MWI: Sean Carroll

I’ve posted more than once regarding my view of the Many Worlds Interpretation (MWI) of quantum physics. I find its rise in modern popularity genuinely inexplicable. (I can’t help but think it’s exactly the sort of thing Dr. Sabine Hossenfelder is talking about in her book, Lost in Math.)

Hoping to find the logic that apparently appeals to so many, I read Something Deeply Hidden: Quantum Worlds and the Emergence of Spacetime (2019), by Sean Carroll. It is, in large part, his argument favoring the MWI. Carroll is a leading voice in promoting the view, so I figured his book would address my concerns.

But as far as I can tell, “there is no there there.”

If anything, the book may have helped me crystallize my concerns.

Which are:

  1. If the wave-function is real, what implements it?
  2. What about energy?
  3. Scale. A quantum measurement affects the universe?
  4. Still non-local; split has to be universal.
  5. Vagueness on exactly what causes a split.
  6. Probability is schizophrenic under MWI.

The first three (especially #2) involve issues that seem to come close to falsifying MWI (if, in fact, they don’t succeed). I see them as serious obstacles. The latter three are objections that don’t have the same argument power as the first three.

More to the point, Carroll does not effectively address any of these objections. I read the book explicitly looking to understand these issues, and I’m no closer to seeing what the attraction is than I ever have been.

As a persuasive argument, I’d have to judge the book a fail.

§

In most popular physics books, the author spends time bringing the reader up to speed on quantum physics basics (I can’t count how many times I’ve read these basics now).

Those parts are always fine, no complaints. It’s what comes after that makes the book. When an author is promoting a view — be it birthed or adopted — I pay a lot of attention to tone.

Warped Passages (2005), by Lisa Randall, Cycles of Time (2010), by Roger Penrose, and Our Mathematical Universe (2014), by Max Tegmark, are three examples of books promoting an author-birthed view. All three gain credence with me, and respect, by framing their view as clearly speculative. (Tegmark goes so far as to call his crazy.)

Carroll, who adopted MWI, implies it is the “courageous” view (so if one doesn’t agree with it, one must be a coward). He actually titled the second chapter “The Courageous Formulation” — but then the prologue is titled “Don’t Be Afraid” (I wasn’t).

I’ll just say it’s a huge red flag with me, and that flag contains the words: “Snake Oil” I’m not saying Carroll is necessarily selling snake oil — I’m saying his tactics of presentation are indistinguishable. Carroll comes off as an evangelist to me, and I do not respond well to evangelists.

I even sometimes got a whiff of persecution complex. If one doesn’t embrace MWI, one is part of an oppressive group opposed to truth. The thing is, big claims require big evidence, and being almost entirely a metaphysical claim, MWI has nothing to offer as evidence. (That should all but put it on the same footing as a religion.)

Everything depends on whether one buys the arguments. (Which makes the chapter title “Why Would Anybody Think This?” entirely appropriate.).

§

The central argument of MWI is a claim to parsimony. The idea is that by removing the vexing thorn of measurement, a big problem of quantum physics goes away.

At the cost of infinite (or nearly infinite) worlds being created at the drop of a photon. So much for parsimony.

In our (single) world duplication of anything concrete has a cost that must be paid — conservation of energy is fundamental to physics. The (single) universe we inhabit, we believe, was created in a Big Bang — an event comprised of infinite density and energy.

But under MWI, an entire universe springs instantly into being when a photon does, or does not, go through a polarizing filter.

It seems to me that what MWI actually does is remove an obvious observational fact: we can measure things. There are aspects of that we don’t fully understand, but I’ve never seen the infamous measurement problem as insurmountable. (On some level it almost seems like whining by physicists that they don’t have the right math to describe what we experience.)

MWI seems to give up on understanding it by throwing it away. To me, that’s throwing out the baby with the bathwater. It’s a mistake!

§

In chapter eight, “Does This Ontological Commitment Make Me Look Fat?” (Yes, Sean, it really, really does), he has a fictional conversation between smart (and courageous!) fictional Alice and her slow-witted (much less courageous) fictional father. The poor guy just can’t wrap his head around this MWI stuff.

(At one point her father says it all sounds like sophistry. Indeed it does!)

Alice points out that our theory of integers is simple, but that it produces an infinite number of integers.

If that’s the best argument Carroll can offer, he’s got zip.

Because integers are abstract — they are nothing but information. (There is also that a theory of integers ignores the rationals and reals, so if MWI really was like a theory of integers, it would be theory that misses a lot.)

Not only can I have an infinite number of different integers, I can have an infinite number of any particular integer.

So if MWI really was like a theory of integers, then it’s a theory of abstractions and math. Which, frankly, is the only way MWI makes any sense at all — if it’s essentially Tegmark’s view that everything is math.

Because then, as with integers, an infinite number of casually and instantly created worlds would be no problem. Neither would be the idea that the wave-function is everything. It almost follows naturally.

But if the world is physical, then MWI is the least parsimonious theory out there. The claim to parsimony is false.

§

Going back to my list of objections to MWI, the first one is about this apparent straddling of the line between concrete and abstract.

MWI focuses tunnel vision on the Schrödinger equation:

It equates the equation with reality and further says that’s all reality is. Which seems identical to Max Tegmark’s Mathematical Universe Hypothesis.

If MWI was such an ontological statement, I’d have no problem with it, and my own brief bout of buying into MWI (long ago) involved such a stance.

But Carroll insists the infinite worlds are “real” which raises the question of what implements the wave-function. Math is abstract. To be useful, it has to be implemented by something.

Integers are abstract until we apply them to count physical objects. In the Schrödinger equation, Ĥ (H-hat) stands for the Hamiltonian operator that describes the physical system in question.

When physicists use the Schrödinger equation, of course they compute it on computers. But if the equation is real, and reality is physical, what computes the wave-function?

§

The situation with energy seems even more dire, and Carroll doesn’t offer much. What he says is through Alice schooling her dad:

“But what about the extra worlds?” her father insisted. “I could measure the energy contained in this world I see around me, and you say it’s being duplicated all the time.”

Alice felt she was on firm ground with this one [ed: Ha!]. “Not all worlds are created equal. Think about the wave function. When it describes multiple branched worlds, we can calculate the total amount of energy by adding up the amount of energy in each world, times the weight (the amplitude squared) for that world. When one world divides in two, the energy in each world is basically the same as it previously was in the single world (as far as anyone living inside is concerned), but their contributions to the total energy of the wave function of the universe have divided in half since their amplitudes have decreased. Each world got a bit thinner [ed: “thinner”?], although its inhabitants can’t tell any difference.”

So, again, how does E=mc2 remain valid in this world? I assume c doesn’t change, so is our mass getting thinner? A  kilogram isn’t a kilogram?

Alice’s answer doesn’t just seem like hand-waving; it seems dead wrong (at the very least, it’s hand-waving).

Without a good answer to this issue, I think MWI is falsified.

§

Scale is another issue I see as a show-stopper. It required a Big Bang to create this universe — a violent event of unimaginable energy and matter density.

But if a photon goes through a half-silvered mirror (or not), poof, a whole new universe just springs into being? Two methods of creating a universe? That is one serious bolt-on to a supposedly parsimonious theory (but I think we’ve put the parsimony claim to bed without dinner already).

