Re: Many Pasts? Not according to QM...
Stathis Papaioannou wrote: > 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. > > --Stathis Papaioannou If there is a continuum of states in the multiverse (or, rather, if the states are continuously indexed by the position and momentum of each particle), then any situation that has a finite or countable description, (in terms of your perception of that state through observer moments, for instance) will occur with uncountably large measure, however unlikely the state. If, however, the underlying basis of states in the multiverse has itself a discrete structure, this would impose a 'cutoff' on very unlikely events, so there would be a small fraction of universes wherein my trousers will fall down at the busstop (why is it always busstops?) but literally none at all wherein my shirt will fall up into the sky, there being no configuration of the underlyimg physical variables that would macroscopically correspond to such an event. -- Chris Collins
Re: Many worlds theory of immortality
Dear Stathis, This ties in with the subject header of this series of posts, which is a rare occurence: Many Wolrds Immortality, according to which there will be some branch of the multiverse in which I hit enough crows and pigeons on the way down to form a lifesaving mushy matress (mattress?), is a special case of a 'many-worlds-absurdity theorem' in which in some branch of the multiverse I will look down and find my leg be a peg and my ass a giraffe. But these will only happen if there are infinitely many, rather than just many, worlds. If you believe in some finite or countable discrete structure underlying physics, then you could ultimately identify definite events in which the universe branches off into a finite number of different cases (which would grow exponentially in time, but would after any given time be finite). -Chris Collins - Original Message - From: "Stathis Papaioannou" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]> Cc: Sent: Thursday, May 12, 2005 2:25 PM Subject: Re: Many worlds theory of immortality > The obvious and sensible-sounding response to Jeanne's question whether it > may be possible to access other universes through dreams or hallucinations > is that it is not really any more credible than speculation that people can > contact the dead, or have been kidnapped by aliens, or any other of the > millions of weird things that so many seem to believe despite the total lack > of supporting evidence. However, this response is completely wrong if MWI is > correct. If I dream tonight that a big green monster has eaten the Sydney > Opera House, then definitely, in some branch of the MW, a big green monster > will eat the Sydney Opera House. Of course, this unfortunate event will > occur even if I *don't* dream it, but I'm not saying that my dream caused > it, only that I saw it happening. It might also be argued that I didn't > really "receive" this information from another branch, but that it was just > a coincidence that my dream matched the reality in the other branch. But > seers don't see things by putting two and two together; they just, well, > *see* them. And if I really could, godlike, enter at random another branch > of the MW and return to this branch to report what I saw, how would the > information provided be any different from my dream? The only difference I > can think of is that with the direct method I would be more likely to visit > a branch with greater measure, but I can probably achieve the same thing by > trying not to think about green monsters when I go to sleep tonight. > > --Stathis Papaioannou > > >I once read an article in, I believe, Time Magazine, about the relatively > >new field of "neurotheology" which investigates what goes on in the brain > >during ecstatic states, etc. One suggestion that intrigued me was that it > >may be possible that in such a state, and I believe that schizophrenics > >were > >also mentioned, that the brain is malfunctioning in such a way as to allow > >it to perceive states of reality other than that which the normal brain > >would perceive. In other words, the "antenna" (brain) is picking-up > >signals > >that are usually beyond the scope of the normal brain. I wondered if > >anyone > >could comment on this, and if there was any reason to even entertain the > >thought that perhaps some people have passed through a crack in the > >division > >between our universe or dimension, into perhaps another? I read this > >several years ago and wish that I could recall the details of the article, > >but I don't have it anymore. > > > >Jeanne > > _ > MSN Messenger v7. Download now: http://messenger.ninemsn.com.au/ > >
Re: many worlds theory of immortality
Quentin Anciaux wrote: " >Le Mardi 10 Mai 2005 19:13, "Hal Finney" a écrit : >> And in terms of your question, I would not act as though I expected to > >be guaranteed a very long life span, because the measure of that universe > >is so low compared to others where I don't survive. >> > >Hal Finney > >Hi, > >but by definition of what being alive means (or being conscious), which is to >experience observer moments, even if the difference of the measure where you >have a long life compared to where you don't survive is enormous, you can >only experience world where you are alive... And to continue, I find it very >difficult to imagine what could mean being unconscious forever (what you >suggest to be likely). >Quentin Anciaux " ..You are working from the assumtion that each person has some sort of transcendental identity that experiences these observer moments, but I would think it more likely that these would be included in the observer moment, with memories being distinguished from "instantaneous" thoughts just by their being repeated several (or even millions of) times. As an illustration, try and remember what you had for dinner on your fifth birthday. Whether you remember or not, tou only know if you remember when you try to recall it, so you can't really pretend the piece of information is continuously present. Even the "knowledge" of your own name (which I suspect is made up, anyway) will have only a finite (or countable, if you live forever) number of instantiations. Chris Collins
