Oct 262015
 

deterministic-universe

The question that often comes up in the free will debate is whether  the universe is deterministic or indeterministic. Regardless of which one, I argue, free will is entirely incompatible. In a deterministic universe we couldn’t have done otherwise, and in an indeterministic universe that would allow for a change in variables that lead to an otherwise, those indeterministic variables wouldn’t have been “of our own accord” or “up to us”. In other words, we couldn’t have, of our own accord, done otherwise.

But this isn’t enough for some people. Some want to insist that the universe is causally deterministic… period… no questions asked. Others insist on the opposite, that the universe is indeterministic (suggesting that determinism has been “disproven”). It seems being agnostic on these just isn’t good enough for a whole lot of people.

So which is it? Is the universe deterministic or is it indeterministic? And if we don’t know, are one of these options more likely than the other? Rather than give you a direct answer (as I am agnostic here), for this post I want to get into some key talking points that I feel are often missed.

To address these questions, the first thing we need to do is clarify what we mean by “determinism” and “indeterminism”. For the free will debate, the term “determinism” simply means that every event in the universe has a cause, and “indeterminism” means that some events (whether that be one or many) do not have a cause – what I will refer to as “acausal events”. To get the specific as to why these are the definitions that are used, please read here:
“Determinism” and “Indeterminism” for the Free Will Debate

There are other ways that these terms can be used, but the link above will explain the one that is most often used in both physics and the free will topic, and why that’s the case.

Once this semantic is clear, we can move on to assessing one over the other. For an indeterministic universe, we are basically saying that some events simply “happen” without a cause. In other words, the event just “pops into existence”. For some this idea is just too much to handle. They can’t imagine something happening without a cause – without a reason for it happening.

They might ask “but why did the acausal event happen”, and that feels like a sensible question. If, however, an event doesn’t have a cause, there is no “why” to answer. A “why” automatically assumes a cause, so the question of “why” is question begging.

The idea of an acausal event is very un-intuitive.  Let’s, however, keep in mind that just because something is un-intuitive doesn’t mean that such is “logically impossible”. To show that something is logically impossible one needs to show how it leads to a contradiction of some sort.

Here are some key talking points that I feel need to be addressed. There may be others I’m missing, but these ones are key factors to have a discussion.

Problems with an Indeterministic Universe

Acausal events aren’t logically impossible (or have not been logically ruled out yet), but let’s look at some of the problems they do have by looking at this infographic I made a while back:

Non-caused Events and Free Will – Infographic

non-caused events and free will infographic

As you can see, there are some problems that acausal events have to contend with. For example, the idea that an acausal event can happen “to” something that is already in existence is problematic, as that suggests the thing is causing the acausal event. This is a problem if we are to say that the radioactive decay of an atom happens without a cause. Rather, the acausal event would need to come into existence first and cause the atom to decay. The problem with this is that an acausal event would have no spatial or temporal determinacy. It would have to be by sheer happenstance that it hit the atom to decay it.

The second part, and the part that is probably the most problematic, is that in physics we have some conservation laws that are generally accepted. For example, the conservation of energy. An event that just comes into existence seems like it would be adding “new energy” into the universe, something that would seem to violate conservation laws.  There are some possible work-arounds such as a compensation that happens where the new energy is only temporary (since conservation laws address the total amount of the system is conserved over time), but these “work-arounds” don’t seem very compelling.

The other thing we could do is reject conservation laws and say they might not be the case. That even though we have not shown a case where energy wasn’t conserved in the laboratory, it could be the situation that there are infrequent cases in which it’s not conserved at the quantum scale. Or there may be other loopholes we are not aware of yet.

Similar types of inconsistencies may occur with special relativity, in which case there may be unconvincing loopholes, or a rejection of special relativity needed.

It’s important to note that there is no real evidence that an event is acausal, and it would be difficult to show it. To be able to prove such an event we would have to rule out both local-causality (which for some events Bell’s theorem, if we accept it, rule such out) and at the same time rule out the possibility of a non-local event taking place. Given those parameters it’s theoretically possible to “rule in” an acausal event – but currently this has not been done.

Some people suggest that at the quantum scale, rather than acausal events, you have ontic probabilities. This notion, however, I think can be ruled out logically. This post isn’t going to get into that but if you want to know why ontic probability is impossible, read here:
Ontic Probability Doesn’t Exist: Assessing “Probability” for the Free Will Debate

This is problematic for quantum interpretations that postulate quantum probability as ontic (existing) rather than simply epistemic (just a part of our lack of knowledge).

Problems with a Deterministic Universe

Though I think ultimately a deterministic universe is less problematic than in indeterministic universe, that doesn’t mean it is without its own problems.

Correlation does not necessarily imply causation

One problem with causality that has been around since David Hume is the understanding that we never truly observe causes, but rather correlations. We then infer causality through consistent observations of correlation. Even something obvious like a cue ball hitting an eight ball we don’t really see the energy transfer, the particle interaction, and so on. This in no way implies that causality isn’t inferred, it is. It does, however, make it problematic for us to assess causality for all observable relations, especially those that we don’t have or can’t assess consistent correlations for.

Problems for deterministic quantum interpretations

Per quantum mechanics, if we are to accept that the universe is deterministic, we need to postulate something that is unintuitive about certain quantum events. For example, if we accept Bell’s theorem, certain causal variables need to be “non-local hidden variables”.  This means that they happen from a distance, rather than our more classical notions of local causality where one event causes another within close proximity. They also need to be “contextual” which has some of its own unintuitive problems when it comes to non-local events. Bohmian mechanics (also known as pilot wave theory) is a popular contextual non-local hidden variable theory.

Non-local hidden variable theories are also problematic for special relativity. Similar to some of the problems with acausal events, there may be unconvincing “loopholes” here, or it might be the case that we need to reject some aspects of special relativity.

There may be some “loophole” theories that allow for local hidden variables, but those have their own uphill battle to contend with in quantum mechanics.

Another deterministic model is to take a realist account of a “many-worlds” interpretation, which postulates an endless number of (real) “universes” or “worlds” that come about (that decohere into each universe). This position itself has its own logical problems to contend with. For example, the idea that what is in superpositioned states are “possibilities”doesn’t make a whole lot of sense. Rather, all of those events would all be the output of the initial cause, each leading to their own specific environment (world). But this isn’t how many-worlds is thought of.

Out of all of the interpretations, the many-worlds interpretation if postulating that these universes actually do exist, is the interpretation that makes one of the more extraordinary claims that aren’t (nor can it be) empirically backed up. This is a falsification problem.

To read more on some of these issues, and also on why the many worlds interpretation is incompatible with free will (and even in ways a fatalistic account), read here:

Many Worlds Away from Free Will!

Did Everything Begin or Not?

One last thing to discuss has less to do with the events within our known universe, and more to do with the start of everything. If we project that there can be no acausal events, we must assume there isn’t really a “beginning of everything”. We must infer an infinite or circular regress, or a static, eventless, everything that always existed.  Each of these options have their own unintuitive problems to contend with that cannot be neglected in discourse about the possibility of acausal events. And if we suggest that everything “began” at some point, we are automatically suggesting an event without a cause – giving credence to that as a possibility. These questions seem unanswerable and speculative at best, but that isn’t the point of the exercise of thinking about these things. Rather, the greater point is to show how a wrench can be thrown into our intuitive thoughts and feelings about everything needing a cause or some things not needing a cause, no matter what side we tend to take.

There are some unintuitive implications no matter how we slice it.

In Conclusion

Those who say that they know for a fact that the universe is entirely deterministic, I’d suspect, usually do so due to the intuitive nature of classical causality. It just feels like this must be the case. It just seems like something couldn’t happen without an event that pushes it to its reality. And that intuition could very well be correct.

And though, on the surface, this feels intuitive, it isn’t as easy as it seems. Suggesting that every event has a cause has its own problems one needs to contend with, some of which are intuitive as well once they are thought about.

On the other end of the spectrum there are people who claim that determinism has been disproven. This, however, is equally as false, and usually stems from the acceptance of an indeterministic interpretation of quantum mechanics (e.g. Copenhagen interpretation), which tend to be the first interpretation taught or a primary focus in quantum physics (which I find problematic).

There are interpretations of quantum mechanics that are entirely deterministic (albeit they may be non-local, etc.). And those interpretations are not any less valid. In other words, no empirical evidence exists that currently removes an interpretation (and when there is such, an interpretation becomes abandoned). Each theory is consistent with the experiments and observations – pushing us to interpret the theories – moving us closer to philosophy rather than science in regards to which interpretation makes the most sense (something I have my own thoughts about).

If you feel like the question about determinism or indeterminism hasn’t been answered at all in this post, you are absolutely correct. The only thing I wanted to address is some of the “talking points” that one needs to go over to even have a discussion about this. We need to be careful of just making blind assertions about one over the other.BTFWI - paperback

If you just want my opinion,  I’m in the camp that there is probably a good chance that the universe is entirely deterministic. I don’t think quantum mechanics rules out (contextual non-local) determinism, and I think some of the so-called “indeterministic” interpretations of quantum mechanics assert a more problematic type of acausality that isn’t really coherent. But quantum interpretations aside, I don’t see acausal events as being logically ruled out, so I cannot know that they are impossible. I cannot take my position as anything strong. In regards to the free will topic this is the reason I insist on Hard Incompatibilism over Hard Determinism, I truly do think we need to show how free will is lacking in both types of universes (and there simply isn’t a third option).

Rather than make hasty conclusions about what universe we live in, let’s look at all of the problems with both, and take all factors into consideration. The moral: though intuitions can be helpful, let’s not be too much of a slave to our own intuitions or preconceptions. There is no need to dogmatically hold firmly to one over the other. Have intuitive leanings, sure…but try not to insist unless you can address each of the points in this post (and probably many I’ve missed – for example, with certain theories of time) and  make strong empirical and logical conclusion of one over the other. If you take up such a daunting task – good luck! :-)

*If you want a complete breakdown about causal and acausal events, check out my book on Amazon.

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'Trick Slattery

'Trick Slattery is the author of Breaking the Free Will Illusion for the Betterment of Humankind. He's an author, philosopher, artist, content creator, and entrepreneur. He has loved and immersed himself in philosophy since he was teenager. It is his first and strongest passion. Throughout the years he has built a philosophy based on analytic logic and critical thinking. Some of the topics he is most interested in are of a controversial variety, but his passion for the topics and their importance drives him to want to express these ideas to others. His other passions include pen and ink line art and digital artwork.

  44 Responses to “Is the Universe Causally Deterministic? Maybe!”

  1. Right now I think it’s practical to assume determinism is true and we have an infinite regress. The important thing is that none of it makes a difference for the falseness of free will. When people try to use indeterminism as a hiding ground for free will I automatically stop listening.

    • I find it more practical to be agnostic rather than assume. That way I’m not pigeon holed into a specific position by others when in fact I don’t really know. :-)

  2. I continue to notice that everything that I think (about) was already there for me to think. That does not preclude learning something new that will “add” to what is there for me think.

  3. This discussion of determinism vs nondeterminism reminds me of a similar discussion at our study group on law vs grace often the two views are looked at as polar opposites and yet there may be truth on both sides of the spectrum. Law and grace determinism and nondeterminism in this article it appeared to me both sides have some valid points. I think that it is more fair to see the support for both realizing there is element of truth in both.

    • Hi Charity, thanks for the visit. They are sort of oppositions, so if the universe is deterministic, it isn’t indeterministic, and vice versa. The main problem is we don’t have sufficient enough evidence to make a conclusion either way. 😉

  4. Trick,
    I think you are insane.
    The evidence is overwhelming in FAVOR of free will, even contra causal free will at the quantum level.
    If you really followed through on the logical implications of your insane and sociopathic beliefs. You wouldn’t get up in the morning. Because nothing you do has a point.

    Instead you are forced by nature to act AS IF the “illusion of free will” is true, that you aren’t a third party passenger watching yourself make decisions passively like a movie theater goer. What would be the purpose of nature designing such an illusion? Maybe because it isn’t an illusion!

    • Edward, thanks for the visit, however…

      Do you really think that starting your comment to me with “I think you are insane” and stating that my beliefs are “insane and sociopathic” to be a productive starting point of discourse? I will have to ask you that, if you do want to discuss this and not just assert things, that you stay away from insults. There is no reason two people with dissenting positions need to go down the rabbit hold of being disrespectful or rude.

      With that, on to your comment:

      “The evidence is overwhelming in FAVOR of free will, even contra causal free will at the quantum level.”

      I’m all for hearing about such evidence. I make the case that free will, as defined here, is logically incoherent no matter if there is determinism or indeterminism. Let’s make sure we are addressing the same semantic of free will before we go on.

      “You wouldn’t get up in the morning. Because nothing you do has a point.”

      Saying “nothing you do has a point” is a non-sequitur that does not follow from a lack of free will:
      Pointlessness Doesn’t Follow from Determinism (combating non-sequiturs)

      Also keep in mind the distinctions between determinism and fatalism in regards to futility:
      Determinism vs. Fatalism – InfoGraphic (a comparison)

      “Instead you are forced by nature to act AS IF the “illusion of free will” is true,”

      We Don’t Have to Act Like Free Will Exists

      “What would be the purpose of nature designing such an illusion?”

      It’s a naturalistic fallacy to think nature has a “purpose”. That beings said I can see there being evolutionary advantages to the illusion.

  5. Trick,
    My anger at you comes from you bring and effective apologist for fatalism and totalitarianism.

    First let me say that discussions have to define terms.

