Fine-Tuning?

[peter]

I suspected the 'optimism' chapter would hit the spot for you Z as it has been a feature of many of your posts [often in the face of mine and others 'doom and gloom' approach]. Deutsch has the ability to make one feel that to be optimistic is ones 'responsibility' - and he's right, it is!

I'm nearly through the multiverse chapter and can say with some confidence that I haven't got a clue as to what he was talking about. I got the 'fungibility of money' idea, but from then on was lost. Power surges and romances that may or may not ehd in disaster - what [rhetorical question] does it all mean?

[:idea: I know - I'll go read the chapter summary and then re-read it with that under my belt. Perhaps that will help.]

[Zarathustra]

Are you rereading, or is this where you stopped the first time?

[peter]

No Z. - This is my second reading. The chapters are [somewhat] self contained in respect of their 'demand for understanding', so I find I can progress even when the finer detail of a given area has eluded me.

The chapter summary of the Multiverse was much easier to grasp than the detail of the chapter itself, to the point where I have 'taken it as read' and [after finishing the chapter] carried on reading. [In fact the short vignette at the start of the following chapter where Deutsch and the Reader engage in a brief Q & A session was illuminating in itself]. Deutsch is [as the following chapter will show] nothing short of self-confident!

[Zarathustra]

I've backed up 10 pages, as I considered doing yesterday, and I'm finding it much easier to understand. I think part of the problem is that he's over-explaining, so that he resumes points that he left dangling several pages back. The main problem (so far) is how to derive a difference between identical/fungible universes that follow deterministic laws. Going back to the analogy to money really helps understand this ... e.g. the fact that dollars in an account can be differentiated by owner if, say, you must allocate a portion of them for a tax. They're all conceptual--even physically--identical, and yet they can acquire real world differentiation.

But I'm reading slowly, still not quite half way through it. That's all I have so far.

[Hashi Lebwohl]

Deutsch is [as the following chapter will show] nothing short of self-confident!

This isn't surprising, given that he thinks he has all the answers or, at the very least, wants the reader to think that he has all the answers. It is easy to toss about conjectures which are neither provable nor non-falsifiable and sound like a genius, especially when you cloak in in sciencespeak.

[Zarathustra]

Have you read the book, Hashi? That's a pretty harsh criticism.

I think Deutsch would reply that no conjecture is certain, though the good ones are all testable, which means they're certainly falsifiable. However, something being falsifiable doesn't necessarily mean it's scientific. I can predict that Jesus will come back tomorrow, and that prediction can easily be falsified, but it's still not scientific.

Instead, he places the focus upon explanation, as opposed to instrumentalism, i.e. the belief that "science can do no more than predict the outcome of observations, and should never purport to describe the reality that brings those outcomes about." (p.15) Instead, he focuses on realism (the physical world exists in reality, and knowledge of it can be achieved).

Which conjectures are you talking about?

Here's something that blew my mind: do you know why an electron doesn't collapse into a proton, in a flash of radiation? One is positively charged while the other is negative. They attract each other. What keeps them apart? You can't invoke nuclear forces, because they only act on the range of the nucleas, and the electron is much, much farther out (besides, they do other things). Nor can you invoke angular momentum, like the planets use to resist gravity while in motion, because the electron is "spread out" in an "electron cloud."

I thought I'd always understood the atom. I didn't understand this. Without Googling, can you explain it, Hashi? If not, you might want to consider his ideas, as wild as they are.

The multiverse chapter is blowing my mind. I'm almost done with it. I had no idea that quantum computers had anything to do with it.

[peter]

It's probably a trivial thing, but I'm having trouble applying Deutsch's analogy of the 'fungibility of money' to the 'fungibility of the paralell universes of the multiverse'. [I'm trying to get my head around exactly what a fungible universe is; ie where it sits in the 'hierarchy of identicalness'.]

Is there not a fundamental difference in that money is 'conceptual' where the paralell universes of the multiverse are [in Deutsch's mind] actualised by really existing? Deutsch uses the example of me borrowing a dollar from you and you paying me back [or something similar]. That I don't give you back the same actual note is neither here nor there - the dollar is fungible [ie it exists in a completely indentical sisterhood with all other extant dollars] of which the actual note is a mere representation. ie All instances of 'the dollar' are the same dollar. If I borrow your racehorse [he observes] it doesn't do for me to return it's indentical twin to you - they are not fungible in the way dollars are.

