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All of Quantumental's Comments + Replies

Living in the shadow of superintelligence
Quantumental20

I find it highly unlikely that a superintelligence would care to create a medieval simulation with tons of suffering

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Privileging the Hypothesis
Quantumental00

EHeller: what if the decision-theoretic approach by Wallace et al. turns out to work? Would you consider MWI "heavily" favoured then?

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Open Thread, January 16-31, 2013
Quantumental00

Because most determinists aren't everettians? Quite simple

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2pragmatist
No, look at the stats again. There are fewer determinists than there are Everettians. That's what I found puzzling. Some of the Everettians in that poll evidently believe in fundamental or irreducible quantum randomness, which suggests they don't really know what Everettianism is.
The ongoing transformation of quantum field theory
Quantumental00

So it's enough to establish a quasi-classical preferred basis, but you still have the Born Rule problem? But one is solved ?

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If MWI is correct, should we expect to experience Quantum Torment?
Quantumental-20

I'm not sure how I am going to cite that, there has never been conducted a gigantic poll on this matter, but the fact that the leading "experts" in the field who are the only ones doing work on Everett says that it's less than 10% (Deutsch's new book Beginning of infinity) should be revealing enough.

As for branching and divergence, Alastair Wilson and Simon Saunders disagrees: http://alastairwilson.org/

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2Luke_A_Somers
Ah! But here's the rub. Consider a physicist who thinks Everett - or anyone who published after, for that matter - nailed it. Is this person going to publish anything on that subject? No. They're going to go off and work on some other physics topic. The experts are generally those who think there's something wrong with what's out there so far! In my little corner of condensed matter, it looks a whole lot more popular than that. In two consecutive groups I've had occasion to say something like, "Well, think of what a 'measurement' IS - your detector, and then you, became entangled with what you were measuring" and not generated the slightest controversy. If you're looking at QM that way, then anything beyond Everett is either a substantive physical prediction or making things more complicated than they need to be. In live conversations on the actual subject, the only objections I've heard from physicists were on theological grounds and general unease (one each). I got a whole lot more objections from philosophers than physicists, and they practically taunted me over it. As for Alastair Wilson - well, he can go and disagree, but the fact remains, QM is a field theory, so you can flip freely back and forth between branching and divergence views of it.
1Luke_A_Somers
Cite, please. It's a field. There's no meaningful distinction here.
Open Thread, August 16-31, 2012
Quantumental30

Dude you are looking at numbers through some 9/11 Truther eyes, you definitely got a long way to go if you plan on travelling the world "working towards life extension". It's great that you are donating money to these funds, but please don't use your story as a "The SAI might be God" thingy. It will only make people look at transhumanism as a religion (like plenty already do).

Congratulations

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Scott Aaronson's cautious optimism for the MWI
Quantumental00

You say there are objective facts, yet you claim it depends on ones perspective...this is contradictory. Have you read any of Wilson's papers? Or Saunders, Lawhead, Ismael etc.? All have written papers clearly indicating the OBJECTIVE difference.

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0Manfred
What I am saying is that there are objective facts, but that a wavefunction being two components or one simply happens not to be one of those facts. It's like "is this painting beautiful?" If you look closely enough at one person and make some idealizations, you can say objectively (well, plus idealizations) whether a painting is beautiful for that person, but what is thus beautiful for one person still doesn't have to be beautiful for the next. On the other hand, if you, say, explained Peano arithmetic to two different people and asked them whether some statement was a theorem or not (and made some idealizations), what is a theorem for one person is a theorem for the next. Or if you asked them to measure the space-time interval between two events. Or if you asked them about the various components of a wavefunction, given a certain basis.
Scott Aaronson's cautious optimism for the MWI
Quantumental00

So you see no objective facts about mwi? non-overlap vs overlap is nonsense in your opinion?

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0Manfred
Yes, there are objective facts. Whether a waveunction is made of 2 components or 1 is still not independent of your perspective. No, it's not necessarily nonsense. I am just claiming that the unsolved problems of stuff like "overlap" are not due to a lack of information about quantum mechanics, but due to a lack of information about very complicated things humans do. If it the difficulty of understanding how humans categorize things and revise categories gets attributed to basic quantum mechanics, then we may get some nonsense.
Scott Aaronson's cautious optimism for the MWI
Quantumental00

Sure I can accept that I might have overestimated how well you should've been able to interpret my post.

Solipsism vs Realism is indeed a metaphor. If you are saying what I think you are saying, then it is quite equivalent.

