If physics is many-worlds, does ethics matter?

post by ioannes_shade · 2019-07-10T15:32:56.085Z · score: 14 (9 votes) · LW · GW · 42 comments

This is a question post.

Contents

  Answers
    26 AlexMennen
    13 orthonormal
    10 Donald Hobson
    10 G Gordon Worley III
    9 Dan Fitch
    4 Closed Limelike Curves
    3 Dagon
    1 strangepoop
    -2 LadyMacbeth
None
6 comments

Cross-posted on the EA Forum.

Sorta related, but not the same thing: Problems and Solutions in Infinite Ethics


I don't know a lot about physics, but there appears to be a live debate in the field about how to interpret quantum phenomena.

There's the Copenhagen view, under which wave functions collapse into a determined state, and the many-worlds view, under which wave functions split off into different "worlds" as time moves forward. I'm pretty sure I'm missing important nuance here; this explainer (a) does a better job explaining the difference.

(Wikipedia tells me there are other interpretations apart from Copenhagen and many-worlds – e.g. De Broglie–Bohm theory – but from what I can tell the active debate is between many-worlders and Cophenhagenists.)

Eliezer Yudkowsky is in the many-worlds camp [LW · GW]. My guess is that many folks in the EA & rationality communities also hold a many-worlds view, though I haven't seen data on that.

An interesting (troubling?) implication of many-worlds is that there are many very-similar versions of me. For every decision I've made, there's a version where the other choice was made.

And importantly, these alternate versions are just as real as me. (I find this a bit mind-bending to think about; I again refer to this explainer (a) which does a better job than I can.)

If this is true, it seems hard to ground altruistic actions in a non-selfish foundation. Everything that could happen is happening, somewhere. I might desire to exist in the corner of the multiverse where good things are happening, but that's a self-interested motivation. There are still other corners, where the other possibilities are playing out.

Eliezer engages with this a bit at the end of his quantum sequence [LW · GW]:

Are there horrible worlds out there, which are utterly beyond your ability to affect? Sure. And horrible things happened during the twelfth century, which are also beyond your ability to affect. But the twelfth century is not your responsibility, because it has, as the quaint phrase goes, “already happened.” I would suggest that you consider every world that is not in your future to be part of the “generalized past.”
Live in your own world. Before you knew about quantum physics, you would not have been tempted to try living in a world that did not seem to exist. Your decisions should add up to this same normality: you shouldn’t try to live in a quantum world you can’t communicate with.

I find this a little deflating, and incongruous with his intense call-to-actions to save the world [LW · GW]. Sure, we can work to save the world, but under many-worlds, we're really just working to save our corner of it.

Has anyone arrived at a more satisfying reconciliation of this? Maybe the thing to do here is bite the bullet of grounding one's ethics in self-interested desire.

Answers

answer by AlexMennen · 2019-07-10T17:37:58.100Z · score: 26 (15 votes) · LW · GW

"Controlling which Everett branch you end up in" is the wrong way to think about decisions, even if many-worlds is true. Brains don't appear to rely much on quantum randomness, so if you make a certain decision, that probably means that the overwhelming majority of identical copies of you make the same decision. You aren't controlling which copy you are; you're controlling what all of the copies do. And even if quantum randomness does end of mattering in decisions, so that a non-trivial proportion of copies of you make different decisions from each other, then you would still presumably want a high proportion of them to make good decisions; you can do your part to bring that about by making good decisions yourself.

comment by sirjackholland · 2019-07-10T20:34:38.748Z · score: 6 (5 votes) · LW · GW

Going along with this, our world doesn't appear to be the result of each individual making "random" choices in this way. If every good decision was accompanied by an alternate world with the corresponding bad decision, you'd expect to see people do very unexpected things all the time. e.g., this model predicts that each time I stop at a red light, there is some alternate me that just blows right through it. Why aren't there way more car crashes if this is how it works?

comment by TAG · 2019-07-12T10:16:07.998Z · score: 3 (4 votes) · LW · GW

Worlds can differ in measure, although no one is quite sure what that means.

answer by orthonormal · 2019-07-11T02:29:10.515Z · score: 13 (8 votes) · LW · GW

Eliezer's real answer to this question is discussed in Timeless Control. Basically, choice is still meaningful in many-worlds or any other physically deterministic universe. There are incredibly few Everett branches starting from here where tomorrow I go burn down an orphanage, and this is genuinely caused by the fact that I robustly do not want to do that sort of thing.