    “Will” to me is the degree of mental energy spent in overcoming on obstacle. Like an alcoholic refusing to take that drink
    Drink his subconscious self craves. Like any muscle it can be trained

    So I would define “freedom of choice” or a
    Free self as something that’s categorically true and what I believe in. My fate is my own. No one else’s. It’s under my control. If I choose to eat eggs on Monday morning it wasn’t predestined. I couldv had something else instead.

    You asked for the evidence. The strongest is the idealistic interpretation of quantum mechanics. It isn’t justthat there is some element of q
    randomness at the quantum level. It’s that the very act of measuring affects the experiment!

    The nature of memory:You would expect memory
    In a predetermined brain to be computer like. Instead, it’s largely constructed by how we interpret our memories. Hypnosis has proven a notoriously effective way to remember things that never actually happened. We can CHOOSE our memories

    Can we control our emotions? Yes we can! Maybe not directlyly, but what else to method
    Actors do but control their emotions.

    the neuroplasticity of the brain. The brain doesn’t just determine the mind. The mind determines the brain just as much.

    My own experiences with hetero-bisexuality. What I’ve explerienced gives lie to the notion that sexual orientation isn’t amenable to change.

    Our free society is based on our natural freedom of choice. Your mistaken and poisonous beliefs would give aid and comfort to
    Totalitarians everywhere.

    Finally do I have to explain the concept of an axiom, or something “a priori” to you? An axiom is something like a “law of thought” that is revealed when you attempt to deny something and use the very thing you are denying in an attempt to deny it. “Humans make choices” You would argue that those choices are predetermined but quantum mechanics has ended that once and for all

    • Hi Edward,

      Please do not strawman my position. I am neither A) a fatalist, B) a totalitarian, or C) a hard determinist who is certain about determinism – nor does my position promote these positions. Perhaps it is the case that you haven’t bothered learning about my actual position and what I’m promoting here – or read any of the links in my last comment, and are simply making assumptions about my position? I have a few simple requests for conversations:

      1) Don’t make assumptions or presumptions or strawmans. If you think someone has a position, show it with quotes rather than claim it. If you don’t know – ask.
      2) Be courteous and calm headed. Think of it as discourse with a friend or friendly person.
      3) Try to be direct and to the point, and as clear as possible.

      I promise to hold myself accountable to those very standards as well, and if I slip up let me know so I can resolve the mistake.

      So let me go along your comment to hash things out if you don’t mind:

      “First let me say that discussions have to define terms.”

      I agree, hence the reason I pointed to my semantic of free will in the last comment. Here it is again:
      http://breakingthefreewillillusion.com/terms/free-will/

      “So I would define “freedom of choice” or a free self as something that’s categorically true and what I believe in. My fate is my own. No one else’s. It’s under my control. If I choose to eat eggs on Monday morning it wasn’t predestined. I couldv had something else instead.”

      From this point on, since you are making a case for an indeterministic universe, I will side with that position. Given an “indeterministic” qm position I absolutely agree that you “could have chosen something else”. Where I disagree is that such a “choosing something else” could have been “under your control” or as I put it “up to you”. But we will address this as we go through your comment.

      “You asked for the evidence. The strongest is the idealistic interpretation of quantum mechanics. It isn’t justthat there is some element of q randomness at the quantum level. It’s that the very act of measuring affects the experiment!”

      I absolutely 100% agree that the very act of measuring “affects the experiment”. This, however, does not grant any special causal or acausal powers. The logic still holds for the two ways events can possibly occur, regardless if measurement causes wave function collapse (or decoherence)… or not.

      “The nature of memory:You would expect memory in a predetermined brain to be computer like. Instead, it’s largely constructed by how we interpret our memories. Hypnosis has proven a notoriously effective way to remember things that never actually happened. We can CHOOSE our memories”

      Technically memories come to the forefront of our consciousness, and conscious processes have an effect on our brain in a way that produces further memories and so on. Keep in mind that I’m not a reductionist but rather I think there is downward causation. Parts create whole with properties (e.g. consciousness) which play a role in the causal alignment of our next brain structure and thoughts.

      Here are some posts that might help with understanding my actual position:
      http://breakingthefreewillillusion.com/hard-determinism-not-reductionistic/
      http://breakingthefreewillillusion.com/mental-causation/

      “Can we control our emotions? Yes we can! Maybe not directlyly, but what else to method actors do but control their emotions.”

      I never claimed we couldn’t. What I am claiming is that if we do, either A) we couldn’t have done otherwise but control our emotion the way we did (given a deterministic universe), or B) if we could have done otherwise (due to an indeterministic universe) that “otherwise” could not be “up to us” – it would be due to an acausal event. There is no way out of this conundrum.

      So yes, we can, if that is what events dictate, “control our emotion”.

      “The neuroplasticity of the brain. The brain doesn’t just determine the mind. The mind determines the brain just as much.”

      Absolutely. That is my position as well. Again:
      http://breakingthefreewillillusion.com/hard-determinism-not-reductionistic/
      http://breakingthefreewillillusion.com/mental-causation/

      “My own experiences with hetero-bisexuality. What I’ve explerienced gives lie to the notion that sexual orientation isn’t amenable to change.”

      Not sure where you were going with this part.

      “Our free society is based on our natural freedom of choice.”

      I think we need to make an important distinction between “choice” and “free choice”. Read here for more info about that:
      http://breakingthefreewillillusion.com/free-choice-vs-choice/

      “Your mistaken and poisonous beliefs would give aid and comfort to totalitarians everywhere.”

      Again, I am not a totalitarian nor do my beliefs align in any way with totalitarianism. I believe in specific democratic processes. This is the reason I try to convince people with words rather than force. I’m a consequentialist and I think totalitarianism leads to harmful consequences – and am against it due to this. Unless you can quote where I ever sided with totalitarian thought, I’ll have to ask that such a strawman ceases. I’m entirely devoted to rational discourse with others in order to change minds democratically.

      And I’m vehemently opposed to fatalistic notions of a lack of free will. Fatalism is not a logical assessment, and it is also dangerous.

      “Finally do I have to explain the concept of an axiom, or something “a priori” to you? An axiom is something like a “law of thought” that is revealed when you attempt to deny something and use the very thing you are denying in an attempt to deny it.”

      I know what an “axiom” is. You just can’t simply assert something as “axiomatic” if it isn’t self-evident or accepted.

      ““Humans make choices” You would argue that those choices are predetermined but quantum mechanics has ended that once and for all”

      This very article that your comment is posted on shows that I am agnostic on whether the universe is deterministic or indeterministic, so no, I would not assert “predeterminism” unless the universe happens to be deterministic. If the universe is indeterminstic, then any “otherwise” happening would stem from events that were entirely outside of “us” (a non-caused event). But please don’t assume I’m a hard determinist, as I’m a hard incompatibilist – meaning free will is incompatible in both a deterministic or indeterminsitic scenario:

      http://breakingthefreewillillusion.com/hard-incompatibilist-not-hard-determinist/

      I do hope my comment has cleared up some of your misunderstandings about what my actual position is. If not, feel free to ask me about something before assuming it or pigeon holing me into something I’m not.

      Best regards,
      ‘Trick

  6. Your argument (suggesting that acausal events are illogical) appears to be attempting to refute false positions that you yourself made up out of whole cloth.

    > For example, the idea that an acausal event can happen “to” something that is already in existence is problematic, as that suggests the thing is causing the acausal event.

    If by “causing” you mean that no other outcome was possible, then the idea that an acausal event can happen “to” something that is already in existence does not suggest the thing is causing the acausal event. You’re just making up an inconsistent position so that you can refute it.

    > This is a problem if we are to say that the radioactive decay of an atom happens without a cause. Rather, the acausal event would need to come into existence first and cause the atom to decay. The problem with this is that an acausal event would have no spatial or temporal determinacy.

    The decay of the atom is itself the acausal event. It is acausal because the atom did not cause it to happen at a particular time. But it is observed to occur at a particular spacial and temporal location. There is no separate acausal event (other than the decay) in this scenario.

    > An event that just comes into existence seems like it would be adding “new energy” into the universe,

    Again, you just made this up out of whole cloth. If it seems that way to you, then your intuition is misleading you.

    > It’s important to note that there is no real evidence that an event is acausal, and it would be difficult to show it.

    It is also important to note that there is no real evidence that events at the quantum level are causal.

    • Your argument (suggesting that acausal events are illogical) appears to be attempting to refute false positions that you yourself made up out of whole cloth.

      I never said that “acausal events are illogical”. In fact I quite often debate that acausal events are not logically impossible (as some determinists suggest), but rather that they are logically possible. I’ll quote the above article: “The idea of an acausal event is very un-intuitive. Let’s, however, keep in mind that just because something is un-intuitive doesn’t mean that such is “logically impossible”.”

      and

      “I don’t see acausal events as being logically ruled out, so I cannot know that they are impossible.”

      I’ll assume you just skimmed the article and are battling a straw-man.

      If by “causing” you mean that no other outcome was possible, then the idea that an acausal event can happen “to” something that is already in existence does not suggest the thing is causing the acausal event. You’re just making up an inconsistent position so that you can refute it.

      Again, I never said that an acausal event can’t come about and effect something already in existence. Rather the thing in existence cannot produce the acausal event (as such a production IS causal). And a cause cannot logically be the variables that lead to X and be the variables that do not lead to X (as that’s a self-contradiction). An acausal event would have to come about and have an effect on the object, but that acausal event can have no spatial or temporal determinacy so cannot account for a probability distribution.

      The decay of the atom is itself the acausal event. It is acausal because the atom did not cause it to happen at a particular time. But it is observed to occur at a particular spacial and temporal location. There is no separate acausal event (other than the decay) in this scenario.

      That depends on the quantum interpretation being postulated (this is important)! I have a section in my book that goes over the problem with suggesting that an acausal starting point of atom decay comes from the atom itself.

      Again, you just made this up out of whole cloth. If it seems that way to you, then your intuition is misleading you.

      And I didn’t make this up, it’s actually a common problem for the notion of acausality and conservation laws. You just aren’t educated on the philosophical topic of causality/acausality…or so it appears. And you also took the quote out of context, in which just after the quote it says “There are some possible work-arounds such as…” See the article above for context.

      It is also important to note that there is no real evidence that events at the quantum level are causal.

      It’s also important to note that there is much evidence that causal events exist in the universe, where there is no evidence that acausal events exist anywhere.

      But again, I’m agnostic over whether acausal events exist or not…I’m just not agnostic over whether probability is ontic or not. Acausal events are not illogical. Ontic probability is illogical. Please understand the distinction between the two.

      Later.

      • > the thing in existence cannot produce the acausal event (as such a production IS causal).

        How do you conclude that such an event is causal? Since you use “causal” to mean a result that could not have been otherwise, that must be part of what you mean, but I don’t see what chain of logic leads you to that conclusion.

        > And a cause cannot logically be the variables that lead to X and be the variables that do not lead to X (as that’s a self-contradiction).

        Indeed, since you use the word “cause” to mean a deterministic result, I agree. However, an *event* X can lead to an *outcome* Y, and can also lead to an *outcome* Z (and not Y). Under MWI this would be thought of as a superposition until entangled with the observer; under the copenhagen interpretation the superposition collapses nondeterministically when observed.

        > An acausal event would have to come about and have an effect on the object, but that acausal event can have no spatial or temporal determinacy

        How do you conclude that an acausal event cannot occur at a particular place and time?

        When you say an acausal event would not conserve energy, you seem to be equating an event (which is an interaction of particles) with the creation of new particles. Indeed, in that view there are workarounds, but an acausal event need not involve the creation of new particles, and therefore need not be problematic from a conservation perspective. Your unstated assumption that an acausal event involves the creation of new particles is unjustified.

        At the quantum level, the evidence is agnotic to whether events are causal or acausal (as you say, it depends on your interpretation). Only when one attempts to account for observed outcomes does the acausal interpretation come to the fore. At the macroscopic level, the illusion of causality arises from an “averaging” of a large number of events at the quantum level. It is certainly useful to treat events at the macroscopic level as causal, as it is common to find systems where the probability of a particular outcome (or, more properly, “measure of existence of all worlds with that outcome” in MWI) is overwhelmingly large (close to 1). I suggest the term “practical causality” to describe this illusion. But I would not confuse this common phenomenon as evidence for causality.

        > Ontic probability is illogical.

        Perhaps you find it easier to say “measure of existence of all worlds with that outcome” than I do.

        • “How do you conclude that such an event is causal?”

          If something in existence produces another thing – that IS causal. Production implies causality. X producing state Y is the very definition of causality. An acausal event has no spatial or temporal determinacy. It isn’t “produced” by something else.

          “However, an *event* X can lead to an *outcome* Y, and can also lead to an *outcome* Z (and not Y). Under MWI this would be thought of as a superposition until entangled with the observer; under the copenhagen interpretation the superposition collapses nondeterministically when observed.”

          No, event X can lead to both outcome Y and outcome Z. Event X cannot lead to outcome Y and at the same time not lead to outcome Y (but to Z instead). This is the same thing for newtonian causality. A cueball can hit both a 4 and 8 ball simultaneously, leading to two rolling events. It cannot hit the 8 ball (and not the 4 ball) and the 4 ball (and not the 8 ball). That is a contradiction. A superpositioned state is a number of causal outputs that happen from the one, all existing in Hilbert space. It is a mistake to think that a superpositioned state is a self-contradictory state that you are proposing.

          “How do you conclude that an acausal event cannot occur at a particular place and time?”