§

Alice and her dad talk about locality. Alice claims the casually created instant new universe can be seen as spreading from the point of creation (the lowly photon that did or didn’t) or as happening everywhere at once.

I think this is false. It has to happen everywhere at once, based on what happens in experiments testing Bell’s Inequality.

These experiments make it clear reality is non-local. More importantly, in an Alice-and-Bob experiment, if Alice measures her photon, according to MWI she creates two worlds — one where she measures spin-up and one where she measures spin-down.

Because the photons are entangled, she necessarily drags Bob into both worlds. He is required to measure spin-down where Alice measures spin-up and vice versa. So Alice has to create two copies of Bob no matter how far away he is.

We know quantum physics seems to be non-local, so this isn’t anything other than the observation that MWI proponents pretty much need to stick with the ontological claim that measuring that little photon instantly creates entire new universes.

§

If MWI is somewhat vague about the nature of the splitting, it’s even more vague when it comes to exactly what causes a split.

Carroll denies that our decisions result in splitting (because our brains are classical). My question is, when I walk around with polarizing sunglasses, am I creating zillions of new worlds depending on which photons pass through versus which don’t?

If I shine a flashlight at the wall, where the individual photons all hit is random and quantum. Does that create zillions of new worlds?

It isn’t just that MWI seems false and vague — it’s kind of half-assed. Everyone bowed down to “it’s the Schrödinger equation!” and called it a day. It’s not a theory so much as a fantasy.

§

And then, finally, there’s the probability thing. Which is also an observation. (Both Everett, in his paper, and Carroll spend a fair bit of time justifying probability.)

The truth is, from our point of view, probability works similarly in both single- and many-worlds interpretations. Under MWI, we’re more likely to find ourselves in a more probable branch than not. Under SWI rare events happen rarely.

But under MWI, long-shots always happen. Carroll used his random app to create a random string of 64 bits. Under MWI, the overwhelming number of Sean Carrolls all got reasonable results.

But there is a version that got all 1s and another that got all 0s. That would cause surprise and doubt about the “random” device working. Most of the surprised Carrolls tried again and got reasonable results. But again, there’s one that got all 1s and another that got all 0s.

In fact, there are versions that got 0s (or 1s) no matter how long they tried. There’s a version that replaced the device and still got the same bits. There are also versions that got other kinds of decidedly unexpected results.

They are vastly overwhelmed by the versions with reasonable results, but under MWI those versions always must exist. (No matter how “thin” their realities are.)

This one is a judgement call, but I think that’s beyond the pale.

§

The only place left for me to explore is Everett’s paper that started all this, perhaps along with Bryce DeWitt’s extension of it using decoherence (which Everett didn’t know about).

So I suppose there might someday be a MWI: Everett post… or maybe MWI: Origins would be appropriate. 🙂

Stay safe, my friends! Wear your masks — COVID-19 is airborne!

About Wyrd Smythe

The canonical fool on the hill watching the sunset and the rotation of the planet and thinking what he imagines are large thoughts. View all posts by Wyrd Smythe

33 responses to “MWI: Sean Carroll

  • Wyrd Smythe

    One thing I know to be true about myself is that I can be swayed by logical argument. I have revised my worldview more times than I can count due to logical arguments.

    But as long as I’ve been worrying this MWI bone,… it just seems more and more clearly false to me. I truly don’t understand what people see in it.

    For me it’s like trump supporters. I understand the arguments they’re presenting, but I don’t see any logic behind them.

  • Wyrd Smythe

    In contrast, here’s an online presentation Jim Baggott did earlier this month for The Royal Institute (a good source of science presentations). It’s to promote his new book, Quantum Reality.

  • Wyrd Smythe

    Here’s the Q&A session after the presentation (RI often has a separate Q&A video associated with the presentation).

    I like Baggott a lot and very much see eye-to-eye with him. (I posted about his book Farewll to Reality back in April.) I especially like how he ranks MWI as his least favorite realist interpretation. Right on, Jim! 😀

  • Wyrd Smythe

    I think the keys to quantum lies in fully understanding three things: superposition, measurement, and decoherence. (I’m starting an online MIT course to learn more about the Schrödinger equation and superposition.)

    Here’s a recent video by Dr. Sabine Hossenfelder discussing decoherence:

  • Michael

    Enjoyed this post, Wyrd. I haven’t read Carroll’s book, but have enjoyed a few of his YouTube videos of late. He is a good presenter, and I’ve enjoyed brushing up on a few topics.

    I’m curious if you read Lee Smolin’s book Einstein’s Unfinished Revolution, which of course has the requisite summary of various quantum physics interpretations that have arisen over the years. The final third though, which I wish was more developed and carried more of the text, was about his conviction that something is indeed missing from our current understanding, and some of the paths he is pursuing in his research. Smolin is a realist at heart, so he is looking at the possibility of a deeper order to things. I found it quite interesting. All of this stuff is interesting really.

    And I have no idea what to make of it. I kind of like Neal Stephenson’s take on things in Anathem. 🙂

    Michael

    • Wyrd Smythe

      Hi Michael; thanks!

      I’ve been meaning to check out that video series Carroll’s been doing (he’s up to #21, I think, so I have some catching up). At least some of the titles sound pretty interesting (others seem very familiar territory to me).

      I’ve been a fan of Smolin’s ever since The Trouble with Physics, but I haven’t read that one. Most books like these get a little hand-wavy once past the basics. Some are worse than others. Lawrence Krauss’s book, A Universe From Nothing, which seeks to explain why we’re here at all, is a good example. I read it three times trying to figure out what he was saying and never did find any there there. It became my canonical example of utter empty hand-waving. (Sad to say, this book of Carroll’s is a strong runner up.)

      I’m definitely firmly on the realist side of things, although I have some spiritual leanings. I think the jury is still out on the metaphysics of things. Existence is a most amazing and curious thing, and human consciousness even more so.

      Stephenson is one of my favorite modern SF authors! (I’ve written a few posts about his work.) I liked Anathem quite a bit. You’re saying you liked his idea of multiple levels of Platonic realities? That was definitely a unique take!

      • Michael

        I’ve read (or listened to, which I grant you is not quite the same thing) The Trouble With Physics, Three Roads to Quantum Gravity (but it’s been too long for me to say anything intelligent about it), Time Reborn, and Einstein’s Unfinished Revolution. I do enjoy Smolin as a physicist and writer. I also read Julian Barbour’s book a while back and remember enjoying it, even if I didn’t quite no what to make of it. I mention it because I think Barbour and Smolin have at least had interesting conversations together.

        I haven’t read Tegmark or Krauss yet. You’re not exactly warming me up to the idea, but on the flipside I like reading all sorts of perspectives so I’d probably give them a go under the write prompt.

        What you wrote about being a realist, but with the caveat of some spiritual leanings, resonates, Wyrd. What do you mean by spiritual leanings? As you likely know from watching me dig holes for myself on Mike Smith’s page, I have more than a leaning. But having said that, my spirituality is the type that says basic science is correct and must be one of the very worthy variables grappled with amongst all the others. I just think that if and when we ever have any sort of ultimate understanding, much of what we think we know now may stand in a very different light, and we just can’t predict what that light will be. So anyway, I’m curious what you mean by spiritual leanings.