Re: Many worlds theory of immortality
Dear Stathis, This was an interesting post. You're right in that, until quite recently, we've understood the world only as well as we've needed to, in order to survive. But if you believe, as some people on this list do, that instantaneous 'observer moments' are the only fundamentally real objects in the universe, (and that the reasoning, 'I think therefore I am' runs primarily in that direction) then it is the logical struture of our thopughts that is at each moment retrospectively generating a history in which there evolved a creature intelligient enough to think them. From this perspective, there is then a difference when someone becomes too mentally disfunctional to survive by themselves; then their incoherent patterns of thought will have to go one better and retrospectively generate a history in which a successful species evolved, of which they are a defective variant (we might all belong in this category, and keep each other sane..) But really, here we have to be more specific about what constitutes an observer moment, and what does not. Do dogs, worms, viruses have observer moments, or did they just coevolve in the history we might claim to have created by thinking and being? I would suggest that they are as real as we are, and that human consciousness is only distinguished from the animal sort in matters of quantity and capacity, and believe that the sorts of thoughts thatcan be taken as the fundamental objects of the universe are those that appear in the context of an organism successful response to its surrounding environment. This could be seen as a compromise between taking thoughts as fundamental, and a more old-fashioned 'physicalist' perspective, but I would see it more as observer moments being associated with the observer and his/her/its environment. After all, the distinction between these is pretty vague: Does the apple I just ate count as me or my environment? What if I made myself sick? What if I cut off my appendage? Don't worry; I will do neither of these things. Yours Sincerely, Chris Collins. - Original Message - From: "Stathis Papaioannou" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]>; Sent: Monday, May 09, 2005 2:02 PM Subject: Re: Many worlds theory of immortality > Dear aet.radal ssg, > > I think you missed my point about the amnesic and psychotic patients, which > is not that they are clear thinkers, but that they are conscious despite a > disability which impairs their perception of time. Your post raises an > interesting question in that you seem to assume that normally functioning > human minds have a correct model of reality, as opposed to the "broken" > minds of the mentally ill. This is really very far from the truth. Human > brains evolved in a specific environment, often identified as the African > savannah, so the model of the world constructed by the human mind need only > match "reality" to the extent that this promoted survival in that > environment. As a result, we humans are only able to directly perceive and > grasp a tiny, tiny slice of physical reality. Furthermore, although we are > proud of our thinking abilities, the theories about physical reality that > humans have come up with over the centuries have in general been > ridiculously bad. I have spent the last ten years treating patients with > schizophrenia, and I can assure you that however bizarre the delusional > beliefs these people come up with, there are multiple historical examples of > apparently "sane" people holding even more bizarre beliefs, and often > insisting on pain of death or torture that everyone else agree with them. > > You might point out that despite the above, science has made great progress. > This is true, but it has taken the cumulative efforts of millions of people > over thousands of years to get to our current level of knowledge, which in > any case is still very far from complete in any field. Scientific progress > of our species as a whole is mirrored in the efforts of a psychotic patient > who gradually develops insight into his illness, recognising that there is a > difference between real voices and auditory hallucinations, and learning to > reason through delusional beliefs despite the visceral conviction that "they > really are out to get me". > > --Stathis Papaioannou > > >From: "aet.radal ssg" <[EMAIL PROTECTED]> > >To: everything-list@eskimo.com > >Subject: Re: Many worlds theory of immortality > >Date: Sat, 07 May 2005 10:44:25 -0500 > > > > _ > REALESTATE: biggest buy/rent/share listings > http://ninemsn.realestate.com.au >
Re: An All/Nothing multiverse model
There do exist consistent approaches to set theory where you do have a
universal set and can therefore consider taking complements to be a
sinle-argument operation. to bypass the obvious paradox (that any set can be
used to make a necessarily larger powerset) you need to concoct a map from
the universal set onto its own powerset. The easiest way to do this is to
have lots of 'urelements' or' indivisible but somehow different sets, which
can then be mapped to larger sets in the powerset. If you find urelements
philosophically objectionable (which most computationally-minded people do)
then there exist other more difficult approaches: Try a google search for
"Alonzo Church", "Willard Quine" or "Thomas Forster" to see some people who
have tried...
