On Fri, Nov 6, 2015 at 2:57 AM, Pierz <pier...@gmail.com> wrote: > > > On Thursday, November 5, 2015 at 8:48:49 PM UTC+11, telmo_menezes wrote: > >> >> >> On Mon, Nov 2, 2015 at 1:20 PM, Pierz <pie...@gmail.com> wrote: >> >>> >>> >>> On Monday, November 2, 2015 at 5:27:04 AM UTC+11, telmo_menezes wrote: >>> >>>> >>>> >>>> On Sun, Nov 1, 2015 at 3:14 AM, Pierz <pie...@gmail.com> wrote: >>>> >>>>> >>>>> >>>>> On Saturday, October 31, 2015 at 11:20:32 PM UTC+11, telmo_menezes >>>>> wrote: >>>>>> >>>>>> >>>>>> >>>>>> On Sat, Oct 31, 2015 at 5:19 AM, Pierz <pie...@gmail.com> wrote: >>>>>> >>>>>>> >>>>>>> >>>>>>> On Saturday, October 31, 2015 at 1:01:08 PM UTC+11, Brent wrote: >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> On 10/30/2015 5:39 AM, Pierz wrote: >>>>>>>> >>>>>>>> So imagine a guy washed up on a small desert island after a plane >>>>>>>> crash. Unfortunately during the plane crash he suffered a traumatic >>>>>>>> injury >>>>>>>> which caused him to completely lose his memory. He wakes up on the sure >>>>>>>> without the faintest clue about who he is or where he comes from. He >>>>>>>> doesn't even remember that there are other people in the world and >>>>>>>> that he >>>>>>>> was born of a mother and father. After sorting out his immediate >>>>>>>> survival >>>>>>>> needs, being a philosophical type, he begins to wonder about his own >>>>>>>> origins. He begins to speculate about the what conditions might have >>>>>>>> given >>>>>>>> rise to him and the island he finds himself on. >>>>>>>> >>>>>>>> Without the benefit of the memory of any scientific knowledge, he >>>>>>>> is struck by the strangeness of the fact that the world he finds >>>>>>>> himself in >>>>>>>> seems so well-adapted to him - or he to it. Isn't it marvellous, he >>>>>>>> reasons, that when I feel this particular unpleasant sensation of >>>>>>>> dryness >>>>>>>> (which we, but not he, would call "thirst"), it happens that there is >>>>>>>> some >>>>>>>> abundant substance I can locate that, if conveyed into my mouth, >>>>>>>> relieves >>>>>>>> that sensation? Isn't it astonishing that I have these dextrous digital >>>>>>>> appendages that seem so perfectly made for constructing a shelter, or >>>>>>>> making and throwing a spear? How to explain it? >>>>>>>> >>>>>>>> Being more of a mathematician than a naturalist by nature, he >>>>>>>> reasons that perhaps the explanation is simply this: the ocean that he >>>>>>>> sees >>>>>>>> that appears to extend indefinitely in all directions is in fact >>>>>>>> infinite. >>>>>>>> And scattered across that infinite ocean there are other islands. He >>>>>>>> can >>>>>>>> see at least a couple from where he is, so if the ocean is infinite >>>>>>>> there >>>>>>>> would end up being an infinity of such islands. And if there are an >>>>>>>> infinite number of such islands, then all possible arrangements of >>>>>>>> matter >>>>>>>> will eventually form by chance. If they happen to form something >>>>>>>> conscious >>>>>>>> - and conscious enough to reason about its origins - then that >>>>>>>> conscious >>>>>>>> being will be required to be complex enough and well adapted enough to >>>>>>>> the >>>>>>>> stuff around it that it can maintain its own integrity long enough to >>>>>>>> form >>>>>>>> such deep thoughts. >>>>>>>> >>>>>>>> >>>>>>>> Interestingly, as Lawrence Krauss and Sean Carroll both mention in >>>>>>>> their popular lectures, in the far future the accelerating expansion >>>>>>>> of the >>>>>>>> universe will leave the Milkyway alone with no other galaxy within the >>>>>>>> Hubble sphere. The universe will appear to our sucessors, if there are >>>>>>>> any, completely empty with a lone island of stars and matter. >>>>>>>> >>>>>>>> >>>>>>>> OK, there are still some holes in his Theory of Everything (where >>>>>>>> did the ocean come from?) but a man has to draw the line >>>>>>>> *somewhere*. He is smart enough to see the lurking possibility of >>>>>>>> infinite regress and skirt around it. With this he is satisfied and >>>>>>>> settles >>>>>>>> back to eat another coconut, convinced he has found a coherent >>>>>>>> explanation >>>>>>>> of his own existence... >>>>>>>> >>>>>>>> The problem with his impoverished account, of course, is that it >>>>>>>> misses a vast amount of structure in the world. The line he has drawn >>>>>>>> to >>>>>>>> stave off infinite explanatory regress is clearly far too high in the >>>>>>>> hierarchy of complexity, but because of the limited range of his >>>>>>>> experience, he