        As to Stephenson, he is definitely a favorite of mine. He cracks me up on a regular basis, which I greatly appreciate in a writer, and I just generally enjoy him. It’s been too long since I read Anathem as well, but I remember liking how the Thousanders (or whatever they were called) had some ability to nudge reality in a particular direction through some sort of quantum effects. It made for great fiction there at the end. Another writer who has cracked me up a time or two and whose book had some interesting use of quantum possibilities was Adam Roberts, whose book Yellow Blue Tibia I recall enjoying quite a bit. There’s an interrogation scene in there that just totally cracked me up. But I’m easily amused, Wyrd. 🙂

      • Wyrd Smythe

        One thing I always liked about Smolin is his belief in the importance of philosophy in physics. I’m not familiar with Julian Barbour — I’ll keep an eye open. (Although my reading list is very long right now. So many books, so little time.)

        Tegmark is interesting and worth exploring if you’re looking for something new. I don’t buy his MUH, but I give him a lot of credit for being up front in saying his idea does seem a bit crazy. Krauss, like Carroll, seems to lack that humility of having an idea that might be right, but also might be wrong. They both seem to feel they’re right on the money.

        Spiritual leanings (yes, I did pick up on your position)… well, my dad was a Lutheran minister (mom was the choir director and organist — my musical skills, such as they are, come from her), so I was raised in the church, but also had a sense of it as my dad’s job. My parents were both what I think of as true Christians — loving, gentle, steeped in faith, but clear that it was their path, their choice, not something to impose on others.

        They were free-thinkers who let their two children pick their own way, so in high school I went through a phase of hard-core atheism (probably part of growing up and finding my own way apart from my parents). Various experiences in life pulled me back to the point of Decisive Agnosticism as a baseline, but to the extent I lean, I lean towards deism, and some of my personal experiences make me wonder sometimes about theism.

        In particular I’ve had two specific, and rather profound, experiences that were either rather astonishing coincidences (which certainly do happen) or were little messages from God saying, “Yes, I really am here.” And there are the times of deep feelings of spirituality and connectedness.

        I think the two greatest questions are: Why does existence exist? Why does consciousness exist? I’m fully aware the answer might be ‘it just does’ and even call it a form of Pascal’s Wager, but neither my heart nor my head believe all this just happened. (And if it did, it seems kind of a waste of a whole universe.)

        I absolutely believe in science. I think it’s the Yin. I also think there might be a Yang.

        “[Stephenson] cracks me up on a regular basis,”

        Have you read The Rise and Fall of D.O.D.O., yet? That one was hysterical! I still consider Snow Crash as my favorite of his (for lots of reasons), but D.O.D.O. is a very close second.

        Adam Roberts. Not familiar with him. Another author to keep an eye out for. (Damn, that list is getting longer, too.) Are you familiar with John Scalzi? His Redshirts is one of the best reads I’ve had recently. I can also recommend The Android’s Dream. I think I’m on my way to becoming a Scalzi fan!

        “But I’m easily amused, Wyrd.”

        Ha, likewise! I fight hard to keep my child-like sense of wonder and joy and awe (and laughter, which I consider the most important of all).

      • Michael

        Thanks for this, Wyrd. Appreciate the background.

        My father grew up on a farm in rural Nebraska, my mother in a Catholic family in Niagara Falls, and I grew up Catholic. Like yourself, though perhaps in a different mode, I branched out to explore the universe on my own, or at least expanded, terms. I fell in love with physics, and also did some decently in-depth research into other philosophies and orientations–Buddhism and Native American (Lakota specifically) spirituality. I met my wife through this interest in the Native American path, and spent ten or twelve years with a group that participated in ceremony on a fairly regular basis. Certain experiences there leave me unequivocally convinced there is more to this universe than a materialist explanation can provide, but exactly what it is or how it is, I don’t know. And I don’t know if it matters that we know, ultimately. I’m with you on there being something true in both great poles of our collective orientation. A passion of mine over the years has been to try and truly understand various positions, and when I do, I generally find myself concluding there’s at least part of the truth everywhere.

        So believe it or not I haven’t read The Rise and Fall of D.O.D.O. yet. I think the dual authorship was a turn-off when I passed in on the shelf for whatever reason. And oddly I just checked Neal’s website and that one doesn’t appear in his pull-down menu of Books. I think I’ve read most of the rest. I haven’t read either of his essay collections, or The Big U, but believe I’m current otherwise. My first was Cryptonomicon and it holds a special place in my heart. I need to read it again one of these years.

        I will put Scalzi on the list. I’ve never read him. I actually don’t have a list and I need to make one so I don’t forget these things. I’ve been reading a lot of literary fiction the past few years, as I’ve been doing some writing these past several years. I went through a phase where I focused on short stories to see if I could actually get a publication or two. I’ve had five or so stories published in literary journals–none of the “big” ones, but it’s astonishing the competition–and am working on editing a novel that may not be fit for publication. Whatever happens with that, it does feel good to start and actually complete a literary task of that magnitude. It puts into perspective the astonishing skill and tenacity of writers in general.

        Your questions are great ones. I won’t demean them with an attempt at an answer. Haha. It’s nice to connect directly, Wyrd. I kind of thought you might have written me off altogether after a comment you made at Mike’s place, but I was probably being over-sensitive at the time. It’s amazing what different sites and conversations bring to the fore, and it seems there’s no substitute for direct engagement.

        Michael

      • Wyrd Smythe

        Cool background, Michael! I share some of that interest in Native American culture, in part from loving nature and living outdoors and on the land, but also in part from their metaphysics. “Primitive” cultures are not stupid cultures — the human brain hasn’t really changed in 10,000 years. Everyone has that power of intellect, and I find it fascinating what it accomplishes when not distracted by all our modern noise.

        (I think it’s Stephenson’s Fall where he refers to the interweb as “the din” and the combination of Facebook, Twitter, email, chats, newfeeds, etc, as “the miasma” — perfect words.)

        I’m a huge fan of the Tony Hillerman Navajo Tribal Police series. A big part of the draw is how the books are steeped in Navajo culture (and often the culture of the other nations in the area, Hopi, Ute, and a few others). I lived in Los Angeles nearly 20 years and loved that part of the country. Now that I’m retired, an option I’ve considered is New Mexico.

        I know what you mean about the co-authorship of D.O.D.O. — it makes one wonder. I can’t say I’m discerning enough to have identified any style differences. I can say I thoroughly enjoyed the book.

        I’ve recently gotten into a couple of library apps (CloudLibrary and Libby) that allow “checking out” ebooks from libraries if you have a library card or can register with them and get one. Access to lots of free books you can download and read on your device. Many of the science books I’ve reviewed here are library ebooks. Especially useful with the social distancing!

        Likewise on connecting directly! It’s always nice to get to know people. What you said about there being a bit of truth everywhere, for me, it’s with individuals where I see that in great measure. Everyone has a story to tell, and it’s like “interesting” numbers. There are numbers that are “interesting” for some mathematical reason or other, but the ones that supposedly aren’t actually are because it’s interesting they aren’t “interesting.”

        A favorite line from Desiderata: “Speak your truth quietly and clearly; and listen to others, even the dull and the ignorant; they too have their story.”

        (Not that anyone here is either dull or ignorant! Quite the opposite.)

