Domino Valdano

So here we come finally to the quantum suicide booth. I'm getting rid of the "instrumentalism vs realism" title now because I think we've strayed far enough from the original topic that this is pretty tangential. Truth be told, that whole series ended up being a lot of tangential stuff and not a whole lot directly related to the debate between instrumentalism and realism. That's the way things go I guess. But everything is connected, and in surprisingly intricate ways.

So there's this classic thought experiment called the "quantum suicide" experiment, originated by AI researcher Hans Moravec, and developed further by cosmologist Max Tegmark. It's a derivative of the Schrodinger's Cat and Wigner's Friend thought experiments, but not quite as ancient or well known.

The Quantum Suicide experiment is the closest thing we have to an experimental test that distinguishes between Copenhagen and Many Worlds. However, it is very one-sided in that if Many Worlds is correct, you can be certain it is (however only the person performing the experiment can appreciate that certainty, nobody else in the world can). But if Copenhagen is correct, you will die so you will never know which is correct.

The experiment goes something like this: Construct a device with connects the outcome of a truly random quantum observable, similar to the one used in the Schrodginer's Cat experiment, to a lethal device that kills the experimenter. Have the experimenter (you, let's say) repeat this many times in a row. Assuming Many Worlds is true, then what should you expect to happen? Well, in most of the worlds you will die, but there is guaranteed to be at least one world where you survive. You won't experience anything in the worlds where you die, so the rational thing to do would be to expect your next experience will be seeing yourself miraculously survive the experiment many times in a row. If you perform the experiment and witness this, as expected, then you can be pretty sure Many Worlds is true and Copenhagen is false. Unfortunately, if anyone else witnesses this, without being in the machine themselves, you will be unable to convince them that it wasn't just crazy luck or some kind of divine intervention, since neither of the 2 theories predict that they should see you survive that many times in a row. (Many Worlds only predicts that you should see yourself survive, from your own perspective.)

There's a variant of this which leads to something called Quantum Immortality, but that's considered much more controversial, and depends on other assumptions, so we won't get into that. (My personal feelings are that quantum suicide makes sense and would work assuming Many Worlds is correct, but that Quantum Immortality is an exaggeration/distortion of the thought experiment which leads to nonsensical conclusions.)

At work, we've talked about a lot of different versions of the quantum suicide experiment, because it's pretty relevant to themes we want to explore in the movie we're making (or rather, discussing making). And the most interesting version that's come up is one I've decided to call the "coin operated quantum suicide booth". It was proposed by my coworker as a way of attacking some of the assumptions I hold about observer selection (mostly stemming from Nick Bostrom's Self Sampling Assumption). We argued about it for a while, and at some point, he had succeeded in convincing me that I was probably wrong. But then after a lot more thinking about it, I changed my mind and decided I had been right all along, and do not have to give up the Self Sampling Assumption or any of my views on the anthropic principle.

In this version, there is a booth which contains the above described quantum suicide device. But there is also a coin that gets automatically flipped once you step into the booth. If it comes up heads, then after 10 minutes of waiting in the booth, the quantum suicide experiment is performed on you 1 million times in a row in rapid succession. If it comes up tails, then nothing else happens for 10 minutes, and then either way the door opens and you're allowed to walk out (if you're still alive).

Now imagine that your friend bets you that the coin will land on heads. What odds should you be willing to take on that bet? This hinges on what you think the chances are you'll win the bet, assuming you survive and walk out of the booth. Another related way of asking it is: what do you expect to see happening after you walk out of the booth? There are strong arguments to support several things being true here. 1.) you should be extremely certain that if you end up surviving, you will remember the coin coming up tails and you will win the bet. 2.) you should expect that when you walk into the booth, if you look at the coin, you will see it come up heads with 50% chance and tails with 50% chance, and 3.) whether you look at the coin should not affect in any way the chances that it will come up tails, or that you will remember it having come up tails, and 4.) if you do look at the coin while you're still in the booth, and you see heads, you should expect with 100% probability that after you walk out of the booth, you'll remember seeing heads and lose the bet.

The interesting thing about this thought experiment is, that the 4 things above do not seem consistent with each other at first glance. And yet, I do think they are consistent, and if Many Worlds is true and there is any consistent notion of "what to expect to see next", then it implies they are all true. Before you walk into the booth, you should expect you will win the bet. This should be true regardless of whether you intend to look at the coin. If you don't look at the coin, there's nothing more to be said. In nearly all of the worlds where you survive, you do win the bet. If you do choose to look at the coin while you're in the booth, there's a 50% chance you'll see heads and a 50% chance you'll see tails. If you see tails, then you know you have won the bet. If you see heads, then you're in a really weird situation. You should expect now that you will *lose* the bet (even though before you looked at the coin, you thought you would win it). However, a more nuanced thing to say is that you should expect yourself to be killed in nearly all of the branches, and the only one where you survive you'll lose the bet. So therefore, it's useful to be prepared for that one case where you do survive... so be prepared to pay up! It seems as though, if you were really in this situation, you might be a bit afraid to look at the coin. Like it would ruin your chances of winning the bet. Because then there's a 50% chance you'll be in this weird situation thinking you're either going to die or lose the bet. But if you don't look at the coin, you'll never be in that situation. But the illusion here is that looking at the coin has somehow influenced what's going to happen. The only thing it really affects though is whether you know you're about to die and/or lose the bet. If you don't know, then you don't have to deal with as many weird feelings. Although you still know that a lot of your future selves (roughly half of them) will die, and that in some very obscure branch of the multiverse, you will survive but lose the bet. (For simplicity, we can assume that the outcome of the coin itself is chosen based on some other quantum random variable, which could have been determined far ahead of time. If it's a purely classical coin, then I don't think it changes anything about this analysis, but it makes the whole thing a bit more difficult to think about since the outcome is pseudorandom rather than purely random.)