--Chris Collins
- Original Message -
From: "Georges Quenot" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Wednesday, November 17, 2004 10:36 AM
Subject: Re: An All/Nothing multiverse model
> Hal Ruhl wrote:
> >
> > Hi George:
>
> Hi Hal,
>
> > At 09:13 PM 11/16/2004, you wrote:
> >
> >> Hal Ruhl wrote:
> >>>
> >>> My use of these words is convenience only but my point is why should
> >>> existence be so anemic as to prohibit the simultaneous presence of an
> >>> All and a Nothing.
> >>
> >> The "prohibition" does not "come from" an anemia of existence
> >> (as you suggest) but rather from the strength of nothing(ness),
> >> at least in my view of things.
>
> I am not sure I understand where we disagree (and even if we
> really disagree) on this question of the "{something, nothing,
> concept, existence}" question.
>
> Even if we consider that defining something automatically
> defines (a complementary) something else, this happens at the
> concept level. It might well be that both defined concepts
> simultaneously exists (say at least in the mind/brain of a
> few humans beings) but this says noting about whether either
> one or the other actually gets at something that would exist.
>
> Even if the *concepts of* something (or all) and nothing do
> need to exist simultaneously for any of them to exist, it
> (obviously ?) does not follows that something (or all) and
> nothing also needs to exist simultaneously (or even simply
> makes sense in any absolute way).
>
> Last but not least, what is the complementary concept of a
> given concept is not that obvious. Let's consider the concept
> of a "winged horse". Regardless of whether it actually gets
> at something or not, it can be considered to be opposed to
> "non winged horses" or to "winged things that are not horses"
> rather that to "anything that is not a winged horses". In
> set theory, a complementary of a set is always considered
> only within a given larger set and never in any fully open
> way (and there are well known and very good reasons for that
> whatever common sense may say). Similarly, defining an all
> or something in a fully open way is likely to be inconsistent.
> The situation is different here from the case of the winged
> horse and probably from all other cases and there is no reason
> that common sense be still relevant (like in the set of all
> sets paradox). This might be a case (possibly the only one)
> in which defining/considering something does not automatically
> make appear a complementary something (even simply at the
> concept level).
>
> >>> This would be an arbitrary truncation without reasonable
justification.
> >>
> >> Just as the opposite.
> >
> > I provided a justification - a simple basis for evolving universes -
> > which does not yet seem to have toppled.
>
> It might be not so simple. I went through it and I still can't
> figure what "evolving universes" might get at. Up to this point,
> I did not find something that would sound to me as a (more)
> reasonable justification. This may well comme from me.
> What appears reasonable or not or what appears as an actual
> justification or not is certainly very relative. Currently, I am
> still in the process of trying to find some sense (in my view of
> things) in what you are talking about (and/or of trying to
> figure out what your view of things might be). *Not* to say it
> necessarily hasn't.
>
> Georges.
