memory resetting etc. After the memory resetting, you are notified why the memory was reset. Since the relevant things happen in the realm where classical physics applies, the probabilities are the same as what you would find using purely classical reasoning. The interpretation of these probablilites is, however, different from classical physics. When the memory is reset, you evolve to some state while the rest of the inverse will be in some superposition of states in which the memory was reset for various reasons. Then, before finding out why the memory was reset, the outcome of that observation is not pre-determined --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Everything List group. To post to this group, send email to everything-list@googlegroups.com To unsubscribe from this group, send email to everything-list+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/everything-list?hl=en -~--~~~~--~~--~--~---
Re: Changing the past by forgetting
That's correct. It is not really irreversible. The point is that it doesn't matter as you end up in a state where the outcome of finding out what happened is not pre-determined. Saibal - Original Message - From: Bruno Marchal marc...@ulb.ac.be To: everything-list@googlegroups.com Sent: Tuesday, April 21, 2009 07:27 PM Subject: Re: Changing the past by forgetting Accepting QM without collapse, I am not sure you can dump your memory in the environment in any truly irreversible way. Bruno On 21 Apr 2009, at 15:22, Saibal Mitra wrote: Yes, I agree, and that's then why we cannot do this in practice. The verification of the MWI would have to wait untilk we have artificially intelligent observers implemented by quantum computers. However, ass uming that the MWI is indeed correct, it doesn't matter if you undo the measurement. If you just dump your memory in the nvironment in an irreversible way, you end up in a superposition like: |you[ |universe_1| + |universe_2 ] As far as |you are concerned, it doesn't matter if |universe_1 and |universe_2 differ by one electron state or the state of 10^23 particles: the result of a new measurement is not pre-determined in either case. - Original Message - From: Brent Meeker meeke...@dslextreme.com To: everything-list@googlegroups.com Sent: Sunday, March 15, 2009 08:06 PM Subject: Re: Changing the past by forgetting Saibal Mitra wrote: If we consider measuring the spin of a particle, you could also say that the two possible outcomes just exist and thatthere are two possible future versions of me. There is no meaningful way to associate myself with either of the two outcomes. But then, precisely this implies that after a measurement and forgetting about the result will yield a version of me who is in a similar position as that earlier version of me who had yet to make the measurement. If one could perform measurements in a reversible way, this would be possible to experimentally confirm, as David Deutsch pointed out. You can start with a spin polarized in the x direction. Then you measure the z-component. There then exists a unitary transformation which leads to the observer forgetting about the outcome of the measurement and to the spin to be restored in the original state. The observer does remember having measured the z-component of the spin. Then, measuring the x-component again will yield spin-up with 100% probability, confirming that both branches in which the observer measured spin up and spin down have coherently recombined. This then proves that had the observer measured the z-component, the outcome would not be a priori determined, despite the observer having measured it earlier. So, both branches are real. But then this is true in general, also if the quantum state is of the form: |You[|spin up|rest of the world knows the spin is up + |spin down|rest of the world knows spin is down] You're contemplating reversing three different things: 1) Your knowledge, by forgetting a measurement result. Something that's easy to do. 2) The spin state of a particle. 3) The state of what the rest of the world knows. Because of the entanglement, I don't think you can, in general, reverse the spin state of the particle without reversing what is known about it by the rest of the world. If it was a known state (to someone) the particle can easily be put back in that state. But to do so for a general, unknown state, after a measurement would require invoking time-reversal invariance of the state of whole universe (or at least all of it entangled with the particle spin via the measuring apparatus). Brent Meeker although you cannot directly verify it here. But that means that you cannot rule out an alternative theory in which only one of the branches is real when performing a measurement in this case. But if the reality of both branches is accepted, then each time you make a measurement and you don't know the outcome, the outcome is not fixed (proovided, of course, there is indeed more than one branch). - Original Message - From: Jack Mallah jackmal...@yahoo.com To: everything-list@googlegroups.com Sent: Thursday, March 12, 2009 03:47 AM Subject: Re: Changing the past by forgetting --- On Tue, 3/10/09, Saibal Mitra smi...@zeelandnet.nl wrote: http://arxiv.org/abs/0902.3825 I've written up a small article about the idea that you could end up in a different sector of the multiverse by selective memory erasure. I had written about that possibility a long time ago on this list, but now I've made the argument more rigorous. Saibal, I have to say that I disagree. As you acknowledge, erasing memory doesn't recohere the branches. There is no meaningful sense
Re: Changing the past by forgetting
Thanks! This is like undoing historical events. If you forget about the fact that dinosaurs ever lived on Earth and there is an alternative history that led to your existence in the multiverse, and you do the memory erasure also in sectors were dinosaurs never lived, you have some nonzero probability of finding yourself on an Earth were the dinosaurs never lived. - Original Message - From: Bruno Marchal marc...@ulb.ac.be To: everything-l...@googlegroups.com Sent: Wednesday, March 11, 2009 06:54 PM Subject: Re: Changing the past by forgetting Nice! I did refer often to the Saibal Mitra backtracking procedure (in immortality discussions). I will take a further look on your paper. If valid, it should work in the comp frame. Amnesia could lead you to the original singularity, which could be a kind of blind spot of universal consciousness, except that with comp such a singularity should looks like a little Mandelbrot set, at first sight, I mean something like a compact view of a universal dovetailing. Bruno On 10 Mar 2009, at 19:55, Saibal Mitra wrote: http://arxiv.org/abs/0902.3825 I've written up a small article about the idea that you could end up in a different sector of the multiverse by selective memory erasure. I had written about that possibility a long time ago on this list, but now I've made the argument more rigorous. http://iridia.ulb.ac.be/~marchal/ --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Everything List group. To post to this group, send email to everything-l...@googlegroups.com To unsubscribe from this group, send email to everything-list+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/everything-list?hl=en -~--~~~~--~~--~--~---
Re: Changing the past by forgetting
If we consider measuring the spin of a particle, you could also say that the two possible outcomes just exist and thatthere are two possible future versions of me. There is no meaningful way to associate myself with either of the two outcomes. But then, precisely this implies that after a measurement and forgetting about the result will yield a version of me who is in a similar position as that earlier version of me who had yet to make the measurement. If one could perform measurements in a reversible way, this would be possible to experimentally confirm, as David Deutsch pointed out. You can start with a spin polarized in the x direction. Then you measure the z-component. There then exists a unitary transformation which leads to the observer forgetting about the outcome of the measurement and to the spin to be restored in the original state. The observer does remember having measured the z-component of the spin. Then, measuring the x-component again will yield spin-up with 100% probability, confirming that both branches in which the observer measured spin up and spin down have coherently recombined. This then proves that had the observer measured the z-component, the outcome would not be a priori determined, despite the observer having measured it earlier. So, both branches are real. But then this is true in general, also if the quantum state is of the form: |You[|spin up|rest of the world knows the spin is up + |spin down|rest of the world knows spin is down] although you cannot directly verify it here. But that means that you cannot rule out an alternative theory in which only one of the branches is real when performing a measurement in this case. But if the reality of both branches is accepted, then each time you make a measurement and you don't know the outcome, the outcome is not fixed (proovided, of course, there is indeed more than one branch). - Original Message - From: Jack Mallah jackmal...@yahoo.com To: everything-l...@googlegroups.com Sent: Thursday, March 12, 2009 03:47 AM Subject: Re: Changing the past by forgetting --- On Tue, 3/10/09, Saibal Mitra smi...@zeelandnet.nl wrote: http://arxiv.org/abs/0902.3825 I've written up a small article about the idea that you could end up in a different sector of the multiverse by selective memory erasure. I had written about that possibility a long time ago on this list, but now I've made the argument more rigorous. Saibal, I have to say that I disagree. As you acknowledge, erasing memory doesn't recohere the branches. There is no meaningful sense in which you could end up in a different branch due to memory erasure. You admit the 'effect' has no observable consequences. But it has no unobservable meaning either. In fact, other than what I call 'causal differentiation', which clearly will track the already-decohered branches (so you don't get to reshuffle the deck), there is no meaningful sense in which you will end up in one particular future branch at all. Other than causal differentiation tracking, either 'you' are all of your future branches, or 'you' are just here for the moment and are none of them. --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Everything List group. To post to this group, send email to everything-l...@googlegroups.com To unsubscribe from this group, send email to everything-list+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/everything-list?hl=en -~--~~~~--~~--~--~---
Changing the past by forgetting
http://arxiv.org/abs/0902.3825 I've written up a small article about the idea that you could end up in a different sector of the multiverse by selective memory erasure. I had written about that possibility a long time ago on this list, but now I've made the argument more rigorous. --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Everything List group. To post to this group, send email to everything-l...@googlegroups.com To unsubscribe from this group, send email to everything-list+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/everything-list?hl=en -~--~~~~--~~--~--~---
QTI --- Expanding brains
Yes, I should have mentioned ASSA and RSSA as discussed on this list in the dark ages. I don't buy QTI for quite a few reasons. A model independent objection I have is the following. If you accept QTI, then the information you have about your history will have to grow without limit (if not, then effectively you have a finite lifetime as you can only store a finite amount of information in a finite volume). Your identity must be preserved as your brain continues to expand to make room for all that informaton that must be stored. Now, I find it hard to believe that a superlarge brain the size of the galaxy would still be me. :) - Original Message - From: Russell Standish [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Wednesday, April 16, 2008 03:24 AM Subject: Re: Quantum Immortality = no second law On Wed, Apr 16, 2008 at 02:22:23AM +0200, Saibal Mitra wrote: First off, how is it that the MWI does not imply quantum immortality? MWI is just quantum mechanics without the wavefunction collapse postulate. This then implies that after a measurement your wavefuntion will be in a superposition of the states corresponding to definite outcomes. But we cannot just consider suicide experiments and then say that just because branches of the wavefuntion exist in which I survive, I'll find myself there with 100% probability. The fact that probabilities are conserved follows from unitary time evolution. If a state evolves into a linear combination of states in which I'm dead and alive then the probabilities of all these states add up to 1. The probability of finding myself to be alive at all after the experiment is then less than the probability of me finding myself about to perform the suicide experiment. The probability of me finding myself to be alive after n suicide experiments decays exponentially with n. Therefore I should not expect to find myself having survived many suicide experiments. Note that contrary to what you often read in the popular accounts of the multiverse, the multiverse does not split when we make observations. The most natural state for the entire multiverse is just an eigenstate of the Hamiltonian. The energy can be taken to be zero, therefore the wavefunction of the multiverse satisfies the equation: One should also note that this is the ASSA position. The ASSA was introduced by Jacques Mallah in his argument against quantum immortality, and a number of participants in this list adhere to the ASSA position. Its counterpart if the RSSA, which does imply quantum immortality (provided that the no cul-de-sac conjecture holds), and other list participants adhere to the RSSA. To date, no argument has convincingly demonstrated which of the ASSA or RSSA should be preferred, so it has become somewhat a matter of taste. There is some discussion of this in my book Theory of Nothing. Cheers -- -- -- A/Prof Russell Standish Phone 0425 253119 (mobile) Mathematics UNSW SYDNEY 2052 [EMAIL PROTECTED] Australiahttp://www.hpcoders.com.au -- -- --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Everything List group. To post to this group, send email to [EMAIL PROTECTED] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list?hl=en -~--~~~~--~~--~--~---
Re: Quantum Immortality = no second law
Citeren nichomachus [EMAIL PROTECTED]: In the description of the quantum immortality gedanken experiment, a physicist rigs an automatic rifle to a geiger counter to fire into him upon the detection of an atomic decay event from a bit of radioactive material. If the many worlds hypothesis is true, the self-awareness of the physicist will continue to find himself alive after any length of time in front of his gun, since there exist parallel worlds where the decay does not occur. This has never been rigorously proven. I can give you some argumetns why the MWI does not imply Quantum Immortality. On a microscopic scale this is analogous to the observing a reality in which the second law of thermodynamics does not hold. for example, since there is a non-zero probability that molecular interactions will result in a decrease in entropy in a particular sealed volume under observation, there exist histories in which this must be observed. This is never observed. Therefore the MWI is shown to be false. This is also not a correct conclusion (if you replace MWI by quantum immortality). --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Everything List group. To post to this group, send email to [EMAIL PROTECTED] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list?hl=en -~--~~~~--~~--~--~---
Re: Quantum Immortality = no second law
Citeren nichomachus [EMAIL PROTECTED]: In the description of the quantum immortality gedanken experiment, a physicist rigs an automatic rifle to a geiger counter to fire into him upon the detection of an atomic decay event from a bit of radioactive material. If the many worlds hypothesis is true, the self-awareness of the physicist will continue to find himself alive after any length of time in front of his gun, since there exist parallel worlds where the decay does not occur. This has never been rigorously proven. I can give you some argumetns why the MWI does not imply Quantum Immortality. On a microscopic scale this is analogous to the observing a reality in which the second law of thermodynamics does not hold. for example, since there is a non-zero probability that molecular interactions will result in a decrease in entropy in a particular sealed volume under observation, there exist histories in which this must be observed. This is never observed. Therefore the MWI is shown to be false. This is also not a correct conclusion (if you replace MWI by quantum immortality). --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Everything List group. To post to this group, send email to [EMAIL PROTECTED] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list?hl=en -~--~~~~--~~--~--~---
Re: Request to form 'Social Contract' with SAI
The best thing you could do is to freeze your brain. I think that will preserve the connections between the neurons, although the cells will be destroyed. This will make it easier for a future civilization to regenerate you digitally - Original Message - From: [EMAIL PROTECTED] To: Everything List [EMAIL PROTECTED] Sent: Monday, October 15, 2007 07:17 AM Subject: Re: Request to form 'Social Contract' with SAI On Oct 14, 3:39 am, Bruno Marchal [EMAIL PROTECTED] wrote: Take care, trust yourself and kill all the SAI on the road, to paraphrase a well known Buddhist idea. Either you are sufficiently clever to understand the SAI arguments, showing you are already an SAI yourself, and your message is without purpose, or you are not, in which case, to keep soundness (by lobianity), you better be skeptical, (and not to abide so quick imo). Unless you want to loose your universality, and be a slave, a tool. Bruno http://iridia.ulb.ac.be/~marchal/ Heh. Bruno, I continue to analyse my current (human) condition to try to find a way out of this mess (I'm not a happy bloke). Still considering many possibilities. Given the possibility that super- intelligences do already (or will in the future) exist, there's a chance that a non-interference policy is being/will be pursued, but that there's a way to get their attention - it could be a simple matter of indicating that you are aware of the possibility and requesting to 'sign' a 'social contract'. Get in early now! ;) --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Everything List group. To post to this group, send email to [EMAIL PROTECTED] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list?hl=en -~--~~~~--~~--~--~---
Re: how to define ASSA (was: The ASSA leads to a unique utilitarism)
1) looks better because there is no unambiguous definition of next. However, I don't understand the shared by everyone part. Different persons are different programs who cannot exactly represent the observer moment of me. As I see it, an observer moment is a snapshot of the universe taken by my brain. The brain simulates a virtual world based on information from the real world. We don't really experience the real world, we just experience this simulated world. Observer moments for observers should refer to the physical states of the virtual world they live in. Since different observers live in different universes which have different laws of physics, these physical states (= qualia) cannot be compared to each other. We can only talk about an absolute measure for programs (simulated by other programs or not)... Citeren Wei Dai [EMAIL PROTECTED]: Russell Standish wrote: This is actually the SSSA, as originally defined by Bostrom. The ASSA is the SSSA applied to next observer moments. I guess there is a bit of confusing on these terms. I did some searching in the mailing list archives to find out how they were originally defined. First of all SSSA was clearly coined by Hal Finney, not Bostrom. Here's Hal Finney on May 18, 1999: Perhaps we need to distinguish a Strong Self-Sampling Assumption, which is like the SSA but instead of discussing observers, it refers to observer-instants. Followed by Bruno Marchal's reply defining RSSA/ASSA: Perhaps we need to distinguish a Strong Self-Sampling Assumption, which is like the SSA but instead of discussing observers, it refers to observer-instants. Useful distinction, indeed. Nevertheless I do think we should also distinguish between a relative strong SSA and a absolute strong SSA. The idea is that we can only quantify the first-person indeterminism on the set of consistent observer-instants extensions. I mean : consistent with the observers memory of its own (first person) past. Actually now I'm not sure what Bruno really meant. I had assumed that ASSA was the same thing as SSSA, only with the clarification that it's not relative. But if Bruno had really meant to define ASSA as SSSA applied to the next observer moment then I have been using the term ASSA incorrectly. So to sum up, there are two possible meanings for ASSA currently. Does anyone else have an opinion on the matter? Here are the competing definitions: 1. You should reason as if your current observer-moment was randomly selected from a distribution that is shared by everyone and independent of your current observations (hence absolute). 2. You should expect your next observer-moment to be randomly selected from a distribution that is shared by everyone and independent of your current observations. --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Everything List group. To post to this group, send email to [EMAIL PROTECTED] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list?hl=en -~--~~~~--~~--~--~---
Re: how to define ASSA
Of course, we all live in the same universe in the sense that we are all simulated by brains that exist in this universe (described approximately by the Standard Model and General Relativity). The problem is how to define the observer moments rigorously at least in principle. It is undeniable that we experience a the world that our brains are simulating and not the real world. We experience the real world only indirectly. If you touch a hot object and burn your finger then you experiencing the pain is really an event that happens in the virtual world simulated by your brain. Your brain simply uses the results of the simulation to compute what action to take in the real world (and the simulation will then be updated accordingly). The burning sensation exists only in the simulated world, not in the real world. Of course, you can infer that the object must have been hot. So, it seems to be more sensible to me to say that an observer moment is itself an entire universe (= program) in some state. This looks equivalent to specifying the exact state a brain is in, but the brain contains more information than is accessible to the observer. We really have to extract the program the brain is running from the brain and use that to define OMs, otherwise an OM becomes an inherently ambiguous concept (e.g. where does the brain end, do the nerves in my feet also count? etc. etc.). One can simply define an observer as some program and look at the entire multiverse to seek out these programs that are in such and such state. Then one adds up all the absolute measures to obtain the total probability that the program is experiencing that state. One would then expect that it is likely that a program defining a human observer is simulated by a brain in a universe described by the Standard Model. citeren Brent Meeker [EMAIL PROTECTED]: Saibal Mitra wrote: 1) looks better because there is no unambiguous definition of next. However, I don't understand the shared by everyone part. Different persons are different programs who cannot exactly represent the observer moment of me. As I see it, an observer moment is a snapshot of the universe taken by my brain. The brain simulates a virtual world based on information from the real world. We don't really experience the real world, we just experience this simulated world. Observer moments for observers should refer to the physical states of the virtual world they live in. Since different observers live in different universes which have different laws of physics, these physical states (= qualia) cannot be compared to each other. How do you know they live in different universes? The great agreement among observers is what leads us to believe in an objective world. It appears that it is more economical (both ontologically and algorithmically) to explain the agreement by supposing there is an objective world as described by physics. In which case the observer moments are derivative from the objective world - that's what makes it a more efficient hypothesis. Brent Meeker --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Everything List group. To post to this group, send email to [EMAIL PROTECTED] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list?hl=en -~--~~~~--~~--~--~---
Re: How would a computer know if it were conscious?
If it feels bafflement and confusion, then surely it is conscious :) An AI that takes information from books might experience similar qualia we can experience. The AI will be programmed to do certain tasks and it must thus have a notion of what it is doing is ok., not ok, or completely wrong. If things are going wrong and it has to revert what it has just done, it may feel some sort of pain. Just like what happens to us if we pick up something that is very hot. So, I think that there will be a mismatch between the qualia the AI experiences and what it reads about that we experience. The AI won't read the information like we read it. I think it will directly experience it as some qualia, just like we experience information coming in via our senses into our brain. The meaning we associate with the text would not be accessible to the AI, because ultimately that is linked to the qualia we experience. Perhaps what the AI experiences when it is processing information is similar to an animal that is moving in some landscape. Maybe when it reads something then that manifests itself like some object it sees. If it processes information then that could be like picking up that object putting it next to a similar looking object. But if that object represents a text about consciousness then there is no way for the AI to know that. Saibal - Original Message - From: Hal Finney [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Sunday, June 03, 2007 09:52 PM Subject: Re: How would a computer know if it were conscious? Part of what I wanted to get at in my thought experiment is the bafflement and confusion an AI should feel when exposed to human ideas about consciousness. Various people here have proffered their own ideas, and we might assume that the AI would read these suggestions, along with many other ideas that contradict the ones offered here. It seems hard to escape the conclusion that the only logical response is for the AI to figuratively throw up its hands and say that it is impossible to know if it is conscious, because even humans cannot agree on what consciousness is. In particular I don't think an AI could be expected to claim that it knows that it is conscious, that consciousness is a deep and intrinsic part of itself, that whatever else it might be mistaken about it could not be mistaken about being conscious. I don't see any logical way it could reach this conclusion by studying the corpus of writings on the topic. If anyone disagrees, I'd like to hear how it could happen. And the corollary to this is that perhaps humans also cannot legitimately make such claims, since logically their position is not so different from that of the AI. In that case the seemingly axiomatic question of whether we are conscious may after all be something that we could be mistaken about. Hal --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Everything List group. To post to this group, send email to [EMAIL PROTECTED] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list?hl=en -~--~~~~--~~--~--~---
Re: Believing in Divine Destiny
The only connection I can think of is as follows. For any given religious text there should exist a universe which best fits those text. Saibal - Original Message - From: Wei Dai [EMAIL PROTECTED] To: everything-list@googlegroups.com Sent: Tuesday, February 27, 2007 11:55 PM Subject: Re: Believing in Divine Destiny A year ago or so Wei Dai put an end to religious discussions on the list. I don't remember if I did that a year ago or not, but I certainly think the current discussion is off-topic. This mailing list is based on the premise that all possible universes exist. Unless someone can think of a connection to this idea, can we please drop this thread? I have also noticed that all of [EMAIL PROTECTED]'s posts are copy-and-pastes from online sources: http://www.islamanswers.net/destiny/recorded.htm http://www.islamanswers.net/unity/understand.htm http://sg.answers.yahoo.com/question/index?qid=20070226110342AAy6SG5 http://www.themodernreligion.com/basic/quran/quran_proof_preservation.htm Copying other people's writings without attribution is plagiarism, which I certainly do not approve of. And aside from that, if anyone wants to reference large amounts of online material, please post a link instead of copying the text. P.S., I find that I am not always able to keep up with all of the discussions on the list. Putting my name in a post is a good way to get my attention, and please always feel free to email me directly with any administrative issues related to the list. --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Everything List group. To post to this group, send email to everything-list@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list?hl=en -~--~~~~--~~--~--~---
Re: testing
The listserver was experiencing a lot of computer pain recently and that prevented it from function normally :) John Mikes [EMAIL PROTECTED]: This is the 3rd time I send a 'test' to myself. I receive list-post on this gmail address, but my mail does not show up, neither here nor on the YAHOO-mail address I unsubscribed from. Am I still on the No e-mail exclusion? Or does the listserve not recognise my mailing? John Mikes --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Everything List group. To post to this group, send email to everything-list@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list?hl=en -~--~~~~--~~--~--~---
Re: Zuse Symposium: Is the universe a computer? Berlin Nov 6-7
uncompoutable numbers, non countable sets etc. don't exist in first order logic, see here: http://www.earlham.edu/~peters/courses/logsys/low-skol.htm [EMAIL PROTECTED] [EMAIL PROTECTED]: Ah the famous Juergen Schmidhuber! :) Is the universe a computer. Well, if you define 'universe' to mean 'everything which exists' and you're a mathematical platonist and grant reality to infinite sets and uncomputables, the answer must be NO, since if uncomputable numbers are objectively real (strong platonism) they are 'things' and therefore 'part of the universe' which are by definition not computable. But if by 'universe' you just mean 'physical reality' or 'discrete mathematics' or you refuse to grant platonic reality to uncomputables or infinite sets (anti-platonism or weaker platonism) then the answer could be YES, the universe is a computer. Cheers! --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Everything List group. To post to this group, send email to everything-list@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list?hl=en -~--~~~~--~~--~--~---
Re: Proof that QTI is false
- Original Message - From: Brent Meeker [EMAIL PROTECTED] To: everything-list@googlegroups.com Sent: Wednesday, September 13, 2006 5:47 AM Subject: Re: Proof that QTI is false Saibal Mitra wrote: QTI in the way defined in this list contradicts quantum mechanics. The observable part of the universe can only be in a finite number of quantum states. So, it can only harbor a finite number of observer moments or experiences a person can have, see here for details: http://arxiv.org/abs/gr-qc/0102010 If there can only be a finite number of observer moments you can only experience a finite amount of time. QED. So that would imply that when predicting states at some fixed finite time in the future there is a smallest, non-zero probability that is realizable. So if our prediction, using continuum variables as an approximation, indicates a probability lower than this value we should set it to zero?? Brent Meeker Yes, but you don't have to set anything to zero by hand. What happens is that if there are only a finite number of quantum states there is one which has the smallest non zero probability. Saibal --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Everything List group. To post to this group, send email to everything-list@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list -~--~~~~--~~--~--~---
Re: Proof that QTI is false
Yes, I agree that you could still have some form of QTI if there are only a
finite number of states. I just don't believe in it, because I don't think
the use of the relative measure is justified in case the observer isn't
conserved. In all other case the absolute measure and the relative measure
lead to the same predictions.