I'd like to write a bit more about the mind/body problem and the anthropic principle. Clearly things like cloning and the quantum suicide experiments described here tie in heavily to that, and call into question how to tie consciousness (in the sense of subjective personal experience or identity) to physical copies of our bodies. If nobody has written up a paper on this coin operated quantum suicide booth, I'm thinking it might be worthwhile.

I wrote two posts in January of this year ("instrumentalism vs realism" and "instrumentalism vs realism part 2") and wrote "to be continued..." at the end of part 2. The main point of both of them was really to voice my thoughts on the Copenhagen Interpretation of quantum mechanics, to see if I could make any sense of it, and to compare it to the Many Worlds Interpretation, which has always seemed easier for me to understand.

Several new things have happened since then. I started thinking along these lines to try to come up with some material for the microtalk I gave at FreezingWoman in March 2015. I ended up deciding to avoid the dicey subject of realism vs instrumentalism, and even for the most part avoided the entire topic of quantum mechanics. Instead focusing on the question of "what is the universe made of?" and keeping to things I feel that I understand well such as relativity and some aspects of quantum field theory. By the time I finished putting it together, I realized that I had a pretty good case that something more like neutral monism is the right way to look at metaphysics rather than materialism. The idea that metaphysics is even meaningful sort of presumes realism over instrumentalism. And yet because I defined "neutral monism" in my talk as "none of the above" (metaphysical theories) I felt like I left it a little bit open that perhaps instrumentalism is true after all and we just need to give up metaphysics entirely.

After returning from Freezing Woman, I spent a month and a half expanding my 5 minute microtalk into a 15-minute video presentation, which I released on Vimeo and linked to on Facebook and Google+. A handful of my friends viewed it and gave me positive feedback, some of them resharing it, but overall it didn't get a lot of attention. Then later, I found out that someone on Youtube had downloaded the Vimeo video and uploaded it to their Youtube channel, where it did get a lot of attention. (13,467 views, 164 upvotes, and only 5 downvotes... with lots of positive comments from people, many asking if there will be a sequel!):

Materialism and Beyond: What is Our Universe Made Of?

This weekend I uploaded it to my own Youtube channel, which I had been meaning to do (apparently, hardly anyone is on Vimeo; I original chose it primarily because I don't like the idea of ads being inserted in the middle of my video). So far not much action there either, but we'll see I guess.

I can't remember when it was, but at some point this year (maybe around May?) I ran across a *really* interesting post that my adviser in graduate school, Tom Banks, made defending the Copenhagen Interpretation of quantum mechanics:

http://www.preposterousuniverse.com/blog/2011/11/16/guest-post-tom-banks-on-probability-and-quantum-mechanics/

(There's another version of it hosted by Discover magazine but the mathematical equations don't show up right there.) I was shocked that this has been online since 2011 and I somehow managed to not find it until 2015. Not only because it is written by someone I knew personally and hold in great regard, but because it basically explains almost everything I've ever wanted to understand about quantum mechanics in one shot. I often wanted to ask him about this subject, but I was always too shy to do it. I guess I felt like to him, it might be considered a waste of time. But if he could have summed it up this well in one sitting, I would have surely asked and gotten a lot of benefit out of it. Sadly, I finally find it now long after I've quit physics.

So, it took me a while to understand everything he says there. He does make a lot of simple mistakes in his explanation, which confuses things. (For example, he uses the term "independent" several times to mean "mutually exclusive", something anyone--including him--who knows anything about probability knows are two very different things.) Nevertheless, there is a core of what he's saying that turns out to be very important. At first when I read it I sensed that, but it hand't fully sunk in. Since then, I have read a lot more things, gotten into some discussions and debates with people coming from different perspectives on this (one being a mailing list I got invited to as a consequence of people liking my video), and mulled it over in my head. And gradually, it sunk in and I feel like I have now absorbed the message. And it's a really important message that I had sort of suspected before but hadn't really understood.

This week I was thinking through this stuff again and went back to read the Koopman-von Neumann (KvN) formulation of classical mechanics Wikipedia page again (for like the third time since reading my advisor's post about KvN, which I had never heard of until then). (And in connection with the mailing list I'm on, just before that reading some more about Quantum Darwinism and Zurek's existential interpretation of QM). And suddenly halfway through the week, I felt like everything clicked. After all of these years, I finally understand Copenhagen. And it's a lot more coherent than I had imagined.