I do not think that your example of a diagonal line is the same as overlap vs non-overlap at all. In overlap vs non-overlap the ontological differences matter. In a overlapping world, if you are shot, you are guaranteed to survive in another branch, so QI has to be true. In non-overlap, if you get shot, you just die. There is no consciou... (read more)

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0Manfred
Ah, I see. "Metaphysics." By which you mean "taking human morality and decision-making, which evolved in a classical world, and figuring out what decisions you should make in a quantum universe." Would you agree that overlap vs. non-overlap cannot be answered without looking inside humans, and in fact has little to do with the universe apart from a few postulates of quantum mechanics? For some reason I thought we were talking about the universe. Anyhow, I think Shane Legg had a nice paper on porting utility functions, though of course humans are inconsistent and you immediately run into problems of how to idealize them. The basic idea being that you split up changes into "new things to care about" and "new ways to express old things." Quantum suicide is probably the easiest thing to deal with via this method.
Scott Aaronson's cautious optimism for the MWI
Quantumental00

I understand what you are saying, which I think my last post showed quite clearly, but this still does not answer the actual question at hand. What you are saying really amounts to saying that "realism and solipsism are the same", because we cannot really distinguish either through science, all we can do is use logic and metaphysical "reasoning".

Obviously both overlap and non-overlap cannot be true, they are ontologically different, yet you seem to say that "because the equations doesn't decide, reality isn't decided" which is... (read more)

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0Manfred
Maybe you're just used to talking with people who are better at interpreting you, or people who are more similar to you. Clearly understandable to people you talk with every day isn't always clearly understandable to me, as we've seen. Could you explain this? Is this a metaphor, or are have you interpreted my statements about vectors to actually bear on realism vs. solipsism? Perhaps we have been talking about two different things. Ah. See, this is the sort of thing I was trying to illustrate with the example of the diagonal line. A line being made of one component is ontologically different from a line being made of two components. Does this matter? What happens if a one-componenter runs into a two-componenter? Do they argue? Does the first say "because of [insert convincing component-ist argument here], it's ONE component!" Are there valid component-ist arguments? How can the two-componenter respond? I think it would go more like this: the first one says "hey, if you describe lines in terms of plus and minus diagonals, this one is clearly just a plus diagonal, so why say it has two components?" And the second says "Oh, huh, you're right. But there are lots of horizontal and vertical lines out there, so two-components is more useful." And the first says "yeah, that makes sense, unless you were building a ramp or something." "Well then, cheerio." "Toodles." The reason this was so anticlimactic is because each participant could frame their ontology in a universal language (vectors!), and the ontologies were lossless transformations of each other - in this case the transformation was as simple as tilting your head. This clarity of the situation leaves no room for appeals to componentism. Arguments are for when both people are uncertain. When people know what's going on, there's simply a difference. Could you point me to an example? Similar to how we are potentially talking about two different things, Alastair Wilson seemed to be talking about something other tha
Scott Aaronson's cautious optimism for the MWI
Quantumental30

To be perfectly honest, I do not see an answer to my question here.

You do explain some, but it seems that you end up indirectly stating that it is "semantics" whether the worlds overlap or not overlap. From what you say here it all depends on how you look at it, but that there is no "truth" of the matter. But that cannot be, either the worlds are overlapping or they are not. That is just the very fact of objective reality.

So while "both pictures are valid" in terms of math, not both can be the same. Metaphysically they are not... (read more)

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1Manfred
What I am saying is that if one person says "all the worlds have always existed" and another says "the worlds spread out from one world," it's possible that both of them are being consistent, but then they are using two different definitions of "world." I am also saying that there is no basis that is "more real" than the others - only that some are more useful, and it's okay that people use different definitions as long as they're clear about it. And yes, both pictures can describe the same thing. Have you worked with Bell states at all? Or am I misinterpreting your name and you actually haven't taken a class on quantum mechanics before? The quantum world is like a diagonal line. One person comes up to it and says "Ah! Here is a diagonal line! It has just as much horizontal as it does vertical, therefore it is a mixture between horizontal and vertical." Another person comes up to it and says "Ah! Here is a diagonal line! It is a perfect rising diagonal, and is not even a little biased towards the falling diagonal." Will these two people argue over whether the line is made of two components or one?
Scott Aaronson's cautious optimism for the MWI
Quantumental30

Although they do not "split off" in the same envisioned early on by DeWitt, there is definitely some unanswered questions here. Alastair Wilson and Simon Saunders has raised this issue. Are all the worlds in the wavefunction from the beginning of time or do they somehow spring out from one world? This is called overlap vs non-overlap (first discussed by David Lewis).

Since you are the expert, by all means answer this for us.