Actually, in standard quantum mechanics, there is an infinity of
observer moments, 2^{\aleph_0} of them in fact.
What you are talking about are various quantum gravity theories, such
as string theory, which appear to have a finite number of observer
moments.
However, even if as observers we are locked into a Nietschian cycle at
some point in time due to finiteness of the number of possible states,
the number will be so large that the practical effects of QTI will
still need to be considered.
Cheers
- Original Message -
From: Russell Standish [EMAIL PROTECTED]
To: everything-list@googlegroups.com
Sent: Wednesday, September 13, 2006 4:31 AM
Subject: Re: Proof that QTI is false
On Tue, Sep 12, 2006 at 11:58:14PM +0200, Saibal Mitra wrote:
QTI in the way defined in this list contradicts quantum mechanics. The
observable part of the universe can only be in a finite number of
quantum
states. So, it can only harbor a finite number of observer moments or
experiences a person can have, see here for details:
http://arxiv.org/abs/gr-qc/0102010
If there can only be a finite number of observer moments you can only
experience a finite amount of time.
QED.
--
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email came from me if you have PGP or GPG installed. Otherwise, you
may safely ignore this attachment.
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A/Prof Russell Standish Phone 0425 253119 (mobile)
Mathematics
UNSW SYDNEY 2052 [EMAIL PROTECTED]
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Saibal
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Re: Russell's book
I think I can prove that QTI as intepreted in this list is false, I'll post the proof in a new thread. The only version of QTI that makes sense to me is this: All possible states exist out there in the multiverse. The observer moments are timeless objects so, in a certain sense, QTI is true. But then you must consider surviving with memory loss. E.g., if I'm diagnosed with a terminal illness, then there is still a branch in which I haven't been diagnosed with that illness. If I'm 100 years old, then I still have copies that are only 20 years old etc. etc. Saibal - Original Message - From: Johnathan Corgan [EMAIL PROTECTED] To: everything-list@googlegroups.com Sent: Tuesday, September 12, 2006 7:43 PM Subject: Re: Russell's book David Nyman wrote: [re: QTI] This has obvious implications for retirement planning in general and avoidance of the more egregious cul-de-sac situations. On the other hand, short of outright lunacy vis-a-vis personal safety, it also seems to imply that from the 1st-person pov we are likely to come through (albeit possibly in less-than-perfect shape) even apparently minimally survivable situations. This struck me particularly forcibly while watching the 9/11 re-runs on TV last night. It's the cul-de-sac situations that interest me. Are there truly any? Are there moments of consciousness which have no logically possible continuation (while remaining conscious?) It seems the canonical example is surviving a nearby nuclear detonation. One logical possibility is that all your constituent particles quantum-tunnel away from the blast in time. This would be of extremely low measure in absolute terms, but what about the proportion of continuations that contain you as a conscious entity? This also touches on a recent thread about how being of low measure feels. If QTI is true, and I'm subject to a nuclear detonation, does it matter if my possible continuations are of such a low relative measure? Once I'm in them, would I feel any different and should I care? These questions may reduce to something like, Is there a lower limit to the amplitude of the SWE? If measure is infinitely divisible, then is there any natural scale to its absolute value? I raised a similar question on the list a few months ago when Tookie Wiliams was in the headlines and was eventually executed by the State of California. What possible continuations exist in this situation? In effect, we are being presented with a kind of 'yes doctor' in everyday life. Do you find that these considerations affect your own behaviour in any way? A very interesting question. If my expectation is that QTI is true and I'll be living for a very long time, I may adjust my financial planning accordingly. But QTI only applies to my own first-person view; I'll be constantly shedding branches where I did indeed die. If I have any financial dependents, do I provide for their welfare, even if they'll only exist forever outside my ability to interact with? -Johnathan --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Everything List group. To post to this group, send email to everything-list@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list -~--~~~~--~~--~--~---
Proof that QTI is false
QTI in the way defined in this list contradicts quantum mechanics. The observable part of the universe can only be in a finite number of quantum states. So, it can only harbor a finite number of observer moments or experiences a person can have, see here for details: http://arxiv.org/abs/gr-qc/0102010 If there can only be a finite number of observer moments you can only experience a finite amount of time. QED. --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Everything List group. To post to this group, send email to everything-list@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list -~--~~~~--~~--~--~---
Re: Interested in thoughts on this excerpt from Martin Rees
- Original Message - From: Hal Finney [EMAIL PROTECTED] To: everything-list@googlegroups.com Sent: Wednesday, July 26, 2006 08:28 AM Subject: Re: Interested in thoughts on this excerpt from Martin Rees The real problem is not just that it is a philosophical speculation, it is that it does not lead to any testable physical predictions. The string theory landscape, even if finite, is far too large for systematic exploration. Our ideas, with an infinite number of possible universes, are even worse. Physicists see acceptance of anthropic explanations as the end of physics because there is no way to make quantitative predictions when there are so many degrees of freedom. I'm not so sure that our ideas are worse. If you read some recent articles, e.g.: http://arxiv.org/abs/astro-ph/0607227 you see that they haven't really formulated rigorous theories about measure, probabilities etc. of the multiverse. It's still very much in the handwaving stage. Saibal --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Everything List group. To post to this group, send email to everything-list@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list -~--~~~~--~~--~--~---
Re: A calculus of personal identity
- Original Message - From: Stathis Papaioannou [EMAIL PROTECTED] To: everything-list@googlegroups.com Sent: Friday, June 30, 2006 09:23 AM Subject: Re: A calculus of personal identity Brent Meeker writes: I think it is one of the most profound things about consciousness that observer moments don't *need* anything to connect them other than their content. They are linked like the novels in a series, not like the carriages of a train. It is not necessary that the individual novels be lined up specially on a shelf: as long as they have each been written and exist somewhere in the world, the series exists. But the series exists, as a series, by virtue of the information in them. They are like Barbour's time-capsules; each contains enough references and characters from the others to allow them to be put into order. It's not clear to me what duration obserever moments have - but I don't think they are novel length. I imagine them more like sentences (a complete thought as my English teacher used to say), and sentences *don't* have enough information to allow them to be reconstructed into the novel they came from. A book is the analogy that came to mind, but there is an important difference between this and conscious experience. Books, sentences, words may not need to be physically collected together to make a coherent larger structure, but they do need to be somehow sorted in the mind of an observer; otherwise, we could say that a dictionary contains every book ever written or yet to be written. Moments of consciousness, on the other hand, by their nature contain their own observer. That's why I suggest that OMs are not an adequate ontological basis for a world model. On the other hand, if we include brain processes, or more abstractly, subconscious thoughts, then we would have enough information to string them together. I know some people on this list have attempted world-building with OMs, but my starting point is the less ambitious idea that consciousness can in principle extend across time and space without being specially linked. If a person's stream of consciousness were chopped up into seconds, minutes, days or whatever, using whatever vehicle it takes to run a human mind, and these moments of consciousness randomly dispersed throughout the multiverse, they would all connect up by virtue of their information content. Do you disagree that it would in principle be possible? You can take time evolution as an example. In both classical physics and quantum mechanics, information is preserved. All the information about us was already present in the early universe Saibal --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Everything List group. To post to this group, send email to everything-list@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list -~--~~~~--~~--~--~---
Re: Teleportation thought experiment and UD+ASSA
Hal, thanks for explaining! I think that your approach makes a lot of sense. Applying this to copying experiments, the probability of finding yourself to be the digital copy is: m1/[m1 + m2] where m1 is the measure of the mental experience corresponding to knowing that you are the digital copy and m2 the measure of the mental experience corresponding to knowing that you are still in biological form. I think that for practical implementations m1 = m2 because the digital implementation will just simulate the brain, so the complexity of the translation program would be practically the same. Saibal - Original Message - From: Hal Finney [EMAIL PROTECTED] To: everything-list@googlegroups.com Sent: Wednesday, June 21, 2006 08:49 AM Subject: Re: Teleportation thought experiment and UD+ASSA Saibal Mitra [EMAIL PROTECTED] writes: I don't understand why you consider the measures of the programs that do the simulations. The ''real'' measure should be derived from the algorithmic complexity of the laws of physics that describe how the computers/brains work. If you know for certain that a computation will be performed in this universe, then it doesn't matter how it is performed. I think what you're saying here is that if a mental state is instantiated by a given universe, the contribution to its measure should just be the measure of the universe that instantiates it. And that universe's measure is based on the complexity of its laws of physics. I used to hold this view, but I eventually abandoned it because of a number of problems. I need to go back and collect the old messages and discussions that we have had and put them into some kind of order. But I can mention a couple of issues. One problem is the one I just wrote about in my reply to Russell, the fuzziness of the concept of implementation. In at least some universes we may face a gray area in deciding whether a particular computation, or more specifically a particular mental state, is being instantiated. Philosophers like Hans Moravec apparently really believe that every system instantiates virtually every mental state! If you look at the right subset of the atomic vibrations inside a chunk of rock, you can come up with a pattern that is identical to the pattern of firing of neurons in your own brain. Now, most philosophers reject this, they come up with various technical criteria that implementations have to satisfy, but as I wrote to Russell I don't think any of these work. The other problem arises from fuzziness in what counts as a universe. The problem is that you can write very simple programs which will create your mental state. For example, the Universal Dovetailer does just that. But the UD program is much smaller than what our universe's physical laws probably would be. Does the measure of the UD count as a contribution to every mind it creates? If so, then it will dominate over the contributions from more conventional universes; and further, since the UD generates all minds, it means that all minds have equal measure. To reject the UD as a cheating non-universe means that we will need a bunch of ad hoc rules about what counts as a universe and what does not, which are fundamentally arbitrary and unconvincing. Then there are all those bothersome disputes which arise in this model, such as whether multiple instantiations should add more measure than just one; or whether a given brain in a small universe should get more measure than the same brain in a big universe (since it uses a higher proportion of the universe's resources in the first case). All these issues, as well as the ones above, are addressed and answered in my current framework, which is far simpler (the measure of a mental state is just its Kolmogorov measure - end of story). The algorithmic complexity of the program needed to simulate a brain refers to a ''personal universe''. You can think of the brain as a machine that is simulating a virtual world in which the qualia we experience exist. That world also exists independent of our brain in a universe of its own. This world has a very small measure defined by the very large algorithmic complexity of the program needed to specify the brain. I agree with this, I think. The program needed to specify a mental state a priori would be far larger than the program needed to specify the laws of physics which could cause that mental state to evolve naturally. Both programs make a contribution to the measure of the mental state, but the second one's contribution is enormously greater. The key point, due to Wei Dai, is that you can mathematically treat the two on an equal footing. As you have described it, we have a virtual world with qualia being created by a brain; and you have that same world existing independently as a universe of its own. Those are pretty different in a Schmidhuber type model. The second case is the output of one
Re: Teleportation thought experiment and UD+ASSA
I don't understand why you consider the measures of the programs that do the simulations. The ''real'' measure should be derived from the algorithmic complexity of the laws of physics that describe how the computers/brains work. If you know for certain that a computation will be performed in this universe, then it doesn't matter how it is performed. The algorithmic complexity of the program needed to simulate a brain refers to a ''personal universe''. You can think of the brain as a machine that is simulating a virtual world in which the qualia we experience exist. That world also exists independent of our brain in a universe of its own. This world has a very small measure defined by the very large algorithmic complexity of the program needed to specify the brain. Saibal From: Hal Finney [EMAIL PROTECTED] To: everything-list@googlegroups.com Sent: Tuesday, June 20, 2006 06:35 PM Subject: Re: Teleportation thought experiment and UD+ASSA Bruno writes: Hal, It seems to me that you are introducing a notion of physical universe,=20 and then use it to reintroduce a notion of first person death, so that=20 you can bet you will be the one annihilated in Brussels. I should first mention that I did not anticipate the conclusion that I reached when I did that analysis. I did not expect to conclude that teleportation like this would probably not work (speaking figurately). This was not the starting point of the analysis, but the conclusion. The starting point was the framework I have described previously, which can be stated very simply as that the measure of an information pattern comes from the universal distribution of Kolmogorov. I then applied this analysis to specific information patterns which represent subjective, first person lifetime experiences. I concluded that the truncated version which ends when the teleportation occurs would probably have higher measure than the ones which proceed through and beyond the teleportation. Although I worked in terms of a specific physical universe, that is a short-cut for simplicity of exposition. The general case is to simply ask for the K measure of each possible first-person subjective life experience - what is the shortest program that produces each one. I assume that the shortest program will in fact have two parts, one which creates a universe and the second which takes that universe as input and produces the first-person experience record as output. This leads to a Schmidhuber-like ensemble where we would consider all possible universes and estimate the contribution of each one to the measure of a particular first-person experience. It is important though to keep in mind that in practice the only universe which adds non-negligible measure would be the one we are discussing. In other words, consider the first person experience of being born, living your life, travelling to Brussels and stepping into a teleportation machine. A random, chaotic universe would add negligibly to the measure of this first-person life experience. Likewise for a universe which only evolves six-legged aliens on some other planet. So in practice it makes sense to restrict our attention to the (approximately) one universe which has third-person objective events that do add significant measure to the instantiation of these abstract first-person experiences. You agree that this is just equivalent of negating the comp hypothesis.=20 You would not use (classical) teleportation, nor accept a digital=20 artificial brain, all right? Do I miss something? It is perhaps best to say that I would not do these things *axiomatically*. Whether a particular teleportation technology would be acceptable would depend on considerations such as I described in my previous message. It's possible that the theoretical loss of measure for some teleportation technology would be small enough that I would do it. As far as using an artificial brain, again I would look to this kind of analysis. I have argued previously that a brain which is much smaller or faster than the biological one should have much smaller measure, so that would not be an appealing transformation. OTOH an artificial brain could be designed to have larger measure, such as by being physically larger or perhaps by having more accurate and complete memory storage. Then that would be appealing. I think that one of the fundamental principles of your COMP hypothesis is the functionalist notion, that it does not matter what kind of system instantiates a computation. However I think this founders on the familiar paradoxes over what counts as an instantiation. In principle we can come up with a continuous range of devices which span the alternatives from non-instantiation to full instantiation of a given computation. Without some way to distinguish these, there is no meaning to the question of when a computation is instantiated; hence functionalism fails. My
Re: Reasons and Persons
John, actually I don't want to do that per se. I think that ultimately we live in a universe described by the very complex ''laws of physics'' that describe the qualia we experience. Perhaps it is better to say that we are such complex universes. We are simulated in a universe described by simple laws of physics. Our brains are simulating us. We shouldn't confuse the hardware with the software Saibal Quoting [EMAIL PROTECTED] [EMAIL PROTECTED]: And why do you want to restrict a 'person' to a cut view of its neurons only? Isn't a person (as anything) part of his ambience - in a wider view: of the totality, with interction back and forth with all the changes that go on? Are you really interested only in the dance of those silly neurons? John M - Original Message - From: Saibal Mitra [EMAIL PROTECTED] To: everything-list@googlegroups.com Sent: Monday, May 29, 2000 9:07 PM Subject: Re: Reasons and Persons There must exist a ''high level'' program that specifies a person in terms of qualia. These qualia are ultimately defined by the way neurons are connected, but you could also think of persons in terms of the high-level algorithm, instead of the ''machine language'' level algorithm specified by the neural network. The interpolation between two persons is more easily done in the high level language. Then you do obtain a continuous path from one person to the other. For each intermediary person, you can then try to ''compile'' the program to the corresponding neural network. - Original Message - From: Jesse Mazer [EMAIL PROTECTED] To: everything-list@googlegroups.com Sent: Tuesday, May 30, 2006 02:29 AM Subject: Re: Reasons and Persons Russell Standish wrote: On Mon, May 29, 2006 at 07:15:33PM +1000, Stathis Papaioannou wrote: I don't see why you are so sure about the necessity of passing through non-functional brain structures going from you to Napoleon. After all, there is a continuous sequence of intermediates between you and a fertilized ovum, and on the face of it you have much more in common mentally and physically with Napoleon than with a fertilized ovum. However, technical feasibility is not the point. The point is that *if* (let's say magically) your mind were gradually transformed, so that your We need to be a bit more precise than magically. In Parfit's book he talks about swapping out my neurons for the equivalent neurons in Napoleon's brain. Sure this is not exactly technically feasible at present, but for thought experiment purposes it is adequate, and suffices for doing the teleporting experiment. The trouble I have is that Napoleon's brain will be wired completely differently to my own. Substituting enough of his neurons and connections will eventually just disrupt the functioning of my brain. I agree that Parfit's simple method would probably create a nonfunctional state in between, or at least the intermediate phase would involve a sort of split personality disorder with two entirely separate minds coexisting in the same brain, without access to each other's thoughts and feelings. But this is probably not a fatal flaw in whatever larger argument he was making, because you could modify the thought experiment to say something like let's assume that in the phase space of all possibe arrangements of neurons and synapses, there is some continuous path between my brain and Napoleon's brain such that every intermediate state would have a single integrated consciousness. There's no way of knowing whether such a path exists (and of course I don't have a precise definition of 'single integrated consciousness'), but it seems at least somewhat plausible. Jesse -- No virus found in this incoming message. Checked by AVG Free Edition. Version: 7.1.394 / Virus Database: 268.8.0/353 - Release Date: 05/31/06 -- _ Tele2 - The company that brings you small bills! http://www.tele2.nl --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Everything List group. To post to this group, send email to everything-list@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list -~--~~~~--~~--~--~---
Re: Reasons and Persons
There must exist a ''high level'' program that specifies a person in terms of qualia. These qualia are ultimately defined by the way neurons are connected, but you could also think of persons in terms of the high-level algorithm, instead of the ''machine language'' level algorithm specified by the neural network. The interpolation between two persons is more easily done in the high level language. Then you do obtain a continuous path from one person to the other. For each intermediary person, you can then try to ''compile'' the program to the corresponding neural network. - Original Message - From: Jesse Mazer [EMAIL PROTECTED] To: everything-list@googlegroups.com Sent: Tuesday, May 30, 2006 02:29 AM Subject: Re: Reasons and Persons Russell Standish wrote: On Mon, May 29, 2006 at 07:15:33PM +1000, Stathis Papaioannou wrote: I don't see why you are so sure about the necessity of passing through non-functional brain structures going from you to Napoleon. After all, there is a continuous sequence of intermediates between you and a fertilized ovum, and on the face of it you have much more in common mentally and physically with Napoleon than with a fertilized ovum. However, technical feasibility is not the point. The point is that *if* (let's say magically) your mind were gradually transformed, so that your We need to be a bit more precise than magically. In Parfit's book he talks about swapping out my neurons for the equivalent neurons in Napoleon's brain. Sure this is not exactly technically feasible at present, but for thought experiment purposes it is adequate, and suffices for doing the teleporting experiment. The trouble I have is that Napoleon's brain will be wired completely differently to my own. Substituting enough of his neurons and connections will eventually just disrupt the functioning of my brain. I agree that Parfit's simple method would probably create a nonfunctional state in between, or at least the intermediate phase would involve a sort of split personality disorder with two entirely separate minds coexisting in the same brain, without access to each other's thoughts and feelings. But this is probably not a fatal flaw in whatever larger argument he was making, because you could modify the thought experiment to say something like let's assume that in the phase space of all possibe arrangements of neurons and synapses, there is some continuous path between my brain and Napoleon's brain such that every intermediate state would have a single integrated consciousness. There's no way of knowing whether such a path exists (and of course I don't have a precise definition of 'single integrated consciousness'), but it seems at least somewhat plausible. Jesse --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Everything List group. To post to this group, send email to everything-list@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list -~--~~~~--~~--~--~---
Re: Smullyan Shmullyan, give me a real example
From: Patrick Leahy [EMAIL PROTECTED] To: everything-list@googlegroups.com Sent: Friday, May 12, 2006 12:56 PM Subject: Re: Smullyan Shmullyan, give me a real example On Fri, 12 May 2006, Saibal Mitra wrote: Einstein seems to have believed in ''immortal observer moments''. In a BBC documentary about time it was mentioned that Einstein consoled a friend whose son had died in a tragic accident by saying that relativity suggests that the past and the future are as real as the present. I'm sure Einstein would turn in his grave at your quoted expression. An immortal moment is a contradiction in terms, unless it implies a second time which passes as we contemplate first time embedded in 4-D space-time. Unfortunately a lot of popular discussion of space-time implicitly invokes this spurious second time, because it is hard to decouple the language of existence from the language of existence *in time*. To believe, with Einstein, that all points in space-time are equally real (because the relativity of simultaneity means that there is no unique now) is quite the opposite of the nutty idea that all events exist now --- not even wrong, from Einstein's point of view. Einstein actually expressed this view in a letter of condolence to the widow of his old friend Michele Besso. His words are worth quoting accurately: In quitting this strange world he has once again preceded me by just a little. That doesn't mean anything. For we convinced physicists the distinction between past, present, and future is only an illusion, however persistent. Later physicists, in particular John Bell, have pointed out that relativity doesn't *prove* that now is an illusion, it just makes it impossible to identify any objective now. Not that any of this has anything to do with the sort of immortality contemplated by Everett, which is not at all enticing: like the Sibyl in classical myth, his immortality would not be accompanied by eternal youth... a rather horrible fate. Thanks for the correction and the exact quote. I only vaguely remembered what was said in the program. Of course, ''immortal observer moment'' is indeed contradictory. The point is, of course, that ''now'' implies a localization in time just like ''here'' implies localization in space. Just like things that don't exist here but do exist elsewhere are ''real'' so should things that don't exist now anymore but did exist at some time in the past. Saibal --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Everything List group. To post to this group, send email to everything-list@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list -~--~~~~--~~--~--~---
Re: Smullyan Shmullyan, give me a real example
Einstein seems to have believed in ''immortal observer moments''. In a BBC documentary about time it was mentioned that Einstein consoled a friend whose son had died in a tragic accident by saying that relativity suggests that the past and the future are as real as the present. Saibal From: Russell Standish [EMAIL PROTECTED] To: everything-list@googlegroups.com Sent: Thursday, May 11, 2006 01:07 AM Subject: Re: Smullyan Shmullyan, give me a real example On Wed, May 10, 2006 at 11:13:27PM +0100, Patrick Leahy wrote: On who invented quantum suicide, the following is from the biography of Hugh Everett by Eugene B. Shikhovtsev and Kenneth W. Ford, at http://space.mit.edu/home/tegmark/everett/ Atheist or not, Everett firmly believed that his many-worlds theory guaranteed him immortality: His consciousness, he argued, is bound at each branching to follow whatever path does not lead to death --- and so on ad infinitum. (Sadly, Everett's daughter Liz, in her later suicide note, said she was going to a parallel universe to be with her father...) Sadly, because this is based on a total misunderstanding of QTI, I guess. The reference is to Everett's views in 1979-80, but there is no reason to suppose that Everett had only just thought of it at the time. On a personal note, some time in the '80s I met one of Everett's co-workers who told me that Everett used to justify his very unhealthy lifestyle on exactly these grounds. In our world, Everett died of a heart attack aged 52. I have always assumed that John Bell was thinking along these lines when he commented on Everett's theory: But if such a theory was taken seriously it would hardly be possible to take anything else seriously. (1981, reprinted in _Speakable Unspeakable in Quantum Mechanics). These dates all mesh with Don Page's anecdote about Ed Teller : immortality consequences widely known, but rarely talked about by the early '80s. For that matter, this idea is implicit in Borges' story The Garden of Forking Paths (written before 1941), which provides the epigraph to the DeWitt Graham anthology on The Many Worlds Interpretation. == 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 Very interesting. Its a shame my manuscript is already at the printers, I would have loved this for my background info on QTI. -- -- -- A/Prof Russell Standish Phone 8308 3119 (mobile) Mathematics0425 253119 () UNSW SYDNEY 2052 [EMAIL PROTECTED] Australia http://parallel.hpc.unsw.edu.au/rks International prefix +612, Interstate prefix 02 -- -- --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Everything List group. To post to this group, send email to everything-list@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list -~--~~~~--~~--~--~---
Re: why can't we erase information?