This doesn't mean I have converted now to a Copenhagenist. I'm still not sure whether I prefer Copenhagen, Many Worlds, or something in between. (And almost certainly, the right answer is somewhere in between, at least compared to what Bohr's original ideas were and what Everett's original ideas were.) And while I call my advisor a Copenhagenist, I'm not even sure he uses that term. I think his view is a modern version of Copenhagen, but does include all of the insights that have been gleaned since the time of Heisenberg and Bohr.
(Although I think he denies that those new insights have significantly changed anything about the interpretation.) I've also read a bit more about consistent histories lately and decided that there are slight differences between it and Copenhagen, it's not just a clarification of Copenhagen because in some ways, it does away with the idea of quantum measurement (or makes it less central/important to the theory). I still think QBism is a form of Copenhagen, although some of its advocates seem to think it has features which distinguish it from Copenhagen.

At any rate, using the broad definition of Copenhagen which I have always used (to include modern versions of it rather than a more narrow one focusing strictly on Bohr and Heisenberg's writings), I'd like to try to sum up the new insights I've absorbed. This was my intention in writing this post, but since I've only introduced that intention and not gotten there yet, I'll start my summary in part 4.

To be continued...

I have to admit, in trying to tie all of this together, I have realized that there still seems to be something big that I don't understand about the whole thing. And there is at least one minor mistake I should correct in part 8. So from here on out, we're treading on thin ice, I'm doing something more akin to explaining what I don't understand rather than describing a solution.

It seemed that if I could understand wandering sets, then all of the pieces would fit together. And it still seems that way, although the big thing I still don't get about wandering sets is how they related to mixing. And that seems crucial.

The minor mistake I should correct in part 8 is my proposed example of a completely dissipative action. I said you could take the entire space minus the attractor as your initial starting set, and then watch it evolve into the attractor. But this wouldn't work because the initial set would include points that are in the neighborhood of the attractor. However, a minor modification of this works--you would just need to start with a set that excludes not only the attractor but also the neighborhood around it.

In thinking about this minor problem, however, I realized there are also some more subtle problems with how I presented things. First, I may have overstated the importance of dimensionality. In order to have a completely dissipative action, you could really just use any space which has an attractor that is some subset of that space, where it attracts any points outside of it into the attractor basin. The subset wouldn't necessarily have to have a lower dimension--my intuition is that in thermodynamics that would be the usual case, although I must admit that I'm not sure and I don't want to leave out any possibilities.

This leads to a more general point here that the real issue with irreversibility need not be stated in terms of dimension going up or down--a process is irreversible any time there is a 1-to-many mapping or a many-to-1 mapping. So a much simpler way of putting the higher/lower dimensionality confusion on my part is that I often am not sure whether irreversible processes are supposed to time evolve things from 1-to-many or from many-to-1. Going from a higher to lower dimensional space is one type of many-to-1 mapping, and going from lower to higher is one type of 1-to-many mapping. But these are not the only types, just types that arise as typical cases in thermodynamics, because of the large number of independent degrees of freedom involved in macroscopic systems.

Then there's the issue of mixing. I still haven't figured out how mixing relates to wandering sets at all. Mixing very clearly seems like an irreversible process of the 1-to-many variety. But the wandering sets wiki page seems to be describing something of the many-to-1 variety. However, they say at the top of the page that wandering sets describe mixing! I still have no idea how this could be the case. But now let's move on to quantum mechanics...

In quantum mechanics, one can think of the measurement process in terms of a quantum Hilbert space (sort of the analog of state space in classical mechanics) where different subspaces (called "superselection sectors") "decohere" from each other upon measurement. That is, they split off from each other, leading to the Many Worlds terminology of one world splitting into many. Thinking about it this way, one would immediately guess that the quantum measurement process therefore is a 1-to-many process. 1 initial world splits into many different worlds. However, if you think of it more in terms of a "collapse" of a wavefunction, you start out with many possibilities before a measurement, and they all collapse into 1 after the measurement. So thinking about it that way, you might think that quantum physics involves the many-to-1 type of irreversibility. But which is it? Well, this part I understand, mostly... and the answer is that it's both.

The 1-to-many and many-to-1 perspectives can be synthesized by looking at quantum mechanics in terms of what's called the "density matrix". Indeed, you need the density matrix formulation in order to really see how the quantum version Lioville's theorem works. In the density matrix formulation of QM, instead of tracking the state of the system using a wavefunction--which is a vector whose components can represent all of the different positions of a particle (or field, or string) in a superposition--you use a matrix, which is sort of like the 2 dimensional version of a vector. By using a density matrix instead of just a vector to keep track of the state of the system, you can distinguish between two kinds of states--pure states and mixed states. A pure state is a coherent quantum superposition of many different possibilities. Whereas a mixed state is more like a classical probability distribution over many different pure states. A measurement process in the density matrix formalism, then, is described by a mixing process that evolves a pure state into a mixed state. This happens due to entanglement between the original coherent state of the system and the environment. When a pure state becomes entangled in a random way with a large number of degrees of freedom, this is called "decoherence". What was originally a coherent state (nice and pure, all the same phases), is now a mixed state (decoherent, lots of random phases, too difficult to disentangle from the environment).