      • Michael

        Wyrd, The Rise and Fall of D.O.D.O. is in hand, and the assimilation has begun. I’m only twenty pages in, so don’t say anything… Haha… but did you ever read Jonathan Strange & Mr. Norrell by Susanna Clarke. I know enough to know the first twenty pages of Stephenson’s work probably are nowhere close to where we’ll land, but that book is about magicians at a time when magic has all but faded, and they are trying to go through old texts and stuff to recreate it. I read it a while ago… just remember I really enjoyed it.

        And re: Murakami, you’re probably right it’s on a different spectrum than your typical read. Strange & Norrell may be too because it’s more like a fantasy novel than sci fi.

        But all that said… have you read The Sellout by Paul Beatty? If you’re not hooked after reading the preview on Amazon, it’s not for you. But it’s an astonishing novel I think. I laughed about 2.1 times per page…

        Michael

      • Wyrd Smythe

        I’ve heard of the Jonathan Strange & Mr. Norrell story due to the TV series, but haven’t checked into it. Based on the Wiki article, it sounds interesting. (I did enjoy the Harry Potter series, both books and movies. There is fantasy I like, especially what’s called magical realism, which it sounds very much like this Strange & Norrell series is.)

        A lot would depend on whether the writing wallows in this post-modern deconstructive “everyone is shit and life sucks” mode that seems to have infected so much modern storytelling. I read to escape (and learn), not to be confronted with realities I sadly deal with daily. (I truly don’t fathom why people like this “dark, edgy” mode in everything they watch or read.) So if there is joy and optimism to the writing I’m far more likely to like it.

        (Needing escape from this crazy world is why I’ve been reading a lot of Agatha Christie Hercule Poirot lately. 😀 )

        The Sellout sounds kind of interesting, too. With fiction, I don’t often venture outside SF or crime/sleuth/mystery but sometimes something catches my fancy. (To be honest, most “mundane” fiction is, well, mundane to me.)

        One I loved enough to read several times is Between the Bridge and the River by TV’s Craig Ferguson. The guy wrote an autobiography that’s really good, but his one fiction novel blew me away. I highly recommend it. (I was hooked by the first line: “Cloven-hoofed creatures passed this way.”)

        (BTW, as an SF fan, you might get a kick out of this recent post.)

      • Wyrd Smythe

        I found Strange & Norrell and The Sellout available as ebooks on one of my library apps, so I added both to my queue. (I have multiple TO-READ queues, so it might be a while…)

      • Michael

        👍

        I will hazard a guess you may prefer The Sellout. Based on what you’ve told me here. It is literary fiction but its satire, and it is cracking!

      • Wyrd Smythe

        Could be. Somehow the author’s name, Paul Beatty, rings a bell. I’m sure I haven’t read him, but I think I’ve heard him talked about. I put The Sellout on hold, but it’ll be six weeks before it becomes available.

        I’d heard people raving about Infinite Jest, by David Foster Wallace. It’s apparently a central book for some. I bought it, and have tried reading it three times. Each time I put it down and somehow don’t return to it. To me it was a bit like science fiction without the science fiction somehow. It wasn’t that I disliked it; it was that it just didn’t do anything for me. I think I just don’t do that well with surrealism.

  • Wyrd Smythe

    A little bookmark for a video lecture series I’ve started watching. I’ve decided I want to learn how to actually do the Schrödinger equation.

    https://ocw.mit.edu/courses/physics/8-04-quantum-physics-i-spring-2013/

  • Wyrd Smythe

    Bell’s actual Inequality:

    n({A}\cap\overline{B})+n({B}\cap\overline{C})\geq{n}({A}\cap\overline{C})

    For any A, B, and C, that are orthogonal properties of a given object type. For example, cars. Let A=red cars; B=cars with two doors; C=cars with NY plates. Take any photo of a number of random cars, and the counts will follow Bell’s Inequality. The inequality is true for any objects and set of orthogonal properties…

    Except quantum objects!

    Post to follow…

    (So the equation with cars says: The number of red cars that don’t have two doors plus the number of cars with two doors and without NY plates is greater-than or equal-to the number of red cars without NY plates.)

  • Michael

    Hi Wyrd,

    I think I read on one of your other posts, a reply you gave to Mike Smith suggesting that perhaps what we don’t know about consciousness and what we don’t know about quantum mechanics may be related, or mutually resolvable. I don’t remember exactly how you said it. I think you ended up discussing MWI on another thread or something. Anyway, I came back here to read your arguments again.

    I find this stuff really interesting. I have to say that I’m a proponent of some form of MWI, though for reasons that are not explicitly scientific. There are a number of spiritual books I’ve enjoyed over the years, like A Course in Miracles (or ACIM for short) that I mentioned in my earlier note to you tonight, that touch upon this notion. And while a bridge doesn’t quite exist yet between some of these notions and present scientific theory, in general they also not incompatible with it.

    So while I have nothing like a scientific theory of it, I’ll just say a couple of things that ring true for me. It makes sense, I think, to note that I don’t begin with the notion that the universe is a random fluctuation or a lifeless jamboree of stuff floating around. I think it is an engine to produce experience. Because experience is the most profound thing there could be, at some level, and if we are to know something, we really must experience it to truly know it. So, the universe is a vehicle for expression and experience.

    Given that, I think experiencing various aspects of a given choice would be desirable, and that although as the beings we are, with the particular constraints we have in our nervous systems and such, we generally experience only one aspect of the choices we make, it doesn’t mean an experience-producing engine like the universe wouldn’t explore other choices and their consequences as well. We do this all the time in our own lives–we do thought experiments about what if I did this or that. It doesn’t seem absurd to me that the universe does this, too. We even have a rudimentary science for it.

    That said, I’m very uncertain about the notion that the universe would wish to explore or be beholden to exploring every possibility. Some would obviously be quite painful. Take WWII as a for instance, and multiply it times countless worlds. We might not want that. Or if it arose as a result of a particular set of conditions in our collective choices, we might want to learn from it and avoid it in the future. So I suspect that consciousness somehow relates to selecting those threads that are of the greatest mutual interest. Consciousness might actualize or select those conditions in which the expressions / experiences taking place are serving its purpose, in other words.

    But this consciousness I’m describing is something greater than individual consciousness, although surely it encompasses it. I’m not saying our personal choices don’t impact the reality we experience; I very much think they do. I’m just saying I don’t think that level of consciousness alone is sufficient to keep the place going. Our personal consciousness is a tiny spark in a grand ensemble.

    I suspect that there are myriad and potentially interwoven, or interacting, portfolios of experience at work–(other worlds linked by ensembles of meaning or questions being researched, etc.)–and that through our choices and our learning we very well could be negotiating our paths through this phase space all the time without realizing it. We could be shifting trajectories all the time, without losing any sense of determinism or causality… This is not meant to be a scientific thought right now of course. It’s just a variation on the theme of MWI but with the introduction of the notion that consciousness has some ability to actualize and select tracts of possible experience. It’s make believe for now, Wyrd, if I was to be pressed. And that’s fine with me. I’m just trying to imagine how the little pieces we know might link up to something greater, as described in various spiritual works. I suspect we know astonishingly little–we just keep falling into the trap of thinking we know a lot!

    Michael

    • Wyrd Smythe

      “I don’t remember exactly how you said it.”

      My view boils down to “we don’t know, so lots of things are possible.” It — at least so far — isn’t clear a biochemical description of brain function is sufficient to explain subjective experience. If it is, we haven’t connected those dots yet. The difficulty in doing so might be due to needing new physics or a new description of current physics.