This thread is still alive! It seems that information can't be erased in this thread either :) I think that information can't be erased because of the way time is (or should be) defined. If you take the observer moment approach to the multiverse, then you have to define a notion of time. That definition will then imply conservation of information. --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Everything List group. To post to this group, send email to everything-list@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list -~--~~~~--~~--~--~---
Re: why can't we erase information?
Yes, I agree. But it could be that information loss is a bit ambiguous. E.g. 't Hooft has shown that you can start with a deterministic model exhibiting information loss and end up with quantum mechanics. Saibal - Original Message - From: Jesse Mazer [EMAIL PROTECTED] To: everything-list@googlegroups.com Sent: Monday, April 10, 2006 03:22 AM Subject: Re: why can't we erase information? Saibal Mitra wrote: How would an observer know he is living in a universe in which information is lost? Information loss means that time evolution can map two different initial states to the same final state. The observer in the final state thus cannot know that information really has been lost. If he is able to figure out the fundamental laws of physics of his universe, then he could see whether or not they have this property of it being possible to deduce past states from present ones (I think the name for this property might be 'reversible', although I can't remember the difference between 'reversible' and 'invertible' laws). For example, the rules of Conway's Game of Life cellular automaton are not reversible, but if it were possible for such a world to support intelligent beings I don't see why it wouldn't be in principle possible for them to deduce the underlying rules. As for the question of why we live in a universe that apparently has this property, I don't think there's an anthropic explanation for it, I'd see it as part of the larger question of why we live in a universe whose fundamental laws seem to be so elegant and posess so many symmetries, one of which is time-symmetry (or to be more accurate, CPT-symmetry, which means the laws of physics are unchanged if you switch particles with antiparticles and flip the 'parity' along with reversing which direction of time is labeled 'the future' and which is labeled 'the past'). Some TOEs that have been bandied about here say that we should expect to live in a universe whose laws are very compressible, so maybe this would be one possible way of answering the question. Jesse - Defeat Spammers by launching DDoS attacks on Spam-Websites: http://www.hillscapital.com/antispam/ --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Everything List group. To post to this group, send email to everything-list@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list -~--~~~~--~~--~--~---
Re: why can't we erase information?
- Original Message - From: Wei Dai [EMAIL PROTECTED] To: everything-list@googlegroups.com Sent: Tuesday, April 11, 2006 01:46 AM Subject: Re: why can't we erase information? Saibal Mitra wrote: How would an observer know he is living in a universe in which information is lost? Information loss means that time evolution can map two different initial states to the same final state. The observer in the final state thus cannot know that information really has been lost. If the universe allows two different states to evolve into the same final state, the second law of thermodynamics wouldn't hold, and we would be able to (in principle) contruct perpetual motion machines. I don't know why you say this can't be detected by an observer. In theory all we have to do is prepare two systems in two different states, and then observe that they have evolved into the same final state. Of course in practice the problem is which two different states? And as I suggest earlier, it may be that for anthropic reasons one or both of these states is very difficult to access. Yes, in principle you could observe such a thing. But it may be that generic models exhibiting information loss look like model that don't have information loss to internal observers. 't Hooft's deterministic models are an example of this. I'm also skeptical about observers being able to make more efficient machines. The problem with that, as I see it (I haven't read Lloyd's book yet) is as follows. Consider first a model without information loss, like our own universe. What is preventing us from converting heat into work with 100% efficiency is lack of information. If we had access to all the information that is present then you could make an effective Maxwell's Daemon. Lacking such information, Maxwell's Deamon has to make measurements, which it has to act on. But eventually it has to clear it's memory, and that makes it ineffective. To get rid of this problem Maxwell's Daemon would have to be able to reset its memory without changing the state of the rest of the universe. This could possibly be done in an universe with information loss, but that could only work if the Daemon has control over the information loss process. If information loss interferes with the actions of the Daemon, then it isn't much use. You could also think of the possiblity of some ''physical process'' which would be sort of a ''passive Maxwell's Deamon'' that could reduce the entropy in such universe. Using that you could create a temperature difference between two objects. To extract work you now need to let heat flow between the two objects. So, at that stage you need an entropy to increase again. So, to me this doesn't seem to be a generic world in which you have information loss, rather a world in which it is preserved but where it can be overruled at will. The benefits come from that magical power. Saibal - Defeat Spammers by launching DDoS attacks on Spam-Websites: http://www.hillscapital.com/antispam/ --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Everything List group. To post to this group, send email to everything-list@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list -~--~~~~--~~--~--~---
Re: why can't we erase information?
How would an observer know he is living in a universe in which information is lost? Information loss means that time evolution can map two different initial states to the same final state. The observer in the final state thus cannot know that information really has been lost. - Original Message - From: Wei Dai [EMAIL PROTECTED] To: everything-list@googlegroups.com Sent: Sunday, April 09, 2006 09:11 AM Subject: why can't we erase information? If we consider our observable universe as a computation, it's rather atypical in that it doesn't seem to make use of the erase operation (or other any operation that irreversibly erases information). The second law of thermodynamics is a consequence of this. In order to forget anything (decrease entropy), we have to put the information somewhere else (increase entropy of the environment), instead of just making it disappear. If this doesn't make sense to you, see Seth Lloyd's new book Programming the Universe : A Quantum Computer Scientist Takes On the Cosmos for a good explanation of the relationship between entropy, computation, and information. Has anyone thought about why this is the case? One possible answer is that if it were possible to erase information, life organisms would be able to construct internal perpetual motion machines to power their metabolism, instead of competing with each other for sources of negentropy, and perhaps intelligence would not be able to evolve in this kind of environment. If this is the case, perhaps there is reason to hope that our universe does contain mechanisms to erase information, but they are not easily accessible to life before the evolution of intelligence. It may be a good idea to look out for such mechanisms, for example in high energy particle reactions. However I'm not sure this answer is correct because there would still be competition for raw material (matter and energy) where intelligence can still be an advantage. Anyone have other ideas? --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Everything List group. To post to this group, send email to everything-list@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list -~--~~~~--~~--~--~---
Re: Multiverse concepts in string theory
Hi Stephen,
Yes I agree. But once you have many scientists
believing in a certain paradigm, it takes radical new discoveries to overturn
it. The lack of confirmation is usually not enough.
Saibal
- Original Message -
From:
Stephen
Paul King
To: everything-list@eskimo.com
Sent: Wednesday, February 15, 2006 1:45
AM
Subject: Re: Multiverse concepts in
string theory
Hi Saibal,
Does this not lead one to suspect that
they secretly believe SUSY to be "not even wrong" and yet seek to save face?
My problem is that any scientific theory must be highly falsifiable, otherwise
we are just going back to the days of Scholastic debates...
http://clublet.com/why?AngelsOnTheHeadsOfPins
Onward!
Stephen
- Original Message -
From:
Saibal Mitra
To: Stephen Paul King ; everything-list@eskimo.com
Sent: Tuesday, February 14, 2006 6:20
PM
Subject: Re: Multiverse concepts in
string theory
Stephen,
Theorists are always a bit ahead and they have
already foundways to save SUSY from negative results from the LHC.
Saibal
- Original Message -
From:
Stephen
Paul King
To: everything-list@eskimo.com
Sent: Tuesday, February 14, 2006 1:04
PM
Subject: Re: Multiverse concepts in
string theory
Hi Norman,
It will be a wonderful thing to get a
confirmation by next year but I am afraid that the usual behavior of
theorist will occur: the theory will be re-tinkered so that the particle
masses are too massive to be created by humans. It has been happening
already in astrophysics...
Btw, have you any familiarity with
modeling the dynamics of scalar fields in relativistic situations? I need
some help. ;-)
Onward!
Stephen
- Original Message -
From:
Norman
Samish
To: Everything-list
Sent: Tuesday, February 14, 2006
1:36 AM
Subject: Re: Multiverse concepts in
string theory
Stephen,
As you say, the version of string theorywith an
infinity of universes isan elegant concept. However, when
you say". . . its most fundamental assumption,the existence
of a supersymmerty relation between bosons and fermions, has never even
come close to matching experimental observation,"one could infer
that there is little likelihood that SUSY will ever be shown to
bea good theory.
Thismay change soon.Wikipedia says
"Experimentalists have not yet found any superpartners for known
particles, either because they are too massive to be created in our
current particle accelerators, or because they may not exist at
all. By the year 2007, the Large Hadron Collider at CERN
should be ready for use, producing collisions at sufficiently high
energies to detect the superpartners many theorists hope to
see."
So maybe, in a couple of years, there WILL be
experimental observation supporting SUSY.
I agree that the posts by Hal Finney and Wei Dai are
well said and inspirational. Thanks,
Norman
Re: Quantum Immortality and Information Flow
Hi Bruno, Well, even if you can derive the laws of physics as we know them (in some approximation), you still can't do an experiment to prove that quantum suicide works. It can only be proven to the experimentor himself. This means that the absolute measure cannot be ruled out experimentally. - Original Message - From: Bruno Marchal [EMAIL PROTECTED] To: Saibal Mitra [EMAIL PROTECTED] Cc: everything-list@eskimo.com Sent: Thursday, December 15, 2005 01:25 PM Subject: Re: Quantum Immortality and Information Flow Le 15-déc.-05, à 03:04, Saibal Mitra a écrit : To me it seems that the notion of ''successor'' has to break down at cases where the observer can die. The Tookies that are the most similar to the Tookie who got executed are the ones who got clemency. There is no objective reason why these Tookies should be excluded as ''successors''. They miss the part of their memories about things that happened after clemency was denied. Instead of those memories they have other memories. We forget things all the time. Sometimes we remember things that didn't really happen. So, we allow for information loss anyway. My point is then that we should forget about all of the information contained in the OM and just sample from the entire set of OMs. The notion of a ''successor'' is not a fundamental notion at all. You can define it any way you like. ? It will not lead to any conflict with any experiments you can think of. ? Counterexamples will appear if I succeed to explain more of the conversation with the lobian machines. But just with the Kripke semantics we have a base to doubt what you are saying here. Indeed, it is the relation of accessibility between OMs which determine completely the invariant laws pertaining in all OMs. For example, if the multiverse is reflexive the Bp - p is true in all OMs (that is, Bp - p is invariant for any walk in the multiverse). If the mutliverse is terminal of papaioannou-like) then Dt - ~BDt is a law. In Kripke structure the accessibility relation determined the invariant laws. later, the modal logic is given by the machine interview, and from that, we will determine the structure of the multiverse, including the observable one. Bruno http://iridia.ulb.ac.be/~marchal/
A New Kind of Science Conference
http://www.wolframscience.com/conference/2006/outline.html
Re: Quantum Immortality and Information Flow
- Original Message - From: Johnathan Corgan [EMAIL PROTECTED] To: Stathis Papaioannou [EMAIL PROTECTED] Cc: everything-list@eskimo.com Sent: Wednesday, December 14, 2005 10:39 AM Subject: Re: Quantum Immortality and Information Flow Stathis Papaioannou wrote: In the multiverse, only other people end up in dead ends. Kind of makes you wonder what Tookie is doing right now. To us, he died as a result of lethal injection. What sort of successor observer-moments can follow a thing like that? Better question--what is the most likely type of 1st-person observer-moment that would follow experiencing lethal injection? Sure, there is an infinitesimal probability that all his constituent particles quantum-tunneled to a Pacific island paradise and right now somewhere in the multiverse he's enjoying a drink with an umbrella in it, thanking the fine State of California for his new life. More likely, but still infinitesimally small, is the probability that only the molecules of toxin in the injection syringe quantum-tunneled away and right now there are execution officials puzzling over whether to pardon him after this act-of-God miraculous reprieve from death. But seriously, when the overwhelmingly vast majority of successor moments to an instant in time are all 3rd-person dead-ends, what would would be an example of a high-expectation 1st-person successor observer-moment from the tiny sliver of physically possible (but extremely unlikely) ones left? Is there in fact always one left, no matter how unlikely? To me it seems that the notion of ''successor'' has to break down at cases where the observer can die. The Tookies that are the most similar to the Tookie who got executed are the ones who got clemency. There is no objective reason why these Tookies should be excluded as ''successors''. They miss the part of their memories about things that happened after clemency was denied. Instead of those memories they have other memories. We forget things all the time. Sometimes we remember things that didn't really happen. So, we allow for information loss anyway. My point is then that we should forget about all of the information contained in the OM and just sample from the entire set of OMs. The notion of a ''successor'' is not a fundamental notion at all. You can define it any way you like. It will not lead to any conflict with any experiments you can think of.
Re: Quantum Immortality and Information Flow
This doubling of the absolute measure is important. In another posting you wrote about being teleported to many places and then being annihilated everywhere except at the original place. This won't affect the probability of being alive at the original place. But in a QC experiment where you have many outcomes, all leading to death except one, the probability of experiencing that branch is very small. - Original Message - From: Stathis Papaioannou [EMAIL PROTECTED] To: [EMAIL PROTECTED]; everything-list@eskimo.com Sent: Saturday, December 03, 2005 11:38 AM Subject: Re: Quantum Immortality and Information Flow Well, I did actually intend my example to be analogous to the Tegmark QS experiment. Are you saying that if there is only one world and magically an identical, separate world comes into being this is fundamentally different to what happens in quantum branch splitting? It seems to me that in both cases the relative measure of everything in the world stays the same, even though in absolute terms there is double of everything. Stathis Papaioannou Saibal Mitra writes: Correction, I seem to have misunderstood Statis' set up. If you really create a new world and then create and kill the person there then the probability of survival is 1. This is different from quantum mechanical branch splitting. To see this, consider first what would have happened had the person not been killed. Then his measure would have doubled. But because he is killed in one of the two copies of Earth, his measure stays the same. In a quantum suicide experiment his measure would be reduced by a factor two. If on the basis of a coin toss the world splits, and in one branch I am instantaneously killed while in the other I continue living, there are several possible ways this might be interpreted from the 1st person viewpoint: (a) Pr(I live) = Pr(I die) = 0.5 (b) Pr(I live) = 1, Pr(I die) = 0 (c) Pr(I live) = 0, Pr(I die) = 1 _ Buy now @ Tradingpost.com.au http://a.ninemsn.com.au/b.aspx?URL=http%3A%2F%2Fad%2Eau%2Edoubleclick%2Enet%2Fclk%3B23850242%3B12217581%3Bw%3Fhttp%3A%2F%2Fwww%2Etradingpost%2Ecom%2Eau%2F%3Freferrer%3DnmsnHMetag_t=11482_r=emaildec05_m=EXT
Re: Quantum Immortality and Information Flow
Correction, I seem to have misunderstood Statis' set up. If you really create a new world and then create and kill the person there then the probability of survival is 1. This is different from quantum mechanical branch splitting. To see this, consider first what would have happened had the person not been killed. Then his measure would have doubled. But because he is killed in one of the two copies of Earth, his measure stays the same. In a quantum suicide experiment his measure would be reduced by a factor two. - Original Message - From: Saibal Mitra [EMAIL PROTECTED] To: Stathis Papaioannou [EMAIL PROTECTED]; [EMAIL PROTECTED]; Jesse Mazer [EMAIL PROTECTED] Cc: everything-list@eskimo.com Sent: Sunday, November 27, 2005 02:25 AM Subject: Re: Quantum Immortality and Information Flow The answer must be a) because (and here I disagree with Jesse), all that exists is an ensemble of isolated observer moments. The future, the past, alternative histories, etc. they all exist in a symmetrical way. It don't see how some states can be more ''real'' than other states. Of course, the universe we experience seems to be real to us while alternative universes, or past or future states of this universe are not being experienced by us. So, you must think of yourself at any time as being randomly sampled from the set of all possible observer moments. To get to answer b) you have to redefine your identity so that experiencing having done the experiment becomes a necessary part of your identity. But this is cheating because you wouldn't say that if ''death'' were replaced by a partial memory erasure such that the experience of having done the experiment were wiped out form your memory. - Original Message - From: Stathis Papaioannou [EMAIL PROTECTED] To: [EMAIL PROTECTED] Cc: everything-list@eskimo.com Sent: Saturday, November 26, 2005 11:51 AM Subject: Re: Quantum Immortality and Information Flow Stathis Papaioannou writes: If on the basis of a coin toss the world splits, and in one branch I am instantaneously killed while in the other I continue living, there are several possible ways this might be interpreted from the 1st person viewpoint: (a) Pr(I live) = Pr(I die) = 0.5 (b) Pr(I live) = 1, Pr(I die) = 0 (c) Pr(I live) = 0, Pr(I die) = 1 Even on this list, there are people who might say (a) above is the case rather than (b) or (c). Bruno Marchal replies: Are you sure? I was thinking of people who accept some ensemble theory such as MWI, but don't believe in QTI. I must admit, I find it difficult to understand how even a dualist might justify (a) as being correct. Would anyone care to help? Stathis _ Start something musical - 15 free ninemsn Music downloads! http://ninemsn.com.au/share/redir/adTrack.asp?mode=clickclientID=667referral=HotmailTaglineNovURL=http://www.ninemsn.com.au/startsomething
Re: Quantum Immortality and Information Flow
- Original Message - From: Jonathan Colvin [EMAIL PROTECTED] To: everything-list@eskimo.com Sent: Sunday, November 27, 2005 05:49 AM Subject: RE: Quantum Immortality and Information Flow Saibal wrote: The answer must be a) because (and here I disagree with Jesse), all that exists is an ensemble of isolated observer moments. The future, the past, alternative histories, etc. they all exist in a symmetrical way. It don't see how some states can be more ''real'' than other states. Of course, the universe we experience seems to be real to us while alternative universes, or past or future states of this universe are not being experienced by us. So, you must think of yourself at any time as being randomly sampled from the set of all possible observer moments. delurk I'm not sure how this works. Suppose I consider my state now at time N as a random sample of all observer moments. Now, after having typed this sentence, I consider my state at time N + 4 seconds. Is this also a random sample on all observer moments? I can do the same at now N+10, and so-on. It seems very unlikely that 3 random samples would coincide so closely. So in what sense are these states randomly sampled? It's a bit like symmetry breaking. You have an ensemble of all possible observer moment, but each observer moment can only experience its own state. So, the OM samples itself. There exists an observer moment representing you at N seconds, at N + 4 seconds and at all possible other states. They all ''just exist'' in the plenitude, as Stathis wrote. The OM representing you at N + 4 has the memory of being the OM at N. Subjectively the OMs experience time evolution, even though the plenitude itself doesn't have a time evolution at the fundamental level. Although it is a bit strange to think about time evolution in this way, it is necessary to resolve paradoxes you get when contemplating doubling and suicide experiments. It is precisely in these cases that our naive notion of time evolution breaks down. Saibal
Re: Quantum theory of measurement
Well, as you can see here: http://cabtep5.cnea.gov.ar/particulas/daniel/curri/curreng.html He isn't very experienced yet. I know of some experienced professors of have made worse mistakes :) So, what goes wrong? Well, you don't get an interference pattern at one end even if you don't detect the photon at the other end. To see this, just write down the two particle state and add the phase shifts. If the detectors on the other sides are off, then the two contributions corresponding to the photon being detected at some position z consist of two orthogonal terms; one term correpsonds to the other photon in pipe 1 and the other for that photon in pipe 2 Suppose that you add a plate to detect the photon on that side as well. Then the probability that the photon at one end is detected at position z1 and the other is detected at z2 does contain an interference term of the form: Cos[delta1(z1) + delta2(z2)] If you don't detect where photon 2 is absorbed you have to integrate over z2 and the interference term vanishes. To see an interference term you must keep z2 fixed. This means that you must consider only those photons for which the entangled partners were detected at at some fixed z2. But this means that this value must be communicated by the observer there. - Original Message - From: Hal Finney [EMAIL PROTECTED] To: everything-list@eskimo.com Sent: Thursday, October 13, 2005 03:59 AM Subject: RE: Quantum theory of measurement Now that you are experts on this, try your hand on this FTL signalling device, http://arxiv.org/abs/quant-ph?0204108. The author, Daniel Badagnani, is apparently a genuine physicist, http://cabtep5.cnea.gov.ar/particulas/daniel/pag-db.html. Hal Finney
