Tuesday, September 10, 2019

Book Review: “Something Deeply Hidden” by Sean Carroll

Something Deeply Hidden: Quantum Worlds and the Emergence of Spacetime
Sean Carroll
Dutton, September 10, 2019

Of all the weird ideas that quantum mechanics has to offer, the existence of parallel universes is the weirdest. But with his new book, Sean Carroll wants to convince you that it isn’t weird at all. Instead, he argues, if we only take quantum mechanics seriously enough, then “many worlds” are the logical consequence.

Most remarkably, the many worlds interpretation implies that in every instance you split into many separate you’s, all of which go on to live their own lives. It takes something to convince yourself that this is reality, but if you want to be convinced, Carroll’s book is a good starting point.

“Something Deeply Hidden” is an enjoyable and easy-to-follow introduction to quantum mechanics that will answer your most pressing questions about many worlds, such as how worlds split, what happens with energy conservation, or whether you should worry about the moral standards of all your copies.

The book is also notable for what it does not contain. Carroll avoids going through all the different interpretations of quantum mechanics in detail, and only provides short summaries. Instead, the second half of the book is dedicated to his own recent work, which is about constructing space from quantum entanglement. I do find this a promising line of research and he presents it well.

I was somewhat perplexed that Carroll does not mention what I think are the two biggest objections to the many world’s interpretation, but I will write about this in a separate post.

Like Carroll’s previous books, this one is engaging, well-written, and clearly argued. I can unhesitatingly recommend it to anyone who is interested in the foundations of physics.

[Disclaimer: Free review copy]


  1. Sabine,

    By the two biggest objections, I assume you mean the preferred-basis problem and the probability-measure problem.

    There is, however, an even bigger problem: the universe does not really "split" according to the actual mathematical apparatus of quantum mechanics!

    The dimension of the Hilbert space of course must stay the same, and it would be extremely rare (set of measure zero) for any one of the basis vectors (i.e., basis states) to have probability exactly equal to zero.

    All that happens is that the probabilities slosh around from one basis state to another: sometimes one particular state has more probability, sometimes less, but almost never zero.

    All of us know this for low dimensional systems: I am increasingly perplexed as to why so few people notice this basic fact for MWI.

    I therefore propose that the MWI be renamed the "sloshing-probability interpretation," which, of course, has the nice acronym SPI.

    Somehow, though, I suspect that telling the truth to laypeople about SPI will not sell nearly as many pop-science books as the romantic fantasy about branching universes!


    1. PhysicistDave,

      No, those are not the problems that I mean. See, this is why I say I'm perplexed.

    2. Then, Sabine, I look forward to your explication of your perplexity!

    3. My lay understanding is there's no "split" that you can count but a very non-linear effect happens where a tiny part of the past wave function becomes a prior to a very wide and complex future that looks like a whole new world.

      As you say it looks like degrees of freedom are being re-arranged or "sloshing" but I'm not clear at all how this happens or if there's some destructive interference that isolates a sharp "event" from the broad wave function. Looking forward to getting the book in Europe.

    4. Pavlos,

      The whole idea of MWI is that the (linear) Schrodinger equation is all-ruling.

      So, I doubt you can get a "a very non-linear effect" in MWI.

      I am tempted to suggest some solution to the paradox, but since I think MWI is (probably) false, I think I will leave that to proponents of MWI (or SPI, as I now prefer)!


  2. I have one big objection to the many-words interpretation: my Eyesight is rather poor.

  3. "Like Carroll’s previous books, this one is engaging, well-written, and clearly argued. I can unhesitatingly recommend it to anyone who is interested in the foundations of physics."

    "The second half of the book is dedicated to his own recent work, which is about constructing space from quantum entanglement. I do find this a promising line of research and he presents it well."

    From your review I learn, that Sean Carrol is an excellent physicist. He loves solving "some deeply hidden" mysteries, which is in my view an absolute requirement for beeing a famous researcher.

    I completely agree with you, that the many world interpretation is one of the weirdest ideas in quantum mechanics. The idea has a long history and I really wonder, why still so many people are convinced, that "many worlds" is the only logical consequence of quantum theory. But weird ideas quite often live longer, than common sense would expect. I remenber, that the original motivation for string theory was to explain the strong force, which is nowadays successfully described by the means of QCD. However, string theory is still alive and well. "Landscapes", "Swampland", no observable predictions at all... Nothing can stop people working on this topic.

    Obviously, human beeings are not acting always on a rational basis. In particular, almoust all extraordinary talented scientists have an overwhelming fantasy, it's part of the job.
    There is nothing wrong with it.

    "If you want to be convinced, Carroll’s book is a good starting point"

    ... if you dont want to be convinced, you dont have to...

    I still believe in freedom of will, ie. freedom of choice, regardless what fundamental physics seems to suggest...

    This believe is grounded in my own personal life experience. In case of doubt, I have more trust in my own personal experience than in any physical theory based on "rational assumptions".

    1. Hello Former...

      Re your last two short paragraphs about free will: Forget fundamental physics for a moment. Try biology! Multi-generational heredity is factual. It includes genes, epigenetics, microbiome, viruses, prions... Experiences since conception impact us- chemical, auditory, motion,... Note that all the above are physical, and also includes all memories, thoughts, feelings.

      We make decisions/choices constantly, but they too are physical. There are no "calorie free" behaviors. Despite consciously making what we might think are "free" choices, they are irrefutably fettered by our physical past. If one can evidence a non-physical driver, I suspect a Nobel Prize would be in order!

    2. "I still believe in freedom of will, ie. freedom of choice, regardless what fundamental physics seems to suggest... "

      How is that different from "God said it; I believe it; that settles it"? As Sabine and others have pointed out, there is not a shred of evidence that free will exists.

    3. The fact is that we experience the necessity of making choices. The whole huge debate over whether or not free will exists is quite useless in deciding how to make choices. Morality is about how to deal with our experience of making choices and continues to be valid whether or not we have free will.

    4. @Phillip and Steven, I am convinced, that all of our observations are fully compliant with physical laws. Any definition of "free will" should take this into account. The laws simply describe how nature works. But "freedom of will" is a very different category than the "degrees of freedom" in a physical theory. The usual argumentation against free will would hold also for "fredom of speech". What does freedom of speech mean, if everything to be said is already determined since the big bang?
      Brains of human beeings are not fully developed at birth. Humans are able to learn how to survive within an completly unknown environment. Even if everything what happens is determined from the very beginning, this does not help you to live your own personal live. Even in a deterministic world, freedom of will may emerge from biological or cultural evolution, and therefore I think its a good idea to believe in free will. It should however be a research topic of neuro-science, not of elementary particle physics. Human brains are the most complex matter in the world and in my view freedom of will is an emergent feature - it is in some sense a cultural achievement of mankind, but there should also be a correspondence to the pysical processes within our brains. In the very far future, also a sufficiently complex AI-device should in principal be able to develop some kind of free will.

    5. ...there is not a shred of evidence that free will exists.

      No, there isn't but then, there is not a shred of evidence that it doesn't exist either. Like the existence of God, the existence of free will cannot be proven or disproven by science because both are philosophical concepts which lie beyond the realm of science, in the empirically unbound realm of metaphysics. About such questions, science should remain indifferent, since neither is scientifically resolvable.

    6. "The fact is that we experience the necessity of making choices. The whole huge debate over whether or not free will exists is quite useless in deciding how to make choices. Morality is about how to deal with our experience of making choices and continues to be valid whether or not we have free will."

      Indeed. In particular, lack of free will has no impact on the criminal-justice system. Any enlightened justice system has three reasons for punishment: protect society from known offenders, reform of prisoners, and deterrent. None depend on free will. (How well various countries achieve these three goals is another question.)

    7. "No, there isn't but then, there is not a shred of evidence that it doesn't exist either."

      So you believe in everything whose non-existence has not been proven?

    8. So you believe in everything whose non-existence has not been proven?

      I don't believe that the question, of the existence or non-existence of something not subject to empirical verification, is a matter of scientific interest. Such questions are of a philosophical nature, and as such can only be argued, not resolved in any scientific sense. I find such philosophical questions tedious and uninteresting - because they cannot be resolved.

      All such philosophical questions boil down to a matter of taste or opinion; it's interesting only if you like to argue for the sake of arguing. I prefer the Roman approach: De gustibus non est disputandum.

    9. @AformerLEPexperimentalist
      > Human brains are the most complex matter in the world and [...]

      I really wish smart people would stop propagating this meme. Humans brains only appear more complex than stars because no one asks "what is the precise configuration of plasma in this star, at say m^3 resolution," whereas the questions we're interested in answering about brains require a fine-grained dynamical model. If we just want to know what path a brain follows when you throw it off a cliff, then surprise! Brains are simple too.

  4. A warm and positive -- if constrained -- review of the book. I look forward to your discussions of the objections to many worlds.

  5. Many brilliant people (defined by how we commonly quantify exceptional intelligence) believe in and promote many unsubstantiated thoughts as science. This trend has gotten worse in scientists over the past few decades. Knowing your "brilliant" tends to also lead to summary judgements. It's one the biggest reasons I think scientific progress is slower than it needs to be. No one is immune, but almost all of you think it’s not you just the colleagues you disagree with. Rational logic, empirical analysis, and experimental results, are gradually being replaced by stature, ego, and belief when trying to further the scientific understanding of our universe; and math is being abused as a tool for scientific creation rather than the tool of scientific communication it is suited for.

  6. I guess that we should just consider the process when Carroll makes a statement, for example,

    “We just have to accept that there is more than one of us in the universe. There are many, many Sean Carrolls. Many of every one of us.”

    from the viewpoint of many worlds interpretation. During this process there appears a lot of Sean Carrolls speaking any possible statements including the negation of the above statement. Hence, why should we pay attention to a statement of just one of these copies?

    1. We might consider the possibility that even in MWI there are constraints on possible branching, in which case we might find that every POSSIBLE copy of Sean Carroll is saying the same thing. But in some cases he might be sitting down and in other cases standing up and in other cases just beginning to rise from a seated position...

    2. I believe that this contradicts to the very idea of MWI. Let me take for example a statement from the news

      'The “many worlds” theory in quantum mechanics suggests that with every decision you make, a new universe springs into existence containing what amounts to a new version of you. Bestselling author and theoretical physicist Sean Carroll discusses the concept and his new book, “Something Deeply Hidden,” with NewsHour Weekend’s Tom Casciato.'

      It is hard to say what here "every decision you make" means but I guess that this should include whether I am going to agree with something or disagree. And if in this universe I agree, then my copy in another universe should disagree.

  7. Most remarkably, the many worlds interpretation implies that in every instance you split into many separate you’s, all of which go on to live their own lives. It takes something to convince yourself that this is reality ...