>
>
Re: Quantum Rebel
- Original Message - From: "Jesse Mazer" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Thursday, August 12, 2004 4:28 PM Subject: Re: Quantum Rebel > Is Unruh saying that in figure 2 without the absorber, the amplitude of a > photon travelling along path 4 is zero, but with the absorber in place, > there is some nonzero amplitude for a photon to travel along path 4 but then > be scattered into the "wrong" detector? If he's not suggesting the > possibility the absorber will scatter photons without absorbing them is > relevant here, then I wouldn't think he'd say the possibility the wires will > scatter photons without absorbing them is relevant to Afshar's experiment. > When you say "the mathematics of quantum mechanics assures this", did you > actually do a calculation of the effects of scattering in Afshar's > experiment? > > Jesse Mazer > Until the photon reaches the detector, the mathematics of quantum mechanics are the essentially the same as that of a classical wave, but are not the same as the 'ray tracing' approximation. Without the wires there, according to quantum meachanics, the photon will travel like a wave, passing through both initial slits, forming a diffraction pattern, and eventually producing a superposition of two different states corresponding to the two detectors having been hit. This superposition is unstable and decoheres (thats what makes them 'detectors'; if instead you had two new slits, you could leave the photon to perform more interference shenanigans). The presence of the wires shows that the 'state vector collapse' occurs after the photon reaches the detectors, not at the slits, which is obvious with a flat screen as the detector, but the two detectors positioned at the geometrically significant positions creates the illusion of each photon having traced a single ray-like path. Essentially Ashfar's experiment involves fooling himself (and perhaps a few others) with a new single-path photon thoery, then undermning the new theory, whcih was not quantum mechanics.. --Chris Collins
Re: Is the universe computable
- Original Message - From: "Stephen Paul King" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Cc: <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]> Sent: Wednesday, January 21, 2004 5:39 PM Subject: Re: Is the universe computable SPK wrote: > You are confussing the postential existence of a computation with its "meaningfulness". But in the last time you are getting close to my thesis. We should not take the a priori existence of, for example, answers to NP-Complete problems to have more "ontological weight" than those that enter into what it takes for "creatures like us" to "view" the answers. This is more the realm of theology than mathematics. ;-) > ..This is rather like an argument I like to put forward when I'm feeling outrageous, and one which I've eventually come to believe: That the real number line 'does not exist.' There are only countably many numbers you could give a finite description of, even with a universal computer (which the human mathematical community probably constitutes, assuming we don't die out), and in the end the rest of the real numbers result from randomly choosing binary digits to be zero or one (see eg. anything by G. Chaitin). So while the natural numbers and the integers have a rich internal structure (rich enough to contain the whole universe and more, according to most subscribers on this list, I suspect), the reals can be encoded in the single 'program' of tossing a coin. By this I mean that the only 'use' or 'meaning' you could extract from some part of the binary representation would be of the form 'is this list of 0s and 1s the same as some pre-chosen lis of 0s and 1s?', which just takes you back to the random number choosing program you used to create the reals in the first place. -- Chris Collins --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.561 / Virus Database: 353 - Release Date: 1/13/04
Re: Peculiarities of our universe
Why aren't we our own much smarter descendents? If you see quantum measurement events as 'uncovering' or 'choosing' from a larger set of, in some sense, pre-existing earlier possibilities, then this problem solves itself: the future looks 'bigger' than the present, but in terms of the real microstates, whatever they may be, it would be smaller. So your earliest observer moments would create a history of thermal, galactic, stellar, and biological evolution that traces back the shortest possible route to some sort of generic early universe condition with a very large measure. It is only the first of these evolutionary stages, explaining the origin of matter, that we do not yet understand. But I don't think we're to far off --Chris Collins - Original Message - From: "Jesse Mazer" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Saturday, January 10, 2004 9:41 PM Subject: Re: Peculiarities of our universe > One possibility for why we do not find ourself in an old, galaxy-spanning > civilization has already been mentioned--perhaps after a certain point all > the individual minds in a civilization unite into a single Borg-like > hivemind, and this reduction in the number of minds might imply that the > self-sampling assumption would predict we'll find ourselves in a time before > this happens (although if the hivemind lasts for billions of years, the > argument might not work because this individual mind would probably have > more separate observer-moments than the total number of observer-moments of > the hundred billion or so individuals who lived before the mind-merging). > > Another possibility is suggested by a theory about how the measure on > observer-moments could be influenced by the likelihood of future > duplications, which I discussed a bit in this post (in response to a post by > Bruno Marchal discussing the same idea): > > http://www.escribe.com/science/theory/m4841.html > > If observer-moments which are more likely to have more copies of themselves > existing in the future have higher measure, then this might also suggest why > I find myself living before civilization has spread throughout the > galaxy--perhaps observers who are alive right at the time when the > "technological singularity" occurs are the ones who are most likely to > become the earliest uploads and to have the most copies of themselves living > in the future galaxy-spanning civilization, thus giving the pre-singularity > versions of themselves a much higher measure than any post-singularity > observer-moments. > > Jesse > > _ > Learn how to choose, serve, and enjoy wine at Wine @ MSN. > http://wine.msn.com/ >
Re: Why no white talking rabbits?