      We’re so used to it we forget that chemistry is quantum. The Sun shines because of quantum effects, and some animals use magnetism, which is a quantum effect. Photosynthesis also has quantum (or at least atomic) level aspects. My contention is it wouldn’t be surprising if they play some role in how mind emerges from brain function. As you mentioned to Mike, more likely at the functional level rather than a qubit level.

      “I have to say that I’m a proponent of some form of MWI,”

      Your formulation does feature different metaphysics. 🙂 Are you familiar with the Virtual Reality hypothesis? That also has the idea of trying different versions of reality, but not in the MWI sense.

      I sometimes thing life has gotten so surreal that it almost makes sense this a simulation to test some weird extreme political view. It’s exactly the sort of thing one might do to see what happened. For all we could ever prove, reality began in 2015.

      “Because experience is the most profound thing there could be, at some level, and if we are to know something, we really must experience it to truly know it.”

      Certainly subjective experience is (pardon the pun) phenomenal. There is a version of Mary’s Room where its music that Mary lacks. She might know everything about how her body would respond to it, but actually being moved by music is not (I believe) something objective knowledge can ever grant.

      “Consciousness might actualize or select those conditions in which the expressions / experiences taking place are serving its purpose, in other words.”

      I think you’re going to get a kick out of Stephenson’s D.O.D.O.! 🙂

      I never really thought about it until this, but my metaphysics remains stubbornly old-fashioned. One option is we’re all components in the Mind of God — whatever the heck that actually means. I think I mentioned I lean more towards deism than theism, but I haven’t ruled out theism. Failing something capable of claiming “I am God” I think I fall all the way back to physicalism, although it’s a rich physicalism with emergent properties (even so I find it the empty lonely option).

      It’s funny how I personally don’t find much middle ground that appeals to me (especially things like crystals or tarot). This may trace to my parents who never fooled me or my sister into believing in Santa Claus. I’ve never thought he was real. Their reason: they perceived Santa as a false idol. Likewise money and fame. So I had that installed from the beginning. I can worship God, but it’s that or I’m out.

      That said, that’s my path up the mountain. Just one of very many. The whole point is the climb, not the path you take.

      Couldn’t agree more about the trap of thinking we know a lot. It cracks me up we’re so sure about what happened within microseconds of the Big Bang 13.8 billions years ago. The more one looks into it, the more assumptions one finds. 😀

  • Michael

    My view boils down to “we don’t know, so lots of things are possible.”

    I thought all of this was well said, Wyrd. I agree.

    Are you familiar with the Virtual Reality hypothesis?

    I hadn’t studied it or read in depth on it, but I was aware this notion existed. I think it has some resonance for me, but not perhaps as it is generally formulated. I’m guessing that when this notion is discussed it is in the context of our universe being a simulation that runs on some very advanced technological platform in some other material universe that is in many ways like ours. That notion I’m not entirely keen on. But it’s just my intuition talking. No reason it couldn’t be I suppose.

    The metaphysics I have adopted is somewhat sprawling, and frankly just a loose set of ideas and nothing too rigorous–because I’m keenly aware that what I don’t know is a lot more than I do know. But any vision of the universe I would be inclined to accept at this point would have to be consistent with these few notions, and I don’t think a computational universe is capable of fulfilling the requirement. The notion above is essentially a computational universe, unless I’m mistaken, and I don’t think ours is. So that would be my first concern.

    I should probably say that I don’t think our universe is only computational. I think there is a tremendous amount of housekeeping that must be done on a continuous basis, and I think some sort of computational process could be doing this. I mean… things just have to balance out. I think the physical laws we’ve discovered to date are probably valid under a wide range of conditions, but I don’t think they capture the whole picture.

    But–and I may contradict myself here, I can feel it coming on!–any conceptual universe I would embrace as being a possible match to our own would need to possess a deep underlying unity. This is a hard concept to describe in physical terms because I’m not sure it quite exists on the physical terms we’re used to trading in. But the reason I may contradict myself is that it’s quite possible a deeper knowledge of our own universe would result in an understanding of this fundamental unity in terms that, in light of that future knowledge, would seem physical on those terms.

    The only way I can describe this unity in quasi-physical terms would be that it is a ubiquitous scalar field without mass or energy that is present at every point, and which effectively makes every point in the universe the same point, as well as every time. It would be the ultimate non-locality. And if there were Many Worlds, it would be present in all of them as well. I don’t know what to call this, but it would be the field of being that joins each to each in a very fundamental way, that holds a record of all experience and all events, and which, under certain conditions, may make available “knowing” of what is. “What is” here is beyond what may have already manifested in our particular timeline or “world.”

    Maybe I’d call it the imaginal field or something, but that’s too anthropomorphic still. But it is through this field, which again is just a very naive attempt at a description using language we might both understand, that elements of reality a materialist dismisses out of hand, are mediated. And it is through this field that we perhaps make those movements I think I mentioned earlier, about shifting between timelines in a MWI type universe. Perhaps at some point we might have enough understanding of such a field to bring it into a computational system, and that is where I perhaps contradict myself, but I don’t think that would be the case at this point in my thinking.

    I think the functions of this field are activated moreso by the heart than the intellect. If there was, for instance, such a thing as karma–or some way in which our intentions contribute to the manifest reality that produces experience–then it would be through such a vehicle. Regardless, I cannot at this point in my spiritual and intellectual unfolding make sense of a universe without something along these lines.

    That said, I’m prepared to say that all of reality is a simulation in the sense that the physical world is an effort to express, or simulate, the non-physical contents of this ultimate reality. Without a world such as ours there really can be not tangible vehicle for communication, expression, differentiation into unique beings, or discovery. So in a sense I think our reality is a simulation of who we are. But I think it’s ground is this fundamental unity that holds or allows all possibilities (within the range of material expression possible in our simulation).

    I don’t know how such a universe ranks in your own pantheon of possibility. I think you were saying you’d be comfortable personally with one of two things: either there is a God at the helm somewhere (not exactly what you said I know), or you’d revert back to a rich physicalism. I think what I’ve described maybe covers both. I’m not sure. Have to see what you think!

    And I can’t wait to read D.O.D.O. now! I just started a book, but I was thinking of that or a Scalzi (did I get that right) for my next one.

    Michael

    • Wyrd Smythe

      Michael, I have to say I enjoy these conversations. For many reasons I stick within the domain of physicalism for most conversations; it’s nice to have an intelligent conversation that goes beyond that.

      “I’m guessing that when this notion is discussed it is in the context of our universe being a simulation that runs on some very advanced technological platform in some other material universe that is in many ways like ours.”

      Yes. Certainly similar, definitely material. The VR hypothesis is strictly physical, and the only teleology comes from other intelligent material beings. And, as you say, our reality is computed on some material computing device.

      (Which has interesting consequences for our ability to create computing devices, since those would be computed simulations. It’s like running Windows on a Mac. Our theoretical computing power is limited by what’s computing us. That means the VR hypothesis doesn’t suffer from “turtles all the way down” — there’s a top and bottom to any stack of simulations of simulations of etc.)

      The VR hypothesis has some attractive features, but I agree, I’m dubious reality is calculated — except by itself at the quantum level. Quantum interactions can be viewed as the universe computing itself on a giant quantum computer.