Re: Quantum theory of measurement
Hal gives the correct explanation of what's going on. In general, all you have to do to analyze the problem is to consider all contributions to a particular state and add up the amplitudes. The absolute value squared of the amplitude gives the probability, which may or may not contain an interference term. A simple minded formal description can be given as follows: If you pass a photon through two slits then close to the screen its state would be of the form: Integral over z of [1 + Exp(i delta(z))] |s,z Here z denotes the postion on the screen, s is just a label for the photon and Exp(i delta(z)) is the phase shift between the two paths which gives rise to the interference term. Delta(z) will be zero exactly inbetween the two slits and will be nonzero elsewhere. The probability of having the photon at z is obtained (up to normalization) by taking the absolute value squared of the prefactor of |s,z, which is 2 + 2 cos(delta(z)). Let's do the same for the two entagled photons. The entangled photon pair can be denoted as: |p_x,s_y + |p_y,s_x here x and y denote the polarization states. If you pass s through the two slits then the state becomes: [1 + Exp(i delta(z))] |p_x,s_y,z + [1 + Exp(i delta(z))] ||p_y,s_x,z This has to be integrated over z, but let's focus only at the contribution at some fixed position z. The prefactors of both state vectors |p_x,s_y,z and |p_y,s_x,z are of the same form as in the single photon case and thus you get an interference term Cos(delta(z) as above. If you put the quarter wave plate in then instead of [1 + Exp(i delta(z))] |p_x,s_y,z you get: |p_x,s_r,z + Exp(i delta(z)) |p_x,s_l,z And the complete state vector becomes: |p_x,s_r,z + Exp(i delta(z)) |p_x,s_l,z+ |p_y,s_l,z + Exp(i delta(z)) |p_y,s_r,z All the four state vectors are orthogonal. The probability that you detect the photon s at z is just the sum of the absolute value squared of the four terms, which is constant and doesn't contain an interference term. Now let's pass photon p through the polarizer (45 degrees w.r.t. x). This amounts to measuring the polarization state of photon p in the basis |p_x + p_y and |p_x - p_y. If you don't discard one of these two states and keep them both then, as Hal rightly points out, nothing changes. If you substitute: |p_x = |a + |b; |p_y = |a - |b in the state vector above you get: |a,s_r,z + Exp(i delta(z)) |a,s_l,z+ |a,s_l,z + Exp(i delta(z)) |a,s_r,z+ |b,s_r,z + Exp(i delta(z)) |b,s_l,z+ - |b,s_l,z - Exp(i delta(z)) |b,s_r,z = (collecting the prefactors of like state vectors) = [1 + Exp(i delta(z))]|a,s_r,z + [1 + Exp(i delta(z))]|a,s_l,z + [1 - Exp(i delta(z))]|b,s_r,z - [1 - Exp(i delta(z))] |b,s_l,z The absolute value squared of the terms with the p photons in the |a state contains the term 2 Cos (delta(z)), but for the b terms this is - 2 Cos(delta(z). If you don't observe the polarization of the p photon, the interference terms would thus cancel. This is obvious since all we have done is to write down the same state in a different basis. But if you do observe the polarization of the p photon, then can measure the probability of detecting s at position z and p in polarization state |a then you have to add up the absolute value squared of |a,s_r,z and |a,s_l,z. Then you do get the Cos(delta(z) interference term. - Original Message - From: Hal Finney [EMAIL PROTECTED] To: [EMAIL PROTECTED]; everything-list@eskimo.com Sent: Wednesday, October 12, 2005 08:16 PM Subject: Re: Quantum theory of measurement Ben Goertzel writes about: http://grad.physics.sunysb.edu/~amarch/ The questions I have regard the replacement of the Coincidence Counter (from here on: CC) in the above experiment with a more complicated apparatus. What if we replace the CC with one of the following: 1) a carefully sealed, exquisitely well insulated box with a printer inside it. The printer is hooked up so that it prints, on paper, an exact record of everything that comes into the CC. Then, to erase the printed record, the whole box is melted, or annihilated using nuclear explosives, or whatever. The CC is not what is erased. Rather, the so-called erasure happens to the photons while they are flying through the apparatus. Nothing in the experiment proposes erasing data in the CC. So I don't really see what you are getting at. What will the outcome be in these experiments? It won't make any difference, because the CC is not used in the way you imagine. It doesn't have to produce a record and it doesn't have to erase any records. Let me tell you what really happens in the experiment above. It is actually not so mystical as people try to make it sound. We start off with the s photon going through a 2 slit experiment and getting interference. That is standard. Now we put two different polarization rotations in front of the two slits and interference goes away. The web page author professes
Re: Neutrino shield idea
There are a lot of experiments that have detected neutrinos and verified their properties (which are completely different from photons). - Original Message - From: John Ross [EMAIL PROTECTED] To: 'Saibal Mitra' [EMAIL PROTECTED]; everything-list@eskimo.com Sent: Monday, October 10, 2005 10:49 PM Subject: RE: Neutrino shield idea I think the beta decay model is wrong where it predicts neutrinos are basically different from photons. I understand neutrinos travel at the speed of light. Only photons travel at the speed of light. -Original Message- From: Saibal Mitra [mailto:[EMAIL PROTECTED] Sent: Friday, October 07, 2005 4:30 PM To: John Ross; everything-list@eskimo.com Subject: Re: Neutrino shield idea This means that beta decay proves your model wrong. - Original Message - From: John Ross [EMAIL PROTECTED] To: 'Stephen Paul King' [EMAIL PROTECTED]; everything-list@eskimo.com Sent: Saturday, October 08, 2005 12:35 AM Subject: RE: Neutrino shield idea Thanks for the paper relating to detection of low energy neutrinos. However, according to my model, neutrinos are very, very high energy photons (off everybody's chart, except mine). Therefore, if my model is correct, then low energy neutrinos would merely be the photons we are familiar with and would be very easy to detect. -Original Message- From: Stephen Paul King [mailto:[EMAIL PROTECTED] Sent: Friday, October 07, 2005 12:54 PM To: everything-list@eskimo.com Subject: Neutrino shield idea Howdy! I friend of mine has worked on a related idea that might help this inverstigation. Please see: http://davidwoolsey.com/physics/ideas/neutrinoscope/index.html Kindest regards, Stephen - Original Message - From: John Ross [EMAIL PROTECTED] To: [EMAIL PROTECTED] Cc: everything-list@eskimo.com Sent: Friday, October 07, 2005 11:57 AM Subject: RE: ROSS MODEL OF THE UNIVERSE - The Simplest Yet Theory of Everything Yes. But building a neutrino shield would be difficult.
Re: Neutrino shield idea
I'm sure you saw something else :-) - Original Message - From: John Ross [EMAIL PROTECTED] To: 'Russell Standish' [EMAIL PROTECTED] Cc: 'Hal Ruhl' [EMAIL PROTECTED]; everything-list@eskimo.com Sent: Tuesday, October 11, 2005 01:40 AM Subject: RE: Neutrino shield idea I say a neutrino does not have a rest mass. It is a photon, like a very high energy gamma ray photon. I have seen photos of a neutrino collision in a neutrino trap. From the look of all the resulting ionization tracks, it must have had a lot more energy than 40 ev. I say the energy of neutrinos is in the range of 300 mev! -Original Message- From: Russell Standish [mailto:[EMAIL PROTECTED] Sent: Monday, October 10, 2005 3:00 PM To: John Ross Cc: 'Hal Ruhl'; everything-list@eskimo.com Subject: Re: Neutrino shield idea According to special relativity, anything with a positive rest mass travels slower than the speed of light. Neutrinos have been measured with a positive rest mass, of around 40ev for the electron neutrino IIRC, and higher values for the muon and tauon neutrinos. I have never heard of either tardyon or luxon before either, but have heard of tachyon, or faster than light particle. Clearly tardyon is therefore slower than light, and luxon is at light speed. Luxons therefore have zero rest mass, and tachyons have imaginary (ie proportional to sqrt(-1)) rest mass. Cheers On Mon, Oct 10, 2005 at 03:06:55PM -0700, John Ross wrote: Where is the proof that a neutrino is not a photon. I believe people are only guessing that a neutrino is a tardyon, whatever in the hell a tardyon is. Tardyons are not in my dictionary. -Original Message- From: Hal Ruhl [mailto:[EMAIL PROTECTED] Sent: Monday, October 10, 2005 2:50 PM To: everything-list@eskimo.com Subject: RE: Neutrino shield idea As I understand it a photon is a luxon as is a gluon and a neutrino is a tardyon. Hal Ruhl At 04:49 PM 10/10/2005, you wrote: I think the beta decay model is wrong where it predicts neutrinos are basically different from photons. I understand neutrinos travel at the speed of light. Only photons travel at the speed of light. -Original Message- From: Saibal Mitra [mailto:[EMAIL PROTECTED] Sent: Friday, October 07, 2005 4:30 PM To: John Ross; everything-list@eskimo.com Subject: Re: Neutrino shield idea This means that beta decay proves your model wrong. - Original Message - From: John Ross [EMAIL PROTECTED] To: 'Stephen Paul King' [EMAIL PROTECTED]; everything-list@eskimo.com Sent: Saturday, October 08, 2005 12:35 AM Subject: RE: Neutrino shield idea Thanks for the paper relating to detection of low energy neutrinos. However, according to my model, neutrinos are very, very high energy photons (off everybody's chart, except mine). Therefore, if my model is correct, then low energy neutrinos would merely be the photons we are familiar with and would be very easy to detect. -Original Message- From: Stephen Paul King [mailto:[EMAIL PROTECTED] Sent: Friday, October 07, 2005 12:54 PM To: everything-list@eskimo.com Subject: Neutrino shield idea Howdy! I friend of mine has worked on a related idea that might help this inverstigation. Please see: http://davidwoolsey.com/physics/ideas/neutrinoscope/index.html Kindest regards, Stephen - Original Message - From: John Ross [EMAIL PROTECTED] To: [EMAIL PROTECTED] Cc: everything-list@eskimo.com Sent: Friday, October 07, 2005 11:57 AM Subject: RE: ROSS MODEL OF THE UNIVERSE - The Simplest Yet Theory of Everything Yes. But building a neutrino shield would be difficult. -- *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] Australia http://parallel.hpc.unsw.edu.au/rks International prefix +612, Interstate prefix 02
Re: Neutrino shield idea
Faster than light effects lead to violations of causality. There are very stringent experimental constraints against such effects. - Original Message - From: John Ross [EMAIL PROTECTED] To: 'Russell Standish' [EMAIL PROTECTED] Cc: 'Stephen Paul King' [EMAIL PROTECTED]; everything-list@eskimo.com Sent: Tuesday, October 11, 2005 01:43 AM Subject: RE: Neutrino shield idea I say any massless particle that has a charge supporting a Coulomb force must travel at the speed of light or faster because the Coulomb force travels at the speed of light and a charged massless particle will be repelled by its own Coulomb force. -Original Message- From: Russell Standish [mailto:[EMAIL PROTECTED] Sent: Monday, October 10, 2005 3:04 PM To: John Ross Cc: 'Stephen Paul King'; everything-list@eskimo.com Subject: Re: Neutrino shield idea On Mon, Oct 10, 2005 at 09:11:04AM -0700, John Ross wrote: * Only photons travel at the speed of light. (Except my tronnies that usually go faster than the speed of light.) Who says? Any massless particle will travel at the speed of light. -- *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] Australia http://parallel.hpc.unsw.edu.au/rks International prefix +612, Interstate prefix 02
Tegmark's prediction of neutrino masses
Since we are discussing neutrinos, I thought it is fun to mention antropic constraints on neutrino masses derived by Tegmark, see here: http://arxiv.org/abs/astro-ph/0304536 Anthropic predictions for neutrino masses Authors: Max Tegmark (MIT), Alexander Vilenkin (Tufts), Levon Pogosian (Tufts) Categories: astro-ph Comments: Revised to match accepted PRD version. Added references, discussion of very heavy neutrinos, analytic growth factor fit. 9 pages, 4 figs. Color figs and links at this http URL Journal-ref: Phys.Rev. D71 (2005) 103523 It is argued that small values of the neutrino masses may be due to anthropic selection effects. If this is the case, then the combined mass of the three neutrino species is expected to be ~1eV, neutrinos causing a non-negligible suppression of galaxy formation. http://arxiv.org/abs/astro-ph/0404497 Anthropic predictions for vacuum energy and neutrino masses Authors: Levon Pogosian, Alexander Vilenkin, Max Tegmark Categories: astro-ph gr-qc hep-th Comments: 9 pages, 4 figures Journal-ref: JCAP 0407 (2004) 005 It is argued that the observed vacuum energy density and the small values of the neutrino masses could be due to anthropic selection effects. Until now, these two quantities have been treated separately from each other and, in particular, anthropic predictions for the vacuum energy were made under the assumption of zero neutrino masses. Here we consider two cases. In the first, we calculate predictions for the vacuum energy for a fixed (generally non-zero) value of the neutrino mass. In the second we allow both quantities to vary from one part of the universe to another. We find that the anthropic predictions for the vacuum energy density are in a better agreement with observations when one allows for non-zero neutrino masses. We also find that the individual distributions for the vacuum energy and the neutrino masses are reasonably robust and do not change drastically when one adds the other variable. - Defeat Spammers by launching DDoS attacks on Spam-Websites: http://www.hillscapital.com/antispam/
Re: Neutrino shield idea
This means that beta decay proves your model wrong. - Original Message - From: John Ross [EMAIL PROTECTED] To: 'Stephen Paul King' [EMAIL PROTECTED]; everything-list@eskimo.com Sent: Saturday, October 08, 2005 12:35 AM Subject: RE: Neutrino shield idea Thanks for the paper relating to detection of low energy neutrinos. However, according to my model, neutrinos are very, very high energy photons (off everybody's chart, except mine). Therefore, if my model is correct, then low energy neutrinos would merely be the photons we are familiar with and would be very easy to detect. -Original Message- From: Stephen Paul King [mailto:[EMAIL PROTECTED] Sent: Friday, October 07, 2005 12:54 PM To: everything-list@eskimo.com Subject: Neutrino shield idea Howdy! I friend of mine has worked on a related idea that might help this inverstigation. Please see: http://davidwoolsey.com/physics/ideas/neutrinoscope/index.html Kindest regards, Stephen - Original Message - From: John Ross [EMAIL PROTECTED] To: [EMAIL PROTECTED] Cc: everything-list@eskimo.com Sent: Friday, October 07, 2005 11:57 AM Subject: RE: ROSS MODEL OF THE UNIVERSE - The Simplest Yet Theory of Everything Yes. But building a neutrino shield would be difficult.
Re: What Computationalism is and what it is *not*
Hi Norman, Only when you demand that the computations be done in real time there is a problem. My point is that this problem is not relevant. Any TM that you can build will have limitations because of the laws of physics. Suppose that simulating the time evolution of 1 isolated cubic meter of space containing matter for 1 second takes at least 1 billion years for a computer the size of our solar system. Then I would say that I can simulate a few seconds of your consciousness because you only experience simulated time. You may say that because your simulated brain can't interact with the rest of the (real) universe this doesn't qualify as a ''bona fide'' simulation. Saibal - Original Message - From: Norman Samish [EMAIL PROTECTED] To: Saibal Mitra [EMAIL PROTECTED] Sent: Tuesday, September 06, 2005 05:48 AM Subject: Re: What Computationalism is and what it is *not* Hi Saibal, Thanks for your reply. But semantics once again rears its ugly head! Norman - Original Message - From: Saibal Mitra [EMAIL PROTECTED] To: Norman Samish [EMAIL PROTECTED]; everything-list@eskimo.com Sent: Monday, September 05, 2005 3:08 PM Subject: Re: What Computationalism is and what it is *not* Hi Norman, (SM) A TM in our universe can simulate you living in a virtual universe. If your universe is described by the same laws of physics as ours, then most physicists believe that the TM would have to work in a nonlocal way from your perspective. (NS) What do you mean by nonlocal? Wikipedia says Nonlocality in quantum mechanics, refers to the property of entangled quantum states in which both the entangled states collapse simultaneously upon measurement of one of their entangled components, regardless of the spatial separation of the two states. I don't understand what that has to do with the TM. (SM) Is this a problem? I don't think so, because the TM doesn't exist in your universe, it exists in our universe and it doesn't violate locality here. The TM generates your universe in which locality cannot be violated. So, I don't see the problem. (NS) Are you saying that the universe that the Turing Machine simulates is different from the one that I'm in, and in this simulated universe the speed limits on the speed of the TM don't apply? No - that can't be it. I'm sorry - I guess I don't know what you mean. The problem that I posed is that I don't understand how a finite-speed Turing Machine can simulate a universe, contrary to the assertions of the Church Thesis. Whether or not I'm in the universe to be simulated seem irrelevant. The computation in such a simulation is so immense that it must take a faster-than-light TM, which is not possible. Therefore, it seems to me, computationalism must be false. - Defeat Spammers by launching DDoS attacks on Spam-Websites: http://www.hillscapital.com/antispam/
Re: subjective reality
Hi Norman, I agree that you can assume that one multiverse exists and that that implies that everything describable exists. But If physical existence is not the same as mathematical existence then there is nothing we can do to verify this. So, this like postulating that a powerless God exists. Saibal - Original Message - From: Norman Samish [EMAIL PROTECTED] To: everything-list@eskimo.com Sent: Saturday, September 03, 2005 09:33 PM Subject: Re: subjective reality Hi Saibal, While my simple mind believes that mathematical existence = physical existence, I do not assume that we owe our existence to the mere existence of the algorithm, not a machine that executes it. To me, the reason that mathematical existence means physical existence is that in infinite space and time, everything that can exist must exist. If it's describable mathematically, then it can exist, somewhere in the multiverse - therefore it must exist. Tegmark claims, for example, that in his Level I multiverse, there is an identical copy of (me) about 10^10^29 meters away. (arXiv:astro-ph/0302131 v1 7 Feb 2003) Norman ~~ - Original Message - From: Saibal Mitra [EMAIL PROTECTED] To: [EMAIL PROTECTED]; [EMAIL PROTECTED] Cc: everything-list@eskimo.com Sent: Saturday, September 03, 2005 7:10 AM Subject: Re: subjective reality Hi Godfrey, It is not clear to me why one would impose constraints such as locality etc. here. Ignoring the exact details of what Bruno (and others) are doing, it all all boils down to this: Does there exists an algorithm that when run on some computer would generate an observer who would subjectively perceive his virtual world to be similar to the world we live in (which is well described by the standard model and GR). The quantum fields are represented in some way by the states of the transistors of the computer. The way the computer evolves from one state to the next, of course, doesn't violate ''our laws of physics''. It may be the case that the way the transistors are manipulated by the computer when interpreted in terms of the quantum fields in the ''virtual world'' would violate the laws of physics of that world. But this is irrelevant, because the observer cannot violate the laws of physics in his world. Also, if you believe that ''mathematical existence= physical existence'', then you assume that we owe our existence to the mere existence of the algorithm, not a machine that executes it. Saibal - Defeat Spammers by launching DDoS attacks on Spam-Websites: http://www.hillscapital.com/antispam/
Re: What Computationalism is and what it is *not*
Hi Norman, A TM in our universe can simulate you living in a virtual universe. If your universe is described by the same laws of physics as ours, then most physicists believe that the TM would have to work in a nonlocal way from your perspective. Is this a problem? I don't think so, because the TM doesn't exist in your universe, it exists in our universe and it doesn't violate locality here. The TM generates your universe in which locality cannot be violated. So, I don't see the problem. Saibal - Original Message - From: Norman Samish [EMAIL PROTECTED] To: everything-list@eskimo.com Sent: Monday, September 05, 2005 08:44 PM Subject: Re: What Computationalism is and what it is *not* Hal Finney, You say, . . . the Church Thesis, which I would paraphrase as saying that there are no physical processes more computationally powerful than a Turing machine, or in other words that the universe could in principle be simulated on a TM. I wouldn't be surprised if most people who believe that minds can be simulated on TMs also believe that everything can be simulated on a TM. I'm out of my depth here, but this doesn't make sense to me. My understanding is that the Turing Machine is a hypothetical device. If one could be built that operated at faster-than-light or infinite speed, maybe it could, in principle, simulate the universe. However, this isn't possible. Does this mean that the Church Thesis, hence computationalism, is, in reality, false? Norman Samish - Defeat Spammers by launching DDoS attacks on Spam-Websites: http://www.hillscapital.com/antispam/
Re: How did it all begin?
Hi Norman, I have no idea why it received a dishonorable mention. It could be because some physicists/cosmologists don't like anthropic reasoning. - Original Message - From: Norman Samish [EMAIL PROTECTED] To: Saibal Mitra [EMAIL PROTECTED] Cc: everything-list@eskimo.com Sent: Wednesday, August 31, 2005 12:57 AM Subject: Re: How did it all begin? This is a teaser. Why did Tegmark's paper receive Dishonorable Mention? Who is Godfrey? - Original Message - From: Saibal Mitra [EMAIL PROTECTED] To: everything everything-list@eskimo.com Sent: Tuesday, August 30, 2005 6:14 AM Subject: How did it all begin? http://arxiv.org/abs/astro-ph/0508429 Tegmark's essay was not well received (perhaps Godfrey didn't like it? :-) ) How did it all begin? Authors: Max Tegmark Comments: 6 pages, 6 figs, essay for 2005 Young Scholars Competition in honor of Charles Townes; received Dishonorable Mention How did it all begin? Although this question has undoubtedly lingered for as long as humans have walked the Earth, the answer still eludes us. Yet since my grandparents were born, scientists have been able to refine this question to a degree I find truly remarkable. In this brief essay, I describe some of my own past and ongoing work on this topic, centering on cosmological inflation. I focus on (1) observationally testing whether this picture is correct and (2) working out implications for the nature of physical reality (e.g., the global structure of spacetime, dark energy and our cosmic future, parallel universes and fundamental versus environmental physical laws). (2) clearly requires (1) to determine whether to believe the conclusions. I argue that (1) also requires (2), since it affects the probability calculations for inflation's observational predictions.