If you have altruistic motivation, then the Everett branches starting from here are in fact better (in expectation) than the branches starting from a similar universe with a version of you that has no altruistic motivation. By working to do good, you are in a meaningful sense causing the multiverse to contain a higher proportion of good worlds than it otherwise would.

It really does all add up to normality, even if it feels counterintuitive.

comment by TAG · 2019-07-11T13:36:02.335Z · score: 3 (3 votes) · LW · GW

If you have altruistic motivation, then the Everett branches starting from here are in fact better (in expectation) than the branches starting from a similar universe with a version of you that has no altruistic motivation.

Yes.

By working to do good, you are in a meaningful sense causing the multiverse to contain a higher proportion of good worlds than it otherwise would.

No.

You are conflating two different kinds of counterfactual. In the first sentence, counterfactual multiverses that contain a less well intentioned version of you have worse outcomes. But that is an extra-physical kind of counterfactual, it's like imagining differentt laws of physics.

So it is not something you can choose or affect within a multiverse. Within a multiverse, counterfactuals are Everett branches that you are not in, and there is nothing the "you" that is embedded in a multiverse can do to affect them. Everything proceeds deterministically, including how well intentioned you are, including how much work you do, including how you change and evolve. So there is no "than it otherwise would" in a real sense, only in a conceptual sense

comment by Sinclair Chen (sinclair-chen) · 2019-07-23T01:02:46.377Z · score: 2 (2 votes) · LW · GW

You cause the world to be better when you donate to a good charity in the same sense that you cause your hair to be wet when you take a shower.

comment by TAG · 2019-07-23T09:49:42.262Z · score: 1 (1 votes) · LW · GW

Or (3) the sky causes my rain to be wet when it rains.

Where does moral agency come in, if anywhere? Does the universe make things worse if a bunch of people die of a plague? Is the universe a moral agent? Is anything in it?

The question is about ethics. Saying there is still causality in MWI doesn't answer it, because it doesn't explain whether ethics deflates to causality or causality inflates to ethics.

answer by Donald Hobson · 2019-07-10T19:22:54.008Z · score: 10 (5 votes) · LW · GW

If every time you made a choice, the universe split into a version where you did each thing, then there is no sense in which you chose a particular thing from the outside. From this perspective, we should expect human actions in a typical "universe" to look totally random. (There are many more ways to thrash randomly than to behave normally) This would make human minds basically quantum random number generators. I see substantial evidence that human actions are not totally random. The hypothesis that when a human makes a choice, the universe splits and every possible choice is made with equal measure is coherent, falsifiable and clearly wrong.

A simulation of a human mind running on reliable digital hardware would always make a single choice, not splitting the universe at all. They would still have the feeling of making a choice.

To the extent that you are optimizing, not outputting random noise, you aren't creating multiple universes. It all adds up to normality.

While you are working on a theory of quantum ethics, it is better to use your classical ethics than a half baked attempt at quantum ethics. This is much the same as with predictions.

Fully complete quantum theory is more accurate than any classical theory, although you might want to use the classical theory for computational reasons. However, if you miss a minus sign or a particle, you can get nonsensical results, like everything traveling at light speed.

A complete quantum ethics will be better than any classical ethics (almost identical in everyday circumstances) , but one little mistake and you get nonsense.

comment by TAG · 2019-07-11T14:25:13.165Z · score: 1 (3 votes) · LW · GW

The hypothesis that when a human makes a choice, the universe splits and every possible choice is made with equal measure is coherent, falsifiable and clearly wrong

Maybe, but MWI doesn't imply equal measure.