What happens is that you originally represent the system plus the environment by a single large density matrix. And then, once system becomes entangled with environment, the matrix decomposes into the different superselection sectors. These are different sub matrices, each of which represents a different pure state. The entire matrix is then seen as a classical distribution over the various pure states. As I began writing this, I was going to say that because it was a mixing process, it went from 1-to-many. But now that I think of it, because the off-diagonal elements between the different sectors end up being zero after the measurement, the final space is actually smaller than the initial space. And I think that's even before you decide to ignore all but one of the sectors (which is where the "collapse" part comes in, in collapse based interpretations). From what I recall, the off-diagonal elements wind up being exactly zero--or so close to zero that you could never tell the difference--because you assume the way in which the environment gets entangled is random. As long as each phase is random (or more specifically--as long as they are uncorrelated with each other), when you sum over a whole lot of them at once, they add up to zero--although I'd have to look this up to remember the details of how that works.

I was originally going to say that mixed states are more general and involve more possibilities than pure states, so therefore evolving from a pure state to a mixed state goes from 1-to-many, and then when you choose to ignore all but one of the final sectors, you go back from many-to-1, both of these being irreversible processes. However, as I write it out, I remember 2 things. The first is what I mentioned above--even before you pick one sector out you've already gone from many-to-1! Then you go from many-to-1 again if you were to throw away the other sectors. And the second thing I remember is that, mathematically pure states never really do evolve into mixed states. As long as you are applying the standard unitary time evolution operator, a pure state always evolves into another pure state and entropy always remains constant. However, if there is an obvious place where you can split system from environment, it's tradition to "trace over the degrees of freedom of the environment" at the moment of measurement. And it's this act of tracing that actually takes things from pure to mixed, and from many to 1. I think you can prove that from a point of view of inside the system, whether you trace over the degrees of freedom in the environment or not is irrelevant. You'll wind up with the same physics either way, the same predictions for all future properties of the system. It's just a way of simplifying the calculation. But when you do get this kind of massive random entanglement, you wind up with a situation where tracing can be used to simplify the description of the system from that point on. You're basically going form a fine grained approximation of the system+environment to a more course grained approximation. So it's no wonder that this involves a change in entropy. Although whether entropy goes up or down in the system or in the environment+system, before or after the tracing, or before or after you decide to consider only one superselection sector--I'll have to think about and answer in the next part.

This is getting into the issues I thought I sorted out from reading Leonard Susskind's book. But I see that after a few years away from it, I'm already having trouble remembering exactly how it works again. I will think about this some more and pick this up again in part 10. Till next time...

First, a quick comment about something pretty basic that I completely forgot to mention in part 4 on the "Boltzmann's brain" paradox: why do they call it Boltzmann's brain? Seems obvious I should have explained this, but it's because the type of dilemna raised by it is similar to the "brain in a vat" thought experiment that philosophers of metaphysics like to argue about. The basic question is depicted explicitly in the movie The Matrix: how do you know that you aren't just a brain in a vat somewhere, with wires plugged into you, feeding this brain electrical impulses that it interprets as sensory experiences? I think for the most part, the answer is: you don't. I mentioned that the Boltzmann's brain paradox could involve the vacuum fluxuation of a spontaneously generated galaxy, or solar system, or even just a single room. But the ultimate limit of this would be, just a single brain in a vat, with no actual world around it at all. Anyway, just wanted to add that to make part 4 more clear, because you may have been wondering why it was called "Boltzmann's brain". If I ever decided to make these notes into a book, I guess this would be one of the chapters. Now on to the matter at hand...

One of the most puzzling things about quantum mechanics, especially when you first learn it, is why there appear to be two completely different types of rules for how physics works. One is the microscopic set of rules which physicists usually refer to as "unitary time evolution of the wavefunction". In quantum mechanics, what's called the wavefunction is similar to a probability distribution either in regular space or momentum space (not phase space, the combination of the two) for which state a particle (or field, or string) could be in. (Actually, it's more like the square root of a probability, but no matter.) While it is similar to a probability distribution in regular space or momentum space, it can be much more simply represented as a single vector in a much larger space called a Hilbert space. The Hilbert space in quantum mechanics is usually infinite dimensional, so much much bigger than even the 6N dimensional phase space we talked about in part 5. As the system progresses further into the future, this state vector traces out a single path through the Hilbert space, and that path is always exactly reversible according to these microscopic rules. The key word here is "unitary". The vector is moved around in the Hilbert space mathematically by applying a unitary matrix to it. (Heisenberg's formulation of quantum mechanics was orginally called "matrix mechanics" because of this.) Unitary matrices are matrices whose transpose is equal to their complex conjugate (replacing all imaginary components with real components and vice versa, where by imaginary and real I'm talking about the mathematical notion of i, the square root of -1). If this doesn't make any sense, don't worry about it, the only important thing to understand is that this property of unitarity guarantees many nice things about time evolution in quantum mechanics. It makes things nice and smooth, so that a single state always moves to a single state, and if the total probability of the particle being anywhere is initially 100% then it will stay 100% in the future. But most importantly, it guarantees reversibility. Because the time evolution matrix in quantum mechanics is unitary, it means Louiville's theorem holds and you can always reverse time and go backwards exactly to where the system came from.