          You keep using a strawman. What I said was that an acausal event would have no spatial or temporal determinacy, meaning it could end up in any place or any location, which of course when it happens will be a “particular location”. There is simply nothing forcing it TO a particular location…to where it ends up would be mere happenstance. Certainly not based on anything in existence (as again, any forcing factor is a causal factor).

          but an acausal event need not involve the creation of new particles, and therefore need not be problematic from a conservation perspective. Your unstated assumption that an acausal event involves the creation of new particles is unjustified.

          Let’s be clear that an acausal event does imply new energy. In other words, it implies something coming from nothing. If it comes from something – that is causality. You making claims that it’s “unjustified” simply means that you haven’t thought or learned enough about the implications of an event without a cause.

          At the macroscopic level, the illusion of causality arises from an “averaging” of a large number of events at the quantum level.

          It’s more than an “illusion”, there is good reasons to think that a probability distribution isn’t ontic…as I already explained to you here:
          Ontic Probability Doesn’t Exist: Assessing “Probability” for the Free Will Debate

          The main point is that ontic probability is illogical. Again, if you want to say that quantum events allow for illogical conclusions, then we have a whole different discussion about the methodologies used for QM and for any rational discourse. We don’t have to measure the existence of all worlds to conclude what types of events are logically incoherent and what types of events are not logically incoherent.

          Anyway – I’m outta time so any responses will be delayed.

          Take care.

          • > If something in existence produces another thing – that IS causal. Production implies causality. X producing state Y is the very definition of causality.

            Oh, I misunderstood your definition of causality to include that no other outcome of the interaction is possible. If you intend your use of causality to include events in which alternative outcomes are possible, we’d be having a completely different conversation.

            > No, event X can lead to both outcome Y and outcome Z. Event X cannot lead to outcome Y and at the same time not lead to outcome Y (but to Z instead). It is a mistake to think that a superpositioned state is a self-contradictory state that you are proposing.

            You seem to be saying that the superposition of two mutually exclusive outcomes is both impossible, and that is it a mistake to think that it is self-contradictory. (By “outcome” here I mean the observed result) Which is it?

            > What I said was that an acausal event would have no spatial or temporal determinacy, meaning it could end up in any place or any location, which of course when it happens will be a “particular location”. There is simply nothing forcing it TO a particular location…to where it ends up would be mere happenstance. Certainly not based on anything in existence (as again, any forcing factor is a causal factor).

            Well, the amplitude of the wave function is based on something in existence. While I agree it doesn’t force it TO a particular location, it does constrain the likelihood of the event occurring in various locations. Thus such an acausal event can be said to have a spacial and temporal determinacy as described by its wave function.

            Or, perhaps as I describe in the first paragraph here, we should describe this as causal but not necessarily deterministic. (Since determinism is not part of the definition of – or an implication of – the word causal)

            > Let’s be clear that an acausal event does imply new energy.

            Your assertion is without foundation. Let’s be clear that whether or not an event affects the balance of energy depends on the energy of the system before and after the event.

            > there is good reasons to think that a probability distribution isn’t ontic

            See http://arxiv.org/pdf/quant-ph/0312157v2.pdf
            “(It might appear from the above that probability in the Everett interpretation
            is somehow “not objective”. This is certainly not the case: the weights of
            quantum branches are as objective as any other physical property. In fact, the
            best reading of the decision-theoretic proofs, in my view, is not that they tell us
            that there are no objective probabilities, but rather that they teach us that objective
            probability is quantum weight. See Saunders (2005) or (Wallace 2005a)
            for a more detailed analysis of this point.”

            I agree that to use the term “probability” may not be very precise (perhaps “quantum weight” would be better), but it is much shorter than using a more precise term at every occurrence.

          • Oh, I misunderstood your definition of causality to include that no other outcome of the interaction is possible. If you intend your use of causality to include events in which alternative outcomes are possible, we’d be having a completely different conversation.

            The fact that a cause cannot both be the cause of X and not the cause of X isn’t defined into existence. That is a logical conclusion that if a cause exists, it doesn’t have self-contradictary variables.

            You are confusing a superpositioned state (which IS the outcome) with “alternate possibilities”. It isn’t the case. Every superpositioned state is the way it is due to the cause that precedes it.

            You seem to be saying that the superposition of two mutually exclusive outcomes is both impossible, and that is it a mistake to think that it is self-contradictory. (By “outcome” here I mean the observed result) Which is it?

            No, I’m saying that superpositioned states are *not* mutually exclusive. They both seperately exist in hilbert space. The observation is simply that of the one in which the environment is connected.

            In other words, one event leading to multiple superpositioned states (each ending up in a differing universe) is not the same thing as one event leading to one state OR the other state in which both are possible (which is a contradiction if the event is causal).

            Well, the amplitude of the wave function is based on something in existence. While I agree it doesn’t force it TO a particular location, it does constrain the likelihood of the event occurring in various locations. Thus such an acausal event can be said to have a spacial and temporal determinacy as described by its wave function.

            The very point of my criticism is to show the absurdity of something non-causal being “constrained”. Having spacial and temporal determinacy implies causality.

            Or, perhaps as I describe in the first paragraph here, we should describe this as causal but not necessarily deterministic.

            Then it’s a contradictary cause.

            Your assertion is without foundation. Let’s be clear that whether or not an event affects the balance of energy depends on the energy of the system before and after the event.

            It’s not without foundation that an event that isn’t caused by the energy in the system would be “new energy”. The “possible” work around implies some sort of energy balancing system that controls and conserved the total in the system.

            “(It might appear from the above that probability in the Everett interpretation is somehow “not objective”. This is certainly not the case: the weights of quantum branches are as objective as any other physical property. In fact, the best reading of the decision-theoretic proofs, in my view, is not that they tell us
            that there are no objective probabilities, but rather that they teach us that objective probability is quantum weight. See Saunders (2005) or (Wallace 2005a) for a more detailed analysis of this point.”

            You misunderstand. We could make the same assertion about weighted dice, but that doesn’t mean that the probability is ontic. Causal weights are “objectively” weighted, the probability itself is epistemic. It depends on all of the causal factors that lead to one event over the other, which includes the objective weighting of the dice.

            I agree that to use the term “probability” may not be very precise (perhaps “quantum weight” would be better), but it is much shorter than using a more precise term at every occurrence.

            This is fine. I have no problem with objective weights – only with the idea that the probability that extends from such weights is real rather than epistemic (us not knowing all of the causal influences that pushes the weighted ditribution)

            Gotta run. Catch you much later. 😉

          • > The fact that a cause cannot both be the cause of X and not the cause of X isn’t defined into existence. That is a logical conclusion that if a cause exists, it doesn’t have self-contradictary variables.

            Indeed, it would be a mistake to postulate “variables” as “causative” factors for events that are not deterministic.

            > In other words, one event leading to multiple superpositioned states (each ending up in a differing universe) is not the same thing as one event leading to one state OR the other state in which both are possible (which is a contradiction if the event is causal).

            You and I have completely different understandings of MWI, then. As I understand it, MWI lacks *counterfactual definiteness* – that is, under MWI it is meaningless to speak of the outcome of events that have not been observed. Unless we refer to observations, no event or outcome can properly be said to have occurred. The “different universes” are not separate under MWI – they are part of a single universal wave function.

            From the point of an observer before the observation of the outcome of an event that results in X (or not X), both outcomes are possible futures (superposed). After the observation one or the other (only) is observed. Both are possible; in the universal wave function, both are in some sense have occurred, but subjectively the one that is observed is more real (to the observer) than the other (but only after the observation). From the point of view of the observer, before the observation, both outcome X and outcome “not X” are possible.

            > It’s not without foundation that an event that isn’t caused by the energy in the system would be “new energy”.

            Events are not energy. Events are interactions.

            > You misunderstand. We could make the same assertion about weighted dice.

            The difference being that in the case of weighted dice we would have good reason to believe that there is a separate, underlying mechanics to the behavior. We do not postulate that there is an infinite stack of underlying mechanics in physics, one more primitive than the next.

          • Indeed, it would be a mistake to postulate “variables” as “causative” factors for events that are not deterministic.

            Glad you agree. :-)

            You and I have completely different understandings of MWI, then. As I understand it, MWI lacks *counterfactual definiteness* – that is, under MWI it is meaningless to speak of the outcome of events that have not been observed. Unless we refer to observations, no event or outcome can properly be said to have occurred. The “different universes” are not separate under MWI – they are part of a single universal wave function.

            There is NO real counterfactuals in a MWI – all states and universes are factuals. I agree that the different universes are not separate from the wave function, but that doesn’t imply that they are not separate from each other. It’s important not to conflate that distinction. All superpositioned states and worlds exists as a split-off of an event. It isn’t that

            From the point of an observer before the observation of the outcome of an event that results in X (or not X), both outcomes are possible futures (superposed).

            You miss the point that this is an epistemic problem, not an ontic problem. We simply don’t have access to the superpositioned state and the decoherence event that will take place, so from our perspective it seems like each is a real possibility – when in reality there is a 100% chance that each split will decohere to the only environment each can.

            After the observation one or the other (only) is observed. Both are possible; in the universal wave function, both are in some sense have occurred, but subjectively the one that is observed is more real (to the observer) than the other (but only after the observation).

            Not only are both occurances possible for their prospective universe, they are all necessitated. It is impossible for one of the occurances not to take place, or to decohere into a different environment.

            From the point of view of the observer, before the observation, both outcome X and outcome “not X” are possible.

            This is the same for any situation where we don’t know the variables for the future event. But this type of “possibility” is epistemic, not ontic. The fact of the matter is, in a deterministic non-MWI both outcomes are not possible, and in a MWI both outcomes are not possible in a single universe. For a MWI there is only one possible outcome for each universe, and that depends on an entirely causal decoherence event. It can never be the case that a split off universe contains two of the superpositioned states. They each must decohere into the only universe they “possibly” can…and it is in fact impossible for them not to.

            Events are not energy. Events are interactions.

            At least in out known physical universe there is no such thing as an energy-less interaction.

            The difference being that in the case of weighted dice we would have good reason to believe that there is a separate, underlying mechanics to the behavior. We do not postulate that there is an infinite stack of underlying mechanics in physics, one more primitive than the next.

            For a MWI, there indeed is an underlying mechanism. That is why it’s a deterministic interpretation. You need an indeterministic interpretation if you want no underlying mechanics to the behavior. You need to decide what you are making a case for – indeterminism, or a deterministic MWI. We need to focus one at a time, but rest assured a MWI is as deterministic as it gets! 😉

            CYA

          • > > Indeed, it would be a mistake to postulate “variables” as “causative” factors for events that are not deterministic.

            > Glad you agree. :-)

            Indeed, we now both agree why your reasoning that an event cannot have distinct (exclusive) outcomes is unsound.

            > > From the point of an observer before the observation of the outcome of an event that results in X (or not X), both outcomes are possible futures (superposed).

            > You miss the point that this is an epistemic problem, not an ontic problem.

            Again, we have very different understandings of MWI. Before the observation, there is only one “world” in which both observations are futures. Both are “possible”. It isn’t a matter of knowing or not knowing which one we will end up in – the “we” that exists before the observation will end up in both of them. After the observation the “world” can be though of as “splitting” into two worlds, but both are possible futures of the world that existed before the observation.

            > Not only are both occurances possible for their prospective universe, they are all necessitated. It is impossible for one of the occurances not to take place, or to decohere into a different environment.

            Yes, we both agree that retrospectively, after the observation, what has occurred was necessarily what has occurred. The question we were discussing was what was possible before the observation.

            > in a MWI both outcomes are not possible in a single universe

            Assuming MWI and a single universe is a set of self-contradictory assumptions. MWI is a theory in which universes logically split (unless you’re speaking of it from the POV of the universal wave function, in which no particular observations are ever made).

            > For a MWI there is only one possible outcome for each universe

            That is not how MWI is described. In MWI the universe can be though of as splitting into multiple future universes. The universe before the observation has two possible outcomes, and therefore two futures.

            > At least in our known physical universe there is no such thing as an energy-less interaction.

            In an interaction, energy is typically exchanged, not created.

            > You need to decide what you are making a case for – indeterminism, or a deterministic MWI.

            I’m arguing that either way, more than one outcome of an event is possible.

          • Indeed, we now both agree why your reasoning that an event cannot have distinct (exclusive) outcomes is unsound.

            And I said that where? Obviously you are misunderstanding something I said, so please quote where you are getting this?? We agree that it’s a mistake to postulate causal variables for non-deterministic events. That is all. All events have distinct outcomes.

            Again, we have very different understandings of MWI. Before the observation, there is only one “world” in which both observations are futures. Both are “possible”. It isn’t a matter of knowing or not knowing which one we will end up in – the “we” that exists before the observation will end up in both of them.

            Again, you aren’t getting it. The MWI implies a split into multiple universes. It doesn’t imply that one universe has both options. If you end up throwing a rock at the cat, it was never a possibility (for your world) for you to be climbing the treee to save the cat. Likewise, if you find yourself climbing the tree to save the cat, it was never possible (for your world) to be throwing a rock to knock the cat out of the tree. It isn’t one universe in which the cat is both being saves from the tree and being knocked out with a rock. The universes split off. You seem to not care about the details of the MWI.

            Yes, we both agree that retrospectively, after the observation, what has occurred was necessarily what has occurred. The question we were discussing was what was possible before the observation.

            Before the observation the only possibility was the exact universe splits that will take place after the observation. There is nothing different in regards to possibilities prior to the observation – they are identical. Nothing new could happen. Prior to the observation, the ONLY possibility is that one very specific universe will have you throwing the rock, and the other will have you climbing the tree. Before the observation, it cannot be the case that, for example, the one event decoheres into the other universe. The MWI is an entirely causally deterministic process. There is no indeterminism within the output of the superposition or within the way the superposition plays out. It isn’t a “retrospective” assessment.