      “The metaphysics I have adopted is somewhat sprawling, and frankly just a loose set of ideas and nothing too rigorous”

      Heh, sounds like mine and for the same reason. Just a WAG about May bees.

      “The only way I can describe this unity in quasi-physical terms would be that it is a ubiquitous scalar field without mass or energy that is present at every point, and which effectively makes every point in the universe the same point, as well as every time.”

      I can see why you compare it to MWI — what you’re describing does sound a lot like the universal wave-function. That, too, is a unified element that, in theory, fully describes reality. If I follow what a wave-function is (and I’m not claiming I am), it can describe a reality apparently limited by light speed, but as a single vector is, in a sense, not limited to locality itself. It’s describing everything everywhere.

      You’re attaching a karmic or teleological aspect, so that’s a different metaphysics of course.

      What you’re describing reminds me a little of ideas that consciousness is a fundamental force that manifests in the right structures (i.e. brains, although why the universe should evolve natural instruments to capture this force isn’t explained except in panpsychism where everything feels this force to one degree or another, but brains especially).

      If you think about Quantum Field Theory, our current view is that “particles” are soliton-like vibrations in their respective fields. So imagine a Consciousness field in which minds are similar vibrations in the field. Complex structures, such as brains, resonate with that field.

      But these would be just analogies; you mean a deeper reality with meaning.

      Which is interesting in that when I distill all the spiritual metaphysics, whether it be Buddhism, Islam, Wiccans (which I take seriously), Tarot (which not so much), or whatever, there seems two basic ideas: Firstly, that there is more to reality than physicalism — there is a metaphysical reality and that metaphysical reality is teleological. Secondly, that how we live our lives matters in the context of that greater reality.

      Maybe it’s not judgement and harps or pitchforks, but in that final moment when life slips away and you know it, all the self-falsehoods fall away and you see yourself as you are. Your final eternal moment is your own true judgement of your path through life. Who knows.

      “So in a sense I think our reality is a simulation of who we are.”

      One of my all-time favorite pair of books involves the idea that heaven and hell are literally what you think they are. It turns out consciousness never dies once created. It ends up going somewhere, and the two alien energy beings who were stranded on Earth long ago, created two places for them to go. The two places reflect the personalities of the two brothers — one’s a party guy, the other’s button-down — so “souls” gravitate to whichever realm attracts them and manifest per their belief structure. There really is a part of “heaven” involving clouds and harps, as well as a garden with lots of virgins. All depends on what you believed — a common theme with some fantasy that belief creates reality. A kind of fantastic idealism. We create our gods.

      (Parke Godwin: Waiting for the Galactic Bus and The Snake Oil Wars. See this post for more.)

      “I don’t know how such a universe ranks in your own pantheon of possibility.”

      It resonates with things I’ve thought. I do tend to jump from a self-aware teleology (something that knows it’s God) to some form of physicalism for preference, but I did have ideas about a consciousness field or force for a long time. Still isn’t something I’d rule out, just not something I’ve thought about in a while.

      Certainly a lot of your ideas fit into a rich physicalism. (I’m one of those who do distinguish between materialism and physicalism, with the former being a subset of the latter.)

      Just as an aside about karma, did you ever watch the TV show, My Name is Earl?

      • Michael

        what you’re describing does sound a lot like the universal wave-function…

        A question for you on your description of the wave function, Wyrd. I’m curious what you think of this, particularly as you’ve begun that MIT course. Unless I’m mistaken, when I listened to Smolin’s most recent book, I believe he argued that quantum mechanics is not a theory that can be applied to the universe as a whole. I don’t know if a) I understood him correctly, or b) if other physicists share his view or not. Probably some do and some don’t. But one thing that did make sense is that quantum mechanics does seem to require an arbitrary split between observer and observed, so Smolin’s point I think is that we can only analyze subsets of the whole. We have to decide what we’re measuring, of course, and how we’re going to measure it. And so this methodology, which works wonders, cannot be meaningfully applied to the whole thing at once. That sort of made sense to me, on a non-mathematical level.

        But at the same time it begged questions about decoherence, which as I understand it doesn’t require a conscious observer or even a choice about what to measure–the environment is essentially “the entity conducting the measurement” and interaction of a system in superposition with the environment forces a particular state to be selected and the others fall away. But still, it only ultimately matters to a conscious observer, right? I mean, assume consciousness has nothing whatsoever to do with the physical process, the whole point of science is to generate understanding, so even the “environment as measurement apparatus” is relevant only in the sense that the world is presented to conscious beings like ourselves in a particular way. And that seems like it would always be a partial look at things; never an actual view of the whole thing if you will.

        Anyway, I just wondered what you thought of this, and the notion of there being a universal wave function. If there is what is it and what does it mean?

        Regarding your twofold synopsis of uinversal metaphysics: Firstly, that there is more to reality than physicalism — there is a metaphysical reality and that metaphysical reality is teleological. Secondly, that how we live our lives matters in the context of that greater reality.

        I agree these are fairly universal. I’m not entirely sure a Buddhist would view ultimate reality as teleological or not, to be honest. It may vary with sect or teaching perhaps. But that’s a minor aside. I think the second point is a many-layered onion that we could peel back for some time.

        There’s a very simplistic level of “good and bad” or “light and dark” and when we speak of these things “mattering” it often relates to some ultimate personal outcome. Particularly in Christianity, right? Do good, get rewarded in heaven. Fuck up, and go to hell. That’s kind of the game show version, in a sense. You get to play the game once, and then whatever you get for a prize that’s it.

        If we peel it back just a bit, there’s another understanding which basically says there is no end to things, but there are consequences. There’s not so much a universal good or bad, but there are things like kindness, generosity, compassion, wisdom, etc., and there are things like greed, lust, jealousy, bitterness, etc. It’s not that one is “good” and the other “bad” it’s just that there are some sort of universal dynamics that result in consequences from our thoughts and actions. In this conception our thoughts, intentions and actions don’t make us who we are: we’re kind of all like children. We touch fire, we get burned. We learn, hopefully. We can make mistakes, but that’s all they really are. They are not condemnable offenses by a vindictive God.

        And if we keep peeling it back, we get to where the other thread we have open is going eventually, (about the Course in Miracles), to the notion that the root cause of the intentions, thoughts and behaviors that have adverse consequences may in fact be healed. Another way to say it is that learning is complete. We’ve learned that certain illusory modes of perception are in fact incorrect, and we understand the modes of perception that are natural and true. Once this occurs, this whole “good and bad” thing dissolves, and it’s more like, “what do I want to do today?” At this point, with the root cause of our difficulties healed, life would be a creative expression game, rather than a game of righteousness, or survival, or power.

        I think eventually we’ll get to this third paragraph, but I think humanity in general is operating largely from one of the first two. Perhaps the majority in the first level, where the primary thought processes revolve are “an eye for an eye,” “you get what you deserve,” etc.

        I’ve never seen My Name is Earl. I just started watching the original Star Trek episodes on Netflix. That will probably keep me busy for a while. Haha.

        And I’m curious what a rich physicalism is, Wyrd? I once told Mike I thought that ultimately while our views may appear to diverge quite a bit in the present, that with advances in understanding on both sides we’d probably ultimately converge. And I do believe such is possible, but it would require a slightly broader application of scientific principles, probably some discoveries along the way we cannot explain with current models, etc. And as those things occur the language may move closer to things a spiritual person holds most dear, until both groups realize they’re looking at various sides of the same coin. Maybe that is something like rich physicalism?