is unlikely to see that. If he could witness mating and >>>>>>>> birth, for instance, he might start to wonder if he hadn't been a >>>>>>>> little >>>>>>>> hasty in his invocation of infinite permutation as an explanatory >>>>>>>> principle. With sufficient exposure to time and diverse biology, he >>>>>>>> might >>>>>>>> start to wonder about the role of an *evolutionary* process. >>>>>>>> >>>>>>>> It's clear how much better the evolutionary explanation is because, >>>>>>>> armed with it, he might be able to make predictions. He might be able >>>>>>>> to >>>>>>>> foresee, for instance, that his body should have robust mechanisms for >>>>>>>> dealing with normal environmental vicissitudes. Suffering his first >>>>>>>> minor >>>>>>>> wound, he might predict that the injury would heal. On the other hand, >>>>>>>> with >>>>>>>> the "infinite permutations theory", he could predict nothing at all. >>>>>>>> Though >>>>>>>> it offers a somewhat satisfying conceptual neatness, it also lacks any >>>>>>>> predictive power whatsoever. >>>>>>>> >>>>>>>> You can see perhaps see where I'm going with this. I tend to >>>>>>>> believe in a multiverse. But I also tend to believe that as an >>>>>>>> explanation >>>>>>>> of fine-tunedness *per se*, the combination of a multiverse with >>>>>>>> the anthropic principle is scientifically and philosophically >>>>>>>> bankrupt. I >>>>>>>> believe that we are like desert island amnesiacs, lacking the breadth >>>>>>>> of >>>>>>>> observation that we would need in order to see the correct picture of >>>>>>>> how >>>>>>>> fine tuning arises in our local environment. Lee Smolin's theory of an >>>>>>>> evolutionary universe gets closer, but suffers from the serious flaw >>>>>>>> that >>>>>>>> he sees universes evolving towards black-hole production, which is only >>>>>>>> incidentally or co-incidentally related to life-friendliness. >>>>>>>> >>>>>>>> My hunch is that the true explanation of fine-tuning (and hence of >>>>>>>> the physical laws we observe) is one that involves our universe being >>>>>>>> embedded in much larger multiversal structures and processes which we >>>>>>>> probably can't even guess at with our current technological and >>>>>>>> theoretical >>>>>>>> apparatus. The resort to "all possible structures" flattens out >>>>>>>> infinity to >>>>>>>> a single dimension the same way that the castaway amnesiac flattens out >>>>>>>> infinity to the level of the ocean. I suspect the truth is much deeper >>>>>>>> and >>>>>>>> more complex and that the fined universe we see is a result of a kind >>>>>>>> of >>>>>>>> deep computational process in the same way that biological complexity >>>>>>>> is >>>>>>>> the end result of a long computational process. >>>>>>>> >>>>>>>> >>>>>>>> An interesting viewpoint. However, I think that "fine-tuning" is a >>>>>>>> problem that was invented to satisfy a solution. Smolin had an >>>>>>>> interesting >>>>>>>> evolutionary theory of cosmogony, but it turned out to be empirically >>>>>>>> falsified because this universe doesn't have the physical parameters to >>>>>>>> maximize black hole production. >>>>>>>> >>>>>>>> Hunches that there is a much deeper truth that we can't even guess >>>>>>>> are like "brain in a vat" ideas in that they lead nowhere. >>>>>>>> >>>>>>> >>>>>>> Maybe so. But there's an element to my thought experiment I didn't >>>>>>> quite spell out. The castaway faces a similar problem in explaining his >>>>>>> organismic adaptation as we face in explaining "fine tuning" (which I >>>>>>> don't >>>>>>> agree is a pseudo-problem - there are many physicists who remain >>>>>>> resistant >>>>>>> to the multiverse + anthropic principle explanation). A developmental or >>>>>>> selection hypothesis makes some predictions about adaptation - wound >>>>>>> healing is an example - which the infinite islands hypothesis does not. >>>>>>> Similarly the multiverse explanation of fine tuning always explains >>>>>>> exactly >>>>>>> what *is* and nothing more. It explains all the fine tuning we've >>>>>>> discovered, but none that we might discover in the future. For example, >>>>>>> it >>>>>>> is quite incredible that there happens to be a substance with all the >>>>>>> life-supporting properties of water, and an element carbon that is >>>>>>> capable >>>>>>> of such extraordinarily complex chemical combinations. By the >>>>>>> multiverse/anthropic explanation, we'd expect to find more than a few >>>>>>> such >>>>>>> remarkable coincidences in any life-supporting