Meccanica quantistica e senso comune

by David Z. Albert, Tullio Cannillo (Translator)

«Quella che mi accingo a raccontare è una storia sconcertante. Si tratta forse della storia più sconcertante che sia mai emersa nell’ambito delle scienze fisiche dal diciassettesimo secolo in poi. Ed è anche una storia vera»: così Albert avvia questa sua appassionante indagine. Di fatto, come base di una tecnologia di uso quotidiano che comprende il laser e il transistor, il «quanto di energia» è familiare anche ai profani. Tuttavia la meccanica quantistica resta, nei suoi fondamenti concettuali, un enigma inquietante. Visti da vicino, i fenomeni quantistici più semplici pongono continue sfide alla logica e al senso comune, e se la scoperta da parte di Einstein che lo spazio e il tempo sono di fatto un continuum deformabile colse il mondo di sorpresa, la nuova meccanica, rivelando un elemento di incertezza e di imprevedibilità al fondo delle cose, fu un vero e proprio trauma, dal quale la fisica non si è mai del tutto ripresa: nel microcosmo atomico, benché Einstein disapprovi, «Dio gioca a dadi». E la via verso il caso è pericolosamente aperta. Un simile stravolgimento delle categorie della mente richiede di solito, per riuscire accettabile, anni di iniziazione. Nell’intento di ridurre al minimo questo tirocinio, Albert ci fa letteralmente toccare con mano, col suo stile inimitabile, i risultati paradossali in cui sfociano le esperienze fondamentali della meccanica quantistica e il fallimento di ogni tentativo di conciliare le osservazioni sperimentali con il senso comune. Dopo un primo capitolo dedicato allo sconcerto del lettore, egli vince la scommessa di rendere accessibile al profano il frammento di matematica necessario all’esposizione di fatti fisici quali la sovrapposizione, il problema della misurazione, il paradosso Einstein-Podolsky-Rosen, la non-località. E offre uno strumento concreto per partecipare a una delle più affascinanti avventure della scienza. Meccanica quantistica e senso comune è apparso per la prima volta nel 1992.

Genres: Science, Physics, Philosophy, Nonfiction, Quantum Mechanics, Stem, Mathematics

273 pages, Paperback

First published January 1, 1992

Reviews

[Jacob J · Rating 4 out of 5]

An excellent explanation of exactly what makes quantum mechanics unfathomable written to the non-physicist. This book takes an approach I have rarely seen of giving just enough math to give the reader an idea of how the strangeness of quantum mechanics falls out of mathematical equations. It does this with only a very basic refresher course in vector math and I got a lot our of this approach.

[Morgan · Rating 3 out of 5]

Quantum Mechanics and Experience discusses the major interpretation issues in standard quantum mechanics formalisms. Specifically, it goes over the idea of collapse and the idea of non-locality and talks about various interpretations that people have tried to make of them.

The idea of collapse is that QM predicts that some particles can be in a superposition of states right up until you measure them, and once you measure them they're in only one state. They collapse from superposition to singleposition in state space. The non-locality question refers to entangled particles remaining entangled regardless of how far apart they are, which is only really a problem given the idea of collapse (you can know which way the distant particle will collapse before the collapse happens).

Albert discusses several ways that people have attempted to deal with this. Most notably probabilistic collapse, Everett's many worlds, and Bohm's hidden variable theory. The book (sensibly) espouses the idea that collapse doesn't actually occur, but only seems to. It then discusses Everett's interpretation of QM, but doesn't do it justice in my mind. The book dismissed many worlds as not making sense, and then develops a different (almost equivalent) way of talking about Everett's theories based on many minds.

Bohm's hidden variable theory was also discussed, and it seems that Albert supports that theory over any others. My understanding is that there have been experiments since the publishing of this book that have ruled out hidden variable theories, but that's something I need to read more about.

Overall, this book was informative for me. The text was sometimes difficult to follow, and has lots of digressions and asides that are confusing. The book also discusses brain states several times in a way that makes me skeptical that the author understands what it means for someone to be conscious.

[Mostafa Alkady · Rating 2 out of 5]

I'm really disappointed. This book could have been a masterpiece if it wasn't for the extremely hard-to-follow arguments used through most of the book (some of these are intrinsically hard I get that, but surely there must have been an easier way to discuss them without confusing the heck out of us). The book is also riddled with unnecessary digressions. I didn't really finish it. (Maybe I will at some other time when I feel a bit masochistic.) However, I liked the color-hardness analogy for the superposition which is used throughout the book, he also tries to encapsulate almost all of the philosophical discourse about the meaning of the dynamics of quantum mechanics, so I give him that.