    Ah, so I am just a data point in the grand theory of physicist's!
    250 years ago the great thinker Soren Kierkegaard revolted against
    this kind of thinking promulgated by Hegel and his Phenomenology. Same thing now.
    You are not the same thing as rocks. You are not a mathematical notation in the Theory of Everything.
    Deny the divinity of humanity and see where this leads you.

    1. Accept the divinity of humanity and you get a dark age. At least that is what happened the last time. The divinity of humanity amounts to magical thinking, no matter how much Kierkegaard implored against the alternative with special pleading over anguish.

  8. Sabine,
    You must feel generous today. Given how you have taken the multiverse argument to task, I would have expected that the parallel worlds view that Sean enthusiastically supports because it is the "simplest interpretation", would have received more than a mild swat. I look forward to seeing your challenges to this.


  9. I know this is silly but in computer science there is an old concept called forking. A process splits into multiple processes, each of which continues from where the original was before the split. Sounds a lot like many worlds.

    The primary differences are that in a many-worlds universe (a) one can't determine which fork one is in and (b) one can't communicate with the other forks. Both are possible with forked processes.

  10. Curiously the one big positive thing I can see about many worlds interpretation is a source for what I see as a major criticism. A decoherent process splits the world onto eigenbranches as defined by the decoherent set. The information that occurs, or what an observer records, is in a sense quantum frame dragged along these paths. This is a very nonlocal process that makes it a good interpretation to quantize gravitation. The flip side is that because of this how is a probability for any outcome assigned to a local measurement of decoherent event?

    Physics has a sort of dichotomy or duality between nonlocality, which is largely quantum mechanical, and locality that is involved with interactions and conservation principles. A measurement or decoherent event is due to a local interaction, and this local process abruptly changes a wave that is nonlocal and without signaling. This perspective is somewhat ψ-ontic with a wave having some reality. However, a more ψ-epistemic perspective would say that nonlocality is just a measure of our “unknowing” and a decoherence manifests itself as a local occurrence (by local interactions) that updates our knowledge of the system. In either case we have some way that eigenvalues measured, with some probability, are obtained by a local interaction that in an acausal manner (no-signaling again) adjusts a quantum wave --- whether ontological or epistemological.

    With MWI there is no fundamental change to the total cosmic Ψ and information, or what an observer records, is a matter of being quantum frame dragged along one of the eigenbranches. This occurs everywhere, and is then nonlocal. Fine, but we than have some conundrum with understanding how probabilities are obtained empirically by local measurements from an ensemble of measurements of identical systems. In some ways this seems to come close to how the Born rule fits into QM. So far it does not seem to be derivable from the other postulates of QM. We might compare this to another quantum interpretation that is almost the polar opposite to MWI and that is QuBism. Here decoherence and measurements are just Bayesian updates, and this fits well within a probability paradigm. It is not so great if you want there to be a well understood nonlocality. If you want a system that is fundamentally nonlocal, such as quantum gravitation, thisis problematic since in this ψ-epistemic perspective nonlocality only means no information is adjusted so information locally obtains.

  11. “Something Deeply Hidden”
    The "something" that is "deeply hidden" being any observational evidence for Many Worlds.
    Better title: "Something Not at All Known to be True".

    Other books in the I'm Making This Up For My Pension series are:
    "A Universe not at all known to be From Nothing" and
    "A Universe not at all known to be Fortunate: Life in a Cosmos that is not at all known to be Finely Tuned"

    1. Steven: There's massive evidence for QM itself, and the Everettian (many worlds) view is just what you get if you take QM seriously, stop making this artificial division between the "quantum world" and the "classical world", and don't add anything extra (such as wave function collapse) to the basic formalism of QM.

      There's no evidence that QM stops applying beyond any specific system size scale, so it's reasonable to expect that it should also apply to the system (experiment + measuring apparatus + environment that includes you). Add in decoherence, and QM says the result of a measurement is a wave function that is a superposition of non-interfering terms, each of which corresponds to a different measurement outcome and different version of you. Whether you want to call these distinct branches of the wave function "worlds" or something else is just a matter of nomenclature.

    2. "Add in decoherence, and QM says the result of a measurement is a wave function that is a superposition of non-interfering terms,"

      But this bit is not proved by experiment, **which was my one point**. It is consistent with observations, as we observe one of the purported non-interfering terms after a measurement, but can't currently be checked by experiment.

      By "taking QM seriously", you just mean there is a consistent theory on how to explain apparent wave function collapse but no experimental evidence. Before you know it you'll be believing in fine-tuning and String Theory. It's a slippery slope.

    3. You don't have to be able to test every prediction of a theory to test the theory. We can't test the laws of chemistry within the Andromeda galaxy, but we can test them on Earth, and it's a very reasonable extrapolation to assume that they're the same there as here. Ditto with QM. We test it at smaller scales in a wide variety of circumstances and get very good agreement with experiment. It's quite natural and reasonable to assume, until you get contrary evidence, that QM continues to hold at larger scales. Occam's Razor.

      And, in fact, we keep on testing QM at larger and larger scales, and it keeps on passing those tests with flying colors. Physicists have even produced superpositions for a macroscopic object large enough to be seen with the naked eye:


      The further up the size scale we move with such experiments, the less tenable becomes the idea that QM fails to apply beyond a certain system size.

  12. Hey Sabine,

    While I'm pretty interested what the 2 main objections are ... I feel whenever I try to gauge what they are going on about (by raising an objection). I seem to fail. Example: https://physics.stackexchange.com/questions/502211/how-many-worlds-are-there-during-branching-in-the-many-worlds-interpretation

    In fact, I'm curious if your aware of any answer to the above question a many worlder might give?

    1. The "probability-measure problem" AKA "whence the Born rule?"

      From time to time, MWI proponents convince themselves they have an answer. As far as I can tell, those answers either involve abstract math that does not connect well to physical reality or decision-theoretic arguments as to why it is rational to believe in the Born rule even if it is not true.

      No doubt MWI boosters find this comment simplistic.

      So... let's just say that there is no answer to your question that is generally accepted.

  13. Many worlds, I'm sorry, is one of the most, if not the most ridicolous ideas ever. It amazes me how one can rightly criticize the hypotheses that God does not exist, and simultanously basically says that one should not believe the only acces we have to reality (empiricism), because he thinks mathimatically it's leaner to say everything happens (although we see that there's one outcome). It's insane. It's making up in principle unobsurvable things (Russel's teapots) because people don't like probabilities. Well I find the God hypotheses less insane, since it only posits one Unobservable being.

  14. If you need to fantasize about matters that are not even theoretically disprovable in order understand the detectable world we find ourselves in, you are not theorizing, you are just fantasizing. We are trained to fantasize very early in life. My mother told me that Santa Clause was real. We have another phrase for that kind of fantasizing . . . Lying Sweetly

  15. As my brother who loved fantasy but bowed to logic said upon finding out that Santa Claus was not real, “I suppose that means the Tooth fairy doesn’t exist either…”

  16. A public debate between Sean Carroll and one or two of Adrian Kent, Rafael Sorkin, Fay Dowker might be more interesting than presenting Many Worlds alone.

    "Yes, we’re saying the multiverse (scientifically speaking, the Many-Worlds theory) is real!"
    (announcement of An Evening with Sean Carroll, September 12, 7:00 pm - 8:00 pm)
    - https://uwm.edu/letters-science/event/an-evening-with-sean-carroll/

  17. If there are many worlds, I'm pretty sure that I will be convinced of their existence in some of them. The only thing I can tell is this world is not one of those. I wonder which copies of Sean Carroll will convince me, and which ones won't.

    1. I must say, well done, great logic. Then again, some number of universes are less logical. Endless regresssion?

  18. I spend most of my time thinking about other things, so haven't completely made up my mind with respect to interpretations of quantum mechanics. As Penrose noted, there can be more interpretations than there are quantum physicists, since it is possible to hold more than one interpretation at a time. :-)

    I tend towards the many-worlds interpretation, though. A good case for it is made by David Deutsch in his book The Fabric of Reality.

    1. But there's not a shred of empirical evidence for Many Worlds.
      The standard of truth in empirical science is observation. You don't seem to have grasped this simple yet fundamental point.

    2. Steven, I agree, that there is no evidence for many worlds at all. However, there is also no evidence against it. My private guess is, that this situation will last forever. There will never be evidence for one or the other. So whatever you think about many worlds, its your private opinion, and its up to you, to make sense of it.

    3. Observation tells us that Many-Worlds is consistent with observation but has not been confirmed by observation. Those are the empirical facts of the case. One's opinion doesn't come into it.

    4. There is a whole lot more to think about than worrying over whether some quantum interpretation is true, or real, and the others false. You need to "pop out of the debate" on this. Quantum interpretations are auxiliary physical axioms added onto quantum mechanics. There are two main types, those that are ψ-ontic and those that are ψ-epistimic. These are respectively for ψ-ontology MWI, dynamic collapse, deBroglie-Bohm, and the ψ-epistemic are The Copenhagen interpretation and QuBism and others. Several big questions loom here that are far more deep than asking whether they can be empirically verified, which honestly I doubt any can.

      One question is what is the relationship between quantum interpretations and the Born rule. Carroll and Sebens advance an argument the Born rule can come from MWI. Can it come from other interpretations? Another question is what is the relationship between local physics of fields and nonlocal physics of quantum states? Different interpretations have different relationships between these. Quantum gravitation is likely a very nonlocal field theory, where this suggests spacetime and quantum entanglements are related, and does this demand the MWI with a nonlocality to a quantum wave even with decoherence?

      There are a lot of things to think about beyond the somewhat puerile worry over whether they can be tested.

  19. The MWI may end up not being correct, but probably not because of the multiverse part of it. Quantum mechanics points to the existence of a multiverse in way that's quite hard to resist. But it's also true that the MWI has some issue with it that are as of yet unresolved. This isn't all that much different from, say, how in the 19th century people were quite sure about the existence of atoms and molecules, but this could not be reconciled with the known physics of the time (classical mechanics).