            Assuming MWI and a single universe is a set of self-contradictory assumptions.

            It’s not.

            That is not how MWI is described. In MWI the universe can be though of as splitting into multiple future universes. The universe before the observation has two possible outcomes, and therefore two futures.

            Yes, it is. No, the universe splits are not seperate possible outcomes. They are ALL the only possible outcomes for each universe. Those “two possible outcomes” you are referring are THE outcome that must occur, even before observation. It can’t be the case that, for example, one of those possible oucomes doesn’t take place in a MWI.

            In an interaction, energy is typically exchanged, not created.

            An energy exchange is causal, not acausal. We were addressing a non-caused event. From what is energy exchanged if the event is not derived from something with energy (caused)? This makes no sense.

            I’m arguing that either way, more than one outcome of an event is possible.

            I think you are confusing “more than one outcome” with the both X and ~X “possibilities” that indeterminism allows for. For a MWI, the X is the multiple worlds that happen, and it cannot be the case that a single one doesn’t happen the way it does (~X cannot happen).

          • Neal,

            If it’s helpful for you to see how perfectly deterministic a many-worlds interpretation of QM is (and how non-retrospective it is), here is what can be said for the interpretation:

            If we postulate the big bang event as the start of our known universe, every split off universe in a MWI was causally dictated since then by those initial conditions.

            Maybe that will crystallize this for you.

          • > > Indeed, we now both agree why your reasoning that “an event cannot have distinct (exclusive) outcomes” is unsound.

            > And I said that where? Obviously you are misunderstanding something I said, so please quote where you are getting this??

            Here is the quote: “The fact that a cause cannot both be the cause of X and not the cause of X isn’t defined into existence. That is a logical conclusion that if a cause exists, it doesn’t have self-contradictary variables.”

            Since your most recent definition of “cause” was “If something in existence produces another thing – that IS causal. Production implies causality. X producing state Y is the very definition of causality.”

            That definition does not imply determinism or the “variables” that you postulated (in the last word of the quote two paragraphs earlier). I now understand that your definition of “causal” does not include the requirement for determinism in the outcome.

            > The MWI implies a split into multiple universes. It doesn’t imply that one universe has both options.

            Yes, it does imply that the world before the split had the option (indeed the requirement) to split into both worlds. There is also a bit of a terminology problem; see “worlds” and “universe” in the penultimate paragraph, below.

            > Those “two possible outcomes” you are referring are THE outcome that must occur, even before observation. It can’t be the case that, for example, one of those possible oucomes doesn’t take place in a MWI.

            Indeed, that was my point. Whatever outcome I observed, the other outcome was a possible (indeed actual) future of my world before the observation. This is the “could have been/done otherwise” I have been trying to point out is a consequence of MWI.

            > An energy exchange is causal, not acausal. We were addressing a non-caused event.

            I now understand that I should have used the phrase “nondeterministic causal” instead of “acausal” by your definition that I quoted above.

            > I think you are confusing “more than one outcome” with the both X and ~X “possibilities” that indeterminism allows for. For a MWI, the X is the multiple worlds that happen, and it cannot be the case that a single one doesn’t happen the way it does (~X cannot happen).

            The evolution of the wave function is not something normally identified as an “event” in MWI. Events are observable interactions.

            MWI lacks counterfactual definiteness; we cannot speak meaningfully of the results of measurements that have not been performed (i.e. the ability to assume the existence of objects, and properties of objects, and the occurrence of events, even when they have not been measured). In the absence of observation no event can properly be said to have occurred in MWI.

            In this sense assertions about events must assume an observer, and the observation occurs in the observer’s frame of reference (i.e. in the observer’s “world”; the two become entangled as a result of the observation).

            > If we postulate the big bang event as the start of our known universe, every split off universe in a MWI was causally dictated since then by those initial conditions.

            The splitting is not a part of the theory per se; it is a way of explaining the meaning of the “world” from the point of view of an observer, particularly to emphasize the sense in which alternative (but mutually exclusive) *observed* outcomes of events are possible (indeed actual, though not necessarily “equally” real). Many writers use different words to distinguish between the objective *universe*, which is the single deterministic universal wave function (which does not split off in any sense and in which events per se cannot properly be said to have occurred), and the “world” (which can be though of as splitting off) which is as the universe appears for a particular observer as a sequence of interactions.

            Using this terminology, quantum *events* that occur (and are observed) can, from the point of view of the observer, be expected to behave *as if* nondeterministic, with the chance of outcomes (ontic, if one believes MWI is “true”) governed by the magnitude of the wave function for the alternative outcomes. There is no sense in which, under MWI, these observed events can be thought of as deterministic features of the *world*, even though the *universe* (multiverse) is deterministic.

          • Here is the quote: “The fact that a cause cannot both be the cause of X and not the cause of X isn’t defined into existence. That is a logical conclusion that if a cause exists, it doesn’t have self-contradictary variables.”

            That quote says the exact opposite of “an event cannot have distinct (exclusive) outcomes”

            That definition does not imply determinism or the “variables” that you postulated (in the last word of the quote two paragraphs earlier). I now understand that your definition of “causal” does not include the requirement for determinism in the outcome.

            Again, the fact that a cause cannot both be the cause of X and not the cause of X isn’t defined into existence. Rather it is logical conclusion that if a cause exists, it doesn’t have self-contradictary variables.

            Yes, it does imply that the world before the split had the option (indeed the requirement) to split into both worlds. There is also a bit of a terminology problem; see “worlds” and “universe” in the penultimate paragraph, below.

            The point I made was that there was no option other than to split, and therefore it is just as determined as any non-split cause in a one-world deterministic interpretation. For the sake of clarity “universe” and “world” are used interchangeably for a MWI.

            Indeed, that was my point. Whatever outcome I observed, the other outcome was a possible (indeed actual) future of my world before the observation.

            I want this to be perfectly clear, it has nothing to do with what you or anyone “observes”. It only has to do with particle interation. Before any creatures evolved to “observe” anything…wave functons decohere based on particle interaction (what we experimentally call “measurement” which is a better word than “observe” (as we observe measurements after the fact of them).

            This is the “could have been/done otherwise” I have been trying to point out is a consequence of MWI.

            What I’m saying is that you are making a huge mistake in thinking that a split means you “could have done otherwise”. Rather, it means that each one of the occurances MUST HAPPEN the exact way they do in each prospective “world”. There was no otherwise possibility than the split happening the way it did and the output of each world being the exact way they are.

            I now understand that I should have used the phrase “nondeterministic causal” instead of “acausal” by your definition that I quoted above.

            I think we need to clarify how you are using the word “determinism” and “indeterminism” (or nondeterminism per your usage.) To clarify my usage read here: “Determinism” and “Indeterminism” for the Free Will Debate
            http://breakingthefreewillillusion.com/determinism-indeterminism-confusions/

            The evolution of the wave function is not something normally identified as an “event” in MWI. Events are observable interactions.

            “Event” only means that something “happens”. That is all. The wave function leads to superposition which leads to environmental decoherence (for MWI). These are all “events”.

            MWI lacks counterfactual definiteness; we cannot speak meaningfully of the results of measurements that have not been performed (i.e. the ability to assume the existence of objects, and properties of objects, and the occurrence of events, even when they have not been measured). In the absence of observation no event can properly be said to have occurred in MWI.

            Again, all deterministic interpretations have definiteness. There is no counterfactual event, only factual events. You again (in the above) are mixing epistemic uncertainty with ontic assessments. They are not the same thing. The fact that we don’t know what “will occur” is irrelevant to the determinacy of the event.

            The splitting is not a part of the theory per se; it is a way of explaining the meaning of the “world” from the point of view of an observer, particularly to emphasize the sense in which alternative (but mutually exclusive) *observed* outcomes of events are possible (indeed actual, though not necessarily “equally” real).

            In a realist MWI the split is definitely part of the theory. In a non-realist MWI the splitting is only a part of the mathematical description but not anything real. Neither have to do with what is “observed” but rather the event that takes place due to measurement (or particle interaction). It has absolutely nothing to do with a conscious POV. In a realist iterpretation splits happened since the beginning of our known universe without any conscious observers at all.

            Many writers use different words to distinguish between the objective *universe*, which is the single deterministic universal wave function (which does not split off in any sense and in which events per se cannot properly be said to have occurred), and the “world” (which can be though of as splitting off) which is as the universe appears for a particular observer as a sequence of interactions.

            I agree these words are often ambigious, many physicists use the two interchangeable. For example, a MWI is often called a multiverse hypothesis or “non-communicating parallel universes” also known as quantum worlds. But for the sake of clarity, we can stick to the word “world” rather than “universe”. Just know that I mean them interchangeably for all of our MWI discussions.

            Using this terminology, quantum *events* that occur (and are observed) can, from the point of view of the observer, be expected to behave *as if* nondeterministic, with the chance of outcomes (ontic, if one believes MWI is “true”) governed by the magnitude of the wave function for the alternative outcomes. There is no sense in which, under MWI, these observed events can be thought of as deterministic features of the *world*, even though the *universe* (multiverse) is deterministic.

            As I said, the observation is irrelevant. “AS IF” (meaning appearing to be) nondeterministic is also irrelevant. Our lack of knowledge over the “variables” is irrelevant to their existence. In a realist MWI the events that take place are entirely deterministic in every way in every sense of the word. It is a feature of the multiverse. Any appearence of indeterminism is entirely an illusion.

            Again, to clarify this, every “world” split is dicatated long before it happens…stemming back to the “big bang” event…and every event in every world is equally as dictated.

          • https://mail.google.com/mail/u/0/#all/152038930f3eaca4

            > Here is the quote: “The fact that a cause cannot both be the cause of X and not the cause of X isn’t defined into existence. That is a logical conclusion that if a cause exists, it doesn’t have self-contradictary variables.”

            > That quote says the exact opposite of “an event cannot have distinct (exclusive) outcomes”

            X and “not X” are distinct (exclusive) outcomes. The statement “The fact [sic] that a cause cannot both be the cause of X and not the cause of X … is a logical conclusion” is not the opposite of “an event cannot have distinct (exclusive) outcomes”. It is rather a restatement of it.

            > Again, the fact that a cause cannot both be the cause of X and not the cause of X isn’t defined into existence. Rather it is logical conclusion that if a cause exists, it doesn’t have self-contradictary variables.

            Indeed, an indeterministic cause wouldn’t have “variables” (self-contradictory or otherwise) that determine the outcome. So while it would not have “self-contradictory variables”, it may have indeterministic results.

            > The point I made was that there was no option other than to split, and therefore it is just as determined as any non-split cause in a one-world deterministic interpretation. For the sake of clarity “universe” and “world” are used interchangeably for a MWI.

            The splits are not “events” in the sense we have been discussing. Among other things they are not observable.

            “Universe” and “world” are not used interchangably in MWI. A typical writer about the theory selects two terms, one to represent the totality of the universal wave function, which does not logically split. The other represents the evolution of time from the point of view of an observer, which does split. See sections 2.1, 3.2, and 3.3 of http://plato.stanford.edu/entries/qm-manyworlds/ .

            > > Indeed, that was my point. Whatever outcome I observed, the other outcome was a possible (indeed actual) future of my world before the observation.

            > I want this to be perfectly clear, it has nothing to do with what you or anyone “observes”. It only has to do with particle interation. Before any creatures evolved to “observe” anything…wave functons decohere based on particle interaction (what we experimentally call “measurement” which is a better word than “observe” (as we observe measurements after the fact of them).

            Under MWI, a particle interaction cannot properly be said to have occurred (from the point of view of an observer who may measure it after the fact – or even in the absence of an observer) until that measurement has occurred, at which time the measurement entangles the observer with the part of the universal wave function in which the event has occurred. In this sense MWI lacks counterfactual definiteness. The “split” is only relative to the observer.

            > What I’m saying is that you are making a huge mistake in thinking that a split means you “could have done otherwise”. Rather, it means that each one of the occurances MUST HAPPEN the exact way they do in each prospective “world”. There was no otherwise possibility than the split happening the way it did and the output of each world being the exact way they are.

            These splits are not events that occur in the world. These splits are precisely what is meant by the “could have been otherwise” of observed events in which there are multiple possible outcomes. The events cannot meaningfully be said to have occurred (in MWI) in the absence of observation. See the discussion of “counterfactual definiteness” below.

            > I think we need to clarify how you are using the word “determinism” and “indeterminism” (or nondeterminism per your usage.) To clarify my usage read here: “Determinism” and “Indeterminism” for the Free Will Debate
            http://breakingthefreewillillusion.com/determinism-indeterminism-confusions/

            Sure, I’m satisfied to use your definition from that link ‘If every event has a variable that can account for the event taking place, such would be considered a “deterministic” model of physics.’ and the associated definition of ’cause’. Unfortunately it is quite different from your most recent definition, which I was working from. I now understand that I should call a nondeterministic event such as radioactive decay acausal, on the basis of the absence of variables that force it to occur at a particular time, and I should avoid using a phrase such as “nondeterministic cause”.

            > > The evolution of the wave function is not something normally identified as an “event” in MWI. Events are observable interactions.

            > “Event” only means that something “happens”. That is all. The wave function leads to superposition which leads to environmental decoherence (for MWI). These are all “events”.

            Under MWI, the observation is what leads to decoherence *relative to the observer*. Environmental decoherence is relative to an observer (in its environment).