How did it all begin?
http://arxiv.org/abs/astro-ph/0508429 Tegmark's essay was not well received (perhaps Godfrey didn't like it? :-) ) How did it all begin? Authors: Max Tegmark Comments: 6 pages, 6 figs, essay for 2005 Young Scholars Competition in honor of Charles Townes; received Dishonorable Mention How did it all begin? Although this question has undoubtedly lingered for as long as humans have walked the Earth, the answer still eludes us. Yet since my grandparents were born, scientists have been able to refine this question to a degree I find truly remarkable. In this brief essay, I describe some of my own past and ongoing work on this topic, centering on cosmological inflation. I focus on (1) observationally testing whether this picture is correct and (2) working out implications for the nature of physical reality (e.g., the global structure of spacetime, dark energy and our cosmic future, parallel universes and fundamental versus environmental physical laws). (2) clearly requires (1) to determine whether to believe the conclusions. I argue that (1) also requires (2), since it affects the probability calculations for inflation's observational predictions.
Re: subjective reality
Hi Godfrey, As you wrote in reply to others, local deterministic models seem to be ruled out. The class of all formally describable models is much larger than that of only the local deterministic models. So, although 't Hooft may be proved wrong (if loopholes like pre-determinism don't save him), non-local models can reproduce QM. Saibal - Original Message - From: [EMAIL PROTECTED] To: [EMAIL PROTECTED]; [EMAIL PROTECTED] Cc: everything-list@eskimo.com Sent: Sunday, August 14, 2005 06:07 PM Subject: Re: subjective reality Hi Saibal, Yes, trans-Plankian physics is likely to be quite different from our cis-plankian one. However I think the main reason 't Hooft claims the no-go theorems of quantum physics are in small print is because his reading glasses are no longer current :-), I am afraid. His arguments for the prevalence of simple deterministic models at this scaled have varied over the years (as his little examples) and some of these are quite clever, I'll agree. However, as you very well point out, any transplankian theory worth looking into has to reproduce a recognizable picture of the cisplankian world we know and that means: quantum mechanics (non-locality and all) in some discernible limit (and General Relativity too in some other limit) and all indications is that this cannot be done from deterministic models alone. 't Hooft has been working around this for the last 10 years or so and he doesn't have much to show for it. Considering that it took him less than 2 years to come up with a renormalization prescription for non-abelian gauge theories in his youth I suspect god's dice are loaded against him this time. However he is always fascinating to read and hear. I saw him at Harvard this winter for the Colemanfest and he had the most fabulous animations... Godfrey Kurtz (New Brunswick, NJ) -Original Message- From: Saibal Mitra [EMAIL PROTECTED] To: [EMAIL PROTECTED]; [EMAIL PROTECTED] Cc: everything-list@eskimo.com Sent: Sat, 13 Aug 2005 01:34:19 +0200 Subject: Re: subjective reality Hi Godfrey, 't Hooft's work is motivated by problems one encounters in Planck scale physics. 't Hooft has argued that the no go theorems precluding deterministic models come with some ''small print''. Physicists working on ''conventional ways'' to unite gravity with QM are forced to make such bold assumptions that one should now also question this ''small print''. As you wrote, 't Hooft has only looked at some limited type of models. It seems to me that much more is possible. I have never tried to do any serious work in this area myself (I'm too busy with other things). I would say that anything goes as long as you can explain the macroscopic world. One could imagine that a stochastic treatment of some deterministic theory could yield the standard model, but now with the status of the quantum fields as fictitional ghosts. If photons and electrons etc. don't really exists, then you can say that this is consistent with ''no local hidden variables''. Saibal Hi Saibal, You are correct that Gerard 't Hooft is one of the world exponents in QFTh. But Quantum Field Theory is but one small piece of QM and one in which non-local effects do not play a direct role (as of yet). Understandably 't Hooft's forays into Quantum Mechanics have not, however, been very insightful as he himself confesses (you can check his humorous slides in the Kavli Institute symposium of last year on the Future of Physics). So far he has supplied mostly some interesting simple CA models from which one can indeed extract something akin to superpositions but that in no way bypasses the basic facts of entanglement and non-local correlations. He may very well be the very last hold out for a deterministic (an thus classically mechanistic) point-of-view but I would not count him out just yet. If any one around has the brain to deal with this its him! That much I will grant you... (Now I have met 't Hooft! 't Hooft was a neighbor of mine and I tell you: Bruno is no 't Hooft! ;- ) Best regards Godfrey Kurtz (New Brunswick, NJ) -Original Message- From: Saibal Mitra [EMAIL PROTECTED] To: [EMAIL PROTECTED]; [EMAIL PROTECTED] Cc: everything-list@eskimo.com Sent: Fri, 12 Aug 2005 21:11:30 +0200 Subject: Re: subjective reality Godfrey Kurtz wrote More specifically: I believe QM puts a big kabosh into any non-quantum mechanistic view of the physical world. If you don't get that, than maybe you don't get a lot of other things, Bruno. Sorry if this sounds contemptuous. It is meant to be. There aren't many people with a better understanding of QFT than 't Hooft. http://arxiv.org/abs/quant-ph/0409021 http://arxiv.org/abs/gr-qc
Re: subjective reality
Godfrey Kurtz wrote More specifically: I believe QM puts a big kabosh into any non-quantum mechanistic view of the physical world. If you don't get that, than maybe you don't get a lot of other things, Bruno. Sorry if this sounds contemptuous. It is meant to be. There aren't many people with a better understanding of QFT than 't Hooft. http://arxiv.org/abs/quant-ph/0409021 http://arxiv.org/abs/gr-qc/9903084 http://arxiv.org/abs/quant-ph/0212095 http://arxiv.org/abs/hep-th/0105105 http://arxiv.org/abs/hep-th/0104219 http://arxiv.org/abs/hep-th/0104080 Saibal
Re: subjective reality
Hi Godfrey, 't Hooft's work is motivated by problems one encounters in Planck scale physics. 't Hooft has argued that the no go theorems precluding deterministic models come with some ''small print''. Physicists working on ''conventional ways'' to unite gravity with QM are forced to make such bold assumptions that one should now also question this ''small print''. As you wrote, 't Hooft has only looked at some limited type of models. It seems to me that much more is possible. I have never tried to do any serious work in this area myself (I'm too busy with other things). I would say that anything goes as long as you can explain the macroscopic world. One could imagine that a stochastic treatment of some deterministic theory could yield the standard model, but now with the status of the quantum fields as fictitional ghosts. If photons and electrons etc. don't really exists, then you can say that this is consistent with ''no local hidden variables''. Saibal Hi Saibal, You are correct that Gerard 't Hooft is one of the world exponents in QFTh. But Quantum Field Theory is but one small piece of QM and one in which non-local effects do not play a direct role (as of yet). Understandably 't Hooft's forays into Quantum Mechanics have not, however, been very insightful as he himself confesses (you can check his humorous slides in the Kavli Institute symposium of last year on the Future of Physics). So far he has supplied mostly some interesting simple CA models from which one can indeed extract something akin to superpositions but that in no way bypasses the basic facts of entanglement and non-local correlations. He may very well be the very last hold out for a deterministic (an thus classically mechanistic) point-of-view but I would not count him out just yet. If any one around has the brain to deal with this its him! That much I will grant you... (Now I have met 't Hooft! 't Hooft was a neighbor of mine and I tell you: Bruno is no 't Hooft! ;- ) Best regards Godfrey Kurtz (New Brunswick, NJ) -Original Message- From: Saibal Mitra [EMAIL PROTECTED] To: [EMAIL PROTECTED]; [EMAIL PROTECTED] Cc: everything-list@eskimo.com Sent: Fri, 12 Aug 2005 21:11:30 +0200 Subject: Re: subjective reality Godfrey Kurtz wrote More specifically: I believe QM puts a big kabosh into any non-quantum mechanistic view of the physical world. If you don't get that, than maybe you don't get a lot of other things, Bruno. Sorry if this sounds contemptuous. It is meant to be. There aren't many people with a better understanding of QFT than 't Hooft. http://arxiv.org/abs/quant-ph/0409021 http://arxiv.org/abs/gr-qc/9903084 http://arxiv.org/abs/quant-ph/0212095 http://arxiv.org/abs/hep-th/0105105 http://arxiv.org/abs/hep-th/0104219 http://arxiv.org/abs/hep-th/0104080 Saibal Check Out the new free AIM(R) Mail -- 2 GB of storage and industry-leading spam and email virus protection.
OMs are events
I agree with the notion of OMs as events in some suitably chosen space. Observers are defined by the programs that generate them. If we identify universes with programs then observers are just embedded universes. An observer moment is just a qualia experienced by the observer, which is just an event in the observer's universe. I don't think that Hal's idea of identifying brain patterns with OMs will be successful. The brain is just the hardware that runs a program (the observer). If I run a simulation of our solar system on a computer, then the relevant events are e.g. that Jupiter is in such and such a position. This is associated with the state of the transistors of the computer running the program. But that same pattern could arise in a completely different calculation. You would have to extract exactly what program is running on the machine to be able to define OMs like that. To do that you need to feed the program with different kinds of input and study the output, otherwise you'll fall prey to the famous ''clock paradox'' (you can map the time evolution of a clock to that of any object, including brains). Saibal - Original Message - From: Aditya Varun Chadha [EMAIL PROTECTED] To: Lee Corbin [EMAIL PROTECTED]; everything-list@eskimo.com Sent: Sunday, July 31, 2005 08:46 AM Subject: Re: What We Can Know About the World [RS] On 7/31/05, Russell Standish [EMAIL PROTECTED] wrote: On Sat, Jul 30, 2005 at 12:25:48PM -0700, Lee Corbin wrote: This is not to say that progress is impossible. Consider an idea like Aditya has: what is the real difference between an event and an observer-moment? In trying to answer that question, many of us may learn something (at least for our own purposes). Err, an event is a particular set of coordinates (t,x,y,z) in 4D spacetime. This is how it is used in GR, anyway. An observer moment is a set of constraints, or equivalently information known about the world (obviously at a moment of time). It corresponds the the state vector \psi of quantum mechanics. Perhaps you have different definitions of these terms, but it seems like chalk and cheese to me. Lets not constrain an event to mean something only in 4-space. Take any N-Space and you can define it in terms of a set of N-dim. events. Ofcourse I agree with your definition, am just making it scale over dimensions. Now consider an observer moment to be exactly what you are defining it to be: information KNOWN about the world at a moment of time. The coming to know of any information corresponds to an event. Thus an observer moment is well-defined if and only if event is defined. In other words, an Observer-Moment exists iff it's corresponding coming to know event exists for some observer. In terms of light cones, OMs are the Events at and after the crossing over of light cones. I think the distinction is not a qualitative one between the two, only those events which interfere with the set of events observable by us (who are also just sets of events) correspond to observer-moments in our universe. So the set of OMs is simply a subset of the set of all events. refer to my previous mail about the multiverse as a partition with equivalence classes which are maximal sets of connected observer moments, in other words, maximal sets of mutually interfering events. visualize this as connected components of a graph. Defining entities in more than one different sets of words does not rule out their qualitative identity. Every Observer-Moment is an event. Every event is an Observer-Moment in some universe. -- Aditya Varun Chadha adichad AT gmail.com http://www.adichad.com
Re: Reference class (was dualism and the DA)
- Original Message - From: Jonathan Colvin [EMAIL PROTECTED] To: 'Russell Standish' [EMAIL PROTECTED] Cc: 'EverythingList' everything-list@eskimo.com Sent: Monday, June 20, 2005 09:52 PM Subject: Reference class (was dualism and the DA) Russell Standish wrote: (JC) If you want to insist that What would it be like to be a bat is equivalent to the question What would the universe be like if I had been a bat rather than me?, it is very hard to see what the answer could be. Suppose you *had* been a bat rather than you (Russell Standish). How would the universe be any different than it is now? If you can answer that question, (which is the key question, to my mind), then I'll grant that the question is meaningful. No different in the 3rd person, very obviously different in the 1st person I don't really know what that means. The only way I can make sense of the question is something like, If I was a bat instead of me (Jonathan Colvin), then the universe would consist of a bat asking the question I'm asking now. That's a counterfactual, a way in which the universe would be objectively different. It wouldn't be counterfactual, because by assumption bats ask this question of themselves anyway. Hence there is no difference in the 3rd person. The 1st person experience is very different though. There are only 1st person counterfactuals. That's quite an assumption. *Do* all conscious things ask this question of themselves? Babies don't. Senile old people don't. I'm not sure that medieval peasants ever thought to ask this question, or pre-literate cavemen. I definitely acknowledge the distinction between 1st and 3rd person. This is not the same as duality, which posits a 3rd person entity (the immaterial soul). This is, I think, the crux of the reference class issue with the DA. My (and your) reference class can not be merely conscious observers or all humans, but must be something much closer to someone (or thing) discussing or aware of the DA). I don't think this is a meaningful reference class. I can still ask the question why am I me, and not someone else without being aware of the DA. All it takes is self-awareness IMHO. You *could* certainly. Perhaps it is important as to whether you actually *do* ask that question (and perhaps it should be in the context of the DA). I note that this reference class is certainly appropriate for you and me, and likely for anyone else reading this. This reference class certainly also invalidates the DA (although immaterial souls would rescue it). But at this point, I am, like Nick Bostrom, tempted to throw my hands up and declare the reference class issue pretty much intractable. Jonathan Colvin Incidently, I think I may have an answer to my Why am I not Chinese criticism, and the corresponding correction to Why am I not an ant seems to give the same answer as I originally proposed. I'd be interested to hear it. Here's something else you could look at...calculate the median annual income for all humans alive today (I believe it is around $4,000 /year), compare it to your own, and see if you are anyway near the median. I predict that the answer for you (and for anyone else reading this), is far from the median. This result is obviously related to the why you are not Chinese criticism, and is, I believe, the reason the DA goes astray. Jonathan Colvin I don't think so, because most people on Earth are not Chinese. The correct refutation of the Doomsday Paradox was given by D. Dieks and involves the Self Indicating Axiom. The definition of the reference class defines the set of observers that you consider to be you. The DA involves applying Bayes's theorem and to do that correctly you have then to use the correct a priori probability which is also fixed by the choice of the reference class. The two effects cancel and there is no Doomsday Problem. This is all explained here: http://arxiv.org/abs/gr-qc/0009081 Saibal - Defeat Spammers by launching DDoS attacks on Spam-Websites: http://www.hillscapital.com/antispam/
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: copy method important?
You ca still create two identical systems starting from another system. E.g. in stimulated emission two photons are created in the same state. Another example is a Bose Einstein condensate, in which all the atoms are in the same state. Note that you can still teleport an unknown quantum state despite Heisenberg's uncertainty principle (you do this without measuring the state). It can be shown that you can't copy an unknown quantum state, because that would violate the Schrodinger equation. Saibal - Defeat Spammers by launching DDoS attacks on Spam-Websites: http://www.hillscapital.com/antispam/ - Original Message - From: Norman Samish [EMAIL PROTECTED] To: everything-list@eskimo.com Sent: Saturday, June 18, 2005 08:36 PM Subject: Re: copy method important? I'm no physicist, but doesn't Heisenberg's Uncertainty Principle forbid making exact quantum-level measurements, hence exact copies? If so, then all this talk of making exact copies is fantasy. Norman Samish ~ - Original Message - From: rmiller [EMAIL PROTECTED] To: Stathis Papaioannou [EMAIL PROTECTED]; [EMAIL PROTECTED]; everything-list@eskimo.com Sent: Saturday, June 18, 2005 10:05 AM Subject: copy method important? All, Though we're not discussing entanglement per se, some of these examples surely meet the criteria. So, my thought question for the day: is the method of copying important? Example #1: we start with a single marble, A. Then, we magically create a copy, marble B--perfectly like marble B in every way. . .that is, the atoms are configured similarly, the interaction environment is the same--and they are indistinguishable from one another. Example #2: we start with a single marble A. Then, instead of magically creating a copy, we search the universe, Tegmarkian-style, and locate a second marble, B that is perfectly equivalent to our original marble A. All tests both magically avoid QM decoherence problems and show that our newfound marble is, in fact, indistinguishable in every way from our original. Here's the question: Are the properties of the *relationship* between Marbles A and B in Example #1 perfectly equivalent to those in Example #2? If the criteria involves simply analysis of configurations at a precise point in time, it would seem the answer must be yes. On the other hand, if the method by which the marbles were created is crucial to the present configuration, then the answer would be no. R. Miller -- No virus found in this incoming message. Checked by AVG Anti-Virus. Version: 7.0.323 / Virus Database: 267.7.8/22 - Release Date: 6/17/2005
Re: more torture
- Original Message -
From: Stathis Papaioannou [EMAIL PROTECTED]
To: [EMAIL PROTECTED]; everything-list@eskimo.com
Sent: Tuesday, June 14, 2005 05:26 PM
Subject: Re: more torture
Saibal Mitra writes:
Because no such thing as free will exists one has to consider three
different universes in which the three different choices are made.
The
three
universes will have comparable measures. The antropic factor of
10^100
will
then dominate and will cause the observer to find himself having made
choice
b) as one of the 10^100 copies in the minute without torture.
But what will happen to the observer when the minute is up?
--Stathis
Pretending that these three universes are all that exists, what will
happen
is that the OM will find himself being another one of the 10^100 copies.
The
copy survives with memory loss.
Saibal
In what sense can the copy (or anything) become another copy with memory
loss? It is almost as if you are postulating a soul, which flies from one
body to another, and somehow contains the original person's identity so
that
it survives memory loss. What is required for an observer moment OM_1 at
time t1 to become the next observer moment at time t2 is that at least
one
successor OM exist with time stamp t2, a belief that he is the same person
as OM_1, and memories of OM_1 up to time t2. If several such OM's exist
{OM_2.1, OM_2.2, OM_2.3...} then either one may be the successor, with
probability determined by the measure of OM_2.n relative to the measure of
the whole set. Amazingly, being completely swamped with other OM's of
various types and vintages, more or less closely related to OM_1, makes
absolutely no difference to the process, because the OM's don't need to
find each other and lock arms, all they need to do is *exist*, anywhere
in
the multiverse, related in the way I have described. This is somewhat
analogous to the fact that the integer 56 is always followed by the
integer
57, even though there are lots and lots of other integers everywhere
amongst
which these two could get lost.
--Stathsi Papaioannou
I'm certainly not postulating a soul. All I'm saying is that all OMs are
real and there is no preference for one over another. Each OM will feel that
he is the successor of a previous one. If an OM checks if he is a typical
creature in the universe, he will find with large probability that this is
indeed the case.
Your proposal about time evolution ignores memory loss. How to assign
probabilities to OM_2.1, OM_2.2, etc. if they don't remember everything
about OM_1? Real people's memories are not perfect. So, you would have to
admit memory loss to make your proposal work in practice. And unless you
believe that QTI makes you immune from Alzheimer's you would have to admit
an arbitrary large amount of memory loss.
So, to me the notion of a successor doesn't make sense in general. You can
always define a set of successors of OM_1 irrespective of measure by saying
that members of that set remember being OM_1. But then there also exists
successors of me with perfect memory but with very small measures. I could
e.g. arise accidentally in a simulation performed by aliens and that
simulation could be a more perfect continuation (memory wise) of my present
OM.
These considerations have led me to believe that one should abandon any
fundamental idea of successors altogether. OMs just exist and each OM has a
memory of ''previous'' experiences. So, each OM remembers being another OM.
There exists a probability distribution over the set of all OMs which is
fixed by the laws of physics. OMs thus ''always'' exist and this is a form
of immortality. In your example of 10^100 copies almost all OMs are one of
these copies. What happens to such an OM when the minute is up? Nothing
really happens. All the OMs are ''static'' mathematical entities.