This paradox has its origin in perception rather than fundamental physics: If I fill a huge jar with sugar and proteins and minerals and shake it, there is no reason why I can't produce a talking rabbit, or even a unicorn with two tails. Yet out out of the vast menagerie of novel objects and creatures I could produce, I always seem to get a bubbling cloudy liquid. The solution, of course, is that there is an even larger menargerie of objects, all of which look the same to me (like a bubbling cloudy liquid, in fact). Similarly, there is no reason ehy such object, could not appear out of the quantum vacuum, but it must be the case that this vacuum throws up a lot of different objects and events that look to us like 'empty space' and 'nothing happening' (although I suspect that the case of the paradox you give of the double slit experiment has its origins in considering too large a set of states as 'possible'; the positions of the photons are not really free variables, with the apparently 'artificial' physical laws following from the initial data. It's like asking why the pegs on my washing line always follow the 'coshine law'...). I described a special case of this in a posting on this list a while ago, suggesting that we're almost certainly not in a simulated, 'second order' universe: Basically, for every arrangement of matter you could append to our universe that would look like some creature controlling/observing us, there would be many more arrangements that looked like no living creature. And every time you looked for your 'God' and found only space-dust, the universe would get bigger and harder to simulate, amking finding god less likely next time you looked. Depending how quickly this unlikelyness increased after each failed attempt, you might expect to look forever and find, along with a lot of dirt and some bacteria, eventually, beings that would have been smart enough to simulate your ancestors or earlier self, but never you and your current 'known universe.' --Chris Collins - Original Message - From: "Jesse Mazer" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Friday, January 09, 2004 8:38 PM Subject: Re: Why no white talking rabbits? > >From: Eric Hawthorne <[EMAIL PROTECTED]> > >To: [EMAIL PROTECTED] > >CC: [EMAIL PROTECTED] > >Subject: Re: Why no white talking rabbits? > >Date: Fri, 09 Jan 2004 10:36:41 -0800 > > > > > >Hal Finney wrote: > > > >>What about a universe whose space-time was subject to all the same > >>physical laws as ours in all regions - except in the vicinity of rabbits? > >>And in those other regions some other laws applied which allow rabbits > >>to behave magically? > >> > >> > > > >While this may be possible, we seem to have found so far that the universe > >admits of many > >simple regularities in its complex systems and its fundamental laws. > >Therefore many of the > >essential properties (future-form-and-behaviour-determining properties) of > >these complex > >systems admit of accurate description by SIMPLE, SMALL theories that > >describe these > >simple regularities in the complex systems. > > But that's an empirical observation about our universe, it doesn't tell us > anything about *why* this should be true if you take seriously the > "everything that can exist, does exist" theory that this list is meant to > discuss. For example, if you consider the set of all possible Turing machine > programs, then for any given complexity, there are an infinite number of > programs that are more complex than that but only a finite number less > complex. So it seems like you need to assign progressively less measure to > the more complex programs in order to get a high likelihood of living in a > universe defined by a simple program (assuming you believe in 'universes' at > all, which advocates of TOEs that deal with first-person probabilities might > not). One solution might be that more complex programs tend to run simpler > ones inside them somehow, increasing their measure (like a detailed physical > simulation which contains, among other things, a simulated computer running > a simpler program), but then you have to address the problem in that > Chalmers paper I posted about how to identify instantiations of a given > program in a way that doesn't imply that every program instantiates every > other possible program. > > Also, the problem with taking the "white rabbit" example too literally is > that programs that create orderly phenomena like talking white rabbits would > almost certainly be very rare unless you had a measure that was specifically > picked to make them likely--this is why I prefer examples where the laws of > physics break down in a region in a more random way, like getting a > completely wrong pattern of photons hitting the screen in the double-slit > experiment. Among the set of all possible distributions of photons you could > get in this experiment, the number of possible "wrong" ones should vastly > outnumber the number of "right" o
Re: Why is there something instead of nothing?
This question seems unanswerable, but set theorists have tried (though
that might not be how they view their own endeavours): One interpretation of
the universe of constructible sets found in standard set theory textbooks is
that even if you start with nothing, you can say "that's a thing," and put
brackets around it and then you've got two things: nothing and {nothing}.