            > > MWI lacks counterfactual definiteness; we cannot speak meaningfully of the results of measurements that have not been performed (i.e. the ability to assume the existence of objects, and properties of objects, and the occurrence of events, even when they have not been measured). In the absence of observation no event can properly be said to have occurred in MWI.

            > Again, all deterministic interpretations have definiteness. There is no counterfactual event, only factual events. You again (in the above) are mixing epistemic uncertainty with ontic assessments. They are not the same thing. The fact that we don’t know what “will occur” is irrelevant to the determinacy of the event.

            You’re not reading MWI properly. From https://en.wikipedia.org/wiki/Many-worlds_interpretation : “MWI is a realist, deterministic, local theory, akin to classical physics (including the theory of relativity), at the expense of losing counterfactual definiteness.”

            From “https://en.wikipedia.org/wiki/Counterfactual_definiteness” : “In quantum mechanics, counterfactual definiteness (CFD) is the ability to speak meaningfully of the definiteness of the results of measurements that have not been performed (i.e. the ability to assume the existence of objects, and properties of objects, even when they have not been measured).”

            MWI treats the “uncertainty” – represented by the wave function – as an ontic description of the world. Assuming MWI is true (i.e. is an ontic description of the world), events cannot properly be said to have occurred in the absence of measurements of their results. This is not for epistemic reasons; under MWI it is the observation event that causes the entanglement which places the observer in a “world” in which the event can properly be said to have occurred.

            > > Many writers use different words to distinguish between the objective *universe*, which is the single deterministic universal wave function (which does not split off in any sense and in which events per se cannot properly be said to have occurred), and the “world” (which can be though of as splitting off) which is as the universe appears for a particular observer as a sequence of interactions.

            > I agree these words are often ambigious, many physicists use the two interchangeable. For example, a MWI is often called a multiverse hypothesis or “non-communicating parallel universes” also known as quantum worlds. But for the sake of clarity, we can stick to the word “world” rather than “universe”. Just know that I mean them interchangeably for all of our MWI discussions.

            Indeed, that will make it very difficult to speak on the topic; as in the universal wave function no object can properly be said to exist and no interaction between objects can properly be said to have taken place. The universal wave function does not logically split in MWI. When we speak of events that we observe, and actions that we take, we must necessarily be speaking of something different than the universal wave function (“universe”).

            I now understand that you prefer to use the word “multiverse” to mean the single, universal wave function (which does not split), and “world” or “universe” to refer to the behavior of the universe from the point of view of an observer, which logically splits as a result of entanglement due to observation.

            > > Using this terminology, quantum *events* that occur (and are observed) can, from the point of view of the observer, be expected to behave *as if* nondeterministic, with the chance of outcomes (ontic, if one believes MWI is “true”) governed by the magnitude of the wave function for the alternative outcomes. There is no sense in which, under MWI, these observed events can be thought of as deterministic features of the *world*, even though the *universe* (multiverse) is deterministic.

            > As I said, the observation is irrelevant. “AS IF” (meaning appearing to be) nondeterministic is also irrelevant. Our lack of knowledge over the “variables” is irrelevant to their existence.

            There are no “variables” that can be said to cause the distinct outcomes that distinguish two worlds. Such variables are not part of the MWI, and it is precisely one of the things that MWI has tried to eliminate. The existence of such variables, in fact, would conflict with the view that the distinct future worlds that MWI posits are possible.

            > In a realist MWI the events that take place are entirely deterministic in every way in every sense of the word. It is a feature of the multiverse. Any appearence of indeterminism is entirely an illusion.

            Indeed, the appearance of objects and interactions between objects is, under MWI, entirely an illusion (that is, subjective) within the context of the multiverse too. It is therefore useless in analyzing any “could have done otherwise” that would be useful to understand the original topic of discussion (free will). In the multiverse, a “murder event” cannot properly be said to have definitely occurred except from the point of view of an observer with which the event is entangled. The decoherence events that distinguish worlds are precisely the observations of object interactions that we need to link MWI’s multiverse to experience in a way that would make it philosophically meaningful to our everyday experience.

          • X and “not X” are distinct (exclusive) outcomes. The statement “The fact [sic] that a cause cannot both be the cause of X and not the cause of X … is a logical conclusion” is not the opposite of “an event cannot have distinct (exclusive) outcomes”. It is rather a restatement of it.

            You are thinking about superposition incorrectly. All superpositioned states extend from the one and are the only possible output for the one. Again, to analogize, you can think of a cueball hitting between an 8 ball and a 4 ball, causing the 8 ball to go in one direction and the 4 ball go in another. For a MWI of a superpositioned state the very superpositioned state that holds each option is the “8 ball” and “4 ball”, the main difference is that the motion of the 8 ball happens in world A while the motion of the 4 ball happens in world B.

            The cause of the superpositioned state is the cause that leads to both events in different worlds (causes the split). X is the superpositioned state. The cause doesn’t: 1) lead to superpositioned state (X) and 2) at the same time not lead to superpositioned state (not lead to X)…as that cause would be a self contradiction.

            Rather, the cause has the veriables that lead to X (the superpositioned state) …and that is the only state that the cause can lead to.

            This is similar to saying the cause (cueball hitting) leads to both the 8 ball rolling and the 4 ball rolling. It’s not saying that the cause leads to the 8 ball rolling (and not the 4 ball rolling) and the 4 ball rolling (and not the 8 ball rolling). Rather, the effect is that both the 8 ball and 4 ball roll (and there is no “not rolling). For a MWI, the event leads to ALL STATES, not ONE AND NOT THE OTHER. Those states are either suspended in hilbert spapce or decohere into a world. But it isn’t the case that one happens and not the other…it is the case that they all happen, and they al MUST HAPPEN, based on the initial cause.

            Hopefully this clears up the confusion.

            Indeed, an indeterministic cause wouldn’t have “variables” (self-contradictory or otherwise) that determine the outcome. So while it would not have “self-contradictory variables”, it may have indeterministic results.

            Indeterministic cause is an oxymoron. For an MWI there is no indeterministic event.

            The splits are not “events” in the sense we have been discussing. Among other things they are not observable.

            I never gave the criteria of being “observable” to an event. We don’t “observe” individual events on the quantum scale…ever. Only results of measurements. But that doesn’t make them not events. We don’t observe the fusion in the sun, but that doesn’t make such not an event.

            “Universe” and “world” are not used interchangably in MWI. A typical writer about the theory selects two terms, one to represent the totality of the universal wave function, which does not logically split. The other represents the evolution of time from the point of view of an observer, which does split. See sections 2.1, 3.2, and 3.3 of http://plato.stanford.edu/entries/qm-manyworlds/ .

            Again, they often are used interchangeably – depending on the source. Either way, the point is moot.

            https://en.wikipedia.org/wiki/Many-worlds_interpretation

            “Many-worlds implies that all possible alternate histories and futures are real, each representing an actual “world” (or “universe”). In lay terms, the hypothesis states there is a very large—perhaps infinite[2]—number of universes, and everything that could possibly have happened in our past, but did not, has occurred in the past of some other universe or universes.”

            Under MWI, a particle interaction cannot properly be said to have occurred (from the point of view of an observer who may measure it after the fact – or even in the absence of an observer) until that measurement has occurred, at which time the measurement entangles the observer with the part of the universal wave function in which the event has occurred.

            If by “observer” you mean “particle interaction of measuring device” then yes. If by “observer” you mean person looking at the results of measurement…no. This conflation over the poorly labeled “observer effect” is one that has a history to it. The measurement doesn’t entangle observers, it entangles environments.

            In this sense MWI lacks counterfactual definiteness. The “split” is only relative to the observer.

            The split only being observed by the person in the particular environment is irrelevant. It is factually definite that they will be in the environment they are. The fact that we can’t observe all of the other worlds is epistemic, not ontic.

            These splits are not events that occur in the world. These splits are precisely what is meant by the “could have been otherwise” of observed events in which there are multiple possible outcomes. The events cannot meaningfully be said to have occurred (in MWI) in the absence of observation. See the discussion of “counterfactual definiteness” below.

            No, you are simply wrong in every sense here. In a MWI you could not have done otherwise. Each iteration of “you” was causally forced into the very position it is in and could not have been otherwise. Each world could not have been otherwise. The superpositioned state could not have been otherwise. The events leading up to superpositioning could not have been otherwise. Your “observations” within the world you are in could not have been otherwise.

            Again, the MWI is as causally deterministic as can possibly be. You are simply incorrect about “counterfactual definiteness”. In a MWI every event is factually definite, and is before the event ever takes place.

            Sure, I’m satisfied to use your definition from that link ‘If every event has a variable that can account for the event taking place, such would be considered a “deterministic” model of physics.’ and the associated definition of ’cause’. Unfortunately it is quite different from your most recent definition, which I was working from. I now understand that I should call a nondeterministic event such as radioactive decay acausal, on the basis of the absence of variables that force it to occur at a particular time, and I should avoid using a phrase such as “nondeterministic cause”.

            I don’t think I defined determinism in this thread, so don’t know what you mean by “most recent definition”. Glad we can agree with the usage though and the fact that “nondeterministic cause” doesn’t make much sense in that context.

            Under MWI, the observation is what leads to decoherence *relative to the observer*. Environmental decoherence is relative to an observer (in its environment).

            You keep using the word “observer” here. Can you clarify what you mean by “observer”? I truly distain that word in QM due to the confusions it has caused…and think it should be simply called “measurement”.

            You’re not reading MWI properly. From https://en.wikipedia.org/wiki/Many-worlds_interpretation : “MWI is a realist, deterministic, local theory, akin to classical physics (including the theory of relativity), at the expense of losing counterfactual definiteness.”

            From “https://en.wikipedia.org/wiki/Counterfactual_definiteness” : “In quantum mechanics, counterfactual definiteness (CFD) is the ability to speak meaningfully of the definiteness of the results of measurements that have not been performed (i.e. the ability to assume the existence of objects, and properties of objects, even when they have not been measured).”

            I believe what I said was, given a REALIST account of MWI, and I quote “There is NO counterfactual event, only factual events.” Either way, the term “counterfactual” in philosophy is usually used as “relating to or expressing what has not happened or is not the case”…rather than what has.

            https://www.google.ca/webhp?sourceid=chrome-instant&ion=1&espv=2&ie=UTF-8#q=define:+counterfactual

            This is why it is called COUNTER factual – meaning counter to the facts. A counterfactual conditional would be subjuntive.

            I assume that, given that usage of the term “counterfactual definiteness”, such is assessed based on the fact that one cannot (and can never) conclude a realist account of MWI because of a lack of access. In that case it’s just being used as a lack of knowledge over the happening. But of course for our talk we are assuming a realist account in which each world happens – for the sake of argument.

            MWI treats the “uncertainty” – represented by the wave function – as an ontic description of the world. Assuming MWI is true (i.e. is an ontic description of the world), events cannot properly be said to have occurred in the absence of measurements of their results.

            Again, you keep conflating the epistemic with the ontic. I never said that there was no “uncertainty” in a MWI (both a realist and non-realist account)…but that is due to an access problem. We don’t have access to the variables.

            This is not for epistemic reasons; under MWI it is the observation event that causes the entanglement which places the observer in a “world” in which the event can properly be said to have occurred.

            NO, it is for epistemic reasons. The “observation event” is irrelevant to the uncertainty. The uncertainty has everything to do with not having access to “wordly” variables (the environments)….but only to a single one depending on the iteration of “you”. Again, I cannot stress this enough. The MWI is entirey deterministic.

            Indeed, that will make it very difficult to speak on the topic; as in the universal wave function no object can properly be said to exist and no interaction between objects can properly be said to have taken place. The universal wave function does not logically split in MWI. When we speak of events that we observe, and actions that we take, we must necessarily be speaking of something different than the universal wave function (“universe”).

            You are simply mistaken here. The events are said to “exist” in hilbert space…at least for a realist account of superpositioning/MWI.And the etire process is causal.

            I now understand that you prefer to use the word “multiverse” to mean the single, universal wave function (which does not split), and “world” or “universe” to refer to the behavior of the universe from the point of view of an observer, which logically splits as a result of entanglement due to observation.

            The observations are irrelevant to the facts about each observation needing to be the exact way they are even before they happen.

            There are no “variables” that can be said to cause the distinct outcomes that distinguish two worlds. Such variables are not part of the MWI, and it is precisely one of the things that MWI has tried to eliminate. The existence of such variables, in fact, would conflict with the view that the distinct future worlds that MWI posits are possible.

            This is a tad frustrating because it is almost as if you are making up your own indeterministic version of MWI. The wave function itself CAUSALLY leads to each state and each decoherence into very specific environments. The entire interpretation sustains variables, and that is why it is said to be deterministic. You are simply incorrect here.

            > In a realist MWI the events that take place are entirely deterministic in every way in every sense of the word. It is a feature of the multiverse. Any appearence of indeterminism is entirely an illusion.

            Indeed, the appearance of objects and interactions between objects is, under MWI, entirely an illusion (that is, subjective) within the context of the multiverse too. It is therefore useless in analyzing any “could have done otherwise” that would be useful to understand the original topic of discussion (free will).

            You assering it as “useless” doesn’t actually make it the case that it is. If we cannot do otherwise in a MWI, if each world must be the way it happens from the start, free will is impossible.

            In the multiverse, a “murder event” cannot properly be said to have definitely occurred except from the point of view of an observer with which the event is entangled. The decoherence events that distinguish worlds are precisely the observations of object interactions that we need to link MWI’s multiverse to experience in a way that would make it philosophically meaningful to our everyday experience.