Saibal
Re: more torture
- Original Message - From: Stathis Papaioannou [EMAIL PROTECTED] To: [EMAIL PROTECTED]; everything-list@eskimo.com Sent: Tuesday, June 14, 2005 08:06 AM Subject: Re: more torture Saibal Mitra writes: Because no such thing as free will exists one has to consider three different universes in which the three different choices are made. The three universes will have comparable measures. The antropic factor of 10^100 will then dominate and will cause the observer to find himself having made choice b) as one of the 10^100 copies in the minute without torture. But what will happen to the observer when the minute is up? --Stathis Pretending that these three universes are all that exists, what will happen is that the OM will find himself being another one of the 10^100 copies. The copy survives with memory loss. Saibal
Re: more torture
Because no such thing as free will exists one has to consider three different universes in which the three different choices are made. The three universes will have comparable measures. The antropic factor of 10^100 will then dominate and will cause the observer to find himself having made choice b) as one of the 10^100 copies in the minute without torture. Saibal - Defeat Spammers by launching DDoS attacks on Spam-Websites: http://www.hillscapital.com/antispam/ - Original Message - From: Stathis Papaioannou [EMAIL PROTECTED] To: everything-list@eskimo.com Sent: Monday, June 13, 2005 01:00 PM Subject: more torture I have been arguing in recent posts that the absolute measure of an observer moment (or observer, if you prefer) makes no possible difference at the first person level. A counterargument has been that, even if an observer cannot know how many instantiations of him are being run, it is still important in principle to take the absolute measure into account, for example when considering the total amount of suffering 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 identical computers were running 10 identical sentient programs. Assume that the torture 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%). The torture will continue for a year, but you are allowed one of 3 choices as to how things will proceed: (a) 9 of the 10 copies will be chosen at random and painlessly killed, 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 that in (a) there is a 90% chance that you will be one of the copies who is killed, and thus a 90% chance that you will escape the torture, better than 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 making plans to decrease suffering, ask the victims. All 10 copies will plead with you to choose (c). What about (b)? ASSA enthusiasts might argue that with this choice, an OM 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 and they wish you had chosen (c). Finally, if you interview each of the 10 copies 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/
Re: Observer-Moment Measure from Universe Measure
- Original Message - From: Brent Meeker [EMAIL PROTECTED] To: Saibal Mitra [EMAIL PROTECTED] Sent: Sunday, June 12, 2005 02:43 AM Subject: RE: Observer-Moment Measure from Universe Measure -Original Message- From: Saibal Mitra [mailto:[EMAIL PROTECTED] Sent: Sunday, June 11, 2000 4:01 PM To: Brent Meeker; :everything-list@eskimo.com Subject: Re: Observer-Moment Measure from Universe Measure - Original Message - From: Brent Meeker [EMAIL PROTECTED] To: Saibal Mitra [EMAIL PROTECTED] Sent: Friday, June 10, 2005 06:41 PM Subject: RE: Observer-Moment Measure from Universe Measure -Original Message- From: Saibal Mitra [mailto:[EMAIL PROTECTED] Sent: Friday, June 10, 2005 11:39 PM To: Brent Meeker; everything Subject: Re: Observer-Moment Measure from Universe Measure - Original Message - From: Brent Meeker [EMAIL PROTECTED] To: Saibal Mitra [EMAIL PROTECTED] Sent: Wednesday, June 08, 2005 02:23 PM Subject: RE: Observer-Moment Measure from Universe Measure -Original Message- From: Saibal Mitra [mailto:[EMAIL PROTECTED] Sent: Wednesday, June 08, 2005 1:16 PM To: Patrick Leahy; Hal Finney; [EMAIL PROTECTED]; [EMAIL PROTECTED] Cc: everything-list@eskimo.com Subject: Re: Observer-Moment Measure from Universe Measure I think one should define an observer moment as the instantaneous description of the human brain. I.e. the minimum amount of information you need to simulate the brain of a observer. This description changes over time due to interactions with the environment. Even if there were no interactions with the environment the description would change, but this change is fixed by the original description. That means that, supposing the brain is a classical, the moment cannot be defined by a description of values, omitting rates; just as the path of a ballistic projectile cannot be specified by it location, omitting its velocity. But to include rates means an implicit introduction of time and continuity of OMs. This implies that OMs form causal chains and it makes no sense to talk about the same OM being in two different chains. That's true in an isolated personal universe that is not interacting with an 'outside world'. I could, e.g. take your brain and simulate that on a computer. The evolution equations for your brain are deterministic, so the simulation will describe a unique chain of causal links provided you fix the boundary conditions. If the personal universe is embedded in another universe (like in our case), then the evolution equations will be constantly perturbed. But a lot of the motivation for OMs comes from the brain *not* being classical; from the idea that the brain gets copied into Everett's multiple relative states or MWIs. Decoherence in the brain is very much faster than the neurochemical processes - that's why it's approximately classical. So what is going on when QM predicts different OMs? From Everett's point of view the brain must be treated as part of the QM system and it gets copied - but not by itself. Its description must include its entanglement with the quantum systems observed. So it seems that in either case, classical or quantum, an OM as a description of a brain state, has links outside itself. In the classical case it has casual links in time. In the QM case it has Hilbert space links to what has been observed. I agree. But the entangled state of a brain with the rest of the universe in the MWI corresponds to an ensemble of different worlds such that in each member of the ensemble the brain is in some definite state. So, I see no problem with Hal's way of thinking about OMs Observers are can be thought of as their own descriptions and thus universes in their own right. Observer moments are observers in particular states i.e. their ''personal'' universe being in a certain state. The causal relation between successive states is already defined when we specify which observer we are talking about. i.e., we have already specified the laws of physics for the personal universe of an observer which defines the observer. Specifying the initial state of the personal universes thus suffices. That would hold for a classical brain in a classical universe. But does it in a QM universe? I see a tension between the idea of personal universe and quantum entanglement. I don't see problems here. If you assume that our universe is described by some fundamental laws of physics then those laws of physics also describe our brains. The way a particular brain works is thus fixed. This then defines the personal universe. There seems to be a big jump between those last two sentences. Defining the laws
RE: Observer-Moment Measure from Universe Measure
- Original Message - From: Brent Meeker [EMAIL PROTECTED] To: Saibal Mitra [EMAIL PROTECTED] Sent: Friday, June 10, 2005 06:41 PM Subject: RE: Observer-Moment Measure from Universe Measure -Original Message- From: Saibal Mitra [mailto:[EMAIL PROTECTED] Sent: Friday, June 10, 2005 11:39 PM To: Brent Meeker; everything Subject: Re: Observer-Moment Measure from Universe Measure - Original Message - From: Brent Meeker [EMAIL PROTECTED] To: Saibal Mitra [EMAIL PROTECTED] Sent: Wednesday, June 08, 2005 02:23 PM Subject: RE: Observer-Moment Measure from Universe Measure -Original Message- From: Saibal Mitra [mailto:[EMAIL PROTECTED] Sent: Wednesday, June 08, 2005 1:16 PM To: Patrick Leahy; Hal Finney; [EMAIL PROTECTED]; [EMAIL PROTECTED] Cc: everything-list@eskimo.com Subject: Re: Observer-Moment Measure from Universe Measure I think one should define an observer moment as the instantaneous description of the human brain. I.e. the minimum amount of information you need to simulate the brain of a observer. This description changes over time due to interactions with the environment. Even if there were no interactions with the environment the description would change, but this change is fixed by the original description. That means that, supposing the brain is a classical, the moment cannot be defined by a description of values, omitting rates; just as the path of a ballistic projectile cannot be specified by it location, omitting its velocity. But to include rates means an implicit introduction of time and continuity of OMs. This implies that OMs form causal chains and it makes no sense to talk about the same OM being in two different chains. That's true in an isolated personal universe that is not interacting with an 'outside world'. I could, e.g. take your brain and simulate that on a computer. The evolution equations for your brain are deterministic, so the simulation will describe a unique chain of causal links provided you fix the boundary conditions. If the personal universe is embedded in another universe (like in our case), then the evolution equations will be constantly perturbed. But a lot of the motivation for OMs comes from the brain *not* being classical; from the idea that the brain gets copied into Everett's multiple relative states or MWIs. Decoherence in the brain is very much faster than the neurochemical processes - that's why it's approximately classical. So what is going on when QM predicts different OMs? From Everett's point of view the brain must be treated as part of the QM system and it gets copied - but not by itself. Its description must include its entanglement with the quantum systems observed. So it seems that in either case, classical or quantum, an OM as a description of a brain state, has links outside itself. In the classical case it has casual links in time. In the QM case it has Hilbert space links to what has been observed. I agree. But the entangled state of a brain with the rest of the universe in the MWI corresponds to an ensemble of different worlds such that in each member of the ensemble the brain is in some definite state. So, I see no problem with Hal's way of thinking about OMs Observers are can be thought of as their own descriptions and thus universes in their own right. Observer moments are observers in particular states i.e. their ''personal'' universe being in a certain state. The causal relation between successive states is already defined when we specify which observer we are talking about. i.e., we have already specified the laws of physics for the personal universe of an observer which defines the observer. Specifying the initial state of the personal universes thus suffices. That would hold for a classical brain in a classical universe. But does it in a QM universe? I see a tension between the idea of personal universe and quantum entanglement. I don't see problems here. If you assume that our universe is described by some fundamental laws of physics then those laws of physics also describe our brains. The way a particular brain works is thus fixed. This then defines the personal universe. There seems to be a big jump between those last two sentences. Defining the laws of physics may define the *way* a brain works - but not its content, not the specifics of its processes - and the same for a universe. Entanglement of the brain with another system can only happen if there are interactions with the outside. Sure, and there must be such interactions according to what we know of physics. Even in the classic case these intercations make the evolution of the personal universe nondeterministic. Right. But in that case on observer moment, defined as: ...one should define an observer moment as the instantaneous
RE: Observer-Moment Measure from Universe Measure
- Original Message - From: Brent Meeker [EMAIL PROTECTED] To: Saibal Mitra [EMAIL PROTECTED] Sent: Wednesday, June 08, 2005 02:23 PM Subject: RE: Observer-Moment Measure from Universe Measure -Original Message- From: Saibal Mitra [mailto:[EMAIL PROTECTED] Sent: Wednesday, June 08, 2005 1:16 PM To: Patrick Leahy; Hal Finney; [EMAIL PROTECTED]; [EMAIL PROTECTED] Cc: everything-list@eskimo.com Subject: Re: Observer-Moment Measure from Universe Measure I think one should define an observer moment as the instantaneous description of the human brain. I.e. the minimum amount of information you need to simulate the brain of a observer. This description changes over time due to interactions with the environment. Even if there were no interactions with the environment the description would change, but this change is fixed by the original description. That means that, supposing the brain is a classical, the moment cannot be defined by a description of values, omitting rates; just as the path of a ballistic projectile cannot be specified by it location, omitting its velocity. But to include rates means an implicit introduction of time and continuity of OMs. This implies that OMs form causal chains and it makes no sense to talk about the same OM being in two different chains. That's true in an isolated personal universe that is not interacting with an 'outside world'. I could, e.g. take your brain and simulate that on a computer. The evolution equations for your brain are deterministic, so the simulation will describe a unique chain of causal links provided you fix the boundary conditions. If the personal universe is embedded in another universe (like in our case), then the evolution equations will be constantly perturbed. But a lot of the motivation for OMs comes from the brain *not* being classical; from the idea that the brain gets copied into Everett's multiple relative states or MWIs. Decoherence in the brain is very much faster than the neurochemical processes - that's why it's approximately classical. So what is going on when QM predicts different OMs? From Everett's point of view the brain must be treated as part of the QM system and it gets copied - but not by itself. Its description must include its entanglement with the quantum systems observed. So it seems that in either case, classical or quantum, an OM as a description of a brain state, has links outside itself. In the classical case it has casual links in time. In the QM case it has Hilbert space links to what has been observed. I agree. But the entangled state of a brain with the rest of the universe in the MWI corresponds to an ensemble of different worlds such that in each member of the ensemble the brain is in some definite state. So, I see no problem with Hal's way of thinking about OMs Observers are can be thought of as their own descriptions and thus universes in their own right. Observer moments are observers in particular states i.e. their ''personal'' universe being in a certain state. The causal relation between successive states is already defined when we specify which observer we are talking about. i.e., we have already specified the laws of physics for the personal universe of an observer which defines the observer. Specifying the initial state of the personal universes thus suffices. That would hold for a classical brain in a classical universe. But does it in a QM universe? I see a tension between the idea of personal universe and quantum entanglement. I don't see problems here. If you assume that our universe is described by some fundamental laws of physics then those laws of physics also describe our brains. The way a particular brain works is thus fixed. This then defines the personal universe. Entanglement of the brain with another system can only happen if there are interactions with the outside. Even in the classic case these intercations make the evolution of the personal universe nondeterministic. Saibal - Defeat Spammers by launching DDoS attacks on Spam-Websites: http://www.hillscapital.com/antispam/
Re: Observer-Moment Measure from Universe Measure
- Original Message - From: Brent Meeker [EMAIL PROTECTED] To: Saibal Mitra [EMAIL PROTECTED] Sent: Wednesday, June 08, 2005 02:23 PM Subject: RE: Observer-Moment Measure from Universe Measure -Original Message- From: Saibal Mitra [mailto:[EMAIL PROTECTED] Sent: Wednesday, June 08, 2005 1:16 PM To: Patrick Leahy; Hal Finney; [EMAIL PROTECTED]; [EMAIL PROTECTED] Cc: everything-list@eskimo.com Subject: Re: Observer-Moment Measure from Universe Measure I think one should define an observer moment as the instantaneous description of the human brain. I.e. the minimum amount of information you need to simulate the brain of a observer. This description changes over time due to interactions with the environment. Even if there were no interactions with the environment the description would change, but this change is fixed by the original description. That means that, supposing the brain is a classical, the moment cannot be defined by a description of values, omitting rates; just as the path of a ballistic projectile cannot be specified by it location, omitting its velocity. But to include rates means an implicit introduction of time and continuity of OMs. This implies that OMs form causal chains and it makes no sense to talk about the same OM being in two different chains. That's true in an isolated personal universe that is not interacting with an 'outside world'. I could, e.g. take your brain and simulate that on a computer. The evolution equations for your brain are deterministic, so the simulation will describe a unique chain of causal links provided you fix the boundary conditions. If the personal universe is embedded in another universe (like in our case), then the evolution equations will be constantly perturbed. But a lot of the motivation for OMs comes from the brain *not* being classical; from the idea that the brain gets copied into Everett's multiple relative states or MWIs. Decoherence in the brain is very much faster than the neurochemical processes - that's why it's approximately classical. So what is going on when QM predicts different OMs? From Everett's point of view the brain must be treated as part of the QM system and it gets copied - but not by itself. Its description must include its entanglement with the quantum systems observed. So it seems that in either case, classical or quantum, an OM as a description of a brain state, has links outside itself. In the classical case it has casual links in time. In the QM case it has Hilbert space links to what has been observed. I agree. But the entangled state of a brain with the rest of the universe in the MWI corresponds to an ensemble of different worlds such that in each member of the ensemble the brain is in some definite state. So, I see no problem with Hal's way of thinking about OMs Observers are can be thought of as their own descriptions and thus universes in their own right. Observer moments are observers in particular states i.e. their ''personal'' universe being in a certain state. The causal relation between successive states is already defined when we specify which observer we are talking about. i.e., we have already specified the laws of physics for the personal universe of an observer which defines the observer. Specifying the initial state of the personal universes thus suffices. That would hold for a classical brain in a classical universe. But does it in a QM universe? I see a tension between the idea of personal universe and quantum entanglement. I don't see problems here. If you assume that our universe is described by some fundamental laws of physics then those laws of physics also describe our brains. The way a particular brain works is thus fixed. This then defines the personal universe. Entanglement of the brain with another system can only happen if there are interactions with the outside. Even in the classic case these intercations make the evolution of the personal universe nondeterministic. Saibal
Re: Observer-Moment Measure from Universe Measure
I think one should define an observer moment as the instantaneous description of the human brain. I.e. the minimum amount of information you need to simulate the brain of a observer. This description changes over time due to interactions with the environment. Even if there were no interactions with the environment the description would change, but this change is fixed by the original description. So, I see no problem with Hal's way of thinking about OMs Observers are can be thought of as their own descriptions and thus universes in their own right. Observer moments are observers in particular states i.e. their ''personal'' universe being in a certain state. The causal relation between successive states is already defined when we specify which observer we are talking about. i.e., we have already specified the laws of physics for the personal universe of an observer which defines the observer. Specifying the initial state of the personal universes thus suffices. Saibal - Original Message - From: Patrick Leahy [EMAIL PROTECTED] To: Hal Finney [EMAIL PROTECTED] Cc: everything-list@eskimo.com Sent: Wednesday, June 08, 2005 01:04 PM Subject: RE: Observer-Moment Measure from Universe Measure On Tue, 7 Jun 2005, Hal Finney wrote: Jonathan Colvin writes: There's a question begging to be asked, which is (predictably I suppose, for a qualia-denyer such as myself), what makes you think there is such a thing as an essence of an experience? I'd suggest there is no such thing as an observer-moment. I'm happy with using the concept as a tag of sorts when discussing observer selection issues, but I think reifying it is likely a mistake, and goes considerably beyond Strong AI into a full Cartesian dualism. Is it generally accepted here on this list that a substrate-independent thing called an observer moment exists? Here's how I attempted to define observer moment a few years ago: Observer - A subsystem of the multiverse with qualities sufficiently similar to those which are common among human beings that we consider it meaningful that we might have been or might be that subsystem. These qualities include consciousness, perception of a flow of time, and continuity of identity. Observer-moment - An instant of perception by an observer. An observer's sense of the flow of time allows its experience to be divided into units so small that no perceptible change in consciousness is possible in those intervals. Each such unit of time for a particular observer is an observer-moment. So if you don't believe in observer-moments, do you also not believe in observers? Or is it the -moment that causes problems? Obviously, its the -moment. I'm pleased to see that Jonathan and Brent have the same problem with the concept that I do. Being an observer is a process. Slicing it into moments is OK mathematically, where a moment corresponds to a calculus dt (and hence is neither a particular length of time nor an instant). But to regard the observer-state at a particular moment as an isolated entity which is self-aware makes as much sense as regarding individual horizontal slices through a brain as being self-aware. It is the causal relation between successive brain states (incorporating incoming sense data) which constitutes intelligence, and self-awareness is just an epiphenomenon on top of intelligence, i.e. I would not agree that anything can be self-aware but have no intelligence. Paddy Leahy
Re: where did the Big Bang come from?
- Original Message - From: Jesse Mazer [EMAIL PROTECTED] To: [EMAIL PROTECTED]; everything-list@eskimo.com Sent: Monday, June 06, 2005 07:53 PM Subject: RE: where did the Big Bang come from? Norman Samish wrote: Norman Samish wrote: And where did this mysterious Big Bang come from? A quantum fluctuation of virtual particles I'm told. On Mon, 6 Jun 2005, Jesse Mazer wrote: 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. Patrick Leahy wrote: 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. Norman Samish writes: Perhaps I didn't express myself well. What I was referring to is at http://www.astronomycafe.net/cosm/planck.html, where Sten Odenwald hypothesizes that random fluctuations in nothing at all led to the Big Bang. This process has been described by the physicist Frank Wilczyk at the University of California, Santa Barbara by saying, 'The reason that there is something instead of nothing is that nothing is unstable.' . . . Physicist Edward Tryon expresses this best by saying that 'Our universe is simply one of those things that happens from time to time.' But as I said, this idea is pure speculation, there isn't any evidence for it and we'd probably need a fully worked-out theory of quantum gravity to see if the idea even makes sense. Jesse This is one of the motivations for believing in a purely mathematical universe. A physical universe can never arise from 'nothing'. If you believe in mathematical reality then there is no mystery. The mathematical model that describes the big bang is eternal. Saibal
Re: Observer-Moment Measure from Universe Measure
- Original Message - From: Hal Finney [EMAIL PROTECTED] To: everything-list@eskimo.com Sent: Friday, June 03, 2005 08:10 PM Subject: Observer-Moment Measure from Universe Measure To apply Wei's method, first we need to get serious about what is an OM. We need a formal model and description of a particular OM. Consider, for example, someone's brain when he is having a particular experience. He is eating chocolate ice cream while listening to Beethoven's 5th symphony, on his 30th birthday. Imagine that we could scan his brain with advanced technology and record his neural activity. Imagine further that with the aid of an advanced brain model we are able to prune out the unnecessary information and distill this to the essence of the experience. We come up with a pattern that represents that observer moment. Any system which instantiates that pattern genuinely creates an experience of that observer moment. This pattern is something that can be specified, recorded and written down in some form. It probably involves a huge volume of data. So, now that we have a handle on what a particular OM is, we can more reasonably ask whether a universe instantiates it. Wouldn't it be better to think of OMs as programs just like we think of universes? If you only look at patterns then you get the problem which you later mention like crystals that can represent an OM of a person etc. The patterns one is looking for should be capable of doing computations If I define OMs as a programs (in a particular computational state), then that is the same as saying that OMs are universes in particular states. One can then argue that these universes are very complex and have high measures and are thus likely to be found embedded in simple, low measure, universes. Then one can also address the problem of what qualia actually are. They are 'events' that occur in an OM's universe. In case of persons one can think of the neural network formed by the brain. The events that take place in the universe defined by the neural network are the qualia we experience. So, I think that Wei's interpretation program has to do more than just spot certain patterns localized in time. Similarly if I simulate the solar system on a pc, then this defines a universe in which an event could be that jupiter is at a certain position at a certain time. To 'see' this in terms of the electrons moving through the transistors one has to first 'see' the program. Seeing the program requires one to study the way the object interacts with its environment which means that you have to take it out of the universe and study how it behaves when you expose it to alternative inputs. Saibal
Re: Many Pasts? Not according to QM...
- Original Message - From: Hal Finney [EMAIL PROTECTED] To: everything-list@eskimo.com Sent: Friday, June 03, 2005 05:00 AM Subject: Re: Many Pasts? Not according to QM... Stephen Paul King writes: I really do not want to be a stick-in-the-mud here, but what do we base the idea that copies could exist upon? What if I, or any one else's 1st person aspect, can not be copied? If the operation of copying is impossible, what is the status of all of these thought experiments? If, and this is a HUGE if, there is some thing irreducibly quantum mechanical to this 1st person aspect then it follows from QM that copying is not allowed. Neither a quantum state nor a qubit can be copied without destroying the original. According to the Bekenstein bound, which is a result from quantum gravity, any finite sized system can only hold a finite amount of information. That means that it can only be in a finite number of states. If you made a large enough number of systems in every possible state, you would be guaranteed to have one that matched the state of your target system. However you could not in general know which one matched it. Nevertheless this shows that even if consciousness is a quantum phenomenon, it is possible to have copies of it, at the expense of some waste. This is actualy another argument against QTI. There are only a finite number of different versions of observers. Suppose a 'subjective' time evolution on the set of all possible observers exists that is always well defined. Suppose we start with observer O1, and under time evolution it evolves to O2, which then evolves to O3 etc. Eventually an On will be mapped back to O1 (if this never happened that would contradict the fact that there are only a finite number of O's). But mapping back to the initial state doesn't conserve memory. You can thus only subjectively experience yourself evolving for a finite amount of time. Saibal
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 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
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: Many Pasts? Not according to QM...
- Oorspronkelijk bericht - Van: Stathis Papaioannou [EMAIL PROTECTED] Aan: [EMAIL PROTECTED] CC: [EMAIL PROTECTED]; everything-list@eskimo.com Verzonden: Friday, May 27, 2005 01:44 AM Onderwerp: Re: Many Pasts? Not according to QM... Saibal Mitra wrote: Quoting Stathis Papaioannou [EMAIL PROTECTED]: On 25th May 2005 Saibal Mitra wrote: One of the arguments in favor of the observer moment picture is that it solves Tegmark's quantum suicide paradox. If you start with a set of all possible observer moments on which a measure is defined (which can be calculated in principle using the laws of physics), then the paradox never arises. At any moment you can think of yourself as being randomly drawn from the set of all possible observer moments. The observer moment who has survived the suicide experiment time after time after time has a very very very low measure. I'm not sure what you mean by the paradox never arises here. You have said in the past that although you initially believed in QTI, you later realised that it could not possibly be true (sorry if I am misquoting you, this is from memory). Or are you distinguishing between QTI and QS? That's correct. In both QTI and QS one assumes conditional probabilities. You just throw away the branches in which you don't survive and then you conclude that you continue to survive into the infinitely far future (or after performing an arbitrary large number of suicide experiments) with probability 1. But if you use the a priori probability distribution then you see that you the measure of versions of you that survive into the far future is almost zero. What does the measure of versions of you that survive into the far future is almost zero actually mean? The measure of this particular version of me typing this email is practically zero, considering all the other versions of me and all the other objects in the multiverse. Another way of looking at it is that I am dead in a lot more places and times than I am alive. And yet undeniably, here I am! Reality trumps probability every time. You have to consider the huge number of alternative states you could be in. 1) Consider an observer moment that has experienced a lot of things. These experiences are encoded by n bits. Suppose that these experiences were more or less random. Then we can conclude that there are 2^n OMs that all have a probability proportional to 2^(-n). The probability that you are one of these OMs isn't small at all! 2) Considering perforing n suicide experiments, each with 50% survival probability. The n bits have registered the fact that you have survived the n suicide experiments. The probability of experiencing that is 2^(-n). The 2^(n) -1 alternate states are all unconscious. So, even though each of the states in 1 is as likely as the single state in 2, the probability that you'll find yourself alive in 1 is vastly more likely than in 2. This is actually similar to why you never see a mixture of two gases spontaneously unmix. Even though all states are equally likely, there are far fewer unmixed states than mixed ones. Saibal
Re: Many Pasts? Not according to QM...
Quoting Stathis Papaioannou [EMAIL PROTECTED]: On 25th May 2005 Saibal Mitra wrote: One of the arguments in favor of the observer moment picture is that it solves Tegmark's quantum suicide paradox. If you start with a set of all possible observer moments on which a measure is defined (which can be calculated in principle using the laws of physics), then the paradox never arises. At any moment you can think of yourself as being randomly drawn from the set of all possible observer moments. The observer moment who has survived the suicide experiment time after time after time has a very very very low measure. I'm not sure what you mean by the paradox never arises here. You have said in the past that although you initially believed in QTI, you later realised that it could not possibly be true (sorry if I am misquoting you, this is from memory). Or are you distinguishing between QTI and QS? That's correct. In both QTI and QS one assumes conditional probabilities. You just throw away the branches in which you don't survive and then you conclude that you continue to survive into the infinitely far future (or after performing an arbitrary large number of suicide experiments) with probability 1. But if you use the a priori probability distribution then you see that you the measure of versions of you that survive into the far future is almost zero. Saibal -- _ Nu 12 maanden gratis Live Eredivisievoetbal bij 20 Mb ADSL voor maar EUR 39,95 per maand. Bestel op www.versatel.nl/voetbal
Re: Many Pasts? Not according to QM...