They would still have the feeling of making a choice

We don't know that because we don't know anything about qualia.

To the extent that you are optimizing, not outputting random noise, you aren’t creating multiple universes. It all adds up to normality

There is not always a single optimal solution to a problem even for a perfect rationalist, and humans aren't perfect rationalists.

A complete quantum ethics will be better than any classical ethics (almost identical in everyday circumstances) , but one little mistake and you get nonsense.

What do you think quantum ethics would look like?

comment by Donald Hobson (donald-hobson) · 2019-07-13T14:00:10.063Z · score: 1 (1 votes) · LW · GW

I know MWI doesn't imply equal measure, I was taking equal measure as an aditional hypothesis within the MWI framework.

We don't know that because we don't know anything about qualia.

Consider a sufficiently detailed simulation of a human mind, say full Quantum, except whenever there are multiple blobs of amplitude sufficiently detached from each other, one is picked pseudorandomly and the rest are deleted. Because it is a sufficiently detailed simulation of a human mind, it will say the same things a human would, for much the same reasons. Applying the generalized anti zombie principle says that it would have the feeling of making a choice.

There is not always a single optimal solution to a problem even for a perfect rationalist, and humans aren't perfect rationalists.

My point is that when we show optimization pressure, that isn't just a fluke, then there is no branch in which we do something totally stupid. There might be branches where we make a different reasonable decision.

I expect quantum ethics to have a utility function that is some measure of what computations are being done, and the quantum amplitude that they are done with.

comment by TAG · 2019-07-22T17:18:52.334Z · score: 1 (1 votes) · LW · GW

Applying the generalized anti zombie principle says that it would have the feeling of making a choice.

The GAZP still isn't any kind of knowledge or understanding. A functional duplicate of an entity that reports having such-and-such a quale will report having it even if doesn't. So you can't infer anything unambiguous from a report of a quale.

There might be branches where we make a different reasonable decision.

There will be branches where we commit crimes if it is not impossible.

I expect quantum ethics to have a utility function that is some measure of what computations are being done, and the quantum amplitude that they are done with.

The sticking point is the motion of making a difference.

comment by dxu · 2019-07-22T18:14:46.664Z · score: 2 (1 votes) · LW · GW

A functional duplicate of an entity that reports having such-and-such a quale will report having it even if doesn't.

In that case, there's no reason to think anyone has qualia. The fact that lots of people say they have qualia, doesn't actually mean anything, because they'd say so either way; therefore, those people's statements do not constitute valid evidence [LW · GW] in favor of the existence of qualia. And if people's statements don't constitute evidence for qualia, then the sum total of evidence for qualia's existence is... nothing: there is zero evidence that qualia exist.

So your interpretation is self-defeating: there is no longer a need to explain qualia, because there's no reason to suppose that they exist in the first place. Why try and explain something that doesn't exist?

On the other hand, it remains an empirical fact that people do actually talk about having "conscious experiences". This talk has nothing to do with "qualia" as you've defined the term, but that doesn't mean it's not worth investigating in its own right, as a scientific question: "What is the physical cause of people's vocal cords emitting the sounds corresponding to the sentence 'I'm conscious of my experience'?" What the generalized anti-zombie principle says is that the answer to this question, will in fact explain qualia--not the concept that you described or that David Chalmers endorses (which, again, we have literally zero reason to think exists), but the intuitive concept that led philosophers to coin the term "qualia" in the first place.

answer by G Gordon Worley III · 2019-07-10T17:56:46.083Z · score: 10 (4 votes) · LW · GW

Cross-posting my answer from EAF.

So assuming the Copenhagen interpretation is wrong and something like MWI or zero-world or something else is right, it's likely the case that there are multiple, disconnected casual histories. This is true to a lesser extent even in classical physics due to the expansion of the universe and the gradual shrinking of Hubble volumes (light cones), so even a die-hard Cophenhagenist should consider what we might call generally acausal ethics.