Now he applies the 'money' level of fungibility to paralell universes of the multiverse - but I can't [mentally] get their level to go above the level of identicalness which has been actualised by existance, which I would have to do in order to raise them to the same level of identicalness of the fungibility of the dollar. It seems to me that existance forever denies universes this conceptual level of fungibility?

It's probably not signifficant but if possible I like to be clear on these things.

[Zarathustra]

It's certainly significant, and I'm trying to wrap my head around it, too. Identical twins aren't fungible because they're not the same person (or horse), for instance they can have different histories. But apparently fungible universes can have different histories, too.

I think it's probably only something that can be understood on an abstract level, which is why it's appropriate to compare it to money. As Deutsch says, imagination balks, but reason does not.

But I feel my reason balking, too ...

[Vraith]

It's certainly significant, and I'm trying to wrap my head around it, too. Identical twins aren't fungible because they're not the same person (or horse), for instance they can have different histories. But apparently fungible universes can have different histories, too.

I think it's probably only something that can be understood on an abstract level, which is why it's appropriate to compare it to money. As Deutsch says, imagination balks, but reason does not.

But I feel my reason balking, too ...

Heh...I'm starting to get the feeling you, at least in some ways so far, like this guy as much as Kaku and Penrose.

I really need to get this book [which I probably could do right now, if there's a kindle version] and time to give it a good thinking read [which can't be done now, and likely not soon].

OTOH, much as I like the balking quote for what it is, look at some really good Dali work [among others, but Dali is instantly available]...or even Escher [since I'm pretty sure you and lots of folk here are fans of G/E/B.]
Your reason will balk all to hell...but your imagination will jump in naked and love it.

[peter]

Here's another place where I feel I'm not getting it. Deutsch makes it clear in a number of places that the paralell universes of the putative explanation of 'fine-tuning' [ie that an infinite number of universes exist that do not have the universal constants set at the level where astrophysicists could exist, and we happen to be (by chance) in one of the ones where they are] are not the same paralell universes as those of the multiverse of quantum mechanics. What is the difference between them?

I have one of those plasma-balls in my front room. When I turn it on I get all those meandering threads of plasma radiating out from the central sphere to the spherical glass shell of the exterior and when I put my hand to it, the threads all gather toward my hand. Take any one of those fifty or so plasma 'lightening' threads and say it moves [apparently] randomly from point A on the globes surface to point B. I assume that in the world of 'paralell universes' every single possible path between A and B that the thread could have taken will have been taken. [That in the simple act of turning on my plasma ball I am responsible for the 'creation' of an infinite number of new variations of the universe that are all extant is a concept that makes my head hurt all on it's own but...] The question is what kind of paralell universes are these - quantum ones or the ones of the 'fine-tuning' type?

[I am now into the final chapter of the book which on it's own throws out some real 'curlers', but not wanting to 'spoiler' what is coming for Z. I'll leave those for the minute. Suffice to say that much of what Deutsch has to say goes against conventional reason, but hey, this is quantum physics - how could it be otherwise . In this chapter though there is one area where his reasoning is so counterintuitive that I can't get my head around it and I'll be very interested as to what you guys make of it when the time comes.]

[Vraith]

Deutsch makes it clear in a number of places that the paralell universes of the putative explanation of 'fine-tuning' [ie that an infinite number of universes exist that do not have the universal constants set at the level where astrophysicists could exist, and we happen to be (by chance) in one of the ones where they are] are not the same paralell universes as those of the multiverse of quantum mechanics. What is the difference between them?

Hee...that I can address without having the book, I think. [[the author and his thoughts are mentioned at most of the places that talk about these things]]
Last I knew, the multiple universe possibilities that arise directly from quantum mechanics implications have the same fundamentals. They will always be "the same", even if in different states [somewhat like H20 is always H20, though it can be solid, liquid, or gas.]

Or, maybe better: quantum-born multiples are like clones. They are always identical genetically...even though the process of living makes them different people.

Fine-tuning here is about places with different constants, of course.
quantum generates the multiples, in some sense, as a result of solving the equations. D's talking about places where the equations...hell the definitions of the terms IN the equation...are different.