But wait--if this is the case, then that also means that all quantum mechanical systems are conservative, ie non-dissipative. Does dissipation not happen in quantum mechanics at all? This brings us to the second type of rule in quantum mechanics: the process of measurement. Originally, this rule was called the "collapse of the wavefunction". Because when looked at through Schrodinger's wave mechanics, it appears that when a macroscopic observer makes a measurement in the lab, of a property of a microscopic system (for instance if he asks the question "where is this particle actually located?") the rule is that what used to be a probability distribution over many different states--suddenly that distribution is reduced to, or collapses to, a single state. Before the measurement, we mathematically describe the particle as being in a "superposition" of many different positions at once, but after the measurement it is only found at one of those positions. Mathematically, this is achieved with a projection matrix. A projection matrix is very different from a unitary matrix. Its action in the Hilbert space is that it maps many vectors onto a single vector, instead of mapping one vector onto a single vector. Because of this, the action is irreversible, and does not satisfy Liouville's theorem. The measurement process is therefore dissipative rather than conservative. In other words, the rule for how an observer of a microscopic system makes measurements in quantum mechanics seems completely opposite to the rule for how microscopic systems evolve in time when they are not being observed. One is nice and smooth and reversible, the other is a sudden reduction, an irreversible collapse. Dissipation only seems to happen during observation.

But the way I've explained this highlights the paradox, called the "measurement problem in quantum mechanics". This paradox is what has spawned many different interpretations of quantum mechanics, which philosophers still argue fiercely about today. But the real question is how to reconcile reversibility with irreversibility, and the answer lies in thermodynamics. And once you understand it, you realize that it doesn't really make a whole lot of sense to talk about measurement in this way, as a sudden "collapse" of the wavefunction. And it leads to deeper questions about whether the wave function is real or just a mathematical abstraction--and if there is anything in quantum mechanics which can be said to be real at all. To be continued...

There's a connected set of issues that rests at the very heart of physics, which I've always thought was not very clearly explained in any of my classes. I had a very vague understanding of it while I was an undergrad, and hoped that I'd be able to sharpen it up in graduate school. To some extent, I did, but I found that even after 6 years of graduate school in physics, these issues were still never quite cleared up in my classes, and I never had enough time while working on other things to read enough on my own about them to fill in all the gaps in my understanding. I have always had the impression that these issues *are* well understood, at least by somebody, but that not many physics professors do understand them fully and they tend to just avoid talking about them in actual classes, or talk about them in a very superficial way. I do think my adviser was among those who understood them, but I always felt a bit shy about wasting his time on questions that were purely for my own curiosity and unrelated to any research we were working on. Especially ones that would take a long time to sort out.

Recently, I've started thinking about them again, but through an unexpected route. A couple months ago, OkCupid added support for bitcoin, so as we got closer to the release of it, several of the people I work with would tend to get into idle conversations about bitcoin during the day. A few of them I got involved in, and in one of them we got on to the subject of bitcoin mining. One guy asked the group if it would be worth it to dedicate his server at home to bitcoin mining. This is where your computer works on various difficult mathematical tasks, like factoring large numbers, and helping to merge block chains into each other, and as a reward you collect newly minted bitcoins that are conjured into existence. One guy commented immediately that it would never be worth it with a standard PC, you'd have to buy very expensive specialized hardware to do it. The original asker of the question objected that he wasn't using his server for anything else anyway, but the cynic replied that with a standard PC, the cost of running the hardware in an increased electric bill was greater than the payoff. (An idle server draws less electricity than one engaged in difficult mathematical computation.) This got us onto a tangent, about whether you could cool the computer down to a point where it didn't cost as much to run because it wasn't dissipating as much heat. Naturally, we went from there to discussing why computing necessarily dissipates heat, and what the ultimate physical limits of that process is. He mentioned that only quantum computers were reversible and didn't dissipate heat. I was first made aware of this fact in 1998 during a gradate quantum computing class that I took as an undergrad at Georgia Tech, where we read some relevant papers on the subject. But while I have long had a superficial understanding for why this was true, and I can repeat the standard things that people say about it, I admitted to him that I never quite understood it fully. He then started talking rapidly about the many worlds interpretation of quantum mechanics, and how the so-called "measurement problem" is really just decoherence and thermodynamics. He said he thought it was fairly straightforward, and this is the point where I mentioned that I had a PhD in theoretical physics and had spent many years working on related topics, but felt that there was just always a missing piece for me conceptually surrounding entropy, Maxwell's demon, reversibility, and dissipation. He shrugged and said "well, it seems straightforward, but I guess if you've studied this more then there must be more to the story than I'm aware of." I told him I didn't want to get into discussing interpretations of quantum mechanics, because it was too complex a subject, and I probably couldn't say anything more on reversibility because I didn't know how exactly to articulate what was missing from my understanding of things.

