I have now added a hopefully suitable paragraph to the post.
In replying initially, I assumed that "indexical uncertainty" was a technical terms for a variable that plays the role of probability given that in fact "everything happens" in MW and therefore everything strictly has a probability of 1. However, now I have looked up "indexical uncertainty" and find that it means an observer's uncertainty as to which branch they are in (or more generally, uncertainty about one's position in relation to something even though one has certain knowledge of that something). That being so, I can't see how you can describe it as being in the territory.
Incidentally, I have now added an edit to the quantum section of the OP.
Great. Incidentally, that seems a much more intelligible use of "territory" and "map" than in the Sequence claim that a Boeing 747 belongs to the map and its constituent quarks to the territory.
Thanks, so to get back to the original question of how to describe the different effects of divergence and convergence in the context of MW, here's how it's seeming to me. (The terminology is probably in need of refinement).
Considering this in terms of the LW-preferred Many Worlds interpretation of quantum mechanics, exact "prediction" is possible in principle but the prediction is of the indexical uncertainty of an array of outcomes. (The indexical uncertainty governs the probability of a particular outcome if one is considered at random.) Wheth...
There are no discrete "worlds" and "branches" in quantum physics as such.
This seems to conflict with references to "many worlds" and "branch points" in other comments, or is the key word "discrete"? In other words, the states are a continuum with markedly varying density so that if you zoom out there is the appearance of branches? I could understand that expect for cases like Schroedinger's cat where there seems to be a pretty clear branch (at the point where the box is opened, i.e. from the point of vie...
Thanks, I think I understand that, though I would put it slightly differently, as follows...
I normally say that probability is not a fact about an event, but a fact about a model of an event, or about our knowledge of an event, because there needs to be an implied population, which depends on a model. When speaking of "situations like this" you are modelling the situation as belonging to a particular class of situations whereas in reality (unlike in models) every situation is unique. For example, I may decide the probability of rain tomorrow is ...
So, to get this clear (being well outside my comfort zone here), once a split into two branches has occurred, they no longer influence each other? The integration over all possibilities is something that happens in only one of the many worlds? (My recent understanding is based on "Everything that can happen does happen" by Cox & Forshaw).
even if in the specific situation the analogy is incorrect, because the source of randomness is not quantum, etc.
This seems a rather significant qualification. Why can't we say that the MW interpretation is something that can be applied to any process which we are not in a position to predict? Why is it only properly a description of quantum uncertainty? I suspect many people will answer in terms of the subjective/objective split, but that's tricky terrain.
you can consider the whole universe as a big quantum computer, and you're living in it
I recall hearing it argued somewhere that it's not so much "a computer" as "the universal computer" in the sense that it is impossible to principle for there to be another computer performing the calculations from the same initial conditions (and for example getting to a particular state sooner). I like that if it's true. The calculations can be performed, but only by existing.
the multiverse as a whole evolves deterministically
So to get back to ...
the truth-value of the claim, which is what we're discussing here
More precisely, it's what you're discussing. (Perhaps you mean I should be!) In the OP I discussed the implications of an infinitely divisible system for heuristic purposes without claiming such a system exists in our universe. Professionally, I use Newtonian mechanics to get the answers I need without believing Einstein was wrong. In other words, I believe true insights can be gained from imperfect accounts of the world (which is just as well, since we may well never have a perfect account). But that doesn't mean I deny the value of worrying away at the known imperfections.
Well, I didn't quite say "choose what is true". What truth means in this context is much debated and is another question. The present question is to understand what is and isn't predictable, and for this purpose I am suggesting that if the experimental outcomes are the same, I won't get the wrong answer by imagining CI to be true, however unparsimonious. If something depends on the whether an unstable nucleus decays earlier or later than its half life, I don't see how the inhabitants of the world where it has decayed early and triggered a tornado (so to speak) will benefit much by being confident of the existence of a world where it decayed late. Or isn't that the point?