        I’m glad you’re enjoying the exchange, Wyrd. I am as well.

      • Wyrd Smythe

        I’m going to split the reply between the wave-function question and the rest. I wanted to think about the wave-function part, so I jumped to the rest…

        “I’m not entirely sure a Buddhist would view ultimate reality as teleological or not”

        It might be a bit of a punt when it comes to Buddhism, I agree. Truth is, I don’t normally include the “teleological” aspect in the first observation. I kinda threw that in because we were talking about universes with metaphysical intentions or consequences. I usually just say there is a metaphysical reality and leave it at that.

        (A further observation about that is that, as far as I know, every human culture on Earth has had some sort of metaphysics. There has never been an innately atheist culture. That could be due to some hard-wiring in our heads — we’re just wired to frame reality that way. Or, and this is what I believe, it might be an apprehension of something real that we can’t yet fathom. Each culture realizes these apprehensions in its own terms — our religions and gods reflect us. In this modern age, people are trying to explain it in modern ways.)

        “That’s kind of the game show version, in a sense. You get to play the game once, and then whatever you get for a prize that’s it.”

        Yes, Christianity and, I believe, Islam. Judaism, among the Abrahamic religions, less so, but all three in that trilogy are generally judgemental. Game show is a good way to put it. 🙂

        “Another way to say it is that learning is complete. We’ve learned that certain illusory modes of perception are in fact incorrect, and we understand the modes of perception that are natural and true.”

        Basically with you, but it starts to get a bit rarefied for me at this level. I think I’ll pick this up in the other post’s thread and leave this one more for the quantum and metaphysics stuff.

        “I just started watching the original Star Trek episodes on Netflix.”

        Enjoy! I grew up with those shows. Used to use my dad’s reel-to-reel to record the sound and listen to the episode repeatedly during the week. There was a time I could see any 60 seconds of any episode and know which one it was. A lot of that’s faded over time, and around the 50th anniversary I found I’d had enough Trek for one lifetime, but Trek was huge to me at one point. (I’ve written a lot of Star Trek posts!)

        “And I’m curious what a rich physicalism is, Wyrd?”

        Kind of what you intuit at the end of the paragraph. Just an open-ended vague view of reality with no metaphysics (nothing “supernatural”) but with ontological emergence and a much richer physics. Certainly a physics that integrates gravity and quantum mechanics, but also one that fully explains spacetime, inflation, dark matter, dark energy, etc.

        It’s whatever level of physical richness and complexity is necessary for minds to arise from brains in the absence of something like a god-given soul. The notorious Hard Problem indicates we need a new understanding of physics, or actual new physics, or some kind of dualism, because we don’t understand subjectivity now.

        I’m not sure I usually see much spiritual richness to this physicalism, for it does align more with Mike’s view, which is type-A materialism. (This, again, is my personally sharp divide between physical theories, which generally lack any metaphysics, and the spiritual views I’ve mentioned involving a self-aware God.)

        But like everyone, I’m just guessing day-by-day!

      • Wyrd Smythe

        “Probably some do and some don’t. But one thing that did make sense is that quantum mechanics does seem to require an arbitrary split between observer and observed, so Smolin’s point I think is that we can only analyze subsets of the whole.”

        You mentioned two of what I think are the three key questions in quantum mechanics: superposition, measurement, and decoherence.

        The problem I think Smolin is getting at is that the wave-function describes some system, and that description is from the outside. A wave-function for the universe includes everyone and everything; there is no outside.

        There is also that a wave-function for the universe is mind-boggling because the quantum Hamiltonian for it has to include every particle. If, on that Wiki link, you look down at the The Schrödinger Hamiltonian section, you’ll see an equation for just one particle:

        \hat{H}=\hat{T}+\hat{V}=\frac{\hbar^2}{2m}(\frac{\partial^2}{\partial x^2}+\frac{\partial^2}{\partial y^2}+\frac{\partial^2}{\partial z^2})+V(\bold{r},t)

        If I’ve gotten that right. Imagine expanding that to include every particle in the universe. For one thing, this assumes their positions are known, which has all kinds of problems.

        Caveat my own ignorance here, but AIUI, the vector, Ψ, has as many dimensions as there are degrees of freedom, which I believe in this case is three (x,y,z) per particle, so the Hilbert space for the vector has 3×N dimensions, where N is the number of particles in the universe (~1080).

        (My first objection to MWI involves the question: What implements this huge wave-function? Since MWI says the wave-function is all there is. As you see, it’s a massively complex mathematical object. If it’s real, what is it real on?)

        Anyway, yes, you’re right that we use QM to study very small subsystems. Decoherence and the very short wavelengths of massive objects destroy quantum effects on the large scale. (You’ll see, in D.O.D.O. how they have to isolate people from the environment.)

        And, bottom line, no, I don’t think “universal wave-function” is meaningful except in the most abstract or theoretical sense.

        “But at the same time it begged questions about decoherence, which as I understand it doesn’t require a conscious observer or even a choice about what to measure”

        Right, and this is another topic I’m starting to explore at a deeper level.

        AIUI, what we mean by decoherence is that the phase information of a given system is beyond our ability to recover (measure). Phase information from surrounding systems mix with it and its phase information is distributed among the surrounding systems. Interaction with passing radiation also degrades the coherence of the system’s phase.

        As you say, the environment is “measuring” any quantum system. Decoherence times are extraordinarily short — pico-seconds; less in larger systems; longer in isolated systems. (I wonder if large enough systems have decoherence times that are sub-Planck time, which might go towards explaining why we don’t see quantum effects at our level.)

        “…so even the “environment as measurement apparatus” is relevant only in the sense that the world is presented to conscious beings like ourselves in a particular way.”

        It certainly means we see a world in which nothing is in superposition and physical uncertainty doesn’t play any role (that is, our macro world seems fully determined). And then, of course, we only apprehend it through our senses, so our reality is just a construct in our head based on the input data.

        For me, quantum reality just means reality is fuzzy around the edges. And there’s some weird non-local stuff going on, and superposition is… really, really disturbing. Fortunately it only seems to happen down at a level that doesn’t really affect us — just blows our damn minds. 😮

  • Michael

    My first objection to MWI involves the question: What implements this huge wave-function?

    It’s a good point, Wyrd, IF the mathematical object is actually what must be implemented. You’re, I think, way more into math than I am, but I view mathematics as a language. We create “sentences” called equations that express a meaning or a relationship. But if that relationship truly exists in reality, why are calculations needed for it to be what it is?

    I don’t know if this is making any sense, but why would implementation of the wave function be any different than a bouncing ball? We could calculate it’s path using Newton’s Laws of Motion, or we could calculate it using a Hamiltonian approach, and the math for each would be somewhat different… yet independently the answer would be the same. But I’m not sure the universe does either one!

    So do you have the same objection to Newton’s Laws?

    AIUI, what we mean by decoherence is that the phase information of a given system is beyond our ability to recover (measure).