            The “observations” or rather “measurements” have to be the exact way that they are for each “world”. They are entirely deterministic events as well. Also note that a MWI is even more defeatist. Even if you don’t murder in one world, rest assured that you must murder in another (and vice versa).

            Sorry, but a realist MWI is the worst end of a lack of free will. We can only hope that all of the horrific things that aren’t done in our “observed” world are not happening in other worlds. 😉

            ****

            Anyway – I think our conversation is becoming quite bloated. Let’s focus down if possible. Rather than address everything that was said making this longer and longer each time, let’s start again using more of a Socratic method (we can each ask one question). Otherwise I think it will become quite unproductive.

            Do you agree that a MWI is a deterministic interpretation (using my semantic of determinism)? Yes or No

          • > Do you agree that a MWI is a deterministic interpretation (using my semantic of determinism)? Yes or No

            MWI is a deterministic interpretation in the sense that every future state of the multiverse (the universal wave function) is fully determined by its state at any previous moment in time.

            MWI is not deterministic in the sense that it denies the *existence* of variables that would determine the (unique) outcome of measurements that have not yet been performed. This is not a matter of epistemic “not knowing” what entangled environment we will end up in – knowing what environment we will end up in (in the future) means the same thing as knowing the outcome of the measurement (in the future). We *know* will end up in all of the possible entangled environments that result from the measurement, but that knowledge leaves us ignorant of the result of the future measurement. It is an ontological feature of the multiverse under MWI that such information does not exist before the measurement takes place.

            As it relates to social questions of free will, blame, praise, and justice, an understanding of the behavior of the *world* is far more relevant to an analysis of how we ought to behave than an understanding of the evolution of the universal wave function. “The MWI is a deterministic theory for a physical Universe and it explains why a world appears to be indeterministic for human observers.” [http://plato.stanford.edu/entries/qm-manyworlds].
            See section 6.5 of that for links to proofs that this understanding corresponds to an analysis of nondeterministic models.

          • MWI is a deterministic interpretation in the sense that every future state of the multiverse (the universal wave function) is fully determined by its state at any previous moment in time.

            Great!

            MWI is not deterministic in the sense that it denies the *existence* of variables that would determine the (unique) outcome of measurements that have not yet been performed.

            I have no idea what you mean by “denies the existence of such variables”. If anything, measurement is a part OF the variables.

            This is not a matter of epistemic “not knowing” what entangled environment we will end up in – knowing what environment we will end up in (in the future) means the same thing as knowing the outcome of the measurement (in the future). We *know* will end up in all of the possible entangled environments that result from the measurement, but that knowledge leaves us ignorant of the result of the future measurement.

            Such “ignorance” IS epistemic ignorance. If we “know we will end up in all of the possible entangled environments that result from the measurement” (in a specific determined way) our ignorance over the future result is entirely due to a lack of future knowledge.

            It is an ontological feature of the multiverse under MWI that such information does not exist before the measurement takes place.

            Bzzzzt. Remember what you agreed to: “MWI is a deterministic interpretation in the sense that every future state of the multiverse (the universal wave function) is fully determined by its state at any previous moment in time.” Let’s be clear that all “information” is dictated in a MWI by the previous moment. There is no acausal information. Measurement is a part OF the causal information, and what causes the measurement is a part OF the causal information, and so on.

            In regards to section 6.5, keep in mind that holding similar behavior (in people thinking about these things) to an indeterministic interpretation does not imply any sort of indeterminism. That being said the “Behavior Principle” is very arguable and should not be accepted on it’s face for a MWI. Keep in mind that for a MWI the “probability” is an illusion (as all events in the wave distribution must happen). But this is a digression.

            Let’s focus down because you didn’t really answer with a “yes” or “no” and you gave what seemed to me to be a contradictory responses (either that or simply language that needs clarification), and I think you could have given a “yes” or “no” given the specific semantic of determinism that is being used. So I’ll ask this again, and let’s try to focus on one thing at a time:

            Do you agree that a MWI is a deterministic interpretation (using MY semantic of determinism)? Yes or No?

            Sidenote: Please excuse any time delay in responses. Pretty busy.

          • You are simply wrong about the meaning of the phrase “counterfactual definiteness”. That phrase has a particular meaning in the context of QM that cannot be derived from the meaning of the individual words as they are used in philosophy. In this context a result that has not been measured is considered a counterfactual. See https://en.wikipedia.org/wiki/Counterfactual_definiteness . MWI as a theory lacks counterfactual definiteness; in this sense a quantity that has not been measured cannot properly be said to *have* a definite value (known or unknown). This is an ontic feature of MWI, not an epistemic issue. MWI is a realist theory of the universal wave function (your “mutiverse”); it is not a realist theory of worlds (objects, events, and measurements).

            You also seem to be applying the fallacious argument form *retrospective determinism* in stating that our ignorance of the future is an epistemic issue. Using your semantic definitions

            > Determinism: All events have a cause.

            > Cause: A variable that forces the result to a particular outcome.

            (Please correct me if I have this wrong, as I could not find a single consistent definition of “cause” in the page you pointed at).

            The variables we speak of include only variables that exist before the event. Otherwise the future result of the event could be thought of as a variable that is the cause of the event. A variable that does not exist until after the event has occurred is not the kind of variable that can properly be considered a cause of the event. With that in mind, the comment

            > Such “ignorance” IS epistemic ignorance. If we “know we will end up in all of the possible entangled environments that result from the measurement” (in a specific determined way) our ignorance over the future result is entirely due to a lack of future knowledge.

            Completely misses the mark. You seem to be equating ontic acausality with epistemic ignorance of the future.

            The “set of possible entangled environments in the universal wave function” (whether we know it or not) does not *determine* the future result of the measurement. The value yielded by the measurement is information that does not exist (known or unknown) until after the measurement has been performed, and it cannot be derived from the universal wave function (which *is* deterministic), even given the universal wave function at any future time.

            > That being said the “Behavior Principle” is very arguable and should not be accepted on it’s face for a MWI.

            Indeed, it is only in the face of its proofs that one should accept it.

            > Do you agree that a MWI is a deterministic interpretation (using MY semantic of determinism)? Yes or No?

            Of what? It is a deterministic interpretation of the multiverse, as described by the universal wave function. Your definition of determinism speaks of events and causes. But in the universal wave function, events cannot properly be said to have occurred. Events (and causes) can only properly be said to occur in (or with respect to) some world (or universe, which you use interchangably) that is in an entangled environment. That is because (as I said earlier) MWI as a theory lacks ‘counterfactual definiteness’ (https://en.wikipedia.org/wiki/Counterfactual_definiteness) – the theory does not allow us to speak meaningfully of the definiteness of the results of measurements that have not yet been performed (i.e. the ability to assume the existence of objects, and properties of objects, even when they have not been measured). This is an ontic property of MWI. So (in the absence of events) the fact that MWI is deterministic (by your definition) is in some sense trivial. MWI is usually described as a deterministic theory because the evolution of the universal wave function over time is unitary; this meaning of deterministic is not the same as yours.

            As applied to the (or a) world, it is not deterministic because (according to MWI) there do not exist variables that force future measurement events to yield particular outcomes. This meaning of deterministic aligns precisely with your definition.

          • I would also like to point out the contradiction in your words:

            > No, you are simply wrong in every sense here. In a MWI you could not have done otherwise. Each iteration of “you” was causally forced into the very position it is in and could not have been otherwise. Each world could not have been otherwise. The superpositioned state could not have been otherwise. The events leading up to superpositioning could not have been otherwise. Your “observations” within the world you are in could not have been otherwise.

            The phrase “could have been otherwise” means, precisely, that the world as it existed at some point in time had more than one possible future. And that is precisely what MWI means by “many worlds” – each “world” acts as a distinct future. For the “you” that exists before the split, there are no variables that distinguish which outcome is your “true” future – both are possible (indeed actual). To suggest otherwise is to invoke the logical fallacy of retrospective determinism.

          • You are simply wrong about the meaning of the phrase “counterfactual definiteness”. That phrase has a particular meaning in the context of QM that cannot be derived from the meaning of the individual words as they are used in philosophy. In this context a result that has not been measured is considered a counterfactual. See https://en.wikipedia.org/wiki/Counterfactual_definiteness .

            I never said the usage wasn’t different. Rather I explained how I was using the word counterfactual…which is the normal usage. If “counterfactual definiteness”in QM simply means “a result that is not measured (but could be)” then it merely means we don’t have access to the measurements (so cannot) in other worlds for a MWI to lack such “counterfactual definiteness”. For MWI it is entirely based on not having access to measure the variables – rather than the variables not existing.

            MWI as a theory lacks counterfactual definiteness; in this sense a quantity that has not been measured cannot properly be said to *have* a definite value (known or unknown). This is an ontic feature of MWI, not an epistemic issue. MWI is a realist theory of the universal wave function (your “mutiverse”); it is not a realist theory of worlds (objects, events, and measurements).

            This is where you are mistaken. For a realist account of the MWI it ONLY implies that the value is unknown. There is nothing about “counterfactual definiteness” FOR THE MWI that implies “cannot properly be said to *have* a definite value” only that “those other outcomes could not have been measured” and therefore it lacks “counterfactual definiteness”. That is all. You are entirely missing the boat on this.

            You also seem to be applying the fallacious argument form *retrospective determinism* in stating that our ignorance of the future is an epistemic issue.

            It has nothing to do with retrospection. In fact I said over and over again that the “worlds” (in a MWI) that will come about in the future all causally stem from the big bang, and they could not be otherwise that what is dictated by those causal events.

            The variables we speak of include only variables that exist before the event. Otherwise the future result of the event could be thought of as a variable that is the cause of the event. A variable that does not exist until after the event has occurred is not the kind of variable that can properly be considered a cause of the event. With that in mind, the comment.

            No, any future variables that have not happened yet are dictated by preceding variables – and hence could not be otherwise. And future variables are a consideration for cause and effect.

            Completely misses the mark. You seem to be equating ontic acausality with epistemic ignorance of the future.

            I don’t know where you are getting “ontic acausality” from (is there any other type?). We are addressing a MWI – and for that it is only causality. The epistemic ignorance is an access issue (we don’t have access to the superpositioned state or other worlds).

            “The “set of possible entangled environments in the universal wave function” (whether we know it or not) does not *determine* the future result of the measurement. The value yielded by the measurement is information that does not exist (known or unknown) until after the measurement has been performed, and it cannot be derived from the universal wave function (which *is* deterministic), even given the universal wave function at any future time.”

            Let’s be perfectly clear that both the measurements and the wave function are part of the causal events that lead to the very specific worlds that could not be otherwise in a realist MWI.It matters not that decoherence doesn’t take place until measurement. The events of the wave, measurement, and decoherence are entirely causal…and could not happen differently.

            “Of what? It is a deterministic interpretation of the multiverse, as described by the universal wave function. Your definition of determinism speaks of events and causes. But in the universal wave function, events cannot properly be said to have occurred.”

            Either you are postulating many worlds or you are not. Are you suggesting that the other worlds cannot be properly said to have occured at all? If so it defeats the entire point of you arguing the case of a MWI. Either the worlds exist, in which case the variables that lead to them do as well – or the worlds do not exist, in which case there is no variables that led to them. The fact that we can’t “know” which one of these is the case is irrelevant. For a realist interpretation we are assuming the other worlds and hence assuming the variables – regardless if they are measurable from the perspective of one world. If you assume other worlds, then events can be said to have taken place from the wave function to the output of the worlds.

            You are mistakenly thinking that lacking “counterfactual definiteness” means “lacking variables or events”. It doesn’t. It ONLY implies a lack of an ability to measure. If you think that the lack of measurement implies the lack of the thing not being measured (in the one world) – then you simply cannot be postulating multiple realist worlds either. If you are postulating that the worlds exist, then you are posulating the variables that produced them. You can’t have this both ways.

            Again, the reason a MWI is deterministic is the postulation that each part of the wave function causally decoheres splitting into multiple worlds. This is an “event”, it has “variables” (hence the point of a MWI to not collapse the wave function), and it is deterministically dictated since the big bang.

            All of this being said I believe we are talking past each other again. If lacking counterfactual definiteness meant lacking variables, then the interpretation would be indeterministic. It isn’t. It only means, as the wikipedia article says: “The single adjective “counterfactual” may also appear in physics discussions where it is frequently treated as a noun. The word “counterfactual” does not mean “characterized by being opposed to fact.” Instead, it is used to characterize values that could have been measured but, for one reason or another, were not.” Since we could not have measured the results on those other worlds, it lacks “counterfactual definiteness”. That is ALL.

            *****

            The phrase “could have been otherwise” means, precisely, that the world as it existed at some point in time had more than one possible future. And that is precisely what MWI means by “many worlds” – each “world” acts as a distinct future. For the “you” that exists before the split, there are no variables that distinguish which outcome is your “true” future – both are possible (indeed actual). To suggest otherwise is to invoke the logical fallacy of retrospective determinism.

            You aren’t seeming to get it. Neither the world nor the entire multiverse had more than one possible future. The world that you “measure” had to take place the exact way and could not have been otherwise. The world for the other iteration of you had to take place the exact way it did and could not have been otherwise. The multiverse with all of the worlds had to take place the exact way it did and could not have been otherwise. There is no real otherwise possibility in a MWI, only a split off of worlds that had to take place the exact way they did and could not have been otherwise.