  20. My objection to MWI is that it unnecessarily complicates the question of how many angels can dance on the head pin.

  21. Firstly, looking at superposition, we can say, I suppose, it is neither up nor down, neither left nor right, neither red nor green, neither offensive nor attractive, neither bitter nor sweet; then, what the deuce is it? It is undefined or not so well defined.
    Secondly, what or who is the observer? The observer is a program. The human-program hears sound in the (human) audible range whereas the elephant-program or the whale-program hears infrasonic sound. These are veritable facts. Now, the program determines the audibility. For example, if I swap the human-program for the elephant-program, then the human can hear infrasonic sound. The actuality is just certain kind of waves; the actuality is soundless. It is the program that interprets sound as a reality whether human audible or infrasonic. The program constructs a reality. Reality is a "construct" based on the program. The program translates some of or most of the actuality into a reality which is either red or green, either up or down, either offensive or attractive odor. The actuality is colorless, odorless, soundless, tasteless etc., This colorless or odorless or soundless or tasteless waves is what I call superposition: not well defined. It is the program that reads color, red or green, into the colorless superposition; it is the program that reads offensive or attractive smell into the odorless superposition; it is the program that reads up or down into the orientation-neutral superposition. In short, it is the program that dictates reality. And the program is the observer; therefore, the observer dictates reality. If the actuality is undefined, if different programs construct their own realities, if each reality is its own world, then each world is a virtue of the program or rather dwells in the program. Therefore, many programs mean many worlds. But each world is not outside or independent of a program or observer, rather it is inside or a construct of the program or observer. In the many worlds interpretation, the worlds are outside the observer; that is, there are many actualities. If each world is inside the observer or a virtue of the observer, then we can do away with the many worlds interpretation. Now, there is only one actuality, which is the undefined, and many programs or observers constructing their own realities or worlds. So, can we do away with many worlds interpretation? There are no many worlds outside, right.

    1. This is not terribly different from Zeh's idea of a Many Minds Interpretation.

    2. I beg to differ with you Sir. It is unlike MMI. What is the mind? To put it simply, the mind is the function of the brain. That is why what we see floating in formalin in the laboratory are brains without the mind. The mind apart, anything that performs a well defined function and invariably gives the same result is a program. So, simply put, anything that performs a function is a program. The bat and the human are two biological programs. The bat is biologically programmed not to sense light; however, the human is programmed to sense light. Then, what is dopplers effect of light to a bat? Nothing. Though there is a wave disturbance, which is the actuality, the bat see no light, and therefore, experiences no dopplers effect. There is "really", mark the word, no dopplers effect for the bat. But, for the human there is "really", mark the word, dopplers effect. Now, tell me what is true? Relativity tells us that both are true, why?
      The program (snake or human) or the observer dictates the reality. How can the same wave disturbance present two different realities? So, reality is not "out there" rather it is "in here", that is, in the program or the observer. This means that if there are two unique observers, then there are two different realities, or if there are ten unique observers, then there are ten different realities; however, there is one and only one actuality which is the wave disturbance. One actuality and many observers means one actuality and many realities. So, if I may put it simply, in all my humbleness, it is rather a many programs interpretation.

    3. It is the Copenhagen interpretation with the emphasis on the observer.

    4. If one says that mind is a function of the neural programming then reality generated within that programming is then done so within the mind. The MMI approach would say the superposition of the quantum system is maintained in the mind, or programming if you will.

      The Copenhagen interpretation, or its Bayesian extension in QuBism, has some things to be said for it. I think the big rub with it was pointed out by Heisenberg. Where it is cut-off between the quantum and classical domains of experience?

      Quantum interpretations in general all have these holes in their explanatory narratives. With MWI the splitting of the world is nonlocal so where is it that a measurement localizes a quantum state and accesses an observable with some probability?

  22. Is Carroll’s hypothesis testable?

    1. It is testable, given patience.
      An implication of MWI is that if I am conscious in this moment, it follows there will be a future where I remain conscious. These are the only "branches" I can be aware of ... thus, cumulatively, awareness equals immortality. (No claim is being made about the *quality* of that immortality. This isn't an argument for a utopian future.)
      We are unaware of any human enduring for 120 years. If I declare now that MWI means I'll be aware 150 years after my birth (2121), then that prediction being realized is a valid data point, regardless of what technological circumstance allowed me to live to such an advanced age.
      I'm still far too young to obsess about old age, but I'm moving forward with the attitude that if immortality is inevitable, I want to maximize the chances for a pleasant experience. In another 20 years, I hope to begin making arrangements to have my head frozen when my body fails. If I awake in an indeterminate future, despite the slim chances that my brain should have survived intact, this would constitute strong evidence for MWI, in my view.

    2. Yes, if by "Carroll's hypothesis" you mean the Everettian (MWI) view. The Everettian view says that there is no QM/classical division, no collapse of the wave function. It implies that we should, in principle, be able to produce superpositions of arbitrarily large systems. This contrasts with theories that posit some form of spontaneous wave function collapse.

      I don't know how you'd even figure out what Copenhagen predicts here, as it's incoherent -- it assumes the measurement apparatus is classical, even though it's made out of atoms whose behavior is described by QM, and it doesn't tell you what, precisely, counts as a measurement.

      To borrow an example from Everett, scientist A measures the spin of an electron, while scientist B stands outside the system (electron + measurement apparatus + scientist A) and measures what outcome scientist A writes down. When does the posited wave function collapse occur, according to the Copenhagen interpretation? When the measurement apparatus registers the electron spin? When scientist A observes the measurement outcomes? Or when scientist B observes what scientist A writes down?

    3. @Len Arends: Are you kidding? I guess you have never been narcotized. When no brain activity is measured any more, then this is called "game over".

    4. Kevin S. Van Horn10:32 AM, September 13, 2019
      But it hasn't been confirmed by test, so it remains a hypothesis.

    5. The classical world seems to emerge from the quantum world. Quantum photosynthesis emerges as apples hanging from the boughs of an apple tree; one such apples falls on Newton's head and lo! we have the theory of gravity.

  23. One of the arguments of Philip Ball against the Many Worlds Interpretation is that he believes that the 'self' or 'soul' cannot branch of in different multiverses. This doesn't seem to be a good argument to me. Imagine one would be able to make a clone of me, kind of twin, in this world. Both versions of me would descent from me (Martien) and live on as Martien-a and Martien-b. An identicical history and memory upto a point in time, and hereafter they live their own lives. In principle the same could be argued for splittng universes. It is akin to speciation of life-forms. Maybe Ball's objection comes from a (religious) belief in a soul which can exist separate from a body, I don't know.

    The link: https://www.quantamagazine.org/why-the-many-worlds-interpretation-of-quantum-mechanics-has-many-problems-20181018/

    1. Actually, Philip Ball's article seems to suggest that MWI leads to consciousness being either immaterial or nonexistent (it is some sort of illusion, or confusion).
      "And if consciousness — or mind, call it what you will — were somehow able to snake along just one path in the quantum multiverse, then we’d have to regard it as some nonphysical entity immune to the laws of (quantum) physics. For how can it do that when nothing else does?"

      But some of the scientific sort are (when one examines closely their "theory") what Galen Strawson calls* "consciousness deniers", so MWI may be a type of consciousness denial - the denial that there one has a real 'self':

    2. But why along just one path?

    3. Selves (unlike "basic" brains) are not considered (very much, if at all) by scientists as something to be part of scientific theories. So maybe there are (self-less) brains, being split every Planck-time second, and then each one independently going on doing what it does. But selves (self-full brains) doing that seems to me to create a nightmarish scenario of spit personalities.

      Galen Strawson - What are Selves?

    4. Imagine God as creator of the multiverse having to send zillions copies of a deceased sinner to hell or purgatory, that is those who did nor repell their sins. Assuming of course that God and hell are not part of the splitting.

  24. Hi Sabine, I started Sean's new book last night. I'm an experimentalist and don't worry too much about the foundations of QM unless there is some experimental result that is different. But I had this other question I wanted to ask. I always hear about the 'measurement problem', but when I look at some experiment, say two slit interference with photons. It also seems to me that there is a 'creation problem'. How did this QM state come into existence? For photons made in an LED, and then detected in a photodiode, creation and annihilation (electron-hole to photon and back again.) looks very similar. Both are random, and unknowable in advance. Is this just sloppy thinking on my part? And finally I have trouble pointing to where the measurement is being made. Is it at the two slits, or downstream at the detector?

  25. Useful theories often lead to absurd conclusions. These need not be real! In Newtonian Mechanics, what does it mean for two particles to touch? "Touch takes place over zero distance. When particles collide, accelerations are infinite. Even if they are elastic spheres, the acceleration at their boundaries on contact is infinite. All absurd, all irrelevant.

    So why worry about MWI? It's an absurd conclusion from a useful theory. That doesn't make real.

  26. @Peter Helbig
    Well, QM being irreducibly probabilistic, hence the state of the universe at time t+dt is not uniquely determined by its state at time t. This leaves quite a few doors open for free will, I think.
    In general, one should beware of simplistic proofs of complex facts. Particularly proofs about the impossibility of something, which, as someone said, are often just a proof of our lack of imagination.

    1. "@Peter Helbig
      Well, QM being irreducibly probabilistic, hence the state of the universe at time t+dt is not uniquely determined by its state at time t. This leaves quite a few doors open for free will, I think."

      In this branch I'm not called Peter. :-)

      Yours is a basic misconception. Just because something is undetermined, or random, or unpredictable to us has nothing to do with free will. Think about it.

    2. QM being probabilistic only means that - in the extreme case - nobody can tell what you will do in the future (including yourself). That does not leave the door open to free will (or only if you equate free will with unpredictability).

    3. @Phillip, @Bahle
      Phillip: sorry for misnaming you!
      You misunderstood me. I do not equate undeterminism with free will. But underdeterminism is surely a prerequisite for free will. A classical deterministic world surely does not leave any space for free will, but for our nondeterministic quantum world, things are not so clear-cut.
      By the way, do you have an operational definition of free will? How you would set up an experiment that reveals free will, as opposite to mere undeterminism?
      If you think about it, it's not so simple.

  27. QM points out to us that there is a fundamental limit in our-math whose fundamentals rest deeply in Newton's absolute views on the world. Hence we stumbled on probability-constructions because of a fundamental thinking-void which for the moment we cannot yet resolve.

  28. Ok, I will turn dopplers effect of sound from a relativistic phenomenon to a quantum mechanical measurement. But firstly, sensing is measuring; we are looking at sensing as an act of measurement. There is a railway platform, a moving train hooting its horn, and there are two observers: one is a human and another is a snake, an Indian Cobra. Initially, there is only the human observer on the railway platform, the train sounding its horn passes by. This causes the human observer to experience waxing and waning of sound or dopplers effect. Then, when the observer hops into the moving train dopplers effect disappears and he hears a single monotonous note. Now, I will introduce the snake as an observer and turn relativity into quantum mechanical measurement. I put the cobra on the railway platform and it spreads its hood flicking its tongue about. The train again passes by sounding its horn. Does the snake experience dopplers effect? No, because the snake is deaf. The snake is programmed not to sense sound. The human is programmed to sense sound. The absence of dopplers effect is as much a reality to the snake as the presence of dopplers effect is a reality to the human. Then, what is reality? What is actuality? Reality is the result of the program. The program dictates reality. How do I prove it? Swap the human-program for the snake-program. Then the snake will experience dopplers effect, won't it? There is no reality independent of the observer. So, what is actuality? When the train sounds the horn, there is a wave disturbance in the air, that's all. This wave disturbance is the actuality but how it is interpreted is the virtue of the observer. The virtue of the observer constructs the reality based on the program.