Heh if both quantum and what D. is suggesting somehow applied [and seems likely to me it should]...it occurs to me I've just implied [probably not the first person who ever pondered this to do so] another infinite multiplication.
Cuz, universes with different constants could [maybe should/must...at least some of them] have their own flavor of quantum...therefore THAT universe would ALSO have infinite quantum/clone parallels.

[Zarathustra]

Vraith, Deutsch isn't talking about universes with different constants. QM doesn't produce this. How could it? QM is a description of our laws of physics.

What Deutsch is talking about when he refers to the multiverse is an interpretation of things like Heisenberg's Uncertainty Principle and Schrodinger's equation, an interpretation which doesn't rely upon ambiguity or ignoring what happens prior to measurement--which is what the Copenhagen interpretation does: it shuts down criticism by denying the possibility of explaining or even addressing what's happening between measurements.

For instance, Schrodinger would say that his equation describes a probability wave which gives the values of probability for finding a particle in a specific location if one makes a measurment, while also claiming that it is meaningless to ask where it was prior to that measurment. But Deutsch is saying that the equation describes reality (not probability), and that all these other possible locations for a particle are actually occupied in a parallel universe, and that measurement just distinguishes one history (or one universe with a specific history) from the others in the multiverse.

So all the universes in this sense have the same constants, and the same laws, but the "fuzziness" which QM theorizes is an actual thing for Deutsch, and not merely a probability. One way he points out the irrationality of the Copenhagen interpretation is the difficulty in theorizing a probability that could affect an actuality. How could something that is merely probable affect anything actual? Wouldn't it then be an actuality itself? Deutsch thinks the answer is a resounding (and infinite) YES! The paths that a quantum object takes in other universes can affect the actual path that it takes in ours, for instance, when its fungible-but-different instances recombine ("interfere") with each other, as for instance in a quantum computer.

This is entirely different from imagining other universes with different constants, because those aren't described by quantum theory. What Deutsch is talking about doesn't violate a single law of physics, as we know it. In fact, it's required by the laws of physics, and explains the results of experiments we've already conducted. In fact, it's the *best* explanation, because the other interpretations depend upon ignoring the problem, or bad philosophy.

Peter, does that answer your question Vraith quoted above?

have one of those plasma-balls in my front room. When I turn it on I get all those meandering threads of plasma radiating out from the central sphere to the spherical glass shell of the exterior and when I put my hand to it, the threads all gather toward my hand. Take any one of those fifty or so plasma 'lightening' threads and say it moves [apparently] randomly from point A on the globes surface to point B. I assume that in the world of 'paralell universes' every single possible path between A and B that the thread could have taken will have been taken. [That in the simple act of turning on my plasma ball I am responsible for the 'creation' of an infinite number of new variations of the universe that are all extant is a concept that makes my head hurt all on it's own but...] The question is what kind of paralell universes are these - quantum ones or the ones of the 'fine-tuning' type?

I think your head would hurt less if you don't think of personally creating infinite universes with your actions. Instead, think of the multiverse as already existing, and it's described by Schrodinger's equation, which can be interpreted as describing a multidimensional object which instantiates every possible value in that equation, one of which are the values which you encounter in your particular history. But you are a multidimensional object, too, so that other "dimensions" of yourself experience different values for things like position and velocity, etc.

[Vraith]

You may be correct, Z. I'm drawing on conversations about the book and issue as a whole [some of which had D's participation] AND on how I interpreted peter's question.
There's been discussion on whether the wave-function is just a concept we use to stand in/symbolize/calculate with peter before...and I think I linked somewhere recent work that has provided evidence that it really is a real thing. D is on that side...and that side is gaining evidence.

Nevertheless, from what I've seen, he is sometimes talking about one, sometimes the other, and that is why he takes pains to mention when he isn't.

Just for fun, though...here's an excerpt from an interview with D, related. Pretty old, but y'all should read it...not cuz you'll get some new understanding, but cuz a number of his answers are witty/funny/zinger-as-hell...it's also short, won't take much time.
www.newscientist.com/article/dn10691-re ... ?full=true

[Hashi Lebwohl]

Have you read the book, Hashi? That's a pretty harsh criticism.

No, I have not. I am basing that only on the snippets which have been presented thus far. True, that make my criticism baseless and probably inaccurate, which is why I am planning to get this book and read it for myself.

