James Higgo OK, Vic - but if you went further and explained WHY the macro world is made
up of all these black boxes then you would be even more persuasive (Answer,
of course, is Weak Anthropic Principle).
Vic Stenger I talk about that in The Unconscious Quantum. Life evolved in the classical domain because of its greater predictability, but on the edge of the quantum domain to take advantage of the randomness in certain places, like in problem-solving with out neural networks which need a random element to innovate.
John H. Mazetier I am still digesting the black box answer. I think I get the gist of it. But in the above, when you refer to the relationship between neural networks and the quantum domain, you seem to imply that quantum domain generated randomness is necessary for neural network innovation. Are there not enough other stochastic processes, ones not directly related to the quantum variety, to do the job? You are sending me back to the library to re-read tUQ.
Vic Stenger I am not talking about anything fancy, like Penrose microtubules. Just things like K40 beta decay in the blood or cosmic ray muons. The QM comes in as the ultimate source of "true" randomness, as opposed to the pseudorandomness you get with computers that ultimately is algorithmic and so does not satisfy Penrose's claim that thinking is non-algorthmic.
Vic Stenger Suppose humanity never evolved. There still will be supernovas that spew out particles in all directions and we need to explain why, greatly separated in space and not in contact, at least for ten billion years or so, this always happens in the same time direction. That is, we do not have some spewing out and some where the same particles converge to make a nice stable star, carbon turning back to hydrogen and deuterium, and so on. Or, why there are (apparently) black holes and no white holes (maybe the gamma bursters are white holes, now that I think of it). As Huw Price makes it clear (I'm reading his whole book a second time, and working on my chapter on time's arrow), this is an unexplained puzzle--why the universe has this highly improbable state at one extreme of the time axis and not the other, thus setting a universal arrow of time for macroscopic (but not microscopic) systems.
James Higgo: Like so many other paradoxes, the question Vic asks about supernovas having an arrow of time is shown to be meaningless when you adopt Deutsch's view that time is an aspect of the relationship between 'snapshots' (individual 3-d universes) in the 'multiverse'. Tme's arrow points forwards, backwards, everywhichwayyou like in the multiverse - it just depends on how you want to look at it. Supernovas would 'exist' without us, but only if someone chose to string snapshots together so they saw supernovas. It's an infinite multiverse, but unless someone is looking along some axis, it is meaningless to say this or that exist. Everything possible exists. e ourselves only exist in some of the tiny fibres of inter- universe connections along which time's arrow happens to point forwards, along which 'cause' precedes 'effect'. Because, although the multiverse is infinite, we could only exist in this sort of stable environment, where lots of things don't 'decay' at once. Decay is not the phenomenon; that any two particles appear to be related is the rarity. But in an infinite multiverse... It is pointless to talk about 'supernovas' *per se* - they are merely a function of the way we string universes together. But there are very few such strings that would result in 'environments' in which life would evolve; of those, most if not all involve supernovas.
Vic Stenger This explanation borders on solipsim. It explains everything by explaining nothing. We see no white holes or imploding supernovae in our universe. Sure this could be because this is just a statisical fluctuation. The average universe has half of each and we are way out on the tail of the distribution.This is very unsatisfying. Just giving up. "Everything is possible." You are welcome to do that. I would prefer to keep trying to see if there is some non-random reason for what we see in our universe. I do not think the WAP, as you use it with your fibers above, is enough.
James Higgo Vic, you may say that recourse to the WAP (weak anthropic principle) is 'giving up'. But in the context of MWI it explains everything, such as the absence of vacuum collapses and all sorts of nasties. It is also the basis for the wacky quantum theory of immortality, which is another reason for you to be prejudiced against it. You seem to be denying the validity of WAP, which makes intuitive sense, as piously as most people deny time's arrow can point both ways. It isn't as 'satisfactory' as a nice experimental 'proof' but what if this is as good as it gets? Perhaps the universe was not designed for satisfaction.
Vic Stenger: I have not said or implied that the WAP does not play a role. It's trivially obvious that it does. In my article on the Anthropic Coincidences I talk about how the WAP was used by Fred Hoyle to make a prediction of a previously unknown resonance in the carbon nucleus. But I would have only one line to write and nothing interesting, novel, or useful to say if my metaphysics was an infinity of universes of which we are in the one that, necessarily, had the conditions needed to produce us.
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James Higgo No we are not compelled to believe that; however we can probably say with some confidence that we would not inhabit realms where water burns. WAP. Ed writes: "The problem is that you cannot simply dismiss such logic as somehow erroneous or invalid, because it is the same logic by which modern science proceeds." But again we get back to the idea of levels. At our everyday level, x is a very good working assumption. Why must we believe x (eg classical physics) is some fundamental property of nature? But I agree that you Vic will be unable to take an objective viewpoint; everything is subjective. Any physics only describes the physics of our own environment.
John H. Mazetier, Jr. Wait a minute James, could you clarify what you mean by "everything is subjective"? Taken at face value the equivalence just renames "everything," which tells us nothing new since the same regularities obtain. Taken to mean "all data is processed through our experience" the statement still does not tell us very much: it can be read as trivially true, i.e. representational systems represent; or it can be read as proposing the claim, all representations are suspect because such systems are subject to error. The latter assertion, while hueristically true, should not be elevated to the level of a principle, on pain of self contradition, to say the least.
James Higgo Despite Vic's efforts I still favour MWI, so I think anything possible exists. So what you choose to see of this infinite and all-containing multiverse is up to you. Everything is in there, us and our environment included, but it is meaningless to say that we exist without reference to an observer looking at this small part of the multiverse. That's what I mean when I say everything is subjective.