I wanted this to be a good book so bad..

[zimu · Rating 5 out of 5]

probably the best book i've ever read in my life! super interesting and fun but it gets difficult in the end. i learned sooooooo much but i still have some questions about bohmian mechanics but hopefully i will figure them out.

also: should probably learn linear algebra before reading this book. reading this with linear algebra knowledge makes the mathematical formalism of quantum mechanics incredibly elegant and beautiful.

[Karl Hallbjörnsson · Rating 4 out of 5]

Frábær bók sem mér fannst þó ansi erfitt að fylgja á köflum. Náði samt að skrifa út heildstæða og skýra röksemdafærslu alla leið í gegn – það var bara erfitt fyrir athyglisgáfuna að halda þræði. Sérstaklega í blálokin var ég orðinn virkilega ringlaður. Mæli samt með fyrir áhugasöm.

[Claudiu Leoveanu-Condrei · Rating 5 out of 5]

This book is… difficult, but thoughtful. It requires intense focus and the capacity to sit with the feeling of being stupid.

Before writing this, I read some of the reviews. Some rated it low because they found it confusing, unclear, verbose, and hard to understand. I find this odd, since for me the exact opposite is true in every respect. I didn't find the book confusing at all—on the contrary, it was clearer than I could have expected. While verbosity is certainly a fair description, the difficulty for me came not from poor explanation but from the sheer subtlety of each argument.

I deeply admire David's ability to craft those arguments. Many I had to reread several times just to barely reach their core, let alone fully "understand" them. But to blame him for that seems unfair. As I think of other philosophical works, I struggle to recall one that presented its arguments more clearly. I even told my wife while reading: "He's explaining this as if we're dumb." And dumb I was, at least in that moment, so I'm grateful he wrote with such care, because his arguments were very well laid out.

The book is also no stranger to strange footnotes and even footnotes within footnotes. But that, at least, didn't surprise me.

[Pino Sabatelli · Rating 4 out of 5]

Testo troppo arduo (matematicamente) per un lettore come me. Voto sulla fiducia perché avrò capito il venti per cento del testo. Forse.

[Carson Phillips · Rating 3 out of 5]

2 star book with some 4 star chapters. Overall, the book just suffered from the same issue as all the other foundations of quantum mechanics books that I’ve read have suffered from: not being pedantic enough. While that seems like an odd request because it is opposed to conciseness, without it, the book just is not clear. I’ve had linear algebra, I suffered through the mathematical formalism chapter carefully, and yet I could still hardly follow the arguments at all without actually sitting down and doing the math myself. That’s fine and expected for a book about the formalism itself, but, for a book about the philosophy, it is overly technical. An expectation with an introductory book is that the material might be repeated a bit ad nauseum, but that is intentional. For the few portions of the book where the author steps back from the formalism and actually discusses theory, he makes great sense. Too bad more of the book didn’t follow that structure. This appears to be a major gap in foundations introductory literature.

[Matt Hogan · Rating 2 out of 5]

Didnt get it

[Kali · Rating 4 out of 5]

Read for Philosophy of Quantum Mechanics — favorite class and great intro QM book. Metacognitively opened so many doors, im grateful.

[Mangoo · Rating 4 out of 5]

Sharp, precise, dense, concise, illuminating, and provocative. Once you accept the partly weird writing style - and in particular the use of weird particle features to exemplify and simplify measurement apparatuses and procedures, in turn supposedly done to remove emphasis from that and leave it allocated to the formalism and fundamental reasoning and issues with the theory - this short but ponderous book on the foundations of quantum mechanics reveals itself as a gem. This written in 1992, so only 2 years after Bell's death and at a time when reasoning on foundations was only starting to appear different than a rather solitary enterprise on the outskirts of an otherwise massively successful theory, in spite of the initiative of Bell himself.
Albert first introduces, with his weird instruments, the experimental evidence of the behavior of particles, then describes the orthodox theory and its formalism by way of 5 principles, and then continues straight through non-separable systems, hence immediately introducing EPR and Bell's theorem, the measurement problem and therein the GRW theory, the possibility that that problem is not existent as postulated in Everett's theory and David's own interpretation of the latter (the so-called many-minds interpretation), and finally presents Bohm's theory and concludes with a speculative chapter where self-measurement would preclude measurement apparatuses with "rich mental life" and perhaps will.
Each chapter presents the subject matter in a very essential way, where the core is put forward clearly if in a personal way, and is scrutinized carefully. The impression is that Albert's ingenuity works like a sieve as much as a simulatrix of scenarios that amplify the plausible until contradictions or limitations appear. That's how Albert found a problem in GRW (it accounts for collapses of wave functions only in macroscopically-registered measurements, which is not the case conversely for Bohm's theory), how he conceived the many-minds interpretation (which he rather uses as a logical possibility and contrapposes for sake of argument to Bohm's theory, concluding that their distinction will be as a matter of fact experimentally never possible), and how he points out that the fundamental limitation of Bohm's theory is in its own ontology, as that requires persistent particles and so imagining how a that can be extended to other entities is hard (recent works are showing the successul extension into relativistic terrirory, though).
The sharp and thorough use of language and the painstaking precision in delineating each logical passage while running his reasoning is worth by itself a read, and if anything testifies to the benefit of a philosophical training in conjunction with a technically adept scientific one.
Overall the book still holds to its fame - it would certainly benefit from an update, though that has perhaps happened in the form of later books by Albert - though I would not recommend it as entry point to quantum mechanics.