And then you also have {nothing and {nothing}}. Proceeding in this manner
you get a mathematical structure equivalent to numbers, a structure which in
turn is known to contain unimaginable richness and texture, in which
mathematical physicists (like me) attempt to 'find' the structures of our
universe embedded.
-Chris C
- Original Message -
From: Norman Samish <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Sunday, November 16, 2003 6:09 PM
Subject: Re: Why is there something instead of nothing?
> Hal Finney,
> Thanks for the thought. I know that there is something instead of nothing
> by using Descartes reasoning. (From
> http://teachanimalobjectivity.homestead.com/files/return2.htm) "The only
> thing Descartes found certain was the fact he was thinking. He further
felt
> that thought was not a thing-in-itself, and had to proceed from somewhere
> (viz., cause and effect), therefore since he was thinking the thoughts, he
> existed --by extension--also. Hence, "thought" and "extension" were the
very
> beginnings from which all things proceeded, "Cogito ergo sum" (I think
> therefore I am)."
>
> I don't understand how there can be both something and nothing. Perhaps I
> don't understand what you mean by "nothing." By "nothing" I mean no
thing,
> not even empty space.
>
> In other words, it is conceivable to me that the multiverse need not
exist.
> Yet it does. Why? This seems inherently unanswerable.
>
> Norman
>
> - Original Message -
> From: "Hal Finney" <[EMAIL PROTECTED]>
> To: <[EMAIL PROTECTED]>
> Sent: Saturday, November 15, 2003 11:12 PM
> Subject: Re: Why is there something instead of nothing?
>
>
> > How do you know the premise is true, that there is something instead
> > of nothing? Maybe there could be both something and nothing. Or maybe
> > the existence of "nothing" is consistent with our own experiences.
> >
> > I don't think all these terms are well enough defined for the question
> > to have meaning in its simple form. It's easy to put words together,
> > but not all gramatically correct sentences are meaningful.
> >
> > Hal Finney
> >
> >
>
>
Re: "spooky action at a distance"
Do we live in a universe in which future coin tosses will invariably result in "heads," or one in which a mixture of results will occur? Of course, we live in both, but the latter constitutes a numerically much larger class of universes; one would imagine it would be the same with physical laws, including those governing "wave-function collapse": That some laws would have a much larger "measure", and would always be the ones we discover. -Chris C - Original Message - From: Hal Finney <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Thursday, November 13, 2003 5:30 PM Subject: Re: "spooky action at a distance" > This list is dedicated to exploring the implications of the prospect > that all universes exist. According to this principle, universes > exist with all possible laws of physics. It follows that universes > exist which follow the MWI; and universes exist where only one branch > is real and where the other branches are eliminated. Universes exist > where the transactional interpretation is true, and where Penrose's > "objective reduction" happens. I'm tempted to even say that universes > exist where the Copenhagen interpretation is true, but that seems to be > more a refusal to ask questions than a genuine interpretation. > > Therefore it is somewhat pointless to argue about whether we are in one > or another of these universes. In fact, I would claim that we are > in all of these, at least all that are not logically inconsistent or > incompatible with the data. That is, our conscious experience spans > multiple universes; we are instantiated equally and equivalently in > universes which have different laws of physics, but where the differences > are so subtle that they have no effect on our observations. > > It may be that at some future time, we can perform an experiment which > will provide evidence to eliminate or confirm some of these possible QM > interpretations. At that time, our consciousness will differentiate, > and we will go on in each of the separate universes, with separate > consciousness. > > It is still useful to discuss whether the various interpretations work > at all, and whether they are in fact compatible with our experimental > results. But to go beyond that and to try to determine which one is > "true" is, according to the multiverse philosophy, an empty exercise. > All are true; all are instantiated in the multiverse, and we live in > all of them. > > Hal >
Re: are we in a simulation?