Here's something that blew my mind: do you know why an electron doesn't collapse into a proton, in a flash of radiation? One is positively charged while the other is negative. They attract each other. What keeps them apart? You can't invoke nuclear forces, because they only act on the range of the nucleas, and the electron is much, much farther out (besides, they do other things). Nor can you invoke angular momentum, like the planets use to resist gravity while in motion, because the electron is "spread out" in an "electron cloud."

I thought I'd always understood the atom. I didn't understand this. Without Googling, can you explain it, Hashi? If not, you might want to consider his ideas, as wild as they are.

For a minute, let us revert to slightly older thinking of an atom, which is like a sphere with the nucleus at the center and the electron(s) on the surface of the sphere. Yes, the positive and negative charges attract each other but the entire surface of the sphere is a negative charge and thus the sphere repels itself. Strangely, this is another way of saying that the electrons repel themselves enough to keep them from falling into the nucleus.

This doesn't take into account the fact that protons and neutrons in the nucleus aren't actually protons and neutrons; rather, there are a bunch of neutrons with some pi muons flying around. proton <--> pi muon(+) + neutron (the equation goes both directions) so at any instant if an electron sees a proton the next instant the proton might be a neutron and the electron is no longer attracted to it.

Of course, these "particles" aren't particles but waves--closely compressed waves in the nucleus, which is almost unthinkably small--and I have to admit that I am, at this time, uncertain how the waves could resist the electromagnetic attraction but maybe how we experience electromagnetism doesn't exist at the quantum level, where other forces are more prevalent.

[Zarathustra]

That's a pretty good conjecture, but (according to Deutsch) it's not electrostatic repulsion of the electron with itself due to being spread out. Deutsch doesn't think that particles actually have a particle/wave duality, and that the reason such duality doesn't make sense is precisely because it's irrational and contradictory to have incompatible properties at the same time.

The "spread" or "shell" property of electrons isn't due to its wavelike nature, but instead due to being an irreducibly multiversal object.

Here's how he says it:

... a collection of fungible instances of a particle in general have several speeds--meaning that in general they will do different things an instant later. ("Diversity within fungibility.")

...

Not only can a fungible collection with the same position have different speeds, a fungible group with the same speed can have different positions. Furthermore, it follows from the laws of quantum physics that, for any fungible collection of instances of a physical object, some of their attributes must be diverse. This is known as the 'Heisenberg uncertainty principle' ...

Hence, for instance, an individual electron always has a range of different locations and a range of different speeds and directions of motion. As a result, its typical behavior is to spread out gradually in space. Its quantum-mechanical law of motion resembles the law governing the spread of an ink blot--so if it is initially located in a very small region it spreads out rapidly, and the larger it gets the more slowly it spreads. The entanglement information that it carries ensures that no two instances of it can ever contribute to the same history.... If a particle’s range of speeds is centered not on zero but on some other value, then the whole of the ‘ink blot’ moves, with its center obeying approximately the laws of motion in classical physics. In quantum physics this is how motion, in general, works.

…

Now, put a proton into the middle of that gradually spreading cloud of instances of a single electron. The proton has a positive charge, which attracts the negatively charged electron. As a result, the cloud stops spreading when its size is such that its tendency to spread outwards due ot its uncertainty-principle diversity is exactly balanced by its attraction to the proton. The resulting structure is called an atom of hydrogen.

Historically, this explanation of what atoms are was one of the first triumphs of quantum theory, for atoms could not exist at all according to classical physics. …

… it turns out that, in the hydrogen atom, the electron in its lowest-energy state is not orbiting at all, but just sitting there like an ink blot—its uncertainty-principle tendency to spread exactly balanced by the electrostatic force. In this way, the phenomena of interference and diversity within fungibility are intergral to the structure and stability of all static objects, including all solid bodies, just as they are integral to all motion.

The term ‘uncertainty principle’ is misleading. … When an electron has more than one speed or more than one position, that has nothing to do with anyone being uncertain what the speed is, any more than anyone is ‘uncertain’ which dollar in their bank account belongs to the tax authority. The diversity of attributes in both cases is a physical fact, independent of what anyone knows or feels.