[Ege]

1) In this part, it'll be talked about 2 properties that precise physical definitions of those don't matter. One of them is 'color' and the other one is 'hardness'. It happens to be an empirical fact that the color and hardness of properties of particles can assume only 2 possible values: white/black and hard/soft. No experiment has shown that there are any other values other than these.
We can build a color box such that if the particle that enters the entrance of the box is measured white, it'll go through one aperture and if the particle is measured black, it'll go through the other one. If the particle is measured black/white in a color box, it'll be measured black/white in a second color box and so on. These are also valid for a hardness box.
One might be curious about the possibility of relation of these properties with each other. One relation might be correlation and we can check if there is a correlation between the properties with our boxes. If we check, we see that there is no such correlation. For example, if we put bunch of white particles into the hardness box, statistically half of them will be measured hard and the other half will be measured soft. This is valid if the particles were black or if the particles were hard/soft and put into a color box.
Now suppose a particle goes through 3 boxes such that 2 of them are color and one of them is a hardness box. The boxes will be replaced such that a particle firstly goes through the color box firstly, then a hardness box, and again goes through another color box lastly. Of course for every outcome, there must be more than 3 boxes(7 boxes). I drew the experiment

so if the measurement done in a hardness box doesn't have an impact on the color of the particle, we expect that 1, 4, 7, 8 baskets will be empty because the measured color in the last box is different from the measured color in the first box. Statistically, in each of 2,3,5,6 boxes there will be %25 of the particles. However, it is not what happens, actually we see that in each of every box there are %12.5 of the particles. It shows that the measurement done in a hardness box does have an impact on the color of the particles. This means the half of the particles measured black in the first box will be measured white and other half will be measured black. So we know half of the black particles changes their color, this fact raises the question 'what determines the half of the black particles changed their color and the other half don't?". This question seems to have no answer because, as I understand, there is no physical difference between the black particles that were measured white in the first box and the black particles that were measured black in the first box. Another question raises 'May there be a hardness box such that changed the color property of the particles or changed statistically different from we showed here?'. Hardness box can be built in a number of entire ways and all of them will produce the same statistics.
Note: Albert says it's striking that we can't even change the statistics one millionth of one percentage point away, but how can we say such a absolute thing when we talk about statistics?
Since the one information about one property disrupts the other property, we can't say something like "the particle X is now black and soft". It's called uncertainty principle, some properties that act like the hardness and color are called 'incompatible'.
Now suppose an experiment such as

Mirrors in the experiment only there to change the direction of the particles that come out of hardness box but the mirrors or anything between the boxes does not change anything else. If we sent white particles to the hardness box, the half of them will take the path s and the other half will take the path h and also if we sent hard particles to the hardness box, it will take h path and if we measure its color at 'h and s, the half of them will be measured white and other half will be measured black. The interesting happens as follows, suppose we sent again white particles to the hardness box . We know the one half will take h path and other one will take s path. If we measure their color before reaching the black box, it will be 50-50 black and white in each path as we do in the previous experiment which we used 7 boxes. However, if we measure the color of the particles. However, if we measure color of the particles at 'h and s', all of them will be measured white. Suppose now we have a wall which we can put in the middle of paths. If we put the wall into the path, which means we block soft particles, only the half of the particles at 'h and s' will be white. If we put the wall in to the h path, which means we block hard particles, again only the half of the particles at 'h and s' will be measured white. However, if we don't block the particles, all of them will be measured white. If we ask ourselves "when there is no block in paths, which path particles we measure white all of them at 'h and s'?". It can't be h or s paths because when we measure the particles at h or s, their color will be 50-50 black/white. Can it be both paths? Well, if we sent particles one by one and measure their paths for each particle, we find half of the particles take path h and the other half take s but not both. The answer is superposition, which something we don't understand. We know, by the experiment, the particles come out of hardness box as hard/soft only if they're hard/soft particles when they enter the box. When a white particle goes into the hard box, it comes out of neither hard aperture nor soft aperture nor both neither. So saying a particle is white must be the same thing as saying the particle is the superposition of hard and soft. Remember that the knowing or blocking the path of individual photons change their probability of position on the screen.
Note: It seems if we don't know what kind of hardness the individual particles have(or measured last time), the measurement of hardness doesn't have an impact on the color of the particles.
Note 2: The properties act like hardness/color seem are not absolute property but depend on the measurement.
Note 3: David Albert asks which path white particles take, but another question also comes to my mind "What happened to the black ones?".