Every few years I pick up this topic, or one of a related set of topics that ties into it, and try to understand it, and I always make a bit more progress. I think the last bit of big progress I made was in reading Leonard Susskind's book on black holes and information, which helped me understand both black hole complimentarity and more about the density matrix and how entropy and information work in quantum mechanics. But this conversation renewed my interest again, so for the past month or so my mind has occasionally drifted back to it, and a couple days ago I managed to stumble onto the Wikipedia page for "Wandering Sets" which I think is a huge part of the missing piece for me. For some reason, wandering sets were never mentioned in any of my undergrad or graduate classes, and yet they seem absolutely crucial to understanding what the word "dissipation" means. Until yesterday, I had honestly never even heard of them. It's no wonder that I went through undergrad and graduate school always feeling frustrated when professors would use the word "dissipation" without giving any definition for it and just assuming that we all knew what it meant. Unfortunately, I feel like the Wikipedia page is poorly written and there are two facts they mention which seem obviously contradictory to me.

I will explain in part 2 what I've learned so far, and how wandering sets are related to the ergodic theorem, Liouville's theorem, and pretty much every foundational area of physics. And then I'll go into what I still don't understand about it--perhaps after this I need to find the right book that covers this stuff. It seems very weird to me that they always gloss over it in physics classes.

I just stumbled upon a really neat little tidbit of history, that actually ties together a lot of different people whom I've had thoughts about over the years, some because I knew them personally, some because I heard things about them that were interesting (some good and bad), some whom I've only met once or twice. But the weird thing is, I never realized how closely connected all these different people are, and it as it slowly dawned on me I realized I had to make a post about all of these interconnections.

Where to start? Well, earlier this year, I went to a wedding in Atlanta, where a friend I hadn't seen in many years started asking me some things about physics. He mentioned that he was reading "The Quantum Enigma" and I immediately let out a groan, and mentally did a "palm-face" kind of thing. I then explained that this was written by two guys, Bruce and Fred, whom I knew well, but they were both idiots and I'd told them to their face that I didn't agree with the basic premise of their book, and my advisor had given a whole lecture retaliating against their accusations that the physics community is hiding "skeletons in the closet" regarding the role of consciousness in physics (which they launched at the weekly seminar preceding his lecture the following week). The two other professors at UC Santa Cruz who spoke out against Bruce and Fred before and after my advisor on that same day, were Anthony Aguirre (one of the founders of the FQXi institute mentioned in the How the Hippies Saved Physics video below) and Michael Nauenberg (who is mentioned by name several times in the video below, and was apparently the person who suggested to Fritjoff Capra while he was a postdoc at my school that he write a book mixing quantum mechanics with Eastern mysticism--one of the many things I had no idea about until seeing this video). I know Nauenberg mostly as a crotchety old man who we call "The Santa Cruz Heckler" because he heckles any string theorists or cosmologists who ever give talks, telling them they aren't real scientists and repeatedly asking "what's the physical meaning of this?". I think the one and only occasion where I've ever agreed with anything that's come out of Nauenberg's mouth was when he shot down Bruce and Fred--although I think everyone present would agree that my advisor did a much better job of that. Wikipedia's entry on "quantum mysticism" says that it was primarily Fritjoff Capra's "The Tao of Physics" that started the whole quantum mysticism movement, and got the new age community interested in quantum mechanics--that I was vaguely aware of.

Anyway, I explained to my friend that Fred is just this obnoxious lab manager who wishes he were a real physicist, and Bruce is this kind but really senile old guy who at some point earlier in his career was an atomic physicist, but doesn't understand quantum mechanics (let alone consciousness) any better than Fred. I once watched Bruce debate an undergrad philosophy major about the nature of consciousness in front of an audience of myself and a bunch of undergrad SPS club members, and it was really sad to watch because the undergrad utterly destroyed him, as Bruce didn't know the first thing about consciousness and had all of these silly naive ideas about free will.

After explaining this, he naturally asked me "ok, well yeah... I kind of thought some of the book sounded a little kooky, but I wasn't sure. So who *should* I read if I want to read a really deep book about physics? Who would you recommend?" I thought for only a moment and then said "this is going to sound strange, because I haven't read it, but I think the book I would recommend the most is Leonard Susskind's book The Black Hole War : My Battle With Stephen Hawking to Make the World Safe for Quantum Mechanics. It's funny, I somehow *knew* this was the best popular book on physics out there, even though I hadn't read it. My intuition was that it would be from a combination of things--one, Leonard Susskind is one of the deepest and most intelligent thinkers in physics, and always explains things in a very interesting way that exposes the philosophical importance of the ideas, not just the math behind it. He has razor sharp intellect as well as wit. He also explains things in a very down to earth way, that makes complicated things just make simple sense--he cuts right to the important stuff. Also, when he published that book, he wrote another book called An Introduction to Black Holes, Information, and the String Theory Revolution : The Holographic Universe on the same topic, but including all the math and intended for physicists, and that one I did read and found it outstanding. My impression was that the content was similar, but the Black Hole War was written at a level that anyone should be able to understand, whereas the one I read has a lot of stuff that only a physicist would be able to make sense of.