  29. Doesn't MWI violate all sorts of conservation laws? Or do these laws apply locally to each "universe" but not to the (infinite?) set of all universes that follows from MWI? If the latter is correct, we need to find a way to tap into that energy source before this version of the Earth gets too hot because of all that hot air we're generating.

  30. Being a twin I've already had one branching. But as we inhabit the same world, I guess that doesn't qualify as an MWI split.

  31. The discussion within this blogpost about Many Worlds Interpretation is quite interesting. Many people argue about evidence in favour of many worlds or against it. Obviously there is no evidence for both views, and any opinion is a private belief. Missing evidence for both interpretations means, that none of them can be excluded. Classical logic requires the principle of excluded middle (A^not(A)) which does not hold here as an argument for/against many worlds.
    There are several other observations and considerations were the principle of the excluded middle does not hold. See for example the classical liar paradox, which plays an important role in Kurt Gödels incompleteness theorems.
    In order to have a more realisic view of mathematics and science, it seems to be necessary to be more familar with the concept of "Intuitionistic Logic", which does not suppose the principle of the excluded middle to hold.

    1. There is a famous quote of Niels Bohr, which is quite popular in germany. " It is the hallmark of any deep truth that its negation is also a deep truth". It is obviously a kind of liar paradox. One can find similar considerations in the cultural heritage from all over the world. However it seems to be quite provocative, to hear this from a famous scientist and a co-founder of quantum mechanics. If taken literally, it should have profound consequences on the way to think of mathematics and scientific research.

    2. The cornerstone of something like this is whether some aspect of QM is undecidable. That may be how it is that QM is a deterministic system, but where outcomes are stochastic. The Schrödinger equation gives a deterministic evolution of quantum amplitudes, but where the outcome in any individual case is stochastic. Interpretations are meant to bridge this apparent contradiction. So far none of them have been found to be either demonstrable in a theoretic sense or testable empirically.

      The result of Carroll and Sebens is the Born rule emerges from MWI. This raises a question in my mind as to whether the Born rule is tied to quantum interpretations as an undecidable proposition.

      We might think of a quantum measurement as a case where some large set of quantum states encode some other set of quantum states. This is a sort of Gödel numbering of qubits by qubits. For an infinite number of possible qubits this appears to be possibly a case of Gödel undecidability.

  32. @ Bud & Former:

    Non-existence in open complex systems is impossible to prove. See "the negative fallacy." Evidence is the sole onus of the claimant. (of free will, supernaturals, etc)

    1. First sentence: yes. Third Sentence: only sort of. You cannot require both evidence of something that is true and the ability to explain why that evidence is correct to just anyone. Cognitive development, or lack thereof, stands between the explainer and the receiver. In simple terms, if the receiver either can't or won't inhale the evidence, it says nothing about the truth of the subject being explained. Likewise, a third party generally serves no function without some demonstration of that party's having sufficient cognitive development to understand the evidence. This is not a binary issue. Rather it is an issue of emergence. See my comment at 7:47

    2. There is certainly experiential evidence for free will, while there is no evidence for it's non-existence.

      Free will is a non-physical human concept - it is not subject to scientific verification. Functionally most people behave as if they have free will. The question of whether humans actually have free will, whether it exists or not, is philosophical in nature.

      This question cannot be resolved by science. All attempts to do so rest on strained, pseudo-scientific, theoretical claims that assume, omniscience with regard to initial conditions and the infallibility of scientific models.

    3. Bud.. First I want to say I always enjoy your comments. I like the way you poke at people's misunderstandings (or wild misconceptions).

      In this case it seems you are positing something that fails to take into account what you yourself just said. Experiential evidence is ALL any of us has to examine. Full stop. If you want to call some of those experiences scientific because they seem to be shared you can do that but it's exactly that seemingness that creates a problem. How is it that verification of (what are sometimes later discovered to be) grossly wrong ideas, just because two parties followed the same rabbit down its hole while sharing precision rabbit tracking techniques as they proceeded, deserves to be called science? Just because they precisely 'confirmed' the same wrong theory using the 'scientific method'? Bjorn Ekeberg in his book Metaphysical Experiments offers 174 pages of well-documented, strictly-reasoned evidence demonstrating that scientific investigation is largely a shared delusion. Mind, I am not saying there is no science, just that it's not what many (most) scientists think it is.

      It all comes back to the inescapable fact that experiential evidence is truly all any of us has to work with and it needs to be treated differently than it currently is in order for it to become actually 'scientific'.

      Surely if scientists can consider multiple universes to be a 'thing', they should be flexible enough to check the source of information they are examining: complex mental extrapolation of experiential evidence. It all starts and ends in the mind, doesn't it? As in most things, the errors in a pursuit can be found in the source (poor reasoning), once they are identified as such by ridiculous 'results'.

    4. Lying sweetly,

      Sorry, I missed this comment earlier. I'm having difficulty following your reasoning because you are not being very specific. For instance:

      ...it seems you are positing something that fails to take into account what you yourself just said.

      I have no idea what it is you are referring to. What do you think I am positing and how does it fail to take into account what, exactly, that I have just said?

      Beyond that I have difficulty following your arguments because, I think, we do not share a common definition for the term science. Here is my working definition:

      Science is the open-ended investigation into the nature of physical reality, employing the complimentary probes of empiricism and logic. (Mathematics being understood to fall under the umbrella of logic.)

      I suspect your definition is somewhat broader and encompasses what is sometimes called the soft sciences. I suspect that Ekeberg's conclusion applies to the soft sciences but not to science as I defined it, which pertains only to what are called the hard sciences.

      It all starts and ends in the mind, doesn't it?

      Well, no. I think of the mind as a fulcrum that receives information about the external world (empiricism), processes that information to create a model (logic) and then compares that model to the external world (logic and empiricism). Applied recursively to physical systems this produces scientific understanding.

      OTOH, modern theoretical physics does start and end in the mind, having all but abandoned empiricism. It has consequently devolved into an unproductive, mathematical navel gazing, solipsism.

    5. Bud, I am not sure we actually have different definitions so much as we have different perspectives on the applications and therefore meaning of those definitions.

      “Science (purports that it) is the open-ended investigation into the nature of physical reality, employing the complimentary probes of empiricism and logic. (Mathematics being understood to fall under the umbrella of logic.)”

      But then it promptly excludes many things that it doesn’t already know how to measure and things that are clearly there but are unacknowledged (for a variety of reasons) by many scientists. Nice circular reasoning that.

      Scientists are studying the (physical) brain but when it comes to looking at the mind they are generally clueless. You acknowledge ‘experiential evidence’ but then promptly conclude that it isn’t really evidence because it is not physical. Why? That doesn’t scan.

      Your brain is physical and it supports physical processes some of which we refer to as the mind. Whether the use of the word ‘mind’ is just a place holder or not (depends on each person using the word) doesn’t affect the fact that logically it is (somehow) an interpretable physical event that is no less visible than bubble tracks through a cloud chamber, which show us what’s what about a particular particle. But brain activity or tracks through a bubble chamber all require interpretation, without which there is no meaning.

      We can certainly measure the electrical activity of the brain and to a much lesser extent brain activity associated with certain activities of the mind. Measurement is one thing. Precision and proper categorization are different kettles of fish. Classically, scientists say that the measurement IS the meaning, thereby hopefully avoiding sticky questions. But, obviously, they immediately make an ‘interpretation’ of the meaning (measurements), with lots of those interpretations being in opposition to each other.

      “Free will is a non-physical human concept - it is not subject to scientific verification.“

      Really? Whatever else ‘free will’ is or is not, the concept is certainly something produced by the human mind (my dog doesn’t have an opinion on the matter). And, that mind is physical, the result of physical processes. For me, that is solid physical evidence. It’s true meaning is subject to much debate, and while philosophy might come into that debate, the debate itself cannot be relegated to the ‘merely philosophical’ pile of things to ignore.

      I have a long list of things to say about the mind and cognition, but this is (mostly) not the place to say them. The one solid thing I can say is that cognitive function varies tremendously among individuals and that cognition is what underlies conception, i.e. certain levels of cognitive function are necessary to support a given level of conceptual ability.

      My dog is conscious and has low levels of cognitive function, which is why she can’t conceptualize what I’m doing, or why.

      We now return you to your regularly scheduled program.

    6. Lying sweetly,

      You feigned quoting me directly, while inserting your own words into the "quote", so as to alter the meaning and sense of what I had said. That is a despicable and deliberately dishonest way to argue. Sorry, but I have no time for that kind of loutishness.

  33. I think the fundamental problem we have with quantum mechanics may be stated this way: the mathematical object that "represents the state of the world" does not yield anything we can see or experience; the "state of the world we experience" emerges only after a mathematical operation on this object. Moreover, there is a huge choice of mathematical operations, each of which can yield a different visible "state of the world we experience". Lastly, these mathematical operations appear to be rather different from the one that time-evolves this mathematical object. This degree of indirection has confused the heck out of a century's worth of physicists and philosophers.

  34. There are a fair number of comments above that reference the concepts of free will and also consciousness. Anyone who wants to argue that consciousness doesn’t *really* exist has just excluded himself from the discussion. For the rest, consciousness is well accepted as an emergent property.

    In the process of evolution, cognitive development likely starts much earlier than the emergence of consciousness. However, by the time consciousness develops it is no longer possible to deny that cognition is a thing in itself, and that cognitive development is an actual emergent process.

    Being aware (conscious) does not imply being self-aware, but it does not exclude it. And, again, anyone who doesn’t think self-awareness is a *real* thing has also exclude himself from the conversation.

    So now we come to the process of cognitive development.
    Almost everyone knows the basic meaning of the words ‘free’ and ‘will’. However, it is manifestly clear that such 'knowledge' of the basic meanings of those separate words does not imply that a person knows the meaning of the phrase ‘free will’. Equally clear is that many who believe they know what ‘free will’ is, simply lack sufficient cognitive development to understand that they are holding a wrong idea. In most cases, it is that same lack of cognitive development that prevents anyone else from being able to explain to them what is missing. This is not a failure in anyone’s ability to explain. It is a lack of ability of the receiver to absorb certain explanations.

    If consciousness is an emergent property and self-awareness is emergent, why wouldn’t it be the case that ‘free will’ is likewise an emergent property, only arising after some significant level of cognitive development? Thus, (many of the) comments and exchanges above about free will and awareness seem to be between people who each have different but somehow wrong ideas about what these words/concepts mean.