I agree, I had thought of mentioning this but it's tricky. As I understand it, living in one of Many Worlds feels exactly like living in a single "Copenhagen Interpretation" world, and the argument is really over which is "simpler" and generally Occam-friendly - do you accept an incredibly large number of extra worlds, or an incredibly large number of reasons why those other worlds don't exist and ours does? So if both interpretations give rise to the same experience, I think I'm at liberty to adopt the Vicar of Bray strategy and align ...
Yes, that looks like a good summary of my conclusions, provided it is understood that "subsystems" in this context can be of a much larger scale than the subsystems within them which diverge. (Rivers converge while eddies diverge).
Perhaps "hedging" is another term that also needs expanding here. One can reasonably assume that Penrose's analysis has some definite flaws in it, given the number of probable flaws identified, while still suspecting (for the reasons you've explained) that it contains insights that may one day contribute to sounder analysis. Perhaps the main implication of your argument is that we need to keep arguments in our mind in more categories then just a spectrum from "strong" to "weak". Some apparently weak arguments may be worth periodic re-examination, whereas many probably aren't.
"having different descriptions at different levels" is itself something you say that belongs in the realm of Talking About Maps, not the realm of Talking About Territory
Why do we distinguish “map” and “territory”? Because they correspond to “beliefs” and “reality”, and we have learnt elsewhere in the Sequences that
my beliefs determine my experimental predictions, but only reality gets to determine my experimental results.
Let’s apply that test. It isn’t only predictions that apply at different levels, so do the results. We can have right or...
I'm not clear what you are meaning by "spatial slice". That sounds like all of space at a particular moment in time. In speaking of a space-time region I am speaking of a small amount of space (e.g. that occupied by one file on a hard drive) at a particular moment in time.
..absent collapse..
Ah, is that so.
But a 4D descriptions of all the changes involved in the copy-and-delete process would be sufficient..
Yes, I can see that that's one way of looking at it.
In fact, your problem would be false positives
I don't think so, since the information I would be comparing in this case (the "file contents") would be just a reduction of the information in two regions of space-time.
Reducing to "physical properties" is not necessarily the same as to "the physical properties of the ingredients". I would have thought physicalists think mental properties can be reduced to physical properties, but reductionists identify these with the physical properties of the ingredients. I suppose one way of looking at it is that when you say "in principle" the principles you refer to are physical principles, whereas when emergentists see obstacles as present "in principle" when certain kinds of complexity are p...
"As a theory of mind (which it is not always), emergentism differs from idealism, eliminative materialism, identity theories, neutral monism, panpsychism, and substance dualism, whilst being closely associated with property dualism. " (WP)
As a theory exclusively of the mind, I can see that emergentism has implications like property dualism, but not as a theory that treats the brain just as a very complex system with similar issues to other complex systems.
OK, not strictly "conserved", except that I understand quantum mechanics requires that the information in the universe must be conserved. But what I meant is that if you download a file to a different medium and then delete the original, the information is still the same although the descriptions at quark level are utterly different. Thus there is a sense in which a quark level description of reality fails to capture an important fact about it (the identity of the two files in information terms).
I don't think this has anything to do with dualism...
"Emergentism" can only be applied to gearboxes if the irreducibility clause is dropped. The high-level behaviour of a mechanism is always reducible to its the behaviour of its parts.
My point is that depends if by "behaviour" you mean "the characteristics of a single solution" or "the characteristics of solution space". In the latter case the meaning of "reduction" doesn't seem unambiguous to me.
The practical debate I have in mind is whether multibody dynamics can answer practical questions about the be...
The problem is when people use the label "emergence" as a semantic stop sign
Agreed, which is why I was trying to replace it by a "proceed with caution" sign with some specific directions.
One lives & learns - thanks.
The boundary between physical causality and logical or mathematical implication doesn’t always seem to be clearcut. Take two examples.