So, I started listening to The Black Hole War on books on tape yesterday. I've only listened to the prologue and Chapter 1, but to my great delight it appears to be everything I'd hoped it would be and more--the ultimate popular book on physics, that both gets things right and exposes what's interesting and deep about physics without watering it down too much. But the best thing about the book that I hadn't realized is that it tells a lot more of the human story behind it than his other book. So it's not just redundant with what I've already read (so far at least).

The First Chapter of the book is about a series of secret meetings that he attended with Hawking (where the famous battle over black holes known as "The Information Paradox" all began) in the upstairs of the house of a guy named Werner Erhard, who ran an organization known as EST (Erhard Seminar Training) and was filthy rich and loved to invite high profile physicists over to his house to have deep conversations. He mentions 3 or 4 regular attenders including Hawking and himself, Savas Dimopolous (whom I've met a few times, my advisor having introduced us) and--to my surprise--David Finkelstein, whom he mentions twice. I knew that Lenny was friends with my advisor (Tom Banks) and figured he would surely mention him in the book, and I wasn't surprised at all that Dimopolous was in there too, since he works at Stanford with Susskind. But I was not at ALL expecting him to start the book off by mentioning (twice in Chapter 1) David Finkelstein, someone who had an enormous personal impact on my life. It may or may not be an exaggeration to say that taking David Finkelstein's Quantum Relativity class with ikioi at Georgia Tech in 1998 was what convinced me to major in physics. But it's not at all an exaggeration to say that he's the man who convinced me that Ayn Rand was wrong and to officially renounce my faith in Objectivism, after ikioi and I invited him to give a talk called "Quantum Objectivism" for our Students of Objectivism club and had dinner with him afterwards. Also, the reason I bought the domain name "spoonless.net" in 1999 (which I've owned for the past 12 years) and adopted "spoonless" as my username is about half related to Finkelstein (in particular his antirealist views on quantum mechanics, which I was fascinated by at the time, later departed from, and now have drifted somewhat back towards) and half related to other things.

So after getting home and googling for this self help guru's name, Werner Erhard, I found more and more additional connections between people that I had never realized were there. Also, before I get to that, let me mention that Landmark Education (which I've met a lot of people who have been involved with, and were in part the inspiration for a circle of friends I spend a lot of time with, called FreedomCommunity) apparently was a direct spinoff of Erhard Seminar Training. And furthermore, the Church of Scientology launched a campaign against him after he allegedly stole a lot of their methods and incorporated them into his own (http://en.wikipedia.org/wiki/Scientology_and_Werner_Erhard).

After reeling from that a bit, then the real fun started once I found Jack Sarfatti's final blog entry at his blog "Destiny Matrix":

http://destinymatrix.blogspot.com/

I had never heard of Jack Sarfatti either, but in his blog post he ties a ton of people I've known or heard about all together, which totally blows my mind. Here are some experps from it:

"Both Fred [Alan Wolf] and I got divorced about same time ~ 1971 and we were room mates. I was too young for that job and was bored and wanted adventure which came soon enough from the CIA with the strange events in 1973 at SRI Remote Viewing Project described in my book" [Fred Alan Wolf is one of the main crazy guys interviewed in What the Bleep Do We Know, along with John Hagelin (also crazy) and David Albert (not crazy at all, but sued them for distorting his words). (On a side note, I found a picture of my advisor somewhere online arm in arm with David Albert at a conference they were at together on the Arrow of Time.)]

"My encounter with Dennis Bardens of British Intelligence in 1974: 'Dr Sarfatti, it is my duty to inform you of a psychic war raging across the continents between the Soviet Union and your country and you are to be in the thick of it.'

"The main thing we did was the Esalen Month in Jan 1976 I think that Gary Zukav writes about in Dancing Wu Li Masters. I brought David Finkelstein there and that's how he met Werner Erhard leading to the big est physics conferences described by Lenny Susskind with Feynman, Gell-Mann, Wheeler, Hawking, Coleman, I think Kip Thorne et-al. I had met David at Yeshiva visiting Lenny Susskind. Finkelstein also worked with Ken Shoulders and Hal Puthoff at a company set up by the Fried Chicken guy William Church as a result of the Esalen month.
We had seminars at the facility on Nob Hill with the Rockefeller-Lanier money."

"I asked Werner in the lobby of the Ritz, he in a silly inappropriate casual outfit, with a woman adorer, what he did. He said "I make people happy." I wanted to run and I said in a strong Brooklyn accent, "I think you're an asshole." Werner got up from his chair a big smile, embraced me warmly and said "I am going to give you money." I had no idea about the message of the est-Training being "You're an asshole." Werner thought I was some kind of Guru I guess."

"Yes. I gave Fritjof $1500 that he needed to pay his lawyer for a Green Card. I also brought my then room-mate Gary Zukav to Esalen and wrote all of the rough draft of the physics parts of Wu Li Masters for him and helped him with the editing in later drafts."