    Why this is important is because our (one’s) level of cognitive development is the only thing we have to evaluate events or objects and come to conclusions. Inasmuch as there is no test of a person’s level of cognitive development that might be required to identify a good scientist, logician, philosopher, mathematician etc., there will inevitably be disagreements about whether a theory is sound, what the meaning of data is, whether proofs are valid, and so forth. And, as observed above, there is no simple way to sort out (disqualify) nor to ‘educate’ people who lack adequate cognitive development to support their examination of certain subjects.

    Ultimately, lack of understanding about how cognitive development occurs, what levels there are and how that impacts scientific study is one of the single greatest sources of problems in all fields of science.

    Does free will actually exist? Kinda depends on your level of cognitive development, doesn’t it?

    If you thought that the ‘incompatibilities’ of scientific views, poor interpretations, and general ‘mysteries of science’ were knotty issues, try studying cognitive development.

    Am I Lying Sweetly? Depends.

    1. To be clear, intellectual development is not closely coupled to cognitive development. Without intellectual development, your cognitive development will stall, but intellectual knowledge does not force further cognitive development, although it can provide a small impetus.

  35. Let us consider a human who can see only quarks and electrons. He cant even see how these are configured to form atoms, molecules... chairs, tables and other living things including man. Since he cant see the configurations, he cant see himself in flesh and blood. When he looks at himself, there are only quarks and electrons; so, there is no "me" either. When it is all quarks and electrons up and down, left and right, and everywhere, then what is reality? There is nothing to abstract, isn't it? Then, what is reality?

  36. @ Lying Sweetly

    You've put your perceived rankings of cognitive development as the absolute arbiter of all. Seems hubristic. Cognition is best explained as energetic (physical) until evidence of another source is presented. Conscious experience likewise. Memories are embodied as well. To assume volition is exempt requires alternative evidence too. Verbal gymnastics ditto!

    1. Cognition is best explained as energetic (physical) until evidence of another source is presented. Conscious experience likewise. Memories are embodied as well.

      Seems that you know the word cognition but your comment fails to demonstrate an actual understanding of the concept, while at the same time you offer Cognition is best explained as energetic (physical) WTF? without giving us a clue what that means.

      I suspect you might also claim understanding of emergent phenomena in complex systems. Please demonstrate something more than passing familiarity with: cognition, emergent phenomena, physiology, living neural networks, and so on. If you don't do that I'll be forced to conclude that you can't/won't inhale the evidence.

      The hubristic ball/title is in your court.

      (not trying to start a flame war but you were just a tad strong in your assumptions and unsupported assertions.)

  37. Carroll and Sebens have a paper on how supposedly the Born rule can be derived from MWI I have yet to fully read their paper, only on a cursory level, but given the newsiness of this I might get to dissecting it. One advantage that MWI does have is that it splits the world as a sort of quantum frame dragging that is nonlocal. This nonlocal property might be useful for working with quantum gravity,

    I worked a proof of a theorem, which may not be complete unfortunately, where the two sets of quantum interpretations that are ψ-epistemic and those that are ψ-ontological are not decidable. There is no decision procedure which can prove QM holds either way. The proof is set with nonlocal hidden variables over the projective rays of the state space. In effect there is an uncertainty in whether the hidden variables localize extant quantities, say with ψ-ontology, or whether this localization is the generation of information in a local context from quantum nonlocality that is not extant, such as with ψ-epistemology. Quantum interprertations are then auxiliary physical axioms or postulates. MWI and within the framework of what Carrol and Sebens has done this is a ψ-ontology, and this defines the Born rule. If I am right the degree of ψ-epistemontic nature is mixed. So the intriguing question we can address is the nature of the Born rule and its tie into the auxiliary postulates of quantum interpretations. Can a similar demonstration be made for the Born rule within QuBism, which is what might be called the dialectic opposite of MWI?

    To take MWI as something literal, as opposed to maybe a working system to understand QM foundations, is maybe taking things too far. However, it is a part of some open questions concerning the fundamentals of QM. If MWI, and more generally postulates of quantum interpretations, are connected to the Born rule it makes for some interesting things to think about.

    1. "To take MWI as something literal, as opposed to maybe a working system to understand QM foundations, is maybe taking things too far. "
      Not maybe. It *is* taking things too far to take MWI literally because there is no empirical evidence to support taking it literally. If empirical evidence appears, then it must be taken literally.

      One cannot fancy theories or tend towards theories or find them very reasonable; either they've been empirically verified or they haven't.

  38. This comment has been removed by the author.

    1. Why would you expect nature to carve out a special exception for measurements? That's what my analogy with chemistry in Andromeda was getting at -- if the wave function evolves according to Schroedinger's equation in all other circumstances, why would you expect a special exception for measurements -- whatever they are? How does nature even know when an interaction is a "measurement", so that it can suspend the usual laws of quantum mechanics and collapse the wave function instead? Decoherence provides an answer -- but decoherence is based on the idea of the measurement apparatus / environment becoming entangled with the subsystem of interest, and that's the superposition of states you object to.

      The point about scaling relates to your insistence that "measurements" are special, obeying different rules. What we think of as measurements always involves an interaction with a macroscopic system consisting of a vast number of atoms.

    2. Kevin S. Van Horn3:04 PM, September 15, 2019

      Yes, it's a fascinating idea, but the point is that you are claiming branches exist that have never been observed, therefore MWI has not been empirically verified and is not a confirmed physical theory. Do you accept that point? You are simply saying that MWI is consistent with observation, that's not the same as empirically verified. Not even close in this case.

  39. Lyall Watson in his book 'Supernature' said that it is "actually" colorless, tasteless . . . there is something out there. So, I am not talking nonsense, am I?
    In Hindu Philosophy they have "Maya". In Sanskrit, "Ma" means "not", and "ya" means "that"; therefore, "Maya" means "not that". So, we now ask the questions:
    Is it up? Maya, not that. Is it down? Maya, not that. Is it left? Maya, not that. Is it right? Maya, not that. Is it red? Maya, not that. Is it green? Maya, not that. Is it sweet? Maya, not that. Is it bitter? Maya not that. Is it offensive? Maya, not that. Is it attractive? Maya, not that. Then, What the deuce is it? It is superposition!

  40. A layman cannot, of course, really understand any of today's physics but I, for one, have read popular accounts of the quantum world for almost sixty years. The Copenhagen Interpretation seemed widely accepted "back in the day" -- not so much now.

    As an uninformed observer I now wonder to what extent current quantum theories are forced on physicists by experimental results. What I mean is that, at times, today's cutting-edge theories seem driven, rather, by a quasi-religious impulse to revive classical physics and de-legitimize the observer's role in creating reality.

    The de Broglie/Bohm pilot wave theory is an example. Its "hidden variables" hint at a return of cause and effect and the subsequent refutation of a purely statistical reality at the particle level. Then, there is superdeterminism and IT tends to restore the lockstep materialism of a century ago.

    The Other World Interpretation produces an endless number of universes based on superdeterminism. As a bonus, it provides a way around "spooky action at a distance."

    The Copenhagen Interpretation had a real appeal in that it was somewhat humble. Bohr argued that we only know what our instruments measure and that an observer-independent reality is very unlikely. So . . "shut-up and calculate."

    The Other Worlds Interpretation offers a way around Bohr's roadblock but does so by asserting that there exist an infinite number of universes -- which ought to make Willam of Ockham spin like a turbine. The pilot wave theory seems, so far, to have no evidentiary basis while superdeterminism cannot be tested even in principle.

    If existence operates the way Sean Carrol argues then so be it. But, I wonder -- and would appreciate informed comments -- to what extent such a theory is based on nostalgia.

    Are we, today, going where evidence drives us? Or, just trying to reconstruct the classical Humpty Dumpty that was kicked off its wall at Solvay in the 1920s?

  41. Correction: the book is "Beyond Supernature" and not "Supernature".

  42. No one has brought up Quantum Darwinism as a way to make many worlds extinct. Anything to it?


  43. @Andros

    According to Abraham Pais biography of Einstein, it seems he is wasn’t as concerned with the loss of determinism in quantum physics, despite his well-known jibe that nature does not play dice, as with the loss of locality.

    As for many worlds, the question is how seriously does nature take quantum mechanics? Perhaps not so seriously when our every day world is classical ...

    Personally, whilst I’m prepared to go along with superpositions and entangled particles in the atomic sized world, I’m rather sceptical of, pace Bose-Einstein condensates, of scaling these notions to the everyday world.

  44. @Lying (not so sweetly). I am a skeptic. With no known/evidenced boundary to reality, what we don't know is infinite. What we can measure is physical, and that includes energy. If you or anyone can evidence cognition without energy throughput , then a Nobel would be likely! Emergence is a fudge word which is useful when myriad variables aren't known. But it evidences nothing aphysical as far as I'm aware. Perhaps you'd care to enlighten us!

    1. Steven... in your appeal to energy you are focused on the octane of the gasoline and not the car it propels or the song playing on the radio. I responded to Bud Rap (way) above, who was in turn responding to you. Both of you seem convinced that your senses can't lie to you and so it would also seem that you have never tried any psychedelics.

      In fact, your physical senses are only given meaning by cognition and, as I said previously, experiential evidence is ALL any of us has to go by. Emergence is well established across all fields of science and does not care if it is jet fuel or diesel that powers it.

      Since you seem sincere, I would advise as complete a review as you have time for of all the scientific fields outside of so-called hard science. It will require you to take a step back and take in an overview of what is there. Someone convinced you that if you can't measure it, it doesn't exist or is at best unimportant and not worth pursuing. If so, you must also be convinced you have no bias in your thoughts because as every hard science person "knows", you can't measure bias. That view inevitably leads to an impoverished life if you can't shake it.

    2. Both of you seem convinced that your senses can't lie to you and so it would also seem that you have never tried any psychedelics.

      Psychedelics taught me that my perceptions of my sensory inputs could be greatly affected by a slight alteration of my body chemistry. This did not lead me to conclude that all, or even most, of my non-psychedelicized perceptions of the external world are unreliable.

      Emergence is well established across all fields of science...

      That is because it is a vapid truism - everything emerges.

    3. If your perceptions varied naturally but slowly over time, and thus affected your point of view without creating glaring inconsistencies, how would you tell? Aren't psychedelics a clear demonstration that perceptions are not absolutely reliable, in the way that people who haven't taken them assume them to be?