My response is generally something like this, keeping in mind my ethical perspective is probably best described as virtue ethics with something like negative preference utilitarianism applied on top:

  • Causal histories I am not causally linked with still matter for a few reasons:
    • My compassion can extend beyond causality in the same way it can extend beyond my city, country, ethnicity, species, and planet (moral circle expansion).
    • I am unsure what I will be causally linked with in the future (veil of ignorance).
    • Agents in other causal histories can extend compassion for me in kind if I do it for them (acausal trade).
  • Given that other causal histories matter, I can:
    • act to make other causal histories better in those cases where I am currently causally connected but later won't be (e.g. MWI worlds that will split causally later from the one I will find myself in that share a common history prior to the split),
    • engage in acausal trade to create in the causal history I find myself in more of what is wanted in other causal histories when the tradeoffs are nil or small knowing that my causal history will receive the same in exchange,
    • otherwise generally act to increase the measure (or if the universe is finite, count) of causal histories that are "good" ("good" could mean something like "want to live in" or "enjoy" or something else that is a bit beyond the scope of this analysis).
answer by Dan Fitch · 2019-07-10T15:53:10.934Z · score: 9 (6 votes) · LW · GW

Either way you fall on the physics, there's no reason that the many-worlds hypothesis forces EVERY choice to be taken in an even distribution. Given a choice A or B, there is probability distribution between them. If A is the more ethical choice, you should still try to strive towards A, so that more of you in all the possible worlds also strive towards A.

If anything, if you think many-worlds could be true, it makes ethics that much more important to think about. You are carving out the corner, and making it expand outward into possibility space.

comment by TAG · 2019-07-11T14:27:09.341Z · score: 2 (2 votes) · LW · GW

If A is the more ethical choice, you should still try to strive towards A, so that more of you in all the possible worlds also strive towards A.

MWI is deterministic, so how much striving you do or do not do is determined.

comment by Aleksi Liimatainen (aleksi-liimatainen) · 2019-07-11T16:09:46.466Z · score: 12 (5 votes) · LW · GW
MWI is deterministic, so how much striving you do or do not do is determined.

Deterministic or not, you are the process by which it is determined, and conversations like these are inputs for the process. This adds up to normality: you'll keep on determining whether you believe in the intuitive notion of free will or not.

comment by TAG · 2019-07-12T09:09:08.994Z · score: 1 (1 votes) · LW · GW

It's clear that choices and efforts can be part of a causal chain that brings about an outcome, even in a deterministic universe. It's also clear that you cannot choose one outcome over another, or to strive more than you were determined to, in a deterministic universe. Because of the latter, it is hard to cash out the meaning of "you should strive to be good". What does it mean to say that you should strive to be good if you have no choice?

comment by Aleksi Liimatainen (aleksi-liimatainen) · 2019-07-12T11:32:27.316Z · score: 1 (1 votes) · LW · GW

Category error. "Meaning" is not a thing in the deterministic frame. It's cause and effect all the way down. If you want to think in terms of deterministic physics, you have to think entirely in terms of deterministic physics.

Try grokking timeless physics [LW · GW] if you haven't yet. Visualizing yourself as a four-dimensional atemporal structure should help clarify the intuitions.

comment by mr-hire · 2019-07-12T14:17:29.760Z · score: 2 (1 votes) · LW · GW

Subjective experiences are objects in an objective frame yes? Just because we can explain what caused an internal experience of meaning does it mean that experience doesn't exist.

comment by TAG · 2019-07-13T07:08:17.418Z · score: 1 (1 votes) · LW · GW

Subjective experiences are objects in an objective frame yes?