    What I know about it is probably heavily skewed. I understand this as well, but much of what I know about decoherence I know from reading some papers Wojciech Zurek wrote, and watching one or two of his lectures on the topic I found on Youtube. What I really enjoyed was learning that when a quantum system in a mixed state interacts with the environment, there are only certain states that are repeatable so to speak. I think he calls them eigenstates, or einstates, like the eigenvalues of an equation. I wish I could remember it a little better, but basically through interaction with the environment only particular states are “broadcast”. So if we had a million people in the same stadium watching the Twins, and there was a close play at the plate, the reason all the trillions of different photons involved in conveying the information from the tag out–(he was safe)–to all those different eyeballs is that mathematically when the “runner-safe-runner-out” quantum state interacts with the tag, only one of those states is unchanged by its interaction with the environment. So the tag–(the environmental measurement)–can be applied six trillion times, and the result will always be the same.

    But other states that were possible, are changed by interaction with the environment, which means they are not repeatable, and so they basically get lost in the noise, or what have you. (That’s kind of the interesting thing. I’m not actually sure where Zurek suggests they go!) But I also think the process involves the loss of phase information, as the “entanglement baton” is passed along.

    The persistence of certain einstates, and the mass broadcasting of their information throughout the environment, is what I believe is termed as Quantum Darwinism.

    For me, quantum reality just means reality is fuzzy around the edges. And there’s some weird non-local stuff going on, and superposition is… really, really disturbing. Fortunately it only seems to happen down at a level that doesn’t really affect us — just blows our damn minds.

    I think I agree, Wyrd. Unless MWI is right of course! Haha.

    Michael

    • Wyrd Smythe

      “But if that relationship truly exists in reality, why are calculations needed for it to be what it is?”

      Here’s how I see it: A thrown ball, for instance, describes a parabola, which is just x-squared. In this case, the effect of kinetic and gravitational force on a mass, through Newton’s equations, gives us that parabola. The math describes the physical system acting according to physical law.

      In “regular” quantum mechanics, the wave-function describes the quantum system, and tells us the probability of given outcomes. Again, the physical system is acting according to physical law. In both cases, our understanding of physical law results in the math that describes the system.

      MWI starts with the math, the wave-function, and says it is reality. Physical reality then results from the W-F. This is not a physical system working according to physical law — duplication of energy/matter has to be accounted for physically.

      Max Tegmark has a view that all reality comes from math, and MWI can be seen to be saying the same thing. In which case it works great! I would be fine with a Tegmark Level IV MWI reality. (But I don’t agree with Tegmark’s view.) Without a Tegmarkean view, MWI needs to explain what putting the W-F int he center of things means. It’s no longer describing a system, it is the system.

      “So do you have the same objection to Newton’s Laws?”

      No, nor of the Hamiltonian approach. In all cases these describe the behavior of physical systems. The analogy to MWI would be as if the equations describing the ball’s motion caused the ball to move.

      It’s kind of a subtle point (and I may be wrong), because the counter-argument is that reality acts this way and the W-F just describes it as math always does. But I think there’s a problem with that when it comes to MWI, as I’ve tried to break out here. I think MWI implies the W-F comes first, which raises the question of what implements the W-F (if it’s not a Tegmarkean abstraction)?

      “The persistence of certain einstates, and the mass broadcasting of their information throughout the environment, is what I believe is termed as Quantum Darwinism.”

      Yes. As I’m sure you know, it’s an idea of Zurek’s. I don’t know much about it. Mostly that it focuses on decoherence.

  • Wyrd Smythe

    I have to confess, I’ve never really liked Sean Carroll. Something about him rubs me the wrong way. I’m creating my own RSS reader (because it seems like a simple thing to make), and of all the blogs I follow on various platforms, guess which one gives me a 403 error apparently because it’s my Python code making the http request and not a known browser. (Assuming the server is triggering off the Agent string. I suppose there might be another reason.)

    PITA. It means I have to use a browser to pull the XML and save it as a file. Which is fine until there’s a new post. Fortunately (I guess) he doesn’t post often to his blog.

    But, dang. Out of all the blogs, only his refuses to play nice. Somehow… I’m not that surprised.

  • MWI: Questions, part 1 | Logos con carne

    […] off-putting). Certainly the naked evangelism, and even occasional persecution complex, of people such as Sean Carroll doesn’t seat the idea well in my […]

  • Rick S.

    The end of your post gave me the following thought: if we assume MWI to be true, then perhaps our universe, where science and logic seem to reasonably explain reality, is the exceptional and rare “all ones” or “all zeroes” universe, when, in fact, the vast majority of “average universes” are completely chaotic, or even better, governed not by science and math, but gods, magic, machine elves, flying spaghetti monsters…. take your choice. Of course I am being facetious and extreme, but if we assume many worlds, then surely we must be wary of our presumptions.

    • Wyrd Smythe

      The thing is, science and logic are based on our observations of physical reality. Science is simply the observation and codifying of physical reality. In a world with different physical laws, the science and logic would descend from those particular laws.

      There is also that for any world with laws to be created there is implied a meta-reality with laws that allow for that creation. For instance, there must be a meta-reality that allowed the Big Bang to take place. This suggests an over-arching set of physical law that constrains the notion that “anything can happen.”

      I think the real problem is the assumption that MWI is correct! I don’t see how it can be.

  • Wyrd Smythe

    MWI and Tegmark

    The connection I see involves the centrality the MWI places on the Schrödinger equation. A key argument, almost a dogma, is that everything comes from taking the Schrödinger equation seriously and not adding anything.

    Back in the 1990s I knew an intelligent fellow who was all in on the MWI. I knew what it was but had never given it much thought other than in SF and comics, where I thought it was fun. He explained the apparent non-physicality of branching by pointing out that x^2-4=0 has two answers (polynomials always have as many roots as their degree). There’s no “cost” to such “branching” of reality. There’s no problem with overlapping realities; +2 and -2 coexist just fine. Also, the notion that decoherence accounts for the coincidence of matter is bonkers except mathematically, where it makes perfect sense. Ever since, I’ve realized that a Tegmarkian view is a natural fit for the MWI.

    Yet most who choose the MWI deny it being a Tegmarkian view. Which is fine, but it requires explaining the coincidence of matter and possibly the branching of energy (which would change gravity). Take the Tegmarkian view, take the Schrödinger equation ultimately seriously, and those issues vanish. Bottom line, all I’m saying, is that Tegmarkian MWI makes perfect sense, but as a physical theory, I think it has massive problems.

    Here’s a key point: the MWI depends on the Schrödinger equation being meaningfully applied to the entire multi-verse. Physics, in general, takes the Schrödinger equation seriously enough to believe it applies to cats and bigger. Under the MWI, exactly as Sean Carroll says, there is a Schrödinger equation, a full description, for the multiverse. All Schrödinger equations deal with a moving vector, |Ψ⟩, the wavefunction, which lives in Hilbert space. In some formulations, mostly because of normalization, that vector is a ray (a constant-length vector).

    So, what Carroll says is exactly correct. The distinction is the same: how real is that mathematical object? Carroll is talking about the wavefunction. If Carroll “asserts that reality is a ray in Hilbert space,” then he’s asserting that Ψ, that vector, is real. I don’t find that very compelling.

    At the very least, we have a useful mathematical model. If we agree reality isn’t Tegmarkian, the central question is: What in the Planck’s constant, Euler’s number, double pipe symbols, does quantum mechanics math model mean?

And what do you think?