  45. Einstien asked something akin to this: Just because I dont look at the Moon, does it mean the Moon does not exist? It is a very interesting question. Just because infrasonic sound and ultrasound are not humanly audible, does it mean they dont exist? Beautiful question(Einstien) isn't it? Well they do exist, and this is a veritable fact, but we cant sense them because we are programmed not to sense them. It is the biological program that limits us to the human audible range. Which means what? To the humans they "really" don't exist. From this it is clear that the program or the observer dictates reality. Reality is what the program or the observer makes of it. We know what the Moon is to us based on the human-program. But what is the Moon to the fly or the amoeba? We can say that the fly-program or the amoeba-program defines the Moon based on thier respective programs, right. So, reality is a construct, which is the virtue of the observer or the program. On a lighter vein, the poet on the earth sings twinkle, twinkle little star... How I wonder what you are. Can a poet on the Moon sing the same song? No, because the Moon has no atmosphere, the stars dont twinkle.

  46. I think the MWI is like hypothetical ether. Just as they introduced hypothetical ether, they have introduced Many worlds.

  47. It might help to recall that any putative Many Worlds resemble a tree-- there is a common root. Or we ought to suppose that there is a common root. In all of the many worlds there would be a CMB with all of the characteristics of the CMB familiar to us, although the precise picture might vary. If we imagine an experimenter going off into different branches after making a measurement, all of these split experimenters share a common history and common memories up to the point of the split. Any causal connections or influences that existed prior to the split carry over into the split. In fact, any entanglements that existed prior to the split are duplicated in the split. So one question might be: can an entanglement be preserved across many worlds? If so, than the many worlds are themselves something of an illusion, and are bound together by entanglement, and perhaps should be regarded as an emergent one world with a structure more complex than we normally model. I'm just trying to find a way to model Many Worlds as one, with a much more complex structure. Unify things, in other words.

    1. Going farther out on a limb, I'm working within the context of an idea I proposed earlier, of reducing spacetime to a discrete matrix of events. We could imagine each event to be a structured matrix of information, and we could imagine each event matrix to be embedded in a higher order matrix composing spacetime. And I talked about correlations as the links but will try for greater generality by simply describing the kinds of relationships available. It seems to me that there are only three types: we could say that null relationships govern information, within event matrices and among the event matrices. Imagine a photon having an "adventure" at point A (emission) and another "adventure" at point B (absorption). These are events and they are in a null relationship. The photon is traveling at light speed. Next, consider one member of an entangled pair at A and the other member at B. They are in a purely spacelike relationship. No information is involved in this relationship. The remaining class of relationship is "spacelike/timelike". This class determines the metric of the spacetime that is emergent from these relationships-- different properties can correspond to closed spherical geometries or open hyperbolic geometries or Euclidean geometries. So in this scheme the purely spacelike relationships provide the abstract or undetermined basis for a "space", and the properties of that space are determined by the exact rules regarding the spacelike/timelike relationship, and in all cases bits of information are linked by the null relationship. Still trying to find a mathematical formalism. But I think many worlds can be contained in this abstract framework, as well as many possible universes.

    2. if there is a common root and a common history, then does it not imply that it is a common superposition? So, it is all starting with superposition, there is no doubt about that. Then you say there is branching, and this branching goes on even before it passes the slits. This means that the superposition is evolving; it is branching or resolving or splitting into many worlds or possibilities, in that, into individual worlds or possibilities. My question is, can the superposition resolve or split or branch without measurement or the observer touching it? Who or What is it that splits or divides? The observer based on his background divides, configures, splits, describes, interprets, or defines(boundaries). This dividing, splitting, or resolving is ant act of measurement--classification is an act of measurement. The moment you describe or interpret a superposition, it is finished. Any division into many worlds is measurement, which decoheres or destroys the superposition. Before passing through the slits, there can be no division or resolution which decoheres the superposition; therefore, there can be no splitting as many worlds.

    3. I'm assuming that any "event" thought of as an intersection of world lines in GR, produces the same effect as a measurement performed in a lab-- definite values appear for variables in a small region of space time. So events in this sense are equivalent to measurements. Without that sort of mechanism, QM is uncomfortably solipsistic. Too subjective.

  48. For those who are interested in theories on how quantum decoherence relates to our 'classical (macro) world', without provoking MWI, here is a link


  49. A.Andros asked: "Are we, today, going where evidence drives us?"

    Of course not. There's not a single shred of evidence that could support the many-worlds-interpretation (MWI).

    "driven ... by a quasi-religious impulse to revive classical physics"

    Yes, the MWI was born not from experimental findings, but from a mathematical fiction: the mythical wave function. It is a wide-spread belief that "every physical system is described by a wave function", whose deterministic evolution is controlled by Schrödinger's equation. But this is not even half the truth.

    The measurement postulate is an integral part of the quantum formalism, but unfortunately Bohr never defined what exactly constitutes a measurement (except that it requires a "classical" apparatus, and the result will be "classical"). Completely oblivious of the central role of "measurement", many physicists today seem to think of quantum theory as a deterministic rather than a statistical theory. This leads to a deluge of rather peculiar posts, as you can find here ...

  50. @Lying (imaginatively) I humbly suggest that you consider the source of the pulpit you've created. My 50 plus years of studies in analytic philosophy are adequate to support skepticism of verbal claims of non-evidenced phenomena. You are free (pun intended) to claim expertise in emergence, but seem unwilling to share the basis for your certainty that it's no more than a descriptor without detail.

    1. Ah, well, ya got me! It’s true. I agree. I’m making it all up with my interpretations. I can only argue about or describe what occurs inside my head when and as it comes to my attention. That’s true no matter if the content in my head is self-generated or seems to come from the outside. Even the stuff that seems to come from the outside only winds up in my head after I have filtered it through neural networks which are almost guaranteed to be different from yours or anyone else’s. But, by then it is too late because in making it ‘mine’ I have no reliable way to check my understandings with others outside, lest I get stuck in the same loop of twisting my ‘confirming’ evidence in the same manner. So, I GIVE UP. YOU ARE RIGHT. I am just describing the things I see in my head. Although, I’m not sure what you are right about. Actually, the inside of my head tells me that your mental self can’t being doing something other than the things I am doing. Isn’t that right? Isn't your analysis of my statements just the descriptor that shows up in your head, and then don’t you have the same problem of corroboration as I do? I guess that makes us BOTH right?

  51. In the double slit experiment, I suspect that when the observer interacts with the electron or photon, the interaction is recorded as memory in the electron or photon, and this memory emphasizes the particle nature. This interaction can takes place at points: when the observer interacts or at the screen. The state at the point of contact is recorded as memory. Prof. Sabine is there an experiment which proves that the interaction is recorded, or can an experiment be devised that proves that the interaction with the observer or the screen is recorded. Can someone help me?

  52. The LHC found that the Higgs field (aka vacuum) is set on the finest of points.

    Calculations show that if the mass of the Higgs boson were just a few times heavier and everything else stayed the same, protons could no longer assemble into atoms, and there would be no complex structures—no stars or living beings. So, what if our universe really is as accidentally fine-tuned as a pencil balanced on its tip, singled out as our cosmic address from an inconceivably vast array of bubble universes inside an eternally frothing “multiverse” sea simply because life requires such an outrageous accident to exist?

    The Higgs field is set exactly on its tipping point, just like if water was set at its triple point

    If the strength of the Higgs field is increased or decreased by the slightest amount then there would be a change of state that would occur in the vacuum. For example, if water is moved off its triple point in the slightest way, it would begin to transform into a vapor, or a liquid, or ice.

    In like manner to what happens in a change of state of water, If the strength of the vacuum changes in the slightest, than atoms would not exist, neither would electrons or protons; all matter would resolve down to pure energy.

    Are there processes that exist in nature in electromagnetic and particle interactions and in chemistry that create a tightly confined bubble of the Higgs field whose character is different from that finely tuned value that keeps our universe from falling apart? Are those bubbles, if they exist, regions where matter that come in contact with these bubbles of rough vacuum dissociate and dissolve into energy? When and if the true Higgs field is restored if such a rough vacuum bubble pops, will matter reassemble into its usual state of protons, electrons, and atoms just like this reformation of matter happened soon after the big bang occured when the Higgs field assumed its current characterization.

  53. In Primates, For intersubjective, shared information consistency; primates require to set the Ontological assumptions that support their Epistemological Frameworks ...

    There are only 3 basic Incompatible Ontological Assumptions:

    1) 'Everything that existed, exists and will exist'(The Universe) is a Unity, or Ontological Monism.

    Physics tends to work under an Ontological Monism Framework.

    2) 'The Universe' is not a Unity, or Ontological Dualism.

    Metaphysics, Theology, Imagination and Arts tends to work under an Ontological Dualism Framework, because the complement of the absolute existential unity must to be absolute non-existential unity or ''things' that could been existed, exist or would exist but never came/comes/will come into existence' or 'Spirit' ...

    3) The Universe is Unmanifested Spirit coming into Partial Manifestations, or Ontological Spiritualism.

    Mysticism tends to work under an Ontological Spiritualism Framework.


    Each of those ontological assumptions imply an Specific Epistemic framework ...

    Ontological Monism imply an Object-Object epistemology.

    Ontological Dualism imply an Subject-Object epistemology.

    Ontological Spiritualism imply a Subject-Subject epistemology.


    Obviously, the 'Many World Interpretation' is a Math Salad that tries to sintetize the 3 incompatible Ontological Assumptions as if the 3 Incompatible Ontologies belongs to the Ontological Monism Framework ...


    The economic asset for establishing a clear ontological assumptions demarcation is for preventing the spread of collective stupidity pandemics through pointless and meaningless incompatible pseudo-intellectual diatribes by idiotic absurdity and implicit ignorance ...

  54. Prof. Hossenfelder, Prof. Hossenfelder I just read this on youtube: "In 1961, the Nobel Prize-winning physicist Eugene Wigner conceptualized a thought experiment revealing a little-known paradox of quantum mechanics... It allows for two observers to experience two different realities from the same event." Also, "Wigner’s thought experiment was put to the test by a team of physicists at Heriot-Watt University in Edinburgh with the results being published in February 2019... the results of that experiment lends considerable strength to Wigner’s thought experiment and interpretations of quantum theory that are observer-dependent... And with experimental evidence edging closer to undermining the idea of observer-independent objective reality, the fundamental assumptions of science itself may be in danger."

    All these years I have been talking about the fly-program and human-program, the snake-program and the human-program, and the bat-program and the human-program, . . . and offensive and attractive odor; and dopplers effect of sound and light. I haven't been talking nonsense, have I?

  55. continued Heriot-Watt experiment Wigner's paradox...

    "Can objective facts even exist? Scientists carry out experiments to establish objective facts, but if they experience different realities how can they agree on what these facts might be?

  56. I'm no scientist, but I recall reading here and elsewhere that quantum behavior re observer dependence is not [necessarily?] equivalent in the macro world. There are likely on-going disputes about this in the field.

    1. Please read all by comments on this blog post. Thank you. Yes, observer dependence applies to the macrocosm too because it applies to us humans, the other living things e.g., circadian rhythm etc., and as I pointed out with reference to machines and devices--ultrasound detection devices etc.