Chapter 2: Mathematical Formalism

[Brian Powell · Rating 3 out of 5]

This is one of the first science books I ever got. It was part of a 5-book introductory set that I received for joining a science book club. I was young and excited and most of these books were quite incomprehensible. After a couple decades of science education, I happened to revisit this one. This a book on the main interpretations of quantum mechanics (collapse theories, many-worlds, Bohmian mechanics), and so lies a bit outside the subject's standard scientific canon. It would not be recommended, for example, that beginning students trouble themselves with these topics.

My first feeling upon completing this work is one of substantial regret: I should have picked this book up earlier! The opening chapter on superposition is perhaps one of the most cogent and pedagogical discussions of this central concept of quantum mechanics. I would say all undergraduate students of physics should read this chapter as they begin to learn quantum mechanics. In fact, the next two chapters (covering mathematical formalism and non-locality) are also excellent introductions to these topics and it seems are at a perfect level for people seeing this stuff for the first time.

David Albert has a casual and light style which makes some of the more accessible topics especially accessible. As an example, rather than abstract properties like "spin projections", Albert talks about the "color" and "hardness" of electrons. But this style is less effective as he confronts the more difficult topics, like the measurement problem and interpretations (really, the meat of the book sadly). In fact, I would recommend these chapters not be read by anyone. For one, the writing style is atrocious: the all-to-frequent parentheticals I think are meant to be witty or fun, but they are totally annoying and detracting. If Albert had an editor they should be fired.

Once students have gone through the standard quantum mechanics education, the measurement problem is a fascinating thing to ponder. At that point, though, I fear Albert's treatment of these more advanced topics is too elementary, and so rather garbled and incoherent. This book therefore seems to fill a niche that isn't really a niche at all.

[Casey Mitchell · Rating 4 out of 5]

David Albert's "Quantum Mechanics and Experience" takes on the mind-bending world of quantum theory with a mix of philosophical insight and scientific rigor. If you're into quantum mechanics and ready to wrap your head around its deepest puzzles, this book is quite the journey.

Albert dives right into the heart of the quantum mystery: how particles can be in multiple states at once, how observations collapse wave functions, and why quantum mechanics defies our everyday intuitions. But what sets this book apart is Albert's philosophical approach. He doesn't just explain the math and experiments; he asks big questions about what it all means for our understanding of reality.

One of the coolest things about Albert's writing is how he balances complex ideas with down-to-earth explanations. He uses thought experiments and analogies to make tricky concepts like superposition and entanglement more digestible. Whether he's talking about Schrödinger's cat or the famous double-slit experiment, he brings these mind-boggling concepts to life.

Albert also delves into the implications of quantum mechanics for our understanding of consciousness and the nature of reality itself. He explores whether quantum effects play a role in our everyday experiences and how our observations might shape the universe around us. It's deep stuff that'll make you question what you thought you knew about how the world works.

That said, this book isn't light reading. If you're new to quantum theory, some parts might leave you scratching your head. Albert doesn't shy away from the complexities, so be prepared to take your time and maybe even re-read a few paragraphs to fully grasp the ideas.

"Quantum Mechanics and Experience" is a thought-provoking journey into the quantum realm, blending physics with philosophy in a way that challenges and stimulates. Whether you're a physicist, a philosopher, or just someone curious about the mysteries of the universe, Albert's insights will leave you pondering the profound implications of quantum mechanics long after you've closed the book.