environment. But now >>>>>>> let's >>>>>>> imagine a society far in the future which has discovered a whole range >>>>>>> of >>>>>>> further remarkable fine-tunings which have supported or enabled a much >>>>>>> more >>>>>>> advanced society. They might find for example a certain fine-tuning >>>>>>> principle which shows that the probability of a planet being hit by a >>>>>>> mass-extinction-causing asteroid is finely tuned to support the >>>>>>> development >>>>>>> of intelligent societies. Perhaps evolution tends to follow a trajectory >>>>>>> towards the evolution of oversized predators which are then typically >>>>>>> wiped >>>>>>> out by collision events because they do not have the intelligence to >>>>>>> prevent them. This then allows the development of an intelligent species >>>>>>> which is capable of predicting and preventing such collisions. Now of >>>>>>> course I'm not suggesting this *is* the case, or that it >>>>>>> necessarily makes a heap of sense as an example (I made it up just >>>>>>> then), >>>>>>> but if we were able to visit many, many inhabited planets and we saw the >>>>>>> same pattern over and over, we might then start to say, "Wow, it's kind >>>>>>> of >>>>>>> remarkable that there always seems to be enough time to develop a >>>>>>> society >>>>>>> capable of gravitational towing technology. If there was just a slightly >>>>>>> higher frequency of collisions in a typical solar system, then most >>>>>>> intelligent species would be wiped out like the dinosaurs before they >>>>>>> reached the stage to be able to prevent it." So there you have an >>>>>>> example >>>>>>> of a newly discovered piece of fine-tuning that we would not predict >>>>>>> from >>>>>>> the theory today. On its own it might not be all that convincing, but if >>>>>>> enough similar examples accumulated, one might start to find it fishy >>>>>>> and >>>>>>> wonder why we kept getting so "lucky". This would point to something >>>>>>> beyond >>>>>>> the huge sample + observer selection hypothesis. It would suggest that >>>>>>> the >>>>>>> universe was an example of something that had been selected or evolved, >>>>>>> with life central to that selection process. So, my idea might not lead >>>>>>> nowhere after all. It will take a long time to verify, but my hunch is >>>>>>> that >>>>>>> fine tunings of precisely the nature I've described (well, not the >>>>>>> specific >>>>>>> example) *will* be found. A sufficient number would ultimately >>>>>>> falsify the purely anthropic explanation of fine-tuning. >>>>>>> >>>>>> >>>>>> Hi Pierz, >>>>>> >>>>>> This is really interesting stuff. I also tend to think that evolution >>>>>> will turn out to be superseded by some more general theory, in the same >>>>>> fashion that happened to classical physics. It will remain viable in a >>>>>> narrow sense, but not the whole story. >>>>>> >>>>>> But to play devil's advocate, this sort of intuition seems to come >>>>>> from a sense of vastness of the universe and even greater vastness of a >>>>>> multiverse. Something I sometimes think about is that this sense might be >>>>>> misguided. It is true that there enormous distances and mind-blowing >>>>>> numbers of galaxies with mind-blowing numbers of stars, but what if we >>>>>> are >>>>>> taking the concepts of distance and repetition too seriously? What I mean >>>>>> is this: instead of looking at the universe spatially, what if we looked >>>>>> at >>>>>> it in terms of information content? >>>>>> >>>>>> Suppose we wanted to store the current state of the universe in some >>>>>> very powerful computer (that would, of course, have to exist in some >>>>>> other, >>>>>> larger universe, whatever that means -- this is just a thought >>>>>> experiment). >>>>>> We could apply a compression algorithm. There is not need to represent >>>>>> large amounts of empty space or repetition as a dense matrix. Instead we >>>>>> could do something similar to what is done to compress images or sound. >>>>>> In >>>>>> this compressed information space, I wonder how much the perceived >>>>>> "sized" >>>>>> of the earth in comparison to the rest of the universe would change. I >>>>>> suspect that, from this perspective, the earth is actually huge, because >>>>>> it >>>>>> is so complex. What if, looking at things through this lens, the earth >>>>>> turns out to be "most of what there is" in information space? Would this >>>>>> change your intuitions somehow? >>>>>> >>>>> >>>>> Interesting, but you may be running