Stephen Paul King wrote: >Does computational complexity (such as NP-Completeness, etc.) >and computational "power" requirements factor into the idea >of simulated worlds? Yes, I think that's a point I was trying to get accross in my previous post under this heading: That although in a certain sense we are simultaeously in lots of different universes, in some of which we are being 'simulated', we might expect never to find ourselves to be in a simulation if our universe is difficult to simulate. Which universe we are actually 'in' is only decided when we make new quantum mechanial measurements. The results of these measurements correspond to us finding new particles, or correlations between particles; the result of a long enough series of 'measurements' might correspond to our meeting an alien, and a sufficiently long series of measurements might yield the result that we meet aliens who turn out to be simulating us. Lets say we'd need to make 10^20 bits worth of measurements to have the possibility of finding someone simulating us, and outnof the 2^(10^20) possible results, only one result would show that w4e a re being 'simulated'. Then we would expect to find that we are not being simulated, and our universe would contain more information making it harder to simulate: If the length of the bit chain which we would have to measure to find that we are being simulated (which corresponds to the log of the amount of information aliens would have to contain to simulate us) increases linearly with the number of measurements we have already made, then the total probability if we lived forever, making more and more measurements, of us finding that we a re being simulated would be finite, and could be very small. -JC
Re: are we in a simulation?
George Levy wrote: >Everytime a "measurement" is made, the set of worlds spanned >by this consciousness is defined more narrowly, but the >number in the set remains infinite. In addition, each >simulation in the set need not belong to the same "level.">We're faced with the strange possibility that the >consciousness spans an infinite number of simulations >distributed over widely different levels. I agree that we are simultaneously in many simulations, and I would agree that there are uncountably many possible 'histories' or situations consistent with our consiousness and known history. But I think only a countable number of the 'classical universes' (and certainly only a small fraction) we might be in are simulations. If we look at the 'total knowledge' of any living being, including the things not consciously known but constrained to be decided by the classical history they evolved from (so, for instance, 'what killed the dinosaurs' is probably a question with a definite answer, for us, but the trajectory of a certain electron is not; the former would form part of my 'total knowledge' because if I worked out the answer by looking at enough historical evidence, I would get the same answer each time), it is always finite. As you suggest, any arrangement of matter consistent with this 'total knowledge' is a possibility for the universe we will find ourselves in on making further measurements, and if we live forever, and keep making new measurements, then there will be a countable number of possible universes we will encounter. But at any finite time, we will only know a finite amount, and therefore only impose a finite number of constraints on the possible universe we will find ourselves in (see my note below on living forever versus having lived forever for more on this). the relevance of this to the current issue is that the super-beings who would emulate us obey the same rules: The 'whole world' of any living being at any given time in their history, being determined only by their thoughts, and the classical histories likely to give rise to those thoughts, can be described by a finite amount of information. Therefore the total number of situations in which a conscious being is simulating our universe is countable. Also, the total number of finite chains of one being simulating another simulating a third etc. is countable (being a set of finite subsets of a countable set). We are left with the infinite chains of simulation. Here there are two possibilities: either the chain forms a 'loop', in whih case it has actually already been counted in the finite chains (so there are countably many of these [you may also reject them as 'unphysical']) or there is a new 'being' at every step up the chain. But I do not see how these constructions could 'really' be said to tend to any limit (which would be uncountable) as there is, unlike with real numbers, no way to say when two chains are 'getting close together': The next stage could always make them totally different, by any measure (but given the axiom of choice, these universes will be 'real', mathematically at least. But they won't be 'dense' as I'll get on to now..). Whether or not you accept that these limits exist, it is nevertheless the case that we are more likely, on making measurements, and reducing the number of universes we might be in to find more assortments of non-living matter than aliens, including those aliens who might 'turn out' to be controlling us. Any series of new measurements we make can be seen as adding to our 'total knowledge' as described above, a new stream of data, whih you could translate into a string of 0s and 1s (The fact that the data is genuinely new to us means that it is necessarily a discrete uniform distribution of 0s and 1s, apart from correlations you may have itroduced into the data by 'translating it' from whatever form you found it in). Then for a sufficiently long 'string' there would be a very small probability that this information would correspond to the existence of some living being, but it would be much more likely to correspond to a bunch of 'dead' particles (physically, I would see a typical measurement process as 'collecting thermal radiation from a black hole' or 'going over the cosmic horizon to see what you find' or 'absorbing a photon' [these examples are roughly in decreasing order of probability of finding 'life', but even with the last eample it is in principle possible: you could fire a super-energy gamma ray at a gold sheet and a virus might come out the other side]).For any finite 'chain' of information there is a small but finite chance of finding 'life', and even finding'life simulating us' but as you make the chain infinite (as we would have to to 'discover' an infinite chain of universes all simulating in a chain) the probability of finding forever higher and higher levels of life tends to zero. This is because a