(1) The product of two and an integer is an even integer. So if I double an integer I will find that the result is even. The first statement is clearly a timeless mathematical implication. But by recasting the equation as a procedure I introduce both an implied separation in time between action and outcome, and an implied physical embodiment that could be subject to error or interruption. Thus the truth of the second formula...
Yes indeed, it is a challenge to understand how the same human moral functionality "F" can result in a very different value system "M" to ones own, though I suspect a lot of historical reading would be necessary to fully understand the Nazi's construction of the social world - "S", in my shorthand. A contemporary example of the same challenge is the cultures that practice female genital mutilation. You don't have to agree with a construction of the world to begin to see how it results in the avowed values that emerge from it,...
Maybe it's just that EY is very persuasive! I'm reminded of what was said about some other polymath (Arthur Koestler I think) that the critics were agreed that he was right on almost everything - except, of course, for the topic that the critic concerned was expert in, where he was completely wrong!
So my problem is, whether to just read the sequences, or to skim through all the responses as well. The latter takes an awful lot longer, but from what I've seen so far there's often a response from some expert in the field concerned that, at the least, puts the post into a whole different perspective.
Confidence in moral judgments is never a sound criterion for them being "terminal", it seems to me.
To see why, consider that ones working values are unavoidably a function of two related things: one's picture of oneself, and of the social world. Thus, confident judgments are likely to reflect confidence in relevant parts of these pictures, rather than the shape of the function. To take your example, your adverse judgement of authority could have been a reflection of a confident picture of your ideal self as not being submissive, and of human soc...
I'm still puzzled, as you seem to be both defending and contradicting EY's view that:
the reductionist thesis is that we use multi-level models for computational reasons, but physical reality has only a single level. (Italics added).
I'm not actually attacking this view so much as regarding it as a particular convention or definition of reality rather than a "thesis".
Perhaps you are reading "best characterized as" as "best modelled as"? I'm not saying that, just that this is the sense of "reality" that EY/the wiki writer prefers to adopt.
Re my claim:
"well, of course Bryan's mental model of his pain doesn't exist in reality by definition"
On reflection I suspect the disagreement here is that I am doubting that Bryan could consciously deny this, and you & EY & others are suspecting that he is unconsciously denying it. Well, that's a theory. I have added an edit to my post recognizing this. This seems to boil down to the LW-wiki "definition" not really defining what reductionists believe, but rather defining why they believe certain criticisms of reductionism ar...
Re Hands vs. Fingers. What worries me about this is the lack of any attention to the different contexts/purposes of different statements about hands & fingers. I have added a comment to the original post to amplify this.
...much later... The thing that puzzles me about this post is that no attention is paid to context.
I had an operation last year to my right index finger. It was carried out by a hand surgeon. I used those terms because it was rather important which finger was operated on, and because the medical specialism relates to any part of the hand indifferently.
A trivial example, of course, but it illustrates the point, which applies also to much more complex issues, that the appropriate choice of "model level" (or other meta-model feature) to best repr...
Many different things can be deduced from this story, as previous comments have illustrated. The step that I question is "carries no information" = "magic". I prefer Karl Popper's account, in which [to paraphrase "Conjectures & Refutations" Chapter 1] "carries no predictive information" = "metaphysical" but "metaphysical" does not mean "unscientific". Rather, science involves two activities, hypothesis creation and hypothesis testing. It is the hypothesis testing that has to be exclu...
Thanks again.
it seems cleaner to consider that a fact about computer science, not meteorology.
I'd call it a fact about any system whose trajectories diverge at a smaller scale and converge at a larger scale (roughly), but that's a radical view that needs a new discussion some time.
I think I can see a useful way of taking the reductionism question further, but will do more reading first...
Well, if the definition said that "reductionists disagree that 2 & 2 make 5" I wouldn't disagree with that either. What worries me is the apparent refusal to engage with the rational critics of reductionism. But I am mainly thinking of critics in fields other than physics - politics "there is no such thing as society", Skinner's psychology, "there are no thoughts, only stimuli and responses", not to mention developmental biology, weather forecasting & even mechanical engineering analysis, none of which actually get nea...