[Anthony O'Connor · Rating 4 out of 5]

Good book

Not an easy read. A lot of very detailed very intricate examples. But How could it be otherwise given the subject matter. A thorough study of the so called quantum measurement problem which will leave your head spinning. It’s almost a hundred years since quantum mechanics was put together. And though it definitely works how to interpret it is still basically not known. As the author points out so laboriously no attempt at an interpretation really quite works when you look at in detail. Which is all very puzzling. My only criticisms of the book are 1. The format. Which at least in the ebook version is cramped and messy. And 2. A tendency to get lost in the branches and lose all sight of the forest. A little more context and history would I’m sure have been more illuminating. Still. Roll your sleeves up, set aside some time and plod through the examples. It’s probably worth it.

[TjeerdFokkens · Rating 2 out of 5]

This book discusses a few interesting interpretations of quantum mechanics: the many-minds interpretations and Bohm's interpretation (which was very nice). In the appendix also modal interpretations are discussed. The author made a good selection in thought experiments to illustrate the workings of the interpretations. Also the conceptual problems are treated in appropriate detail. The main drawback of this book is the writing style: it is absolutely horrible, up to the point that it confuses rather than elucidates. Seriously, ten-line sentences with commas, semicolons, italics, parentheses and footnotes, the footnotes themselves being sometimes page-long. And the repetitiveness: assuming a certain scenario, the author keeps repeating that anything that follows holds under that assumption. Again and again and again. Extremely annoying. Not recommended.

[Liam · Rating 5 out of 5]

"This is the kind of theory whereby you can tell an absolutely low-brow story about the world, the kind of story (that is) that's about the motions of material bodies, the kind of story that contains nothing cryptic and nothing metaphysically novel and nothing ambiguous and nothing inexplicit and nothing evasive and nothing unintelligible and nothing subtile and which no question ever fails to make sense and in which no questions ever fail to have answers and in which no tow physical properties are ever 'incompatible' with one another and in which the while universe always evolves deterministically and which recounts the unfolding of a perverse an gigantic conspiracy to make the world appear to be quantum-mechanical." (of David Bohm's theory, 169)

[Chris · Rating 3 out of 5]

This is a good first look at quantum mechanics.

If you're serious about it though you might want to read something like Tony Zee's QFT in a nutshell. (500pp, so mis-titled)


I'm not sure the philosophical stuff holds up under the more sophisticated microscope. I also stopped caring because representation theory is much more interesting than quantum metaphysics.

[Rohit Goswami · Rating 3 out of 5]

It turns out my rage at Sci fi was because I wanted real math. This is a great book, right until the author starts to talk about air molecules and brains. I couldn't stand selective suspension of belief in high-school physics and I still can't stomach it so many years later. The opening chapters are really 5 star stuff, love the rational simplifications.

[Jeff Vandegrift]

Prof Steven Gimbel's Philosophy of Physics "must read".

As a second book on your shelf he recommends ONE of the following:
* for those NOT versed in math of cosmology: Space from Zeno to Einstein by Nick Huggett
* for those VERSED in math of cosmology: Foundations of Space-Time Theories: Relativistic Physics and Philosophy of Science by Michael Friedman

[Brian Kirkby · Rating 5 out of 5]

i heard about this book through an MIT course on quantum mechanics. the instructor covered albert's expose of the implications and meaning of the bell inequalities and the experiments done to prove them. very insightful.

quantum mechanics can be a difficult subject because the implications for meaning are so strange, unsettling, and even unsettled.

[Olivier Eymere · Rating 4 out of 5]

I really enjoyed the book but will warn anyone that it's not really good as bedtime reading, at least for me. It takes a fair amount of concentration and ideally a notepad to do some of the math to follow along.

[Parker · Rating 4 out of 5]

Clear explanation of an obviously complex topic. There are so many brackets and footnotes and footnotes of footnotes, but they made the story clearer. This was also my first introduction to Bohm’s theory, and I want to look into it more.

[Nick Randazzo · Rating 4 out of 5]

Incredibly interesting topic, thorough coverage of all of the major interpretations of QM (and some minor interpretations like many minds). Not totally clear at all points, which is in some part due to the nature of the material, but I do think some concepts could have been presented more clearly.

[Phillias · Rating 5 out of 5]

very neat, need to explore this

[John · Rating 4 out of 5]

Very clear, and just detailed enough in its descriptions of the math involved. Demands that you pay attention, however.

[Michael · Rating 4 out of 5]

Challenging read. But worth it.

[Nina]

Physics and philosophy class. Cool ideas. Soon bribes difficult to understand

[Mira Nauli Panjaitan · Rating 4 out of 5]

Cute

[Imehdi Imaaref]

Explores interpretations of quantum mechanics and retrocausality.