We don't know.

comment by mr-hire · 2019-07-13T14:49:10.713Z · score: 2 (1 votes) · LW · GW

Fair, but I think it's the best likely explanation. Do you?

comment by TAG · 2019-07-14T11:24:24.178Z · score: 1 (1 votes) · LW · GW

It's not an explanation unless we know how it's true.

comment by Aleksi Liimatainen (aleksi-liimatainen) · 2019-07-12T17:26:49.987Z · score: 1 (1 votes) · LW · GW

Yeah, subjective experiences are real. Point is, there's no term for them or any of our other mentalistic concepts in physics. You can redefine them to fit but it seemed to me that TAG was trying to apply the intuitive notion of meaning in the context of physical determinism. Hence, leaning further into the frame in order to propagate the update. Once you get the mind as a physical thing, it adds up to normality again.

Related: Thou Art Physics [LW · GW].

comment by TAG · 2019-07-13T07:09:27.742Z · score: 1 (1 votes) · LW · GW

Yeah, subjective experiences are real.

It's rather question begging to equate the real and the objective.

Point is, there’s no term for them or any of our other mentalistic concepts in physics

There's no term for shopping centres in physics. You need to look at whether there is a way of reducing something, not whether there is a term for it.

You can redefine them to fit but it seemed to me that TAG was trying to apply the intuitive notion of meaning in the context of physical determinism.

I was trying to apply the intuitive meanings of choice and making a difference to determinism.

Hence, leaning further into the frame in order to propagate the update.

I have no idea what that means.

Once you get the mind as a physical thing, it adds up to normality again.

We don't know how the mind is physical, so you are advising people to adopt a sort of faith.

Is physicalism a falsifiable claim? What would evidence against it look like?

comment by Aleksi Liimatainen (aleksi-liimatainen) · 2019-07-13T12:02:08.449Z · score: 1 (1 votes) · LW · GW

I get the feeling that we've been talking past each other. I took you as mixing levels in a confused way but you may have been trying to address what you took as someone else's confusion.

I broadly agree with your last two comments and feel like you've somewhat misunderstood what I was trying to say. I think our views are more-or-less compatible but articulating them to the point of mutual understanding may be more effort than it's worth.

comment by TAG · 2019-07-13T07:05:12.640Z · score: 1 (1 votes) · LW · GW

Since we dont know that the universe is deterministic, I don't see the point in thinking in purely deterministic terms.

If someone somewhere claims that the there is still "choice" and "making a difference" in a deterministic universe, then the meanings of "choice" and "making a difference" are relevant. Maybe you are not that person.

answer by Closed Limelike Curves · 2019-07-10T23:20:07.834Z · score: 4 (2 votes) · LW · GW

A brief note: I'm not 100% sold on the many-worlds hypothesis -- Bohmian interpretations strike me as similarly plausible, but I'm not going to discuss this right now because I doubt I'm educated enough to do so at a high level that doesn't just retread old arguments. With that out of the way, let's assume many-worlds is correct.

Given the existence of many-worlds, interpreting making a decision as "Choosing your own Everett branch" is not correct for one simple reason: In any case in which your decisions depend on something going on at the quantum level, you will simultaneously make every single decision you possibly could have made. There's a sense in which you're accidentally making the error of importing classical intuitions of "One world" into many-worlds -- in this case, the mistake is in believing that there is only one you, who can only make one decision. The reality is that all possible worlds already exist: Everything that has happened or will happen is fully captured by the mathematics of quantum mechanics, and you can't change anything about it. You can't change what ever has or ever will happen.

Now, the question becomes the same as for any determinist universe: whether or not determinism, and the fact that all decisions you will ever make are fully predictable by mathematics, actually makes ethics pointless. In this case, I suggest looking back at Yudkowsky's post on dissolving the question of free will, and then posting your answer here when you think you've got it. It's a good exercise, since it took me a while to figure it out myself. I look forward to seeing your answer.

comment by TAG · 2019-07-11T14:28:39.163Z · score: 1 (1 votes) · LW · GW

If free will can be illusion, so can ethics.

comment by Closed Limelike Curves · 2019-07-26T03:22:59.006Z · score: 6 (2 votes) · LW · GW

Depends on what you mean by "Illusion" and "Ethics." I'd actually agree that the question of "Does an objective code of ethics exist" is confused like the free will one, and that there's a sense in which it does and a sense in which it doesn't.