  57. Though many people use the word consiousness, I won't go into it because it is loaded, and also because it seems to pertain to living things especially man. Instead, lets use the word observer or program. You may ask why? We have the human biological program which senses light, sound etc. The human ear can hear only sounds which fall within the human audible range, in that, it cannot sense infrasonic sound or ultrasound. This is a veritable fact. To sense infrasonic sound or ultrasound, we use special instruments, special equipment. But what are these? These are simply programs. Say, the infra-program senses infrasonic sound, and the ultra-program senses ultrasound. Say, they not only sense but also convert their data into human intelligible format so that humans can make sense of what is being measured by these special instruments. If we bring consiousness into this, it will be confusing, instead we use the word program or observer. To the infra-program and the ultra-program there is "really" a sound, right. But to the human-program there is "really" no sound. Both realities, presence and absence of either infrasonic or ultra sound, are true by the virtue of their own programs; this is what relativity tells us even if we apply it to subjective observers. Now, we are talking about something akin to what Dr. Wigner said, but we have removed the ambiguity introduced by using the word consiousness. I feel that the word observer or a program keeps things simple and unambiguous.

  58. Do devices which detect infrasonic or ultrasound have consiousness? It is confusing, isn't it? That is why we use the words observer or program because these devices are programs, "hardware programs" because detection of ultrasound or infrasonic sound is "hardwired" into them. The very word "hardwired" means "programmed", that is, "hard" programmed and not "soft" programmed. A device which detects ultrasound cannot detect infrared light; therefore, it is "hard": the program or the function is put together by hardware; there is no code in assembly language or high level language; it is "hard"-code, for example, like levers and pulleys and wheels yet they together perform a function to produce the same result invariably. Anything which performs a well-defined function to give ,invariably, the same result is a program. What is "soft" programmed is software. It is "soft" because we have code written in assembly or high level languages, and this code performs functions. It is "soft" because the same hardware can perform several "soft" functions, in that, the functions are not defined and determined by the hardware, rather they are defined and determined by the software or soft-code.

  59. IMHO - when we all agree that a complete description of reality has to include consciousness... then maybe we can start to move forward.

  60. @Hyperlink 1: "Einstien asked something akin to this: Just because I dont look at the Moon, does it mean the Moon does not exist?"

    @Hyperlink 2: "Let us consider a human who can see only quarks and electrons. He cant even see how these are configured to form atoms, molecules... chairs, tables and other living things including man. Since he cant see the configurations, he cant see himself in flesh and blood. . . When it is all quarks and electrons up and down, left and right, and everywhere, then what is reality?"

    Hyperlinking @1 and @2, we ask this: If there are only quarks and electrons everywhere, and these are everything, then where is Einstein's Moon? Where is the Moon?

    Out of this bear minimum, the observer or a program craves out a reality: the human carves out a Human-Moon based on his program; a fly carves out fly-Moon based on its program; an amoeba carves out an Amoeba-Moon based on its program. The Human-Moon is as real to the human as the fly-Moon is to the fly and the Amoeba-Moon is to the Amoeba. The same "thing" has three different realities. And we abstracted or drew "the thing" away from the universe of quarks and electrons, and translated or interpreted or described it based on three different programs; therefore, three different realities.

  61. https://www.youtube.com/watch?v=zsXCwUsuvKo

    The "many worlds" theory in quantum mechanics suggests that with every decision you make, a new universe springs into existence containing what amounts to a new version of you. Bestselling author and theoretical physicist Sean Carroll discusses the concept and his new book, "Something Deeply Hidden," with NewsHour Weekend's Tom Casciato.

  62. A dialogue between Miss. Superposition and Mr. Observer.

    Miss. Superposition: Please don't touch me!
    Mr. Observer: But, why?
    Miss. S: Because, the moment you touch me, it is no longer "me", it is "you"!
    Mr. O: What?!
    Miss S: If you want me, then you get me as a whole, so, don't touch me.

  63. This comment has been removed by the author.

  64. Let us say I choose a superposition of up and down. I introduce an observer apparatus made by an alien civilization. That observer resolves the superposition as either left or right but not up or down. However, an observer apparatus constructed by a human civilization resolves the superposition as up and down. What I am getting at is, in my choice of the properties of superposition, that is, up and down, I am not introducing the observer very subtly. My choice of the properties of superposition is itself observer dependent. Am I not starting off with observer dependence?

  65. Prof. Hossenfelder, Prof. Hossenfelder, Here is an article I read in Science Daily a few year back and completely forgot about: "In a study reported in the February 26 issue of Nature (Vol. 391, pp. 871-874), researchers at the Weizmann Institute of Science have now conducted a highly controlled experiment demonstrating how a beam of electrons is affected by the act of being observed. The experiment revealed that the greater the amount of "watching," the greater the observer's influence on what actually takes place. . . To demonstrate this, Weizmann Institute researchers built a tiny device measuring less than one micron in size, which had a barrier with two openings. They then sent a current of electrons towards the barrier. . . The "observer" in this experiment wasn't human. . . Institute scientists used for this purpose a tiny but sophisticated electronic detector that can spot passing electrons. The quantum "observer's" capacity to detect electrons could be altered by changing its electrical conductivity, or the strength of the current passing through it. . . Apart from "observing," or detecting, the electrons, the detector had no effect on the current. . . the very presence of the detector-"observer" near one of the openings caused changes in the interference pattern of the electron waves passing through the openings of the barrier. . .

    "In fact, this effect was dependent on the "amount" of the observation: when the "observer's" capacity to detect electrons increased, in other words, when the level of the observation went up, the interference weakened; in contrast, when its capacity to detect electrons was reduced, in other words, when the observation slackened, the interference increased.

    "Thus, by controlling the properties of the quantum observer the scientists managed to control the extent of its influence on the electrons' behavior."

    I forgot about this article and during our discussion on your blog "The Problem with Quantum Measurements " the dialogue lead me into making this statement (7:13 AM, August 2019):

    "Let us start with a superposition of 100% fuzziness of definition; then, let us introduce a detector of 100% observer influence. What will happen to the fuzziness of superposition? The Wave function collapses. That is the detector refines the fuzzy definition by 100%. And let us say the fuzziness becomes 0%.

    Let us reduce the observer influence of the detector to 75%, this refines the fuzziness by 75% and the fuzziness drops to 25%.

    Let us now reduce the observer influence to 50%, this refines the fuzziness by 50%. That is the superposition is 50% defined and 50% fuzzy.

    What happens when we reduce the observer influence to 0%, the superposition is untouched by the observer, untouched by measurement and the interference pattern returns."

    Our dialogue arrived at the same conclusion as the Weizmann Institute of Science's experimental result, did it not? You can follow our reasoning by putting together all my comments on that blog. So, I haven't been talking nonsense, have I?

  66. Continued Weizmann Institute of Science experiment. . .

    Prof. Hossenfedler, what is left of our dialogues so far is to prove that the interaction the electron has with the observer or the screen is recorded in the electron as memory, and it is this memory that emphasizes the particle nature, that is the electron becomes more and more particular as the influence of the observer increases. We need experimental evidence to show that this particularity is due to the interaction with the observer that is recorded as memory in the electron. It is memory that turns the electron more and more particular. This memory may be volatile or stable. If we can prove memory, then we can prove that the observer interaction is programming the electron. If we can prove programming then we can build the non-living world and the living world out this evidence because programming is fundamental to building concrete structures like hard-matter e.g., molecules, chemical compounds, proteins etc.,

  67. All classification is an act of measurement.
    Physics is the science of measurement. I feel it is important do define what we mean by measurement. When we compare one thing or an attribute with another thing or attribute in order to describe either qualitatively or quantitatively what the one is with respect to another, we say that we are measuring. This means that comparison needs at least two things: the thing being compared, and the other thing with respect to which the comparison is being made. For example, the ruler is the reference and the straight line is thing being compared. This implies that there can be no measurement without comparison. And that all measurement needs a reference.

    To understand classification, we must first understand abstraction. The root meaning of the word “abstract” is “”to draw away”. Why does the mind abstract? We learn from Grady Booch’s book on Object oriented programming that abstraction is how the mind deals with complexity. We abstract what is essential and ignore what is not the need of the hour. For example, Sachin Tedulkar is extraordinary at the game of Cricket; however, he has many more attributes like handsomeness, charm, and let’s for example’s sake say that he is a good cook. But what strikes us the most at first glance is his remarkably elegant and exceptional batting skills. And that is what we “draw away” or abstract from Sachin Tedulkar.

    There may be a myriad sounds and odors playing around us, but we pick or abstract only that sound or odor that is the need of the hour. In addition, the very act of sensing, whether it be looking, hearing, or smelling, abstracts one of the sights, sounds, smells etc. or focuses or concentrates on one sight, sound or smell. This focus, this concentration, this choice, this act of “drawing away” one thing from a myriad of things impinging on our senses is abstraction.

    How do you look at a tree? As a botanist what you “draw away” or abstract from a tree is different from what you abstract from a tree as a wood cutter or as a tribal worshiping the tree or as a bird : A botanist sees biology in a tree, a wood cutter sees timber in a tree, a tribal worshiper sees a deity in a tree, and a bird sees food and a resting place in a tree. What meaning or what purpose we find in a tree is based on our background. A tree means botany to a botanist because his background is science; the same tree means timber to a wood cutter because his background is wood cutting, and it means a worshipful deity to a tribal due to tradition or superstition. Superstition and tradition are as much a background as dogma, prejudice, ideology, and scientific orthodoxy.

    How did this background come about? The botanist through training in botany became so. This training is conditioning or programming; the wood cutter is conditioned or programmed to think like a wood cutter, and the tribal is conditioned or programmed through tradition and superstition to make a deity out of a tree psychologically. This reasoning easily leads us to the veritable fact that the background is a program, and that the program is the frame of reference. In addition, the program is the observer. When the botanist program is running, he abstracts or sees biology in a tree; likewise, when the wood cutter program is running, he abstracts or sees timber in a tree, and in the same manner, the tribal abstracts or see a deity in a tree. Now, what happens when their respective programs stop running? They all see the tree as a tree, that is, it has no special meaning anymore, the tree is just a tree that’s all. Abstraction has stopped.

  68. continued...All classification is an act of measurement.

    We said measurement is comparison, and that all measurement needs a reference. Since the frame of reference is the background or the program or the observer according to which we abstract or “draw away” from many things one thing or scale or weigh what we sense, abstraction is measurement. Furthermore, sensing is an act of measurement. Any movement on the part of the observer, that is, when the program is running, is an act of measurement.