afoul of some fuzziness in the >>>>> notion of "information content". What you seem to be referring to is >>>>> complexity rather than information, which is typically equated with >>>>> entropy. >>>>> >>>> >>>> Ok, good point. I was thinking more about Kolmogorov complexity rather >>>> than entropy -- so my compression algorithm would be a generator program as >>>> opposed to something like run length encoding or Fourier transforms. >>>> >>>> >>>>> If you want to reproduce a system by storing information about it, >>>>> then a disordered system like the state of the rings of Saturn can >>>>> typically not be compressed at all, whereas an ordered system contains >>>>> regularities which allow it to be described by some simplifying rules >>>>> which >>>>> can be used to compress the information about the system. >>>>> >>>> >>>> I wonder if this picture changes if one considers the distributions of >>>> possible states of the rings of Saturn vs the distribution of all possible >>>> states of the Earth, within some range. >>>> >>>> >>>>> A jpg compression of a field of pure colour "noise" will be the same >>>>> size as the uncompressed file. But we need to be careful even here, >>>>> because >>>>> I have my doubts that reality can actually be compressed "losslessly" at >>>>> all. Even empty space is a froth of virtual particles which contribute to >>>>> the quantum state of the universe as a whole. You might be able to write >>>>> off huge tracts of the universe as "uninteresting" (for example you could >>>>> reduce it to x quadrillion cubic light years of emptiness) but the >>>>> universe >>>>> may beg to differ. >>>>> >>>> >>>> It is true that true randomness is not compressible, but it is also >>>> true that a program that describes how to generate one of the possible >>>> states of a cubic light years of emptiness according to their probability >>>> of occurrence is probably orders of magnitude smaller that the program >>>> needed to generate one of the possible states of the planet Earth in 2015. >>>> >>>> >>>>> >>>>> Anyway, ignoring these quibbles and accepting that the earth is, from >>>>> a "deep computation" point of view, vastly larger in a certain kind of >>>>> information space than much of the rest of the universe, I very much doubt >>>>> it is *unique *in this respect. Richard Dawkins has argued that it >>>>> might be (in "The Blind Watchmaker" IIRC?), but his argument is flawed. >>>>> Essentially he says that we don't know the probability of life arising on >>>>> a >>>>> given planet, but given that there are *n *planets in the universe, >>>>> then the probability might be as low as 1/*n*. If it *were* of order >>>>> 1/*n, *then it is likely there is only one, which would have to be >>>>> ours, because here we are! However, this begs the question. Given that >>>>> *n* is an extremely large number (about 10^24), then the *probability >>>>> of the probability* of life occurring on a given planet just >>>>> happening to be close to exactly 1/*n* is very, very small. >>>>> >>>> >>>> Humm... I think there are some problems with this argument. If you >>>> allow for any type of multiverse, then you don't know how many universes >>>> contain a planet like Earth, so it becomes impossible to estimate the >>>> probability. Say you know n, and you know for sure that we are in the only >>>> planet with life in the universe, but you don't know the number of >>>> universes with Earths, then p could be anything in ]0, 1/n]. In this case I >>>> don't think you can apply this sort of probability-of-probability >>>> reasoning. >>>> >>> >>> Actually you're just strengthening my argument. The Blind Watchmaker >>> came out a long time ago - before multiverses had much traction - so >>> Dawkins was proceeding from the assumption that the observable universe was >>> pretty much it. If the number of planets in existence is much larger than >>> the ~10^24 in the observable universe, then the claim that there is only >>> one with life becomes an even stronger one - and hence one requiring >>> equally strong supporting evidence. It's asserting that the probability >>> lies in an *extremely* narrow range. But we have no idea what the >>> probability is, so such an assertion is unjustified. If there were only ten >>> planets in the universe, then clearly the claim that ours is the only one >>> with life is a much weaker claim than if there were a googol of them! >>> Unless I don't understand your point? >>> >> >> My point is that, there could