            Perhaps we can go into a thought experiment. In the thought experiment you get into a Star Trek transporter, which disassembles your molecules and recreates them elsewhere. A problem happens, however, where it recreates your molecules twice on to two different planets. Now that there are two iterations of you, it doesn’t mean that you are “doing otherwise” just because one iteration of you is doing X and the other at the same time is doing Y. It just means that a split causally took place, but the split couldn’t have happened otherise and each iteration of you couldn’t have done otherwise. It is no different than the split of decohered “worlds” for a MWI in regards to “otherwise”.

          • > I explained how I was using the word counterfactual…which is the normal usage. If “counterfactual definiteness”in QM simply means “a result that is not measured (but could be)” then it merely means we don’t have access to the measurements (so cannot) in other worlds for a MWI to lack such “counterfactual definiteness”. For MWI it is entirely based on not having access to measure the variables – rather than the variables not existing.

            I understood that this is what you were saying, but that is not the meaning of the phrase “counterfactual definiteness”. In QM, counterfactual definiteness (CFD) is the ability to speak meaningfully of the definiteness of the results of measurements that have not been performed (i.e. the ability to assume the existence of objects, and properties of objects, even when they have not been measured). It does not refer to knowing or not knowing the results of the measurements, it refers to the existence of the measured quantity. In a theory (such as MWI) that lacks counterfactual definiteness, a property that has not been measured cannot be assumed to *exist*. If you think that is wrong, I suggest you edit the page https://en.wikipedia.org/wiki/Counterfactual_definiteness with your correction.

            > Let’s be perfectly clear that both the measurements and the wave function are part of the causal events that lead to the very specific worlds that could not be otherwise in a realist MWI. It matters not that decoherence doesn’t take place until measurement. The events of the wave, measurement, and decoherence are entirely causal…and could not happen differently.

            I’m not sure what you intend by “realist MWI”. MWI is a realist theory of the universal wave function, what you call the multiverse. It is not a realist theory of worlds as MWI lacks counterfactual definiteness (as that term is used in discussions of QM by people other than you). In MWI, none of the variables that exist before measurement determine the value you see displayed by the measurement device; that is a quantity that cannot properly be said to exist (even as a function of variables that do exist) before the measurement.

          • I understood that this is what you were saying, but that is not the meaning of the phrase “counterfactual definiteness”. In QM, counterfactual definiteness (CFD) is the ability to speak meaningfully of the definiteness of the results of measurements that have not been performed (i.e. the ability to assume the existence of objects, and properties of objects, even when they have not been measured). It does not refer to knowing or not knowing the results of the measurements, it refers to the existence of the measured quantity. In a theory (such as MWI) that lacks counterfactual definiteness, a property that has not been measured cannot be assumed to *exist*. If you think that is wrong, I suggest you edit the page https://en.wikipedia.org/wiki/Counterfactual_definiteness with your correction.

            The full quote of the wikipedia article (please see the bold text):

            In quantum mechanics, counterfactual definiteness (CFD) is the ability to speak meaningfully of the definiteness of the results of measurements that have not been performed (i.e. the ability to assume the existence of objects, and properties of objects, even when they have not been measured). The term “Counterfactual definiteness” is used in discussions of physics calculations, especially those related to the phenomenon called quantum entanglement and those related to the Bell inequalities.[1]

            The single adjective “counterfactual” may also appear in physics discussions where it is frequently treated as a noun. The word “counterfactual” does not mean “characterized by being opposed to fact.” Instead, it is used to characterize values that could have been measured but, for one reason or another, were not.

            So perhaps you should edit the wikipedia article. The lack of the ability to “speak meaningfully of the definiteness of the results of measurements that have not been performed” in a MWI comes from the INABILITY to measure “values that could have been measured but, for one reason or another, were not” simply due to the fact that they are on a different world that has decohered from the other.

            I’m not sure what you intend by “realist MWI”. MWI is a realist theory of the universal wave function, what you call the multiverse. It is not a realist theory of worlds as MWI lacks counterfactual definiteness (as that term is used in discussions of QM by people other than you).

            There is a realist account of MWI which postulates actual worlds, and there is one that says those other worlds are never actualized and just a part of the mathematical calculation. Hawking, for example, sides with a non-realist MWI due to the appreciation for the mathematics, but doesn’t believe in those other split off worlds as actually happening:

            According to Martin Gardner, the “other” worlds of MWI have two different interpretations: real or unreal; he claims that Stephen Hawking and Steve Weinberg both favour the unreal interpretation.[80] Gardner also claims that the nonreal interpretation is favoured by the majority of physicists, whereas the “realist” view is only supported by MWI experts such as Deutsch and Bryce DeWitt. Hawking has said that “according to Feynman’s idea”, all the other histories are as “equally real” as our own,[81] and Martin Gardner reports Hawking saying that MWI is “trivially true”.[82] In a 1983 interview, Hawking also said he regarded the MWI as “self-evidently correct” but was dismissive towards questions about the interpretation of quantum mechanics, saying, “When I hear of Schrödinger’s cat, I reach for my gun.” In the same interview, he also said, “But, look: All that one does, really, is to calculate conditional probabilities—in other words, the probability of A happening, given B. I think that that’s all the many worlds interpretation is. Some people overlay it with a lot of mysticism about the wave function splitting into different parts. But all that you’re calculating is conditional probabilities.”[83] Elsewhere Hawking contrasted his attitude towards the “reality” of physical theories with that of his colleague Roger Penrose, saying, “He’s a Platonist and I’m a positivist. He’s worried that Schrödinger’s cat is in a quantum state, where it is half alive and half dead. He feels that can’t correspond to reality. But that doesn’t bother me. I don’t demand that a theory correspond to reality because I don’t know what it is. Reality is not a quality you can test with litmus paper. All I’m concerned with is that the theory should predict the results of measurements. Quantum theory does this very successfully.”[84] For his own part, Penrose agrees with Hawking that QM applied to the universe implies MW, although he considers the current lack of a successful theory of quantum gravity negates the claimed universality of conventional QM.[70]https://en.wikipedia.org/wiki/Many-worlds_interpretation

            This is why I like to preface that we are discussing a realist account of the “other worlds”.

            In MWI, none of the variables that exist before measurement determine the value you see displayed by the measurement device; that is a quantity that cannot properly be said to exist (even as a function of variables that do exist) before the measurement.

            You keep saying “before measurement”. Measurement is what causes the decoherence event, and each world splits from there based on the wave function.All of the variables are in place before, during, and after the event. It’s an entirely deterministic process:

            https://en.wikipedia.org/wiki/Many-worlds_interpretation

            ~ MWI removes the observer-dependent role in the quantum measurement process by replacing wavefunction collapse with quantum decoherence.
            ~ MWI is a realist, deterministic, local theory, akin to classical physics (including the theory of relativity), at the expense of losing counterfactual definiteness. MWI achieves this by removing wavefunction collapse, which is indeterministic and non-local, from the deterministic and local equations of quantum theory

          • > So perhaps you should edit the wikipedia article.

            It agrees with what I said.

            > The lack of the ability to “speak meaningfully of the definiteness of the results of measurements that have not been performed” in a MWI comes from the INABILITY to measure “values that could have been measured but, for one reason or another, were not” simply due to the fact that they are on a different world that has decohered from the other.

            This isn’t relevant to cross-world measurements, if such a thing were even meaningful. What is means for MWI is that *before* a measurement (decoherence event), it is meaningless to hypothesize the existence of a particular (known or unknown) value for a variable that has not yet been measured (even when one intends to measure it imminently). Such a value does not *exist* until after the measurement.

            > > In MWI, none of the variables that exist before measurement determine the value you see displayed by the measurement device; that is a quantity that cannot properly be said to exist (even as a function of variables that do exist) before the measurement.

            > You keep saying “before measurement”. Measurement is what causes the decoherence event, and each world splits from there based on the wave function.All of the variables are in place before, during, and after the event. It’s an entirely deterministic process:

            The phrase “could have been otherwise” (with regards to the result of a measurement) is a question considering what was possible from the point of view before a measurement that has been done. That is why “before measurement” is important when we are trying to answer questions about what “could have been otherwise”.

            In MWI there are no variables that exist before the measurement that determine a value that will be the observed result of the measurement. (In other words MWI lacks counterfactual definiteness) So afterwards, in the world in which we have observed a value, the result of the measurement “could have been otherwise”.

          • This isn’t relevant to cross-world measurements, if such a thing were even meaningful. What is means for MWI is that *before* a measurement (decoherence event), it is meaningless to hypothesize the existence of a particular (known or unknown) value for a variable that has not yet been measured (even when one intends to measure it imminently). Such a value does not *exist* until after the measurement.

            I get that this is what you are saying, but there is nothing that says this or even implies this for either a lack of counterfactual definiteness or for the MWI. You are simply making up the assertion that “such a value does not *exist* until after the measurement”. In a MWI it is the opposite of this, which differentiates it from a Copenhagen collapse theory. Each state stems from each variable of the wave function itself.

            The phrase “could have been otherwise” (with regards to the result of a measurement) is a question considering what was possible from the point of view before a measurement that has been done.

            No, it isn’t about point of views at all. It’s about reality and there being alternate realities that are or were possible. For a MWI it just happens that split off worlds are all a part of the reality that couldn’t have been otherwise.

            That is why “before measurement” is important when we are trying to answer questions about what “could have been otherwise”.

            No, it’s irrelevant. Before measurement is causally produced which leads to measurement which is causally produced which leads to decoherence which is causally produced and on and on. The wave function is causally produced which leads to superposition that is causally produced which measurement causes decohernece which is causally produces, which many worlds decohered from each other are causally produced.

            In MWI there are no variables that exist before the measurement that determine a value that will be the observed result of the measurement. (In other words MWI lacks counterfactual definiteness) So afterwards, in the world in which we have observed a value, the result of the measurement “could have been otherwise”.

            Sorry, you are just making up stuff. Again, counterfactual definiteness says nothing about a “lack of variables” anywhere…and “measurement” is a part OF the variables…it isn’t something excluded from them. You are simply wrong here. Perhaps you are confusing an indeterministic collapse theory with MWI…who knows. Just know that you are mistaken for a MWI. For MWI the wave function HAS variables that exist prior to measurement….and the whole point of MWI is that each world stems from those variables rather than collapsing them with no variables for an indeterministic account.

          • > > This isn’t relevant to cross-world measurements, if such a thing were even meaningful. What is means for MWI is that *before* a measurement (decoherence event), it is meaningless to hypothesize the existence of a particular (known or unknown) value for a variable that has not yet been measured (even when one intends to measure it imminently). Such a value does not *exist* until after the measurement.

            > I get that this is what you are saying, but there is nothing that says this or even implies this for either a lack of counterfactual definiteness or for the MWI. You are simply making up the assertion that “such a value does not *exist* until after the measurement”. In a MWI it is the opposite of this, which differentiates it from a Copenhagen collapse theory. Each state stems from each variable of the wave function itself.

            You can find this right in the Wikipedia articles for MWI and CFD. I’m not talking about values of the wave function. The wave function is not something we ever measure, nor does it determine the outcome of future measurements. I’m talking about the values of properties, e.g of objects, before they have been measured. Part of the reason it makes no sense in MWI to hypothesize particular (known or unknown) values for quantities that have not yet been measured is that such a hypothesis would contradict observations of interference such as the two-slit experiment; this is the most basic thing that any theory of QM must account for.

          • Anyway, I don’t have more time for these discussions this week. Perhaps later. Have a good week. 😀

          • > I get that this is what you are saying, but there is nothing that says this or even implies this for either a lack of counterfactual definiteness or for the MWI. You are simply making up the assertion that “such a value does not *exist* until after the measurement”.

            From https://en.wikipedia.org/wiki/Counterfactual_definiteness :

            “In quantum mechanics, counterfactual definiteness (CFD) is the ability to speak meaningfully of the definiteness of the results of measurements that have not been performed (i.e. the ability to assume the existence of objects, and properties of objects, even when they have not been measured).”

            Counterfactual definiteness is the ability to assume the existence of properties that have not been measured. I’m not making it up; in this case I’m copying it word-for-word from Wikipedia.

            MWI as a theory lacks CFD; see https://en.wikipedia.org/wiki/Many-worlds_interpretation . That means that the theory does NOT include the ability to assume the existence of properties that have not been measured. Again, I’m not making this up, I’m copying it straight from Wikipedia.

            From that same page

            “Many-worlds reconciles the observation of non-deterministic events, such as random radioactive decay, with the fully deterministic equations of quantum physics.”

            Again, I’m not making this up. This is straight from Wikipedia, not my own indeterministic version of MWI.

            The former (the observation of non-deterministic events) is part of a description of the world which includes measurements. The latter (MWI’s description of the multiverse) is a description of the equations of quantum physics, but whose variables are never measured. These are not the same thing; whenever we are speaking of the definite results of measurements, we are necessarily speaking of the former.

            It is very frustrating to have a conversation with you when you seem unable to accept simple definitions that are widely accepted, or the consequences of them in the context of your own defined terms (such as cause and determinism).

          • You can find this right in the Wikipedia articles for MWI and CFD. You can find this right in the Wikipedia articles for MWI and CFD.

            No, what it says in the article is NOT what you are interpreting it to say.

            I’m not talking about values of the wave function. The wave function is not something we ever measure,

            Actually we measure the results of the wave function. The “other” worlds that stem from them are something we never measure either – yet you seem to want to talk meaningfully about their existence.

            nor does it determine the outcome of future measurements.

            Says you against what the MWI ACTUALLY says….which is that the wave function produces the result for each world that is being measured within that specific world.

            Part of the reason it makes no sense in MWI to hypothesize particular (known or unknown) values for quantities that have not yet been measured is that such a hypothesis would contradict observations of interference such as the two-slit experiment; this is the most basic thing that any theory of QM must account for.