    We classify based on attributes or characteristics. Though we may classify based on umpteen number of other things, let us stick to attributes and external characteristics for the sake of simplicity. Classification involves identification and discrimination. The moment I have identified a monkey as a Himalayan langur, then I have discriminated it from all other langurs and monkeys. Discrimination is implicit in identification. Moreover, there can be no identification without recognition. Discrimination also means division because I have singled out the Himalayan langur and, thereby, divided it from the rest of the langurs and monkeys. So, identification involves division, fragmentation, or splitting. When I single out one thing or attribute, I am “drawing away” or abstracting the one from a myriad of things or attributes. Taking this reasoning further, when I “draw away” or abstract a quality or attribute that distinctly identifies a thing or an object and put it into a group of such peculiar attributes I begin classification. All such attributes are now a class of their own. Don’t we say that Sachin Tedulkar’s batting skills are a class of their own? Don’t we say that Einstein’s mathematical thinking and thought experiments are a class of their own?

    I abstract or “draw away” the batting skills of Tendulkar, and I draw away the mathematical thinking ability of Einstien and put them together in a class called Sachinstein. This hybrid abstraction is a class of its own.

    Let us say there is a potter, a lump of clay and the potter’s wheel. The potter has an idea of the design of the pot in this mind. Does the pot exist in reality? Does the pot exist as something concrete or tangible? No. The pot so far only exists as an idea or a design in the mind of the potter. Since the idea or concept of the design is drawn away from the lump of clay and exists only the mind of the potter, the idea or concept is an abstraction. Then, the potter applies his skill to the lump of clay and realizes the abstraction. Lo! You now have a concrete pot that is tangible. In object-oriented programming they call it instantiation, but, here, we are calling it realization.

    We take the class Sachinstein and apply it to a humanoid to realize a being who can bat like Tendulkar on the playing field and think like Einstein in the laboratory. This implies that there can be no classification without abstraction.

  69. continued...All classification is an act of measurement.

    Let us see how our thinking worked. We connected or hyperlinked two classes or dots or hyperlinks, that is, Sachin and Einstein’s skills to create a new idea or concept or hybrid class Sachinstein. We could have added more abstractions in this way to our class Sachintein. In that case, we will be connecting or hyperlinking more dots or hyperlinks to form one hybrid idea or concept. The idea or concept was the result of hyperlinking or connecting the dots, which are but a series of associated dots or hyperlinks brought under one umbrella called sachintien. Therefore, thinking is the act of hyperlinking a series of associated hyperlinks or dots. This series form a network which we may call a neural network.

    As an act of recognition, we may recall a part or the whole neural network, that is, this recall may be partial or total. Thinking is a heightened form of the recognition mechanism. If all the dots or hyperlinks associated with cricket is one nueral network, and all the dots or hyperlinks associated with Physics is another nueral network, then the hyperlinking has jumped between two disparate neural networks and formed a hybrid network Sachinstein. That is, thought has used want it has learnt in two disparate fields to form a new idea or concept that is an application combining both fields. This sounds like general purpose intelligence, doesn’t it? It is just that the hyperlinking is across and among different or disparate nueral networks. (I suspect that the information held by a nueral network is in superposition achieved through entanglement. An when one neuron is activated as an act of recognition then the entire network of entanglement unfolds, and there is a total or partial recall.)
    We said that there can be no identification without recognition. And that identification involves abstraction. We also said that there can be no classification without abstraction. But abstraction is measurement. And all measurement needs a frame reference. This frame of reference is the observer who or which is a program. Since classification involves abstraction, all classification is a form of measurement. Since any movement on the part of the observer or the running of the program which constitutes the observer is measurement, since from j krishnamurti we have thinking as a response of memory, and since there can be no recognition without memory, the movement on the part of the observer is thinking, or the running of the program is thinking; therefore, thinking is an act of measurement.

    We went into how identifying, discriminating, dividing and splitting are the movement of the observer or the running of the program. Dividing and splitting leads to branching, therefore, how do we reconcile observer independence in Many Worlds Interpretation with these activities which only emphasize the observer or the program.

  70. Happy Birthday Prof. Hossenfelder. Thank you for letting me comment on you blog.

  71. I've got an issue with MWI that I haven't seen in these comments. Evolution follows the Schrodinger equation and then the universe splits into two universes (worlds) in the simplest case. But then there is some sense in which *both* of those universes have their *own* Schrodinger equations. The upshot is that the splittings create more and more physical laws and so the purpose for MWI in the first place (just one physical law) doesn't go through at all. Sabine?

    1. Pmer,

      The idea behind MWI is that there is one Universal WaveFunction (Psi) which follows the Schrodinger equation. The many worlds arise because Psi gives alternative possible outcomes, which are sometimes measured. In order not to introduce some theory as to why a specific measurement has occurred, the MWI just says that all Psi-possible outcomes have been measured. Thus Psi (and Schrodinger) live in the Multiverse and not in any Universe.

  72. Bud is on the wavelength of science. Lying Hopefully is using after the fact(of brain/body behavior) awareness/consciousness as an explanatory function. No caloric throughput = no awareness/consciousness. Ignorance of possible measurables is infinite, and is evidence of *nothing.* Search: "Argument from Ignorance Fallacy"

  73. Alteration: Rather than just a "handle", it is a "psychosomatic handle".

  74. This comment has been removed by the author.

  75. This comment has been removed by the author.

  76. What Multiverse Means ?
    It means that there is an infinite / eternal Zero-Vacuum
    continuum (T=0K) that is filled with many-many
    multiverse (galaxies, stars, planets, . . . )
    The local behaviour of star in the T=0K was explained
    in 1915 by Einstein (GRT).

  77. We are not able to sense or make sense of superposition because we are not programmed to; this is akin to the snake or the bat not making sense of dopplers effect of sound or light respectively. What ever we make of it including the beautiful math, which is appealing, is because our programming makes it so. Our mathematical expression or description of quantum mechanics is befitting because our programming, human biological and psychological programming, makes it so. An alien can arrive at the same conclusions or different conclusions through its own framework which may not be mathematical; if it is mathematical, it may be a totally different math. Whatever be the means or the framework, it makes sense, appeals, and befits the alien’s world; it must be practically relevant to the alien world.

    That said, Sean Carroll on pilot wave theory says that there is twist “When we’re not making an observation, we don’t, and can’t, know the actual values of the hidden variables. We can prepare a wave function so that we know it exactly, but we only learn about the hidden variables by observing them. The best we can do is to admit our ignorance and introduce a probability distribution over their possible values.” Let’s pick us this thread. Ignoring the hidden variables, we have a wave function, but how did we set it up? We set it up according to our mathematical framework or our math, logically speaking from our foregoing reasoning, different aliens can set up their own wave functions based on their own frameworks which may me mathematical or not, and even if it is mathematical, it may be a totally different math. Or, they may not set up a wave function at all. Our mathematical framework is based on our programming, the human psychological program. This implies that the wavefunction is observer dependent because the observer is a program; that is, it is a construct of the human-observer set up for mathematical convenience or to express or describe or make sense of superposition in terms of human math. A description is always observer dependent because we are making sense with reference to what we know, which is the mathematical framework.

    Suppose we say that superposition is undefined or not so well defined, and start from there, then what happens? To begin with, there is the uninterpreted primordial or the undefined. Uninterpreted because every interpretation or description is based on the program; if you had no background or knowledge, you can’t describe. Remove the program or the observer, then the interpretation or the description disappears and whatever it is, is undefined or uninterpreted. So, there is one thing and several interpretations, meaning, there are several programs. Each interpretation is an abstraction based on the program. Because the program or the observer is limited it cannot see the whole: it can see only as much as the program allows. The abstraction is the program or the observer because if you remove the observer or the program the abstraction disappears; and the abstraction is never the whole, right. The abstraction, description, or interpretation are perspectives of the whole, partial views of the whole due to the limitation imposed by the observer, viewer or program. The input to the program is limited and the output of the program is also limited because the program itself is limited.

  78. If I have understood MWI correctly, there are, say 10 possibilities or properties, and as many versions of me. There is a superposition of 10 possibilities or properties, and each possibility is hooked to a version of me, which version is hooked to which possibility is the uncertainty. The certainty is they are hooked each to each. Let us say measurement takes place, then there is branching or splitting into many worlds, and in each world one possibility or property is hooked to one version of me. Now, what is that makes me “me”? The psychological and the biological program. Let’s ignore the psychological program for the sake of simplicity. So, I am a human program.

    In 5 of the worlds, I can make sense or sense the respective properties or possibilities. In the remaining 5, I cannot make sense or sense the respective properties or possibilities, why? I can sense or make sense of only that which my human-program allows. Humans cannot sense infrasonic sound or ultrasound, nor can they sense infrared light or ultraviolet light. We need separate devices or hardware programs to sense each of these. Since it is the human-observer-me in all the 10 worlds, otherwise I am not me, and since the human program is limited--it has a definite domain and a definite range—then in 5 of the worlds I sense none of the hooked possibilities or properties. Because the human program is definitive, we are back to the same questions: What are the hidden variables? What happens to the other possibilities? What happens to the other properties? Certainly, Bohm will come along say “hey, those are hidden variables”; and Bohr will come along and say “Hey, they do not exist: they disappear after the wave function collapse.” We are back to square one.

  79. Sean Carroll’s new book argues quantum physics leads to many worlds
    By Tom Siegfried
    20 hours ago
    Some physicists believe that the math of quantum mechanics
    requires reality to consist of many coexisting worlds
    (illustrated conceptually here), a view defended
    by Sean Carroll in Something Deeply Hidden.


    . . . multiplicity of universes . . . the Many-Worlds . . .
    Measuring the spin of an electron, for instance, might yield
    the result that the spin axis points either up or down.
    When the measurement is made, the universe splits,
    branching into two copies, one with the spin up, the other
    with the spin down. As each measurement is made,
    this view of quantum theory insists, additional universes
    are instantly created.
    When an electron changes its ''spin'' (up-north or down-south,
    east or west ) then simultaneous all its physical parameters
    also change.
    In this situation an electron is going out from the classical 3-D
    reference frame to parallel Minkowski an absolute 4-D spacetime.
    All the many quantum particles follow this way.

  80. I do appreciate that Dr. Hossenfelder has shown patience with this blog and wants keep the public eye open to physics.

    The one music video I really liked, "This is How I Pray," was a great display of her passion that reflected my own. That honesty, and sense of humor is what motivated me to look up this blog.

    I want to thank sabine Hossenfelder for her wanting to spread ideas from many points of view.

    Sabine has been fair and tollerent in the manqaging of her blog, but I must say that I have found the pretense of most ot those who leave comments to be discouraging, which makes the whole experience unsatisfying. I just don't see the point, so, despite sabine's honest efforts to be stimulating new ideas, I can only wish you all the best in what you want to find here, and move on.


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