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0Manfred
So, by "world" in this post I'll mean "basis sate for the universe." The basis is arbitrary, so what "world" means will still depend on how I'm choosing what "worlds" are - there's the energy basis, for instance, where nothing ever changes if you look at just one of those "worlds." But you can have animals or computers in your basis states if you want - they aren't energy eigenstates, so they change with time. Anyhow, currently the universe is spread out over a very wide variety of energy eigenstates, which is a fancy way of saying that lots of stuff changes. If we only allow quantum mechanics (that is, strictly follow MWI), this spread over "energy-worlds" is how the universe has been since the beginning of time. But if we look at the exact same state a different way, you could just call the initial state of the universe a basis state, and then, lo and behold, the universe would have sprung from one world, and the distribution of worlds then changed over time. This way of looking at things is probably pretty useful for cosmology. Or you could use worlds that change over time but don't include the original state of the universe, giving you overlap again. This is what we do unintentionally when we choose worlds that have humans in them, which is also pretty useful :) For overlap vs. non-overlap to get more complicated than "both are valid pictures," you'd need some model where there weren't any static worlds to talk about - this would be a change to QM though. Also, this does raise the interesting question of how complicated that initial world (if we look at it that way) was. It doesn't have to be too complicated before we see interesting stuff. Anyhow, it's pretty likely I was too hasty in my mistake-detection. But meh, I rarely regret putting off reading things. And I only occasionally regret putting my foot in my mouth :)
Scott Aaronson's cautious optimism for the MWI
Quantumental50

But obviously reality is not about non-relativistic quantum mechanics. So whenever a discussion about interpretations is brought up, I think it is dishonest to argue FOR a partial version of it that really has nothing to do with reality

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3pragmatist
Fair enough. Unfortunately, the interpretive options for QFT are still not clearly worked out. I think the idea among quantum foundations people tends to be that we first figure out the best interpretation in the relatively simpler domain of NRQM, then think about how to adapt this interpretation to meet any new challenges from QFT. This is no doubt partly due to the fact that the formal structure of NRQM is much better systematized and understood. We basically have a satisfactory axiomatization of NRQM, but attempted axiomatizations of QFT still have many lacunae. So there's definitely a "looking for your keys under the streetlight even though you dropped them in the dark" thing going on here.
2Thomas
By all means! The Relativity complicates this MWI. We have different splits for different observers, since everything is not simultaneous for everyone. Now what, if the future velocity of an observer is a result of a quantum experiment's outcome. What's very often, if not always! MWI, the non-relativistic version is NOT real, anyway.
Scott Aaronson's cautious optimism for the MWI
Quantumental00

I was quite certain that Wallace et al (Oxfordians) dismissed pure WF realism in favour of state space realism when attempting to make it relativistic?

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0pragmatist
I'm assuming this whole conversation is about non-relativistic quantum mechanics.
Cult impressions of Less Wrong/Singularity Institute
Quantumental60

I just can't ignore this. If you take a minute to actually look at the talk section of that wikipedia page you will see those polls being thorn to pieces.

David Deutsch himself has stated that less than 10% of the people doing quantum fundamentals believe in MWI and then within that minority there are a lot of diverging views. So this is still not by any means a "majority interpretation".

As Mitchell_Porter has pointed out Gell-Mann certainly do not believe in MWI. Nor do Steven Weinberg, he denounced his 'faith' in it in a paper last year. Feynma... (read more)

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3Peterdjones
Good question.
Cult impressions of Less Wrong/Singularity Institute
Quantumental30

I still wonder why you haven't written a update in 4 years regarding this topic. Especially in regards to the Born Rule probability not having a solution yet + the other problems.

You also have the issue of overlap vs non-overlapping of worlds, which again is a relevant issue in the Many Worlds interpretation. Overlap = the typical 1 world branching into 2 worlds. Non-overlap = 2 identical worlds diverging (Saunders 2010, Wilson 2005-present)

Also I feel like the QM sequence is a bit incomplete when you do not give any thought to things like Gerard 't Hoofts... (read more)

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Should I believe what the SIAI claims?
Quantumental-20

His monologue on color, for instance.

Well, you didn't link to his view of qualia, but to a link where he explains why MWI is not the "winner" or "preferred" as EY claimed so confidently in his series on QM. You might disagree with him on his stance on qualia ( I do too ) but it would be a logical fallacy to state that therefore all his other opinions are also incoherent.