The original posting about this dates back from the beginning of this list. I just invoked this in this thread to argue why one should consider observer moments (identical ones considered as the same) as fundamental concepts. The suicide paradox I was referring to is just Tegmark's thought experiment where the experimenter measures the spin of a particle. If it is down he is instantly killed, he survives if it is up. Then he argues that according to the MWI the experimenter should always measure that the spin is up, because that's the only branch in which he survives. Saibal Quoting aet.radal ssg [EMAIL PROTECTED]: For some reason I didn't get the original post about the suicide paradox, so if someone could resend it, sans any everything computer lingo, I would appreciate it. The subject of the thread - Many Pasts? - Not according to QM taken on its face seems false, at least from the standard MWI model. If you have parallel worlds you have parallel pasts. In fact, that's why MWI is supposed to be the solution to time travel paradoxes. Take an arbitrary moment, when a measurement, or any other trigger, causes a decoherence, move forward in time from that moment and look back - you have parallel pasts that begin from the point of decoherence. - Original Message - From: Saibal Mitra To: everything-list@eskimo.com Subject: Re: Many Pasts? Not according to QM... Date: Wed, 25 May 2005 01:24:23 +0200 - Oorspronkelijk bericht - Van: Patrick Leahy Aan: Verzonden: Wednesday, May 18, 2005 05:57 PM Onderwerp: Many Pasts? Not according to QM... Of course, many of you (maybe all) may be defining pasts from an information-theoretic point of view, i.e. by identifying all observer-moments in the multiverse which are equivalent as perceived by the observer; in which case the above point is quite irrelevant. (But you still have to distinguish the different branches to find the total measure for each OM). This is indeed my position. I prefer to define an observer moment as the information needed to generate an observer. According to the ''everything'' hypothesis (I've just seen that you don't subscibe this) an observer moment defines its own universe. But this universe is very complex and therefore must have a very low measure. It is thus far more likely that the observer finds himself embedded in a low complexity universe. One of the arguments in favor of the observer moment picture is that it solves Tegmark's quantum suicide paradox. If you start with a set of all possible observer moments on which a measure is defined (which can be calculated in principle using the laws of physics), then the paradox never arises. At any moment you can think of yourself as being randomly drawn from the set of all possible observer moments. The observer moment who has survived the suicide experiment time after time after time has a very very very low measure. Even if one assumes only a single universe described by the MWI, one has to consider simulations of other universes. Virtual observers living in such a simulated universe will perceive their world as real. The measure of such embedded universes will probably decay exponentialy with complexity Saibal -- ___ Sign-up for Ads Free at Mail.com http://www.mail.com/?sr=signup -- _ Nu 12 maanden gratis Live Eredivisievoetbal bij 20 Mb ADSL voor maar EUR 39,95 per maand. Bestel op www.versatel.nl/voetbal
Re: Plaga
Plaga's paper has been published: ''Proposal for an experimental test of the many-worlds interpretation of quantum mechanics'' Found.Phys. 27 (1997) 559 arXiv: quant-ph/9510007 -Defeat Spammers by launching DDoS attacks on Spam-Websites: http://www.hillscapital.com/antispam/ - Oorspronkelijk bericht - Van: aet.radal ssg Aan: everything-list@eskimo.com Verzonden: Wednesday, May 25, 2005 05:59 PM Onderwerp: Re: Plaga From the initial page from the included link to the archive: "I'm no physicist so I don't know for sure that these implications wouldfollow, but I am very doubtful that interworld communication is consistentwith the basics of quantum mechanics. The fact that this paper has notbeen published in peer reviewed journals in 7 years indicates that itprobably doesn't work." Back when I wasn't long in the field of video production I was well aware of the insistance and belief of TV engineers that a single tube industrial color video camera was not broadcast quality. Working in cable, where they were used for cablecast, I had plenty of opportunity to look at picture quality, etc. and came to the conclusion that it shouldn't be a problem. 2 years later I got the chance to prove it when a local news station sent a crew out to cover something that I was shooting. In the end I gave them theeditied sequence I had shot (now downtwo generations), and they took it and edited it into their story, which would have taken it down a third. Then they broadcasted it over the air. I taped it off-air and the results were conclusive - I wasright, all the nay-sayer engineers were wrong.A $40,000 Ikegami vs a $1,500 Panasonic and it was a tie except for one slight red bleed from a costume due to the Saticon tube bias toward red in the camera I used, which could have been color corrected with a time base corrector, but whoever dubbed the tape left the red level a little too hot. My point being that that was the first in a long line of "you can'ts" that I've faced which I eventually proved, "you can". Thus I have a dim view of such positions when they aren't backed up with experiments that prove so *conclusively*. As long as the possibility exists, I keep an open mind. Besides, if unbriddled skepticism was right all the time, we wouldn't be using computers, flying, or even have phones of any kind, just to name a few things.- Original Message - From: [EMAIL PROTECTED] To: everything-list@eskimo.com Subject: Re: Plaga Date: Tue, 24 May 2005 17:51:13 -0700 (PDT) We discussed Plaga's paper back in June, 2002. I reported some skeptical analysis of the paper by John Baez of sci.physics fame, at http://www.escribe.com/science/theory/m3686.html . I also gave some reasons of my own why arbitrary inter-universe quantum communication should be impossible. Hal Finney -- ___Sign-up for Ads Free at Mail.comhttp://www.mail.com/?sr=signup
Hamel Basis
A Hamel basis is a set H such that every element of the vector space is a *unique* *finite* linear combination of elements in H. This can be proven using Zorn's lemma, which is a direct consequence of the Axiom of Choice. The idea of the proof is as follows. If you start with an H that is too small in the sense that some elements of the vector space cannot be written as a finite linear combination of members of H, then you make H a bit larger by including that element. Now H has to satisfy the constraint that any finite linear combination of its elements be unique. Adding the element that could not be written as a linear combination will not make the larger H violate this constraint. You can imagine adding more and more elements until you reach some maximal H that cannot be made larger. The existence of this maximal H is guaranteed by Zorn's lemma. If you now consider the union of H with any element of the vector space not contained in H, then the condition that any finite linear combination be unique must fail (otherwise the maximality of H would be contradicted). From this you can conclude that the element you added to H (which was arbitrary) can be written as a unique linear combination of elements from H. Saibal - Defeat Spammers by launching DDoS attacks on Spam-Websites: http://www.hillscapital.com/antispam/ - Oorspronkelijk bericht - Van: Hal Finney [EMAIL PROTECTED] Aan: everything-list@eskimo.com Verzonden: Tuesday, May 24, 2005 06:07 PM Onderwerp: RE: White Rabbit vs. Tegmark Lee Corbin writes: Russell writes You've got me digging out my copy of Kreyszig Intro to Functional Analysis. It turns out that the set of continuous functions on an interval C[a,b] form a vector space. By application of Zorn's lemma (or equivalently the axiom of choice), every vector space has what is called a Hamel basis, namely a linearly independent countable set B such that every element in the vector space can be expressed as a finite linear combination of elements drawn from the Hamel basis I can't follow your math, but are you saying the following in effect? Any continuous function on R or C, as we know, can be specified by countably many reals R1, R2, R3, ... But by a certain mapping trick, I think that I can see how this could be reduced to *one* real. It depends for its functioning---as I think your result above depends--- on the fact that each real encodes infinite information. I don't think that is exactly how the result Russell describes works, but certainly Lee's construction makes his result somewhat less paradoxical. Indeed, a real number can include the information from any countable set of reals. Nevertheless I'd be curious to see an example of this Hamel basis construction. Let's consider a simple Euclidean space. A two dimensional space is just the Euclidean plane, where every point corresponds to a pair of real numbers (x, y). We can generalize this to any number of dimensions, including a countably infinite number of dimensions. In that form each point can be expressed as (x0, x1, x2, x3, ...). The standard orthonormal basis for this vector space is b0=(1,0,0,0...), b1=(0,1,0,0...), b2=(0,0,1,0...), With such a basis the point I showed can be expressed as x0*b0+x1*b1+ I gather from Russell's result that we can create a different, countable basis such that an arbitrary point can be expressed as only a finite number of terms. That is pretty surprising. I have searched online for such a construction without any luck. The Wikipedia article, http://en.wikipedia.org/wiki/Hamel_basis has an example of using a Fourier basis to span functions, which requires an infinite combination of basis vectors and is therefore not a Hamel basis. They then remark, Every Hamel basis of this space is much bigger than this merely countably infinite set of functions. That would seem to imply, contrary to what Russell writes above, that the Hamel basis is uncountably infinite in size. In that case the Hamel basis for the infinite dimensional Euclidean space can simply be the set of all points in the space, so then each point can be represented as 1 * the appropriate basis vector. That would be a disappointingly trivial result. And it would not shed light on the original question of proving that an arbitrary continuous function can be represented by a countably infinite number of bits. Hal
Re: Hamel Basis
Hi Patrick, Welcome to the list! When I was a student a friend told me about transfinite induction. While ordinary induction allows you to generalize from n to n + 1 and thus to a countable set, transfinite induction enables you to explore the continuum. He didn't explain how it was done, though. I learned later while following a functional analyses class. Saibal I know this one! I had a friend who published a magazine called Zorn printed on pale yellow paper... ;) Paddy Leahy
Re: Many Pasts? Not according to QM...
- Oorspronkelijk bericht - Van: Patrick Leahy [EMAIL PROTECTED] Aan: everything-list@eskimo.com Verzonden: Wednesday, May 18, 2005 05:57 PM Onderwerp: Many Pasts? Not according to QM... Of course, many of you (maybe all) may be defining pasts from an information-theoretic point of view, i.e. by identifying all observer-moments in the multiverse which are equivalent as perceived by the observer; in which case the above point is quite irrelevant. (But you still have to distinguish the different branches to find the total measure for each OM). This is indeed my position. I prefer to define an observer moment as the information needed to generate an observer. According to the ''everything'' hypothesis (I've just seen that you don't subscibe this) an observer moment defines its own universe. But this universe is very complex and therefore must have a very low measure. It is thus far more likely that the observer finds himself embedded in a low complexity universe. One of the arguments in favor of the observer moment picture is that it solves Tegmark's quantum suicide paradox. If you start with a set of all possible observer moments on which a measure is defined (which can be calculated in principle using the laws of physics), then the paradox never arises. At any moment you can think of yourself as being randomly drawn from the set of all possible observer moments. The observer moment who has survived the suicide experiment time after time after time has a very very very low measure. Even if one assumes only a single universe described by the MWI, one has to consider simulations of other universes. Virtual observers living in such a simulated universe will perceive their world as real. The measure of such embedded universes will probably decay exponentialy with complexity Saibal
Implications of MWI
- Oorspronkelijk bericht - Van: Bruno Marchal [EMAIL PROTECTED] Aan: Saibal Mitra [EMAIL PROTECTED] CC: everything everything-list@eskimo.com Verzonden: Tuesday, May 03, 2005 11:39 AM Onderwerp: Re: Implications of MWI Le 01-mai-05, à 16:51, Saibal Mitra a écrit : The MWI made me take the idea of multiple universes/multiple realities serious. When I joined this list I believed that quantum suicide could work, but I later found out that it cannot possibly work. I now believe that there exists an ensemble of all possible mathematical models/descriptions/computer programs. These things exist in a mathematical sense. For this idea to work (to yield predictions that are consistent with the known laws of physics) one has to assume that there exists a measure that prefers simple programs over complex programs. Why? You may be right, but why? How will you make abstraction of complex programs generated by the DU and getting close to your actual computational states? What about complex programs generating simple programs? I do believe simple programs play some role, but not because they would have an higher measure, just because they will handle genuine relationship with all the running of all other programs. Well, I just obseve that we live in a universe which is described by relatively simple laws of physics. The actual reason for that could perhaps be explained by your theory. Saibal
Many worlds theory of immortality
I would have to read about these theories, but I think that it doesn'tmatter if you work with complex measures. Saibal - Oorspronkelijk bericht - Van: Ben Goertzel Aan: Bruno Marchal ; Saibal Mitra CC: everything-list@eskimo.com Verzonden: Tuesday, May 03, 2005 02:11 PM Onderwerp: RE: Many worlds theory of immortality Saibal, Does your conclusion about conditional probability also apply to complex-valued probabilities a la Youssef? http://physics.bu.edu/~youssef/quantum/quantum_refs.html http://www.goertzel.org/papers/ChaoQM.htm -- Ben Goertzel -Original Message-From: Bruno Marchal [mailto:[EMAIL PROTECTED]Sent: Tuesday, May 03, 2005 4:20 AMTo: Saibal MitraCc: everything-list@eskimo.comSubject: Re: Many worlds theory of immortalityLe 16-avr.-05, à 02:45, Saibal Mitra a écrit : Both the suicide and copying thought experiments have convinced me that thenotion of a conditional probability is fundamentally flawed. It can bedefined under ''normal'' circumstances but it will break down precisely whenconsidering copying or suicide.This is a quite remarkable remark. I can related it to the COMBINATORS thread.In a nutshell: in the *empirical* FOREST there are no kestrels (no eliminators at all),nor Mockingbird, warblers or any duplicators. Quantum information behaveslike incompressible fluid. Universes differentiate, they never multiplies. Deutsch is right on that point. I use Hardegree (ref in my thesis(*)) He did show thatquantum logic can be seen as a conditional probability logic. We will come back on this (it's necessarily a little bit technical). I am finishing atechnical paper on that. The COMBINATORS can help to simplify considerablythe mathematical conjectures of my thesis.Bruno(*) Hardegree, G.M. (1976). The Conditional in Quantum Logic. In Suppes, P., editor, Logic and Probability in Quantum Mechanics, volume78 of Synthese Library, pages 55-72. D. Reidel Publishing Company, Dordrecht-Holland.
Fw: Many worlds theory of immortality
I think we agree on the observer moment. One should formulate questions in terms of observer moments and then there are no problems (in principle). Saibal - Oorspronkelijk bericht - Van: Stathis Papaioannou [EMAIL PROTECTED] Aan: [EMAIL PROTECTED]; everything-list@eskimo.com Verzonden: Tuesday, May 03, 2005 03:47 PM Onderwerp: Re: Many worlds theory of immortality 2 weeks ago Saibal Mitra wrote: I don't think that the MW immortality is correct at all! In a certain sense we are immortal, because the enseble of all possible worlds is a fixed static entity. So, you ''always'' find yourselve alive in one state or another. However, you won't experience youself evolving in the infinite far future. If you encounter a ''branching'' in which one of the possibilities is death, that branch cannot be said to be nonexistent relative to you. Quantum mechanics doesn't imply that you can never become unconscious, otherwise you could never fall asleep! Of course, you can never experience being unconscious. So, what to do with the branch leading to (almost) certain death? The more information your brain contains, the smaller the set of branches is in which you are alive (and consistent with your experiences stored in your brain). The set of all branches in which you could be alive doesn't contain any information at all. Since death involves complete memory loss, the branch leading to death should be replaced by the complete set of all possibilities. ...and despite reading the last paragraph several times slowly, I'm afraid I don't understand it. Are you saying there may never be a next moment at the point where you are facing near-certain death? It seems to me that all that is required is an observer moment in which (a) you believe that you are you, however this may be defined (it's problematic even in normal life what constitutes continuity of identity), and (b) you remember facing the said episode of near-certain death (ncd), and it will seem to you that you have miraculously escaped, even if there is no actual physical connection between the pre-ncd and the post-ncd observer moment. Or, another way to escape is as you have suggested in a more recent post, that there is an observer moment somewhere in the multiverse in which the ncd episode has been somehow deleted from your memory. Perhaps the latter is more likely, in which case you can look forward to never, or extremely rarely, facing ncd in your life. It all gets very muddled. If we try to ruthlessly dispense with every derivative, ill-defined, superfluous concept and assumption in an effort to simplify the discussion, the one thing we are left with is the individual observer-moments. We then try to sort these observer-moments into sets which constitute lives, identities, birth, death, amnesia, mind duplication, mind melding, multiple world branchings, and essentially every possible variation on these and other themes. No wonder it's confusing! And who is to judge where a particular individual's identity/life/body/memory begins and ends when even the most detailed, passed by committee of philosophers set of rules fails, as it inevitably will? The radical solution is to accept that only the observer-moments are real, and how we sort them then is seen for what it is: essentially arbitrary, a matter of convention. You can dismiss the question of immortality, quantum or otherwise, by observing that the only non-problematic definition of an individual is identification with a single observer-moment, so that no individual can ever really live for longer than a moment. Certainly, this goes against intuition, because I feel that I was alive a few minutes ago as well as ten years ago, but *of course* I feel that; this is simply reporting on my current thought processes, like saying I feel hungry or tired, and beyond this cannot be taken as a falsifiable statement about the state of affairs in the real world unless recourse is taken to some arbitrary definition of personal identity, such as would satisfy a court, for example. Let me put it a different way. Situation (a) life as usual: I die every moment and a peson is reborn every moment complete with (most) memories and other attributes of the individual who has just died. Situation (b) I am killed instantly, painlessly, with an axe every moment, and a person is reconstituted the next moment complete with (most) memories and other attributes of the individual who has just died, such that he experiences no discontinuity. Aside from the blood and mess in (b), is there a difference? Should I worry more about (b) than (a)? This is of course a commonplace thought experiment on this list, but I draw from it a slightly different conclusion: we all die all the time; death doesn't really matter
Many worlds theory of immortality
Russell Standish wrote: With my TIME postulate, I say that a conscious observer necessarily experiences a sequence of related observer moments (or even a continuum of them). To argue that observer moments are independent of each other is to argue the negation of TIME. With TIME, the measure of each observer moment is relative to the predecessor state, or the RSSA is the appropriate principle to use. With not-TIME, each observer moment has an absolute measure, the ASSAThat's an interesting idea, although I do have some problems with it. Ifonecompletely specifies the state of an observer at a given time, then thisalready contains a notion of time as experienced by the observer. So, Iwould say that the notion of an abserver moment is more like that of atangent space in General Relativity than that of a single space-time point.Saibal -Defeat Spammers by launching DDoS attacks on Spam-Websites: http://www.hillscapital.com/antispam/
Re: Memory erasure
If you accept that you can experience having been unconscious, then you also have to accept that you can survive with memory loss in any branch. This means that if you are faced with almost certain death, it is more likely that you will find yourself alive in a completely different sector of the multiverse than experiencing a miracle that saves your life. Saibal Stathis Papaioannou wrote: Hal Finney wrote: Arguing against this is that every night you fall asleep, a similar loss of consciousness (often with memory erasure of the last few thoughts before sleep). This theory would predict that each night you only experience universes where, for whatever reason, you never again lose consciousness. I don't know why this objection to QTI/QS keeps coming up. It is surely a truism that you cannot *experience unconsciousness*, but this is certainly not the same as saying that you cannot lose consciousness, or experience worlds where you lose consciousness. If the loss of consciousness is permanent (i.e., death), then yes, since it is imposssible to *experience unconsciousness*, you will not experience those worlds. But if the loss of consciousness is temporary, as in sleep, you will experience only a discontinuity from which you might conclude you have gone through a period of unconsciousness. You can turn this whole chain of logic around and make it an argument against QS. Sleep proves that loss of consciousness is possible, and that memory erasure is possible. Imagine memory erasure becoming so complete that it erases your entire life. Is that possible? If so, isn't it essentially the same as suicide? Or if it's not possible, where is the dividing line between the amount of memory erasure that is and is not possible? I agree, complete memory erasure is essentially the same as suicide. Therefore, you cannot experience complete memory erasure if QTI is true. The dividing line between the amount of memory erasure that is and is not possible is a problem in the philosophy of personal identity: how much you can change and still be you. The MWI predicts that every possible variation on your mind will exist in some world, and although you can get into complex discussions about amnesia, delusions etc., a simple answer might be, those versions which think they are you, are in fact you. --Stathis Papaioannou _ Buy what you really want - sell what you don't on eBay: http://adfarm.mediaplex.com/ad/ck/705-10129-5668-323?ID=2 Yahoo! Groups Sponsor ~-- In low income neighborhoods, 84% do not own computers. At Network for Good, help bridge the Digital Divide! http://us.click.yahoo.com/S.QlOD/3MnJAA/Zx0JAA/pyIolB/TM ~- Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Fabric-of-Reality/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: Implications of MWI
The MWI made me take the idea of multiple universes/multiple realities serious. When I joined this list I believed that quantum suicide could work, but I later found out that it cannot possibly work. I now believe that there exists an ensemble of all possible mathematical models/descriptions/computer programs. These things exist in a mathematical sense. For this idea to work (to yield predictions that are consistent with the known laws of physics) one has to assume that there exists a measure that prefers simple programs over complex programs. Saibal - Defeat Spammers by launching DDoS attacks on Spam-Websites: http://www.hillscapital.com/antispam/ - Oorspronkelijk bericht - Van: Mark Fancey [EMAIL PROTECTED] Aan: everything-list@eskimo.com Verzonden: Wednesday, April 27, 2005 04:36 PM Onderwerp: Implications of MWI Did accepting and understanding the MWI drastically alter your philosophical worldview? If so, how? I cannot answer this question myself because I do not truly understand many parts of it. Thanks -- Mark Fancey Anti-Bushite Bullshite
Re: Memory erasure
- Oorspronkelijk bericht - Van: Hal Finney [EMAIL PROTECTED] Aan: [EMAIL PROTECTED]; [EMAIL PROTECTED] CC: everything-list@eskimo.com Verzonden: Sunday, May 01, 2005 07:30 PM Onderwerp: Re: Memory erasure You can turn this whole chain of logic around and make it an argument against QS. Sleep proves that loss of consciousness is possible, and that memory erasure is possible. Imagine memory erasure becoming so complete that it erases your entire life. Is that possible? If so, isn't it essentially the same as suicide? Or if it's not possible, where is the dividing line between the amount of memory erasure that is and is not possible? Complete memory erasure is probably the same as suicide. You can imagine deleting almost all of your memory, storing it on some machine. Before the procedure you leave a note to yourself explaining how to retrieve your memory. When you read the note, you are identical to all your versions who have decided to do the same thing. If you then load the data back in your memory you could thus end up in any of these branches in which you decided to do this. Perhaps this happens all the time to us when we forget something and then later remember it or look it up... Saibal
Quantum Behavior of Deterministic Systems with Information Loss. Path Integral Approach