"George was a "spook" who managed Tim Leary when Nixon let him out of prison."

"Indeed Nick Herbert's FLASH paper led to the no-cloning theorem so important in quantum computing today."

"Fred Wolf and I were edged out probably because they thought we were too crazy? Finkelstein sort of took over and I was the guy who brought him there in the first place. It was the usual academic shark cut-throat back-stabbing both Fred & I left SDSU for."

"I am cc'ing this to some of the participants who I am still in touch with. Fred Wolf recently spoke to Werner who now lives in London. I also ran into Stan Klein only a few days ago who is doing very interesting brain research with Stapp. I think Fritjof Capra is still in Berkeley and Stan Klein is in touch with him. Unfortunately Tim Leary, George Koopman and Robert Anton Wilson have died. I think Gary Zukav lives on Mount Shasta. You should also talk to David Finkelstein."


It turns out, this whole post is an interview he did a couple years ago with a science historian at MIT named David Kaiser, who was writing a book called "How the Hippies Saved Physics". Here is a lecture he gave at MIT on the book, it sounds really good! And he mentions even more people I know...



http://forum-network.org/lecture/how-hippies-saved-physics

After watching this video, lots more became clear to me. He talks about FQXI, which Anthony Agueirre helped found and Garrett Lisi, a personal friend of mine, who used to have an active lj here, was one of the main initial recipients of their funding. Both Jack Sarfatti in his blog and this guy in the video also mention Garrett.

Nick Herbert, whom they both talk about a lot, happens to be another guy whom I have met personally. Actually that's a funny story, I met him in Robert Anton Wilson's apartment, actually I think when we shook hands we were just walking in together.

Sarfatti it seems is clearly one of the crazy guys, similar to the What the Bleep people, but Nick Herbert is sort of borderline. Like Capra, he's kind of halfway crazy, and exaggerates a lot of things, but at least seems like he understands some physics, like Bruce and Fred. But I don't think he has that great of a grasp on it, personally. One thing that annoys me in the video, that I disagree with, is the premise. The main premise seems to be that, since Nick Herbert (one of the "Hippies") was able to get a paper published saying that he thought he could send communications faster than light... and that since that prompted a real physicist to respond by proving that you couldn't, that they contributed greatly to physics. While that may be true in a sense, the way I interpret it is more that everyone knew you couldn't do that, but the fact that a bunch of annoying new agers went to the trouble of trying to claim that you could, this made it worth proving that you couldn't. But it did attract more attention to Quantum Information, which overall is a good thing. He sort of glosses over the fact that what the hippies contributed was just that they were totally wrong.

I found this paper online, which was written a couple years ago by the referee who approved Nick Herbert's paper for publication... defending his decision to do it, since many physicists think it was never worthy of publication...
http://arxiv.org/abs/quant-ph/0205076
"Abstract: I was the referee who approved the publication of Nick Herbert's FLASH paper, knowing perfectly well that it was wrong. I explain why my decision was the correct one, and I briefly review the progress to which it led."

"Early in 1981, the editor of Foundations of Physics asked me to be
a referee for a manuscript by Nick Herbert, with title “FLASH —A superluminal communicator based
upon a new kind of measurement.” It was obvious to me that the paper could not be correct, because it
violated the special theory of relativity. However I was sure this was also obvious to the author. Anyway,
nothing in the argument had any relation to relativity, so that the error had to be elsewhere."

(Incidentally, I do think Nick is a very entertaining guy, he's a real fun person to hang out with. I just wouldn't expect him to come up with any interesting ideas in physics. Nor would I ever expect Jack Sarfatti or Fred Alan Wolf to)

Oh, and the How the Hippies Saved Physics guy also talks a lot about Esalen, which is a place various friends of mine have visited, and where some have worked. Apparently lots of these people used to hang out there, and they eventually got Richard Feynman to come. I also think I remember Susskind mentioning that Feynman came to some of those secret meetings at Werner Erhard's house, because there was some story about ordering a Feynman sandwich he tells... where he asks Feynman what a Feynman sandwich would be like and Feynman says "it's like a Susskind sandwich but with less ham." And then Susskind replies "but at least a Susskind sandwich has less baloney." He mentions that that was the only time he remembers one-upping Feynman in terms of wit. I can't remember for sure if this was at Erhard's house but I think so.

At the end of Susskind's first chapter in The Black Hole War, he goes home from the meeting with Hawking where Hawking first told him that he thought information would be completely erased in black holes, and even that information was being erased all of the time in empty space due to microscopic virtual black holes. And he says "as soon as I got back, I went to my friend Tom Banks and we talked about it, and eventually figured out why it bothered us so much... erasing information means increasing entropy, which means you end up producing a lot of heat!" Soon after that, they published a paper arguing that Hawking's proposal violated the laws of thermodynamics, which was the first shot fired in the great war (which Hawking eventually conceded, although not until several decades later--in fact, he conceded it while I was in graduate school, just before I started working with Tom Banks, a couple years before Lenny wrote the book).