be a very large proportion of >> non-observable universes with zero instances of life. This would mean that >> the probability is so small that, given a universe with life, it is likely >> to be a single instance. But since we do not know the proportion of >> non-observable universes with zero instances of life, we cannot estimate >> the probability at all. >> >> Notice that I am not claiming this to be the case, just that it is a >> possible scenario. It is really hard to do statistical inference with just >> one data point :) >> > > Interesting - it does perhaps make a case for the possibility that earth > might be the only inhabited planet in the *observable* universe, if the > number of universes is very very large. But the larger the number of > universes, the larger the number of planets, and by the extension of my > logic above, the more inhabited planets there re likely to be in the > *multiverse. > *So really the multiverse just allows the space between inhabited places > to become larger, it does not suggest that earth is the only planet with > life anywhere, which is what Dawkins was arguing. It's also what you were > suggesting when you argued the earth might be "most of what there is" in > information (complexity) space. >
Good points, but notice that I am arguing for the impossibility of estimating the likelihood of any theory in the spectrum from "the Earth is the only place with life" to "the universe is teeming with life, separated by large distances and/or spread across universes". > > >> >> >>> >>> >>> >>>> >>>> >>>>> >>>>> Furthermore, cosmology now points to an extremely large and possibly >>>>> spatially infinite universe. In that context, the idea that this is the >>>>> only "island" is vanishingly small to non-existent. >>>>> >>>> >>>> I agree. >>>> >>>> >>>>> >>>>> When I was a kid I remember looking up at the stars and wondering if >>>>> we mightn't be a "germ in the left leg of God." In other words, what vast >>>>> structures of time, space and possibly mind might we be a part of without >>>>> our being aware of it? It's incredible that humanity has seen as far and >>>>> as >>>>> deeply as it has, but in the context of "infinity in all directions", we >>>>> should also be humble enough to recognise that we are still microscopic >>>>> germs and the farthest we can see may still be immensely limited. >>>>> >>>> >>>> Agreed. My intuition is that there are other advanced civilizations, >>>> but probably very far away in space and/or time. >>>> >>>> >>>> >>>>> >>>>>> Best, >>>>>> Telmo. >>>>>> >>>>>> >>>>>>> >>>>>>> >>>>>>>> >>>>>>>> Brent >>>>>>>> >>>>>>> -- >>>>>>> You received this message because you are subscribed to the Google >>>>>>> Groups "Everything List" group. >>>>>>> To unsubscribe from this group and stop receiving emails from it, >>>>>>> send an email to everything-li...@googlegroups.com. >>>>>>> To post to this group, send email to everyth...@googlegroups.com. >>>>>>> Visit this group at http://groups.google.com/group/everything-list. >>>>>>> For more options, visit https://groups.google.com/d/optout. >>>>>>> >>>>>> >>>>>> -- >>>>> You received this message because you are subscribed to the Google >>>>> Groups "Everything List" group. >>>>> To unsubscribe from this group and stop receiving emails from it, send >>>>> an email to everything-li...@googlegroups.com. >>>>> To post to this group, send email to everyth...@googlegroups.com. >>>>> Visit this group at http://groups.google.com/group/everything-list. >>>>> For more options, visit https://groups.google.com/d/optout. >>>>> >>>> >>>> -- >>> You received this message because you are subscribed to the Google >>> Groups "Everything List" group. >>> To unsubscribe from this group and stop receiving emails from it, send >>> an email to everything-li...@googlegroups.com. >>> To post to this group, send email to everyth...@googlegroups.com. >>> Visit this group at http://groups.google.com/group/everything-list. >>> For more options, visit https://groups.google.com/d/optout. >>> >> >> -- > You received this message because you are subscribed to the Google Groups > "Everything List" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to everything-list+unsubscr...@googlegroups.com. > To post to this group, send email to everything-list@googlegroups.com. > Visit this group at http://groups.google.com/group/everything-list. > For more options, visit https://groups.google.com/d/optout. > -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