http://arxiv.org/abs/quant-ph/0504200 Quantum Behavior of Deterministic Systems with Information Loss. Path Integral ApproachAuthors: M. Blasone, P. Jizba, H. KleinertComments: 11 pages, RevTeXSubj-class: Quantum Physics; Mathematical Physics 't Hooft's derivation of quantum from classical physics is analyzed by means of the classical path integral of Gozzi et al.. It is shown how the key element of this procedure - the loss of information constraint - can be implemented by means of Faddeev-Jackiw's treatment of constrained systems. It is argued that the emergent quantum systems are identical with systems obtained in [quant-ph/0409021] through Dirac-Bergmann's analysis. We illustrate our approach with two simple examples - free particle and linear harmonic oscillator. Potential Liouville anomalies are shown to be absent. -Defeat Spammers by launching DDoS attacks on Spam-Websites: http://www.hillscapital.com/antispam/
Re: Many worlds theory of immortality
I agree with Hal. The measure is doubled after copying. So, this is sort of the reverse of a suicide experiment in which the measure decreases. If you consider a doubling in which one of the copies doesn't survive then the measure stays the same, while in suicide experiment it decreases. Both the suicide and copying thought experiments have convinced me that the notion of a conditional probability is fundamentally flawed. It can be defined under ''normal'' circumstances but it will break down precisely when considering copying or suicide. Saibal - Defeat Spammers by launching DDoS attacks on Spam-Websites: http://www.hillscapital.com/antispam/ - Oorspronkelijk bericht - Van: Hal Finney [EMAIL PROTECTED] Aan: everything-list@eskimo.com Verzonden: Saturday, April 16, 2005 12:27 AM Onderwerp: Re: Many worlds theory of immortality Jesse Mazer writes: Would you apply the same logic to copying a mind within a single universe that you would to the splitting of worlds in the MWI? If so, consider the thought-experiment I suggested in my post at http://www.escribe.com/science/theory/m4805.html -- Generally, I don't think the same logic applies to copying a mind in a single universe than to splitting of worlds in the MWI. Copying a mind will double its measure, while splitting one leaves it alone. That is a significant practical and philosophical difference. Practically, copying a mind leaves it with half as many resources per new-mind, while splitting it leaves it with the same number of resources per mind. This means that you might take very different practical actions if you knew that your mind was going to be copied than if you were about to split a coin. Philosophically, the measure of the observer-moments associated with a copied mind are twice as great as the measure of the observer-moments associated with a split one. Obviously 2 is not equal to 1. This puts the burden of proof on those who would claim that this difference is philosophically irrelevant in considering issues of consciousness. Hal Finney
Re: Many worlds theory of immortality
I more or less agree with Jesse. But I would say that the measure of similarity should also be an absolute measure that multiplied with the absolute measure defines a new effective absolute measure for a given observer. Given the absolute measure you can define effective conditional probabilities, except in cases where branches lead to death. In these cases, the ''conditional probability'' of there being a next experience at all would be less than 1. Saibal - Defeat Spammers by launching DDoS attacks on Spam-Websites: http://www.hillscapital.com/antispam/ - Oorspronkelijk bericht - Van: Jesse Mazer [EMAIL PROTECTED] Aan: everything-list@eskimo.com Verzonden: Thursday, April 14, 2005 10:20 AM Onderwerp: Re: Many worlds theory of immortality Stathis Papaioannou wrote: Stathis Papaioannou writes: QM or QTI do not imply that you can never lose consciousness. The idea is that you can never *experience* loss of consciousness. You can fall asleep, but when you wake up, you don't remember being asleep. If you never wake up - i.e. if you die in your sleep - then you never experience that particular branch of the MW. In other words, you can only experience those worlds where the loss of consciousness is temporary. How about impairment of consciousness? Can you experience that? Can you experience going crazy, or having a reduced level of consciousness where you are drugged or barely alive? That's how death is for most people, it's not like flicking off a light. Will Quantum Immortality protect you from spending an eternity in a near-coma? Exactly how much consciousness does it guarantee you? Hal Finney Alas, you are right. Immortality is not all fun and games, and in some worlds you may experience a drawn out fizzling out, reduced to the consciousness of an infant, then a fish, then an amoeba. I believe Max Tegmark aknowledged this in a commentary on his original paper. If you're really unlucky, you will experience eternal torment in the flames of hell. And unlike the Christian Hell, you don't actually have to do something wrong to end up in QTI hell: it all depends on the fall of the cosmic dice. One question which comes up is, when do you stop being you? I suppose this is an answer to your how much consciousness is guaranteed question: when you lose enough consciousness that you forget who you are, that is the cutoff where you can really be said to have lost consciousness. I think that's too handwavey--I think that to really have a satisfying answer to this question, you need some kind of formal theory of consciousness that answers questions like, If I am currently experiencing observer-moment A, what is the probability that my next experience will of observer-moment B vs. observer-moment C? I think the answer should depend both on some sort of measure of the similarity of A and B vs. A and C (to deal with the 'when do you stop being you' question), and also on some notion of the absolute probability of B vs. C (for example, if B and C are both equally 'similar' to your current experience A, but B is experiencing some kind of thermodynamic miracle while C is experiencing business as usual, then C would be more likely). I elaborated on these ideas in my posts in the Request for a glossary of acronyms thread at http://tinyurl.com/5265d Jesse
2^(-program length)
There is another argument (also mentioned by Hal on this list some time ago) that also suggests that the measure must decay faster than 2^(-program length). This arguments involve the anthropic factor. The measure for an observer to find himself in a universe is the product of an ''intrinsic'' measure of the universe times the number of times that he will be generated in the universe. This last anthropic factor cannot be omitted, because that would lead to the Doomsday Paradox. The anthropic factor is infinite, and must be ''renormalized'' to a well defined measure. Suppose that the measure is a function of program length only. For some fixed universe with containing observers generated by a program p, consider the set of programs p_n that generate p n times. The measure of observers in p_n will thus be n times larger than in p. The measure of p_n must thus decay faster than 1/n in order to end up with normalizable probability distributions for the observers. The program length of p_n is the program length of p plus Log_2(n), therefore the measure must decay faster than 2^(-program length). Saibal - Original Message - From: Hal Finney [EMAIL PROTECTED] To: everything-list@eskimo.com Sent: Tuesday, February 01, 2005 7:19 PM Subject: RE: Belief Statements Bruno writes: I am not sure that I understand what you do with that measure on programs. I prefer to look at infinite coin generations (that is infinitely reiterated self-duplications) and put measure on infinite sets of alternatives. Those infinite sets of relative alternative *are* themselves generated by simple programs (like the UD). Here is how I approach it, based on Schmidhuber. Suppose we pick a model of computation based on a particular Universal Turing Machine (UTM). Imagine this model being given all possible input tapes. There are an uncountably infinite number of such tapes, but on any given tape only a finite length will actually be used (i.e. the probability of using an infinite number of bits of the tape is zero). This means that any program which runs is only a finite size, yet occurs on an infinite number of tapes. The fraction of the tapes which holds a given program is proportional to 1 over 2^(program length), if they are binary tapes. This is considered the measure of the given program. An equivalent way to think of it is to imagine the UTM being fed with a tape created by coin flips. Now the probability that it will run a given program is its measure, and again it will be proportional to 1 over 2^(program length). I don't know whether this is what you mean by infinite coin generations but it sounds similar. I believe you can get the same concept of measure by using the Universal Dovetailer (UD) but I don't see it as necessary or particularly helpful to invoke this step. To me it seems simpler just to imagine all possible programs being run, without having to also imagine the operating system which runs them all on a time-sharing computer, which is what the UD amounts to. Now we cannot know in which computational history we belong, or more exactly we belong to an infinity of computational histories (undistinguishable up to now). (It could be all the repetition of your simple program) And by repetition of your simple program I think you mean the fact that there are an infinite number of tapes which have the same prefix (the same starting bits) and which all therefore run the same program, if it fits in that prefix. This is the basic reason why shorter programs have greater measure than longer ones, because there are a larger fraction of the tapes which have a given short prefix than a long one. It's also possible, as you imply, that your consciousness is instantiated in multiple completely different programs. For example, we live in a program which pretty straightforwardly implements the universe we see; but we also live in a program which implements a very different universe, in which aliens exist who run artificial life experiments, and we are one of those experiments. We also live in programs which just happen to simulate moments of our consciousness, purely through random chance. However, my guess is that the great majority of our measure will lie in just one program. I suspect that that program will be quite simple, and that all the other programs (such as the one with the aliens running alife experiments) will be considerably more complex. The simplest case is just what we see, and that is where most of our measure comes from. But to make an infinitely correct prediction we should average on all computational histories going through our states. Yes, I agree, although as I say my guess is that we will be close enough just by taking things as we see them, and in fact it may well be that the corrections from considering bizarre computational histories will be so tiny as to be unmeasurable in practice. Your measure could
Quantum Theory from Quantum Gravity
http://arxiv.org/abs/gr-qc/0311059 Authors: Fotini Markopoulou, Lee Smolin We provide a mechanism by which, from a background independent model with no quantum mechanics, quantum theory arises in the same limit in which spatial properties appear. Starting with an arbitrary abstract graph as the microscopic model of spacetime, our ansatz is that the microscopic dynamics can be chosen so that 1) the model has a low low energy limit which reproduces the non-relativistic classical dynamics of a system of N particles in flat spacetime, 2) there is a minimum length, and 3) some of the particles are in a thermal bath or otherwise evolve stochastically. We then construct simple functions of the degrees of freedom of the theory and show that their probability distributions evolve according to the Schroedinger equation. The non-local hidden variables required to satisfy the conditions of Bell's theorem are the links in the fundamental graph that connect nodes adjacent in the graph but distant in the approximate metric of the low energy limit. In the presence of these links, distant stochastic fluctuations are transferred into universal quantum fluctuations. -- Defeat Spammers by launching DDOS attacks on Spam-Websites: http://makelovenotspam.com/intl
Re: Ambjørn et al.
Download the article free of charge here: http://arxiv.org/abs/hep-th/0404156 - Oorspronkelijk bericht - Van: Pete Carlton [EMAIL PROTECTED] Aan: [EMAIL PROTECTED] Verzonden: Tuesday, October 12, 2004 07:09 PM Onderwerp: Ambjørn et al. Of possible general interest - J. Ambjørn J. Jurkiewicz and R. Loll (also a writeup in Nature news, at http://www.nature.com/news/2004/041004/full/041004-17.html) Emergence of a 4D World from Causal Quantum Gravity http://dx.doi.org/10.1103%2FPhysRevLett.93.131301
Anthropic constraints on dark matter?
The properties of ordinary matterare strongly constrained by the anthropic principle. In soome cases you can even calculate non trivial things. E.g. the anthropic reasoning was used by Hoyle to prove the existence of an energy level of the carbon-12 nucleus. Dark matter seems to be much less constrained. We know that there must exists a lot of dark matter, and this fact could be an observer selection effect. However, since dark matter is believed to have only very weak interactions with ordinary matter, the exact properties of dark matter particles seem to be irrelevant for observers. Some time ago, I noted that annihilations of strongly interacting dark matter can generate large amounts of internal heat inside planets. This is interesting, becauseit is thought that50% of Earth's internal heat is supplied by radioactive decay and 50% comes from cooling of the Earth's core. However, if you calculate back in time, the cooling rate implies that the Earth's core must have been completely molten about a billion years ago. Now, today the inner core is solid (due to the high pressure), and this is essential for generating a magnetic field. Old magnetic rocksshow that the magnetic field did exists more than 3 billion years ago. So, the geophysicists have a problem here, and I thought thatdark matter could be the answer. If dark matter supplies some of the internal heat, the earth's core would be cooling less fast and that would solve the problem. Anthropically, you could say that without a magnetic field life would have had a difficult time on Earth (because of cosmic and solar radiation) and we may not have been here. You would still need to show that we couldn't have evolved on a larger planet where the heat supplied from dark matter annihilations is not necessary. Unfortunately, this idea does not work. Uranus has a very low inernal heat production, and this strongly constrains the properties of strongly interacting dark matter, making the above scenario impossible. See here 40 minutes from now: http://arxiv.org/abs/astro-ph/0408341
Re: Quantum Rebel - complementarity
Maybe we should look at deterministic theories, such as: http://arxiv.org/abs/hep-th/0104219 John M wrote: Yet it would be refreshing to approach the concept from another side (another framework), - maybe a new one??
Re: Quantum Rebel - complementarity
Unfortunately, it seems that there are very few people seriously working on radical ideas like the models proposed by 't Hooft. My favorite idea is that particles are not real. You could imagine that QM is an effective statistical theory (similar to what 't Hooft says) in which particles appear in a similar way as virtual particles appear in quantum field theory. If the Feynman rules had been discovered by experimentalists, you would have discussions about photons and electrons violating causality except when we observe them... - Oorspronkelijk bericht - Van: John M [EMAIL PROTECTED] Aan: Saibal Mitra [EMAIL PROTECTED] CC: [EMAIL PROTECTED] Verzonden: Saturday, August 14, 2004 04:51 PM Onderwerp: Re: Quantum Rebel - complementarity Thanks! Maybe even further? John M - Original Message - From: Saibal Mitra [EMAIL PROTECTED] To: Russell Standish [EMAIL PROTECTED]; John M [EMAIL PROTECTED] Cc: [EMAIL PROTECTED] Sent: Saturday, August 14, 2004 10:35 AM Subject: Re: Quantum Rebel - complementarity Maybe we should look at deterministic theories, such as: http://arxiv.org/abs/hep-th/0104219 John M wrote: Yet it would be refreshing to approach the concept from another side (another framework), - maybe a new one??
Re: Afshar and ...the idea of a photon is dead
Questioning whether the speed of light has changed within a certain class of theories is nonsense and this is not an opinion but an elementary mathematical fact. Of course, one may e.g. question whether photons are massive and whether this mass has changed, leading to a (wavelength dependent) change of speed of light. The recently proposed variable speed of light theories are legitimate theories. However, they don't imply a changing speed of light. That's just the name given to the theory, not its content. The speed of light depends on the way you choose your units and is thus completely arbitrary. It is not possible to measure the speed of light before you define your units of space and time. If you use the speed of light to relate your units of time to that of space, you find that the speed of light is constant, regardless of your theory. If a ''variable speed of light theory'' is confirmed by experiment, it is still a matter of convention to say that the light speed has changed and not some other dimensional constant. Only dimensionless combinations of constants can be said to have changed independent of conventions. This is the point that Duff made. CMR wrote: With respect, I think it was Dawkins in the Blind watchmaker who quipped your incredulity alone is no measure of reality (I paraphrase..) You may well be correct that the speed of light is and has always been constant, but this remains a point of some controversy that only continued scientific research will settle (and never finally, at least according to Popper). Your opinion that questioning the fact of the SOL's constancy is nonsense, is just that (an opinion not nonsense, that is). And such an opinion is less in the spirit of good science and more that of dogma, in my own humble opinion. I submit that just because a position is held by a minority and is not yet well supported by empirical data does not automatically disqualify it or justify ridicule. Indeed, all currently favored theories, including Einstein's, were once so.
Re: Afshar and ...the idea of a photon is dead
I agree. If the photon did behave in an erratic way you would be able to say that the photon is behaving erratic and not the laws of physics that make your instruments work. But in this hypothetical case you would use some other way to relate time to space. This relation also has to involve a constant with the dimensions of a speed. We could call it c. And then someone else could claim that this c is changing as well! Ultimately c is a conversion factor to convert meters into seconds. The TOE doesn't have separate units to measure space, time mass, etc. These are all human constructs. Because we measure time and space in our own units, it is inevitable that dimensional conversion factors will appear in our formulas! - Oorspronkelijk bericht - Van: Henry Sturman [EMAIL PROTECTED] Aan: [EMAIL PROTECTED] Verzonden: Sunday, August 01, 2004 07:18 PM Onderwerp: Re: Afshar and ...the idea of a photon is dead You are right that there are no fundamental dimensional constants, i.e. those constants are determined by our choice of units. But that doesn't in itself imply that the speed of light can't change, although the speed of light might be unchangeable for other reasons. The fact that a pint is an arbitraty unit does not mean that a package of milk in the super market can't contain less milk today than yesterday. If the speed of light were something totally arbitrary, then there would be no point in ever measuring it. If today I measure a speed of light x in whatever units and tomorrow I measure 0.5 x, then the speed of light has changed. Put in a constant-free wording: if today light travels x times the diameter of earth during one earth revolution, and tomorrow it travels 0.5 x times that distance during the same time, then the speed of light has changed. Well, at least something has changed, and if not the speed of light, then either time, the diameter of the earth, or the rotational speed of the earth has changed. And Occam's razor implies we should assume the thing that has changed is that which we can change with the fewest number of associated changes required in our model of the universe and that would typically be the speed of light. At 14:02 1-8-2004 +0200, you wrote: Unfortunately, sensationalists articles that are completely baloney appear in most scientific journals from time to time. Nature published an article claiming that if the fine structure conswtant is changing, as suggested by some astronomical observations, then this change must be due to a change in the speed of light. Now, this must be nonsense, because the value of the speed of light, being a dimensional constant, is determined by our choice of units. In fact, that there are dimensional constants at all, is an artefact of using inconsistent units at the same time. Michael Duff has explained this in the articles: http://arxiv.org/abs/hep-th/0208093 and: http://arxiv.org/abs/physics/0110060 - Oorspronkelijk bericht - Van: Nicole Barberis [EMAIL PROTECTED] Aan: [EMAIL PROTECTED] Verzonden: Friday, July 30, 2004 06:15 PM Onderwerp: Afshar and ...the idea of a photon is dead I was stunned to read Quantum Rebel in July 24th's New Scientist. Shahriar Afshar, an American, comes to the conclusion that we have no other choice but to declare the idea of Einstein's photon dead (page 35). His work has been tested and is now being peer reviewed. How trustworthy is New Scientist as a news source? Is it prone to sensationalists articles. I'm a fairly new reader of this magazine, but it seemed to me to be a good source of science news until last week's rushed Hawking article and this week's no-such-thing-as-a-photon showcase article. Of course, if it is repeatedly proved true than I would welcome the new finding but for now I'm just a bit stunned by the news. -Nicole __ Do you Yahoo!? New and Improved Yahoo! Mail - 100MB free storage! http://promotions.yahoo.com/new_mail Yahoo! Groups Links Yahoo! Groups Links Yahoo! Groups Sponsor ~-- Make a clean sweep of pop-up ads. Yahoo! Companion Toolbar. Now with Pop-Up Blocker. Get it for free! http://us.click.yahoo.com/L5YrjA/eSIIAA/yQLSAA/pyIolB/TM ~- Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Fabric-of-Reality/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: Afshar and ...the idea of a photon is dead
Unfortunately, sensationalists articles that are completely baloney appear in most scientific journals from time to time. Nature published an article claiming that if the fine structure conswtant is changing, as suggested by some astronomical observations, then this change must be due to a change in the speed of light. Now, this must be nonsense, because the value of the speed of light, being a dimensional constant, is determined by our choice of units. In fact, that there are dimensional constants at all, is an artefact of using inconsistent units at the same time. Michael Duff has explained this in the articles: http://arxiv.org/abs/hep-th/0208093 and: http://arxiv.org/abs/physics/0110060 - Oorspronkelijk bericht - Van: Nicole Barberis [EMAIL PROTECTED] Aan: [EMAIL PROTECTED] Verzonden: Friday, July 30, 2004 06:15 PM Onderwerp: Afshar and ...the idea of a photon is dead I was stunned to read Quantum Rebel in July 24th's New Scientist. Shahriar Afshar, an American, comes to the conclusion that we have no other choice but to declare the idea of Einstein's photon dead (page 35). His work has been tested and is now being peer reviewed. How trustworthy is New Scientist as a news source? Is it prone to sensationalists articles. I'm a fairly new reader of this magazine, but it seemed to me to be a good source of science news until last week's rushed Hawking article and this week's no-such-thing-as-a-photon showcase article. Of course, if it is repeatedly proved true than I would welcome the new finding but for now I'm just a bit stunned by the news. -Nicole __ Do you Yahoo!? New and Improved Yahoo! Mail - 100MB free storage! http://promotions.yahoo.com/new_mail Yahoo! Groups Sponsor ~-- Yahoo! Domains - Claim yours for only $14.70 http://us.click.yahoo.com/Z1wmxD/DREIAA/yQLSAA/pyIolB/TM ~- Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Fabric-of-Reality/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: Afshar and ...the idea of a photon is dead
That's correct, but such theories can be mapped to
theories with constant C. Ultimately only dimensionless constants matter,
all other constants are just conversion factors.
- Oorspronkelijk bericht -
Van: Ben Goertzel [EMAIL PROTECTED]
Aan: Saibal Mitra [EMAIL PROTECTED];
[EMAIL PROTECTED]
CC: everything [EMAIL PROTECTED]; [EMAIL PROTECTED]
Verzonden: Sunday, August 01, 2004 07:00 PM
Onderwerp: RE: Afshar and ...the idea of a photon is dead
I don't know anything about Afshar, but I do know that
variable-speed-of-light (VSL) theories of quantum gravity are now being
considered seriously by physics journals and by some leading physicists.
Joao Maguiejo (sp?) has a popular book on the topic entitled Faster than
the Speed of Light. The first half of the book will be too elementary
for
members of this list, but the second half is a good read -- though it
leaves
one eager for the mathematical details, which are found in the author's
and
others' technical papers.
Lee Smolin, who is well-respected for his role in creating loop quantum
gravity, is now taking VSL theories seriously.
-- Ben Goertzel
-Original Message-
From: Saibal Mitra [mailto:[EMAIL PROTECTED]
Sent: Sunday, August 01, 2004 8:03 AM
To: [EMAIL PROTECTED]
Cc: everything; [EMAIL PROTECTED]
Subject: Re: Afshar and ...the idea of a photon is dead
Unfortunately, sensationalists articles that are completely baloney
appear
in most scientific journals from time to time.
Nature published an article claiming that if the fine structure
conswtant is
changing, as suggested by some astronomical observations, then this
change
must be due to a change in the speed of light. Now, this must be
nonsense,
because the value of the speed of light, being a dimensional constant,
is
determined by our choice of units. In fact, that there are dimensional
constants at all, is an artefact of using inconsistent units at the
same
time.
Michael Duff has explained this in the articles:
http://arxiv.org/abs/hep-th/0208093
and:
http://arxiv.org/abs/physics/0110060
- Oorspronkelijk bericht -
Van: Nicole Barberis [EMAIL PROTECTED]
Aan: [EMAIL PROTECTED]
Verzonden: Friday, July 30, 2004 06:15 PM
Onderwerp: Afshar and ...the idea of a photon is dead
I was stunned to read Quantum Rebel in July 24th's
New Scientist. Shahriar Afshar, an American, comes to
the conclusion that we have no other choice but to
declare the idea of Einstein's photon dead (page 35).
His work has been tested and is now being peer
reviewed. How trustworthy is New Scientist as a news
source? Is it prone to sensationalists articles. I'm
a fairly new reader of this magazine, but it seemed to
me to be a good source of science news until last
week's rushed Hawking article and this week's
no-such-thing-as-a-photon showcase article. Of
course, if it is repeatedly proved true than I would
welcome the new finding but for now I'm just a bit
stunned by the news.
-Nicole
__
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