The sense in which it does is twofold. First, codes of ethics can be objectively wrong; for example, any set of ethics which does not attempt to maximize an expected utility function must be inconsistent (See Yudkowsky's post on the von Neumann-Morgenstern axioms). So there's a sense in which moral systems can be straight-up bad. Another criterion that can rule out a moral system is strict Pareto inefficiency: If you have two moral systems, and every single agent agrees that they would be worse off under one of them than the other, then you really should chuck out that worse system.

However, out of these systems, you're not going to find only a single moral law printed on the fabric of the universe, regardless of how hard you try. Try starting with the Euthyphro dilemma, and just replace "God" with "The Universe." Even if in some far-off corner of Alpha Centauri there did actually end up being a "Moral thermometer" that measures how moral the universe is, and it went up whenever I kicked a little kid in the face, I'd tell that thermometer to **** off. The idea of a "Natural law of the universe" is a pretty bad one, given that even if it existed, there would be no reason to follow it if it clearly conflicted with the general human idea of morality.

comment by TAG · 2019-07-26T08:48:53.852Z · score: 1 (1 votes) · LW · GW

None of that is relevant to the ways in which physics impacts ethics. Deterministic causality impacts fee choice, and through that, praise, blame and the moral wort of actions. MWI is also deterministic, and impacts the ability to refrain from an action: if there was ever a non zero probability of you murdering someone, there is a, wield where you did.

comment by Closed Limelike Curves · 2019-07-26T20:18:46.447Z · score: 2 (2 votes) · LW · GW

Which is why, again, I'm suggesting Yudkowsky's writings describing compatibilism. There is a sense in which objective morality exists, and a sense in which it doesn't; there is similarly a sense in which the world is deterministic and a sense in which we have free will, and the appearance of conflict has to do with our intuitions being too vague and needing to be sharpened and defined better.

answer by Dagon · 2019-07-10T16:30:16.381Z · score: 3 (2 votes) · LW · GW

It's unknown whether "free will" exists and what "possible" actually means on the physical level. Whether Copenhagen, MWI, or other high-level models are used, you're going to come up against the question: why do I experience some things and not others?

If you believe MWI, it's fairly easy to come up with a description of action and morality that looks like "what decisions I make help determine which universe is experienced by those versions of me". If you lean toward Copenhagen, you STILL have to explain how anything like a decision exists, and how that influences the wave collapse in any way, and it's going to look roughly the same - actions you choose have some influence over what you experience in the future.

I have yet to think of and execute a test that showed my own free will to be irrelevant or nonexistent. Causality and choice are part of my perceptive model of my universe. I can't prove that it's "real", as opposed to simulated or back-inserted into my memory or just what brains do after experiences. But I can't prove otherwise either. I'm open to suggestions on how to operationalize this question, and until then I'm going with my model.


comment by giroth · 2019-07-12T01:54:56.999Z · score: 1 (1 votes) · LW · GW

That's very interesting. My model is precisely the opposite, that free will is an illusion if we accept any of the theories. From the moment the universe began, it can only proceed on one path or all paths (each quantum event triggers a split so all possible actions happen). Either way, free will is an illusion.

I live my life entirely free from this conclusion, because not believing in free will will soon land you in a place where the doors don't open from the inside.

comment by TAG · 2019-07-12T09:04:17.273Z · score: 1 (1 votes) · LW · GW

What about one path with indeterminism? Copenhagen, IOW.

answer by strangepoop · 2019-07-28T09:05:50.460Z · score: 1 (1 votes) · LW · GW

I want to ask this because I think I missed it the first few times I read Living in Many Worlds: Are you similarly unsatisfied with our response to suffering that's already happened, like how Eliezer asks, about the twelfth century? It's boldface "just as real" too. Do you feel the same "deflation" and "incongruity"?