            No it doesn’t contradict observations of interference. Another thing you are making up out of some place that the sun doesn’t shine.

            MWI as a theory lacks CFD; see https://en.wikipedia.org/wiki/Many-worlds_interpretation.

            I never said it didn’t lack CFD, but lacking CFD doesn’t imply a lack of variables in any way, shape, or form.

            That means that the theory does NOT include the ability to assume the existence of properties that have not been measured.

            That is NOT what it means.

            Again, I’m not making this up, I’m copying it straight from Wikipedia./blockquote>

            From that same page

            “Many-worlds reconciles the observation of non-deterministic events, such as random radioactive decay, with the fully deterministic equations of quantum physics.”

            At this point you are either foolong yourself, being dishonest, or displaying a severe lack of reading comprehension. If it’s a lacking of intellectual honesty, then I’m afraid these conversations here will need to conclude.

            Lets parse out that quote in terms of variables: “Many-worlds reconciles the observation of events with no variables, such as random radioactive decay, with the fully variabled equations of quantum physics.”

            In other words, and I cannot stress this enough, the observations are INCORRECT in a deterministic MWI..as every single event happens due to a variable…regardless of our capacity to observe and measure them.

            The former (the observation of non-deterministic events) is part of a description of the world which includes measurements. The latter (MWI’s description of the multiverse) is a description of the equations of quantum physics, but whose variables are never measured. These are not the same thing; whenever we are speaking of the definite results of measurements, we are necessarily speaking of the former.

            This is complete and utter nonsense. If you want to go there then we cannot even talk of a realist world account of the MWI to begin with…as we never, I repeat, never measure any other world than the one in which we have decohered with. I’ve corrected your misunderstanding over and over here. From the same page:

            MWI removes the observer-dependent role in the quantum measurement process by replacing wavefunction collapse with quantum decoherence.

            Understand?

            The reason a MWI is not counterfactually definite is because of the inability to measure each from our own world. It is a problem with empiricism, not a problem with variabled formulation. If you want to assume that a lack of empiricism implies what cannot be empirically verified or measured simply does not exist (e.g. that the variables do not exist)…then you need to abandon any notion of a realist account (in terms of worlds) of the MWI, as those worlds cannot be empirically verified or measured either. So even if we were to accept your incorrect usage of these terms, you would be stuck in a conundrum. Either the variables can be said to exist based on the formulation that contains them, or you cannot say the other worlds exist either (and must take a non-realist account of MWI in which only one world exists and the others are not real at all).

            It is very frustrating to have a conversation with you when you seem unable to accept simple definitions that are widely accepted, or the consequences of them in the context of your own defined terms (such as cause and determinism).

            I’m actually accepting the definition in the wiki article, you are just misunderstanding what it is saying – which is the frustrating part of it all. The fact that you think there is a “simple definition” or that it is not arguable about MWI means that you have found yourself a single article that you can contrive an incorrect idea from and that is it. Take a look at the wiki talk about your source for example:

            https://en.wikipedia.org/wiki/Talk:Counterfactual_definiteness

            You know, I’ve yet to see a single comprehensible explanation of why it is that Bell’s theorem assumes CFD, nor why many-worlds violates it.

            The only thing that makes sense if MWI is said to abandon counterfactual definiteness is this:

            “In the Everett many-worlds interpretation, the assumption of counterfactual definiteness is abandoned, this interpretation assuming that the universe branches into many different observers, each of whom measures a different observation.”

            Meaning it is ONLY abandoned because we can never have access to the world. Not because the variables do not exist, but only because we have no ability to measure the RESULTS of them. It’s an empirical problem that is meaningless if we are accepting a theory of worlds we have no capacity to measure to begin with (a huge problem for MWI from my POV).

            But no, you are simply wrong on how this is being used for a MWI, even if we accept the original articles semantic, which also says this:

            The single adjective “counterfactual” may also appear in physics discussions where it is frequently treated as a noun. The word “counterfactual” does not mean “characterized by being opposed to fact.” Instead, it is used to characterize values that could have been measured but, for one reason or another, were not.

            Given that semantic of counterfactual, it is the fact that the values could NOT have been measured that rules out CFD for MWI, not the idea that the values do not exist (at least if one is arguing for a realist MWI account of the worlds as you are).

            If you are arguing for a non-realist world account of MWI, then you can say those other variables do not exist – as the worlds that extend from them do not exist. You can’t, however, have your quantum cake and eat it too.

            Okay..I need to work. It is way too time-consuming correcting you over and over again on the same things. Stop pretending to understand the MWI and thinking there is a teenie bit of ontic indeterminism within it. There is not. Any perception of indeterminism for an observer is entirely due to them not being able to access all of the variables in states that have decohered from each other.

          • > > You can find this right in the Wikipedia articles for MWI and CFD.

            > No, what it says in the article is NOT what you are interpreting it to say.

            I wasn’t interpreting it. I was copying it into this thread. From the CFD page

            ‘The word “counterfactual” does not mean “characterized by being opposed to fact.” Instead, it is used to characterize values that could have been measured but, for one reason or another, were not.’

            It does not refer to the values in other words, as you appear to think it does, because those are never “values that could have been measured”.

            > > Part of the reason it makes no sense in MWI to hypothesize particular (known or unknown) values for quantities that have not yet been measured is that such a hypothesis would contradict observations of interference such as the two-slit experiment; this is the most basic thing that any theory of QM must account for.

            > No it doesn’t contradict observations of interference. Another thing you are making up out of some place that the sun doesn’t shine.

            I’m pretty sure the sun shines on the Theoretical Physics department at Caltech. http://www.preposterousuniverse.com/blog/2015/02/19/the-wrong-objections-to-the-many-worlds-interpretation-of-quantum-mechanics/#comment-7295910552604303933 .

            “In QM […] you have a quantum state. You use that quantum state to calculate the probability of experimental outcomes, but we aren’t allowed to think that the outcome we observe represents some truth that was there all along [i.e. ontic], but we just didn’t know [i.e. epistemic]. That’s what interference experiments (and Bell’s theorem etc) tell us.”

            This is an important point as it affects most interpretations of QM, not just MWI.

            You will find on that page a number of useful corrections to other misinterpretations you have of MWI (for example, you assertions that MWI is not testable, or that it postulates the existence of a huge number of worlds).

            > > I’m not talking about values of the wave function. The wave function is not something we ever measure,

            > Actually we measure the results of the wave function.

            I would be very interested in any reference you can produce for this assertion.

            > Given that semantic of counterfactual, it is the fact that the values could NOT have been measured that rules out CFD for MWI, not the idea that the values do not exist (at least if one is arguing for a realist MWI account of the worlds as you are).

            Variables that we could not measure are irrelevant to CFD, as it refers only to values that could have been measured.

            I think this conversation is just about drawing to a close. You seem too attached to a particular belief set to apply basic logic.

          • I wasn’t interpreting it. I was copying it into this thread. From the CFD page

            What you copied said absolutely nothing about “variables not existing”. That is just something that seems to be in your imagination.

            It does not refer to the values in other words, as you appear to think it does, because those are never “values that could have been measured”.

            Let’s be clear that all measurements take place in every world for a MWI, it is just that one instance of you cannot measure those others that are taking place. The variables exist, it is an access problem. Hence the reason that the values could not be measured for a single person in a single world. It has absolutely nothing to do with the variables “not existing”…something you again are imagining.

            Regarding Sean Carroll I need a much better source than a comment he made on his post. Such is a convoluted quote by Carroll (and the distinction between what is true and what will happen – which I think he’s referring to the prior and not the latter for his comment). Bell’s theorem does not tells us that such is not deterministic when it comes to either a many world interpretation or pilot wave theory. A MWI is both realist and deterministic, neither of those being compatible with there being another possibiliy for the outcome observed. Even the probability is not “real” given that that all worlds must happen the way they do:

            http://plato.stanford.edu/entries/qm-manyworlds/

            “The difficulty with the concept of probability in a deterministic theory, such as the MWI, is that the only possible meaning for probability is an ignorance probability, but there is no relevant information that an observer who is going to perform a quantum experiment is ignorant about. The quantum state of the Universe at one time specifies the quantum state at all times. If I am going to perform a quantum experiment with two possible outcomes such that standard quantum mechanics predicts probability 1/3 for outcome A and 2/3 for outcome B, then, according to the MWI, both the world with outcome A and the world with outcome B will exist. It is senseless to ask: “What is the probability that I will get A instead of B?” because I will correspond to both “Lev”s: the one who observes A and the other one who observes B.”

            Every result stems from the universial wavefunction and could not have been otherwise.

            “You will find on that page a number of useful corrections to other misinterpretations you have of MWI (for example, you assertions that MWI is not testable, or that it postulates the existence of a huge number of worlds).

            I never said that it was untestable, only that a realist account of “other” worlds is untestable. Understand the distinction here. Decoherence makes such untestable. And that part about the difference between “postulate” and “derive from what is postulated” is really a contrivance on the part of Carroll:

            “Now, MWI certainly does predict the existence of a huge number of unobservable worlds. But it doesn’t postulate them. It derives them, from what it does postulate.”

            Again, if one accepts a realist account of the worlds (which isn’t necessary to do for a MWI as I already explained), then one is “postulating the worlds”. It’s absurd not to think so.

            I would be very interested in any reference you can produce for this assertion.

            What do you think is being measured when we look at a pattern? What do you think the probabilities of the “wave function” are modeling? The wave function is a model of the probabilitic results of measurement.

            Variables that we could not measure are irrelevant to CFD, as it refers only to values that could have been measured.

            That is WHY a MWI does not have CFI, because it could not have been measured.

            I think this conversation is just about drawing to a close. You seem too attached to a particular belief set to apply basic logic.

            Says the man who A) rules out variables in an entirely realistic and local deterministic interpretation (a contradiction) and B) rules out variables based on an inability to measure them, yet rules in decohered worlds that are entirely unmeasurable.

            Sorry, but you shouldn’t be talking about applying “basic logic” here. Anyway, it is exhausing correcting for all of your errors. Just know that if there was no value that led to the results, the MWI would be considered an indeterministic interpretation, NOT a deterministic one.

            Also know that even if that were the case (IT’S NOT!),…even IF there was an acausal event that lead to the results of each, that has the same problem as any other indeterministic account (any otherwise account wouldn’t be up to you).

            Anyway, this conversation is unproductive. It seems you want to just make up your own quantum theory as you go to suit your needs, even though no matter what theory is postulated (even your imaginary one’s) are incompatible with the ability to have done, of one’s own accord, otherwise. For a deterministic MWI, all possibility happen and couldn’t have been otherwise. For an ENTIRELY FICTIONAL account of an indeterministic MWI, the results you end up with stem from no variables that are in your control. And if each “world” has to happen anyway for a realist account of worlds, it matters not if such stems from a variabled account or your fictitious unvariabled indeterministic version of MWI.

            The only reason I’ve been having this debate is so you stop talking about interpretations that do not exist…but we can talk about those non-existent versions as well and logically they have the very same problems alluded to for Copenhagen.

            END. GAME. SET. MATCH. 😉

  7. > Perhaps we can go into a thought experiment. In the thought experiment you get into a Star Trek transporter, which disassembles your molecules and recreates them elsewhere. A problem happens, however, where it recreates your molecules twice on to two different planets. Now that there are two iterations of you, it doesn’t mean that you are “doing otherwise” just because one iteration of you is doing X and the other at the same time is doing Y. It just means that a split causally took place, but the split couldn’t have happened otherise and each iteration of you couldn’t have done otherwise. It is no different than the split of decohered “worlds” for a MWI in regards to “otherwise”.

    In this though experiment, if my choices were to go to either Mars or Venus, after the transportation event I will see that I have chosen, say, Mars. But the me that existed before the transportation event also had a possible future in which he ends up on Venus. So in this thought experiment, I could have (indeed will have) done otherwise.

    • The mental “choice” prior is a different circumstance than the event which couldn’t have been otherwise. If I choose to run and not fall, yet I trip, I’ve done otherwise than what I wanted to do. That doesn’t mean I could have done otherwise than to fall. Likewise, you couldn’t have done otherwise than to be split to Mars and Venus- regardless if you only wanted one of you to go to Mars and not another iteration to Venus. That split was dictated since before you were even born. Your want was irrelevant to what was causally dictated and could not have been otherwise.

      • The problem with your Star Trek scenario is that I end up in a world where both options (Mars and Venus) have occurred. But in MWI I do not end up in a world where both have occurred. The “me” before the split had two possible future worlds. That is the plain meaning of “many worlds.” In one of them I find myself on Mars. But even though I see myself on Mars afterwards, I can know that the “me” before the split had a possible future on Venus. That is the plain meaning of “could have been otherwise”.

        • It makes no difference if you split or if entire worlds split, that is the point. Both are causally determined. And the fact that you can or cannot verify your existence on Mars or Venus from the other (and make the claim that it happened or not) is irrelevant. Even if the transporter caused a decoherence event where your Mars self could never detect your Venus self and vice versa – that is irrelevant to the happening being necessitated since big bang.

          You couldn’t have done otherwise but to split into two of you, and the worlds could not have done otherwise than to split in a MWI. And both must take place the exact way they do.

          Anyway, I think it’s pretty clear…but you don’t seem to “get it” (no offense…it’s a tad tiresome). Otherwise means X and NOT Y (other than Y), not both X AND Y occuring in different spaces, worlds, etc. When both happen, those are the very events that couldn’t have been otherwise. I’ll keep repeating that a MWI is entirely deterministic. Everything that takes place must take place the very way it takes place.

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