Re: a prediction of the anthropic principle
Hal Finney Wrote: >However I think the anthropic prediction in such cases is >that our history would have been just barely good enough to >allow life like us to form. If meteor bombardment should >have wiped us out, we would predict that we would have >experienced a history of heavy meteor strikes, not quite >enough to wipe us out, but enough to be very troublesome >. Robin Hanson has a>couple of papers on this, http://hanson.gmu.edu/greatfilter.html>and a more technical one at http://hanson.gmu.edu/hardstep.pdf. ..Thanks, they were interesting. I don't think 'not getting suddenly wiped out' can be described in the same terms as the 'difficult steps' he analyses, but we have been hit by a lot of not-completely-deadly astronomical bodies. The effect of these could be very crudely fitted in to his analysis if we suggest that each asteroid impact wastes a certain amount of time, by wiping out promising species, etc. Then if we use as a random variable the total time wasted, and if the expected time wasted is much bigger than the time for one 'step' (about 1/2 a billion years), and the probability distribution of the time lost is sufficiently flat for small times, then we might expect to have 'wasted' one step-size recovering from meteors.. However, I don't think all te conditions I've described are actually met: For one thing, some meteors might be helpful, for instance if they killed off powerful but incurably stupid competition. If the probability distribution for lost time had a large negative tail then we would expect to get as many helpful meteor strikes as possible until the unlikelyness cost of having a larger negative time-loss would equal the likelyness gain achieved by the 'extra time'. On a more general point, I think one thing that isn't stressed clearly enough in the articles you referenced is that if we take as given that intelligient life evolved on preisely one planet within our cosmic horizon, and look at the variation of some parameters corresponding to how difficult the evolutionary steps must have been (and must still be for the pond scum on other planets) we would expect them to be difficult enough so that intelligence only appears once, but for things to then be more difficult is less likely. So where he says the expected time for us to evolve is approximately greater than 30 billion years or something (the precise figure depending on the number of hospitable planets), I would say it's approximately equal.
a prediction of the anthropic principle/MWT
The fact that we're alive shows that as a species we've been historically very 'lucky', the biggest 'break' being in the finely tuned initial conditions for our universe. At least a level I many-worlds theory is needed to explain this. But in a higher level MWT this good luck might have extended further. For instance, our planet might have experienced an unusually high number of 'near misses' with other astronomical bodies. Now that we're here to watch, the universe will be forced to obey the law of averages, so there could be a significantly higher probability of a deadly asteroid collision than would be indicated by the historical frequeny of said events. Perhaps we should carefully compare how often the other planets have been hit with how often we have: They certainly look more craterful Have there been any serious studies into this? It's not just idle philosophial musings, it affects the way our governments should be spending our money (or rather your money; I'm a non-earning student).
are we in a simulation?
The argument that many-worlds theory implies that we are 'almost certainly' in a computer simulation has been put forward by many people, and there are many similarly themed arguments used to suggest that many-worlds theory is 'obviously not true'; most of these arguments contain well hidden logical inconsistencies which involve switching back and forth between many-world and single world ideas. This leads to a rather strange way of counting the different possible 'classical universes' that we might be part of. The sleight of hand (or honest mistake) used in these arguments lies in the seemingly innocent assumption that a powerful god-like being who builds a simulation of our universe must then be the cause of our existence. This would be true in a single classical universe, but it is not true in many-worlds theory, where we should use a definition of 'causing' or 'implying' involving a correlation between different classical universes, ie. that [god-like being does not simulate us] =>(almost always) [we do not exist]. This is discussed in David Deutsch's 'The Fabric of Reality', where he gives the example that no butterflies cause hurricanes by flapping their wings (unless you put one in a human built 'hurricane mahine' with a touch sensitive keyboard).. How we should correctly 'count the universes' in which we live is by starting with what we know exists: Ourselves, the planet Earth, evidence of our ancestry, the surrounding galaxies, etc. and looking at what we can 'append' to this universe: We could have some universes where there is everything we know exists, plus super-intelligient beings who behave as though they are controlling us, but for each of these, one would expect many more universes containing everything we know exists, plus some generic random distribution of (generally non-living) matter, such as some rocks or a cloud.