Mitchell Porter's view on qualia is not non-sense either, it is highly controversial and speculative, no doubt. But his motivation is sound, he think that it is the o... (read more)

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1[anonymous]
Maybe I should have said "reading him in general..." The rest is quibbling over definitions.
Should I believe what the SIAI claims?
Quantumental00

But MWI doesn't get the right calculation in terms of probability

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1Oscar_Cunningham
Good point. I'd say that it doesn't have any calculation of the probability. But some people hope that the probabilities can be derived from just MW. If they achieve this then it would be the simplest theory. But if they need extra hypotheses then it will gain complexity, and may well come out worse than Bohm.
Should I believe what the SIAI claims?
Quantumental-20

Lack of coherence? where? It's true that Bohm requires non-local HV's, but there is a non-local flavor to MWI too. The states are still non-local. Local HV's do exist. Gerard 't Hooft is working on this as we speak: http://arxiv.org/find/all/1/all:+AND+hooft+AND+gerard+t/0/1/0/all/0/1

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0[anonymous]
His monologue on color, for instance. This assumption is made by every other interpretation of quantum mechanics I know. On the other hand, I'm not a physicist; I'm clearly not up to date on things. I meant the classical HV theories that were ruled out by actual experiments detecting violations of Bell's inequality.
Open Thread: November 2009
Quantumental00

Well the one I watched had like 15 guys in it, 9 pro-MWI. Indicating that this talk definitely attracted more MWI'ers than what is regular

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Open Thread: November 2009
Quantumental00

I pointed you towards the evidence. One of the guys in the talksection did a survey of his own of 30 or so leading physicists.

But just the fact that David Deutsch himself says less than 10% believe in any kind of MWI speaks volumes. He has been in the community where these matters are discussed for decades

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Stupid Questions Open Thread Round 3
Quantumental00

Aha, I see. So you do not share EY's view that MWI is "correct" then and the only problem it faces is recovering the Born Rule? I agree that obviously what will end up working will depend on what the foundations are :) I remember that paper by Buosso and Susskind, I even remember sending a mail to Susskind about it, while at the same time asking him about his opinion of 't Hoofts work. If I remember correctly the paper was discussed at some length over at physicsforums.com (can't remember the post) and it seemed that the consensus was that the au... (read more)

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Open Thread: November 2009
Quantumental00

No. If you even just go to the discussion page you will see that the reception part is one of the most erronous and most objected to in that wiki article. The entire article in itself is a disaster and most Many Worldian proponents does not endorse it at all.

You have to understand that there are literally THOUSANDS of physicists who hold a opinion on the matter, a few polls conducted by proponents do no matter at all. Do you really think that a talk held by Max Tegmark will not attract people who share his views?

If someone where to do a global poll, you would see...

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2Shmi
Actually, this is not true. Having been in academia for some time, I can vouch that a celebrity talk like that would attract many faculty members regardless of their views on the matter.
-1Jack
You're making an assertion with zero evidence...
Open Thread: November 2009
Quantumental-20

Well.... It does not have a broad support among physicists for being a VERY plausible. A tiny fraction consider it very plausible. The vast majority consider it very unlikely and downright wrong due to it's many problems.

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5Jack
You're overstating the extent of the opposition.
Stupid Questions Open Thread Round 3
Quantumental00

This is a very good post, but I wonder: One of the authors in the paper you cite is David Wallace, perhaps the most prominent proponent of modern Everettian interpretation. He just published a new book called "The Emergent Multiverse" and he claims there is no problem unifying MWI with QFT because interactions within worlds are local and only states are nonlocal. I have yet to hear him mention any need for serious reformulation of anything in terms of MWI.

You said you suspect this is necessary, but that you hope we can recover a similar MWI, but ... (read more)

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0pragmatist
When I talk about recovering MWI, I really just mean absorbing the lesson that our theory does not need to deliver determinate measurement results, and ad hoc tools for satisfying this constraint (such as collapse or hidden variables) are otiose. Of course, the foundations of our eventual theory of quantum gravity might be different enough from those of quantum theory that the interpretational options don't translate. How different the foundations will be depends on which program ends up working out, I suspect. If something like canonical quantum gravity or loop quantum gravity turns out to be the way to go, then I think a lot of the conceptual work done in interpreting NRQM and QFT will carry over. If string theory turns out to be on the right track, then maybe a more radical interpretational revision will be required. The foundations of string theory are now thought to lie in M-theory, and the nature of this theory is still pretty conceptually opaque. It's worth noting though that Bousso and Susskind have actually suggested that string theory provides a solid foundation for MWI, and that the worlds in the string theory landscape are the same thing as the worlds in MWI. See here for more on this. The paper has been on my "to read" list for a while, but I haven't gotten around to it yet. I'm skeptical but interested. I know of 't Hooft's cellular automata stuff, but I don't know much about it. Speaking from a position of admitted ignorance, I'm skeptical. I suspect the only way to construct a genuinely deterministic local realist theory that reproduces quantum statistics is to embrace superdeterminism in some form, i.e. to place constraints on the boundary conditions of the universe that make the statistics work out by hand. This move doesn't seem like good physics practice to me. Do you know if 't Hooft's strategy relies on some similar move?