;) ... but that's still only matter and information, just that we're now just information....
Sorry no time for a full answer, but roughly, yes, in a sense I do think that many of these disagreements turn out to be linguistic if you dig far enough. But if they are causal, the definition needs to compare two intelligible models of causality, not define one in a self-contradictory way. My reply to buybuydandavis may also help clarify.
That computer programming is easier with the dualist model than the monist model?
Yes, and anything else that requires an intelligible account of what is going on. You start with a monist model and then you have to de...
I find it hard to square that with the Sequence item referred to, but then you imply you also found it confused. So, what do you use the word to mean?
So my objections aren't aimed at you!
I wasn't intending to unless that's what the Wiki definition characterizes it as, because I simply tried to re-express that definition without using the terms map and territory in ways that their definitions exclude.
I think perhaps I can see the problem. My phrase "for the purposes of causal explanation" is ambiguous. I wasn't meaning "as a way of explaining any particular behaviour" but rather "as a way of establishing the root causes underlying any behaviour". Does that make it more acceptable/less "greedy"?
Anoth...
I agree that's a good distinction, though direct explanation of a higher level obviously works in some cases (e.g. the weight of the brain is a simple aggregate of the weight of the constituent atoms).
"Can be explained in terms of.." seems a much less biased way of framing the definition to me than the one in the wiki. I'll add it to my list of starting points for discussion!
The answer is in the rest of the sentence that you truncated! I imagine a dualist would say that there is something out there in the territory which you consider to be a manifestation of a model higher level, but they don't. That isn't the same.
I don't find the monist/dualist distinction helpful. Computers have hardware and information: that's a dualist model, and it has served very well as a model. At any given instant, the information is a state of the hardware, which requires a monist model, but it's information that is downloaded etc. So is information...
Sorry, I don't understand. Are you saying that you don't agree with my definition of reductionism (which was intended as a point of agreement, not a straw man at all)? I agree that an opinion about the likelihood that the standard model will continue to serve is a separate question.
An "emergentist" would probably define their view in the same way. The question is, simpler for what purposes?
Thanks! (Both of you)
In the same way that it's a very good exercise when having a rational debate to start by each side paraphrasing the view they oppose in a manner that is acceptable to holders of that view, otherwise the chances are you haven't understood what is being said. Is "a dialogue of the deaf" really what you want?
The one useful purpose for discussion of "meanings" is to draw attention to distinctions between different usages that may get overlooked. The "epistemic" vs "instrumental" is one such distinction in this case.
I suggest there is a third useful sense, which sort of links epistemic rationality and instrumental rationality.
The example in the sequence post takes consistent Bayesian probability with Occam priors as an example of rational modelling of the world. But in what sense is it rational to believe that the world is an ord...
This is just a test because a previous comment vanished on submission....
By my understanding, rule consequentialism means choosing rules according to the utility of the expected consequences, whereas deontology argues for a duty to follow a rule for reasons which may have nothing to do with the consequences. Kant's "treat another person as an end in him/herself, not as a means to an end" doesn't mention consequences and the argument for it isn't based on assessment of consequences. Admittedly both sorts of rule may lead to the same outcome in most cases, but in totally unprecedented moral dilemmas it helps to have an ...
To reverse your last point, Sam Harris (The Moral Landscape) defends RC on the grounds that only that which is experienced can be morally significant. While agreeing, I would reply that the motivation of acts is experienced, as well as the consequences. EG: Should you vote if you live in a safe seat? You could argue that the rule "vote anyway" has beneficial consequences, but then, so does the rule "vote, except in safe seats". RC doesn't actually invent the rules, it only tells you how to evaluate them once invented! However, I would v...
OK, thanks, I see no problems with that.