I expect that you might think (as I once did) that the notion of "generalized past" is a contrived but well-intentioned analogy to manage your feelings.

But that's not so at all: once you've redone your ontology, where the naive idea of time isn't necessarily a fundamental thing and thinking in terms of causal links comes a lot closer to how reality is arranged, it's not a stretch at all. If anything, it follows that you must try and think and feel correctly about the generalized past after being given this information.

Of course, you might modus tollens here.

answer by LadyMacbeth · 2019-07-14T17:35:12.226Z · score: -2 (2 votes) · LW · GW

How would many worlds reconcile itself with consciousness problem?

If each being (lets assume organic matter conducting electrical impulses as a 'being' ie. bacteria, plant, human) is capable of somehow making decisions on its own volition (move, eat, crap) then each being would have infinite splits of its own world. But each of this already split worlds would have been also split in 0 time by other beings residing within this being world, as all beings have equal power over their decisions. Is such universe even energetically possible? Is such universe anywhere optimal? How such universe would support its own existence where its state is magically changing in 0 time, infinitely?

I could only solve it by imagining that each being has its own separate reality in which other things only exists for said being to be manipulated (by decisions made), therefore, ethics is purely artificial concept.

However, this solution is paradoxical to many worlds hypothesis as there is only one world for one being.

I am not fixed here on any of solutions.


42 comments

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comment by shminux · 2019-07-10T15:50:24.034Z · score: -19 (7 votes) · LW · GW

Consider reading a real physicist's take on the issue: Why the multiverse is religion, not science.

comment by AlexMennen · 2019-07-10T17:24:44.198Z · score: 22 (11 votes) · LW · GW
Consider reading a real physicist's take on the issue

This seems phrased to suggest that her view is "the real physicist view" on the multiverse. You could also read what Max Tegmark or David Deutsch, for instance, have to say about multiverse hypotheses and get a "real physicist's" view from them.

Also, she doesn't actually say much in that blog post. She points out that when she says that multiverse hypotheses are unscientific, she doesn't mean that they're false, so this doesn't seem especially useful to someone who wants to know whether there actually is a multiverse, or is interested in the consequences thereof. She says "there is no reason to think we live in such multiverses to begin with", but proponents of multiverse hypotheses have given reasons to support their views, which she doesn't address.

comment by shminux · 2019-07-10T19:34:29.002Z · score: 2 (3 votes) · LW · GW

I said "a" not "the". Yes, you could also quote Tegmark and Deutsch. I tend to favor a pragmatic approach to science, same as Sabine. You don't have to, but it helps to realize that untestable models still "add up to normality", to quote The Founder, and so have no bearing on your ethics.

comment by dxu · 2019-07-10T17:39:18.162Z · score: 4 (2 votes) · LW · GW

The linked post is the last in a series of posts, the first of which has been linked here in the past [LW · GW]. I recommend that anyone who reads the post shminux linked, also read the LW discussion of the post I just linked, as it seems to me that many of the arguments therein are addressed in a more than satisfactory manner. (In particular, I strongly endorse Jessica Taylor's response, which is as of this writing the most highly upvoted comment on that page.)

comment by shminux · 2019-07-10T19:36:24.441Z · score: 2 (1 votes) · LW · GW

As I mentioned there, Jessica was apparently pissed and uncharacteristically uncharitable in her reply. The upvote count in this case seems to reflect tribal affiliations more than anything.

comment by TAG · 2019-07-11T14:35:04.117Z · score: 2 (2 votes) · LW · GW

As someone who is not a great friend of MWI,I found that poorly argued. She doesnt believe in other branches because they are unobservable. She does believe in the interior of black holes, though no one has come back with a report on them.. because theory says they are observable. But what are MWIers basing things on except theory?

So she is picking and choosing between theories.. although she claims not to be, elsewhere!