…

Thanks to the strong internal interference that it is continuously undergoing, a typical elecron is an irreducibly multiversal object, and not a collection of parallel-universe or parallel-histories objects. That is to say, it has multiple positions and multiple speeds without being divisible into autonomous sub-entities each of which has one speed and one position. Even different electrons do not have completely separate identities. So the reality is an electron field throughout the whole of space, and disturbances spread through this field as waves, at the speed of light or below. This is what gave rise to the often-quoted misconception among pioneers of quantum theory that electrons (and likewise all other particles) are ‘particles and waves at the same time’. There is a field (or ‘waves’) in the multiverse for every individual particle that we observe in a particular universe.

So an electron is actually a field, but this is so because it is continuously possessing different attributes that continuously interfere. This intereference phenomenon happens to other particles, too, but for them it's a collection of fungible parallel-universe objects which acquire a divesrity and then that diversity disappears once they interfere again. So it's like two histories splitting and then recombining. This is only possible in cases where there is no entanglement (with other objects), for as the "sphere of differentiation" widens between two histories, the less likely they'll rejoin ("interfere"). But an electron is small enough that this sphere is self-contained, thus it continuously rejoins with itself. It's almost like it's "vibrating" in parallel universes continuously, through a range of position/speed values that constitute the size and shape of the electron "cloud."

So that's the 'force' that is making it spread out, which is perfectly balanced by the proton's electromagnetic force pulling it in.

[Hashi Lebwohl]

I could have sworn that we already knew that about electrons, that they take on all possible combinations of velocities and and locations at the same time, thus making them non-localized entities. He appears to be taking this thinking to the next level, though, by non-localizing all electrons, even ones which are physically separate, even though "distance" might not mean anything in some dimension we cannot perceive or try to observe.

I have gotten lazy and complacent in the last couple of years and I am starting to fall behind. I really need to get back into some books and move towards the cutting edge before I get left behind completely.

[peter]

In relation to the question I posed above - yes, I think I get it. Deutsch I think referred to what V. did above in the following quote

Let me remind the reader that these highly speculative paralell universes have nothing to do with the universes or histories in the quantum multiverse, for whose existence there is overwhelming evidence. Strictly speaking the standard anthropic explanations postulate infinitely many quantum universes. {my italics}.

And yes - I was forgetting, in the quantum multiverse the universal constants would not be varied in the way postulated by the anthropic explanation. [At least I don't think they would ].

But heres another one. What does he mean by this?

What is the difference between a computer simulation of a person (which must be a person, because of universality) and a recording of that simulation (which cannot be a person).

[nb Deutsch's parentheses and italics]
What is this universality that has the power to demand that a simulation of a person is a person. I know it came up in the 'multiverse' chapter but I don't think I got it there and I certainly don't here. Can anyone explain the concept?

[Hashi Lebwohl]

That almost sounds a lot like the map from On Exactitude in Science, where a map is created that is so detailed that it is the same size as the country it maps. As the country changes the map gets updated and then, ultimately, when the country fails all that is left is the map..but some of the citizens are living on/in the map now, not the country.

I highly doubt, though, that a simulation of a person could be a person. That being said, a sufficiently advanced AI--one that can pass the Turing Test more often than not (wasn't there recently a breakthrough where a program passed the Turing Test in a majority of trials? I'll have to double-check that)--could be considered a person for all intents and purposes, especially if it can come up with new ideas on its own or, the true pinnacle of AI, create never-before-seen works of art which humans may appreciate, whether visual or musical.
Along similar lines of thought, suppose we get to the point where my mind can be uploaded into a computer and executed like a program. Would that computer be me?

[Vraith]

I could have sworn that we already knew that about electrons, that they take on all possible combinations of velocities and and locations at the same time, thus making them non-localized entities. He appears to be taking this thinking to the next level, though, by non-localizing all electrons, even ones which are physically separate, even though "distance" might not mean anything in some dimension we cannot perceive or try to observe.

I have gotten lazy and complacent in the last couple of years and I am starting to fall behind. I really need to get back into some books and move towards the cutting edge before I get left behind completely.

I'll have to look around and make sure I linked them. There's been a lot of activity around wave-function and non-locality. All of it being on the side of realness.

[peter]

[quote="Hashi Lebwohlwhich is why I am planning to get this book and read it for myself.[/quote]

Now this makes me happy! How much do I want to see you guys pitting yourselves against the ideas contained in this book [and I mean this in a positive way]. Hashi - if you can think of a way of me sending you my copy which I have now completed, that does not overstep the bounds of 'safe practice' re the internet, then it's yours with pleasure.