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- Thread starter Schrodinger's Dog
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MWI of course

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Of course but why?

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2. It is deterministic

3. It is realistic

4. It allows our Universe to start from very simple or null initial conditions at t=0

5. It is compatible with Max Tegmarks MUH

6. It's weirdness is beautiful

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I believe in MWI, so QM is *already* complete, and all these collapse things is just invention of the tortles.

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Shut-up-and-calculate is even simpler.

2. It is deterministic

3. It is realistic

4. It allows our Universe to start from very simple or null initial conditions at t=0

5. It is compatible with Max Tegmarks MUH

6. It's weirdness is beautiful

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Would you argue with Dirac or Feynman?

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http://en.wikipedia.org/wiki/Copenhagen_interpretation

"Shut up and calculate" is just a slogan. It really means 'When we do experiments we can forget about these weird things'. Like Big Bang, which is not a Bang at all...

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RUTA

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Relational Blockworld

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Is there somewhere a detailed description of each interpretation to learn "officially" or at least sufficiently professionally?There are many interpretations on the market.

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tom.stoer

Science Advisor

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I tend to agree.

String / M and LQG are not interpretations of QM. In addition the list of interpretations is both incomplete and not detailed enough. If you read papers and books carefully you will learn that the experts are familiar with QM and philosophy; as such two people preferring the "same" interpretation will mostly differ in the details. Even Feynman was a realist in his normal course of life. He surely believed in the continuous existence of his bedroom during his labor time in the office. But of course Feynman would have never agreed to a realistic interpretation of QM. You will find many more examples ...

So I would suggest to read a book on the subject. e.g.

- Bernard d'Espagnat: On Physics and Philosophy

- Jeffrey Bub: Interpreting the Quantum World

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- It explains the whole process of "wave function collapse". Wave function does not magically disappeared after it is collapsed. It canceled out as the transaction is completed.

- Wave function is physically "real" wave.

- It's time symmetric.

- Observer has no special role in collapse of wavefunction. Emitter and Absorber(Observer) of wave function are the same

http://faculty.washington.edu/jcramer/PowerPoint/AAAS_20060621.ppt

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What are emitters and absorbers? Does this interpretation say that there are objects not defined by wave functions? Is Schrodinger equation violated at the places where emitters and absorbers are present?I Like Transactional Interpretation.

- It explains the whole process of "wave function collapse". Wave function does not magically disappeared after it is collapsed. It canceled out as the transaction is completed.

- Wave function is physically "real" wave.

- It's time symmetric.

- Observer has no special role in collapse of wavefunction. Emitter and Absorber(Observer) of wave function are the same

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What are emitters and absorbers? Does this interpretation say that there are objects not defined by wave functions? Is Schrodinger equation violated at the places where emitters and absorbers are present?

Emitter and Absober are exactly the charged particle that radiate the wave. E.g., electron emits/absorbs a photon during transition to another energy state.

See http://en.wikipedia.org/wiki/Wheeler–Feynman_absorber_theory" [Broken]. The idea of Transactional Interpretation came from this theory.

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Observer, or emitter, or absorber are not well defined and magic

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Can you write down equations that govern the behavior of this particle? Is it the classical equation of motion? Also the question that I have already asked but you didn't answer: Is Schrodinger equation violated at the positions of charged particles? Finally, what about particles without charge?Emitter and Absober are exactly the charged particle that radiate the wave. E.g., electron emits/absorbs a photon during transition to another energy state.

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Good point, but I'm afraid that the problem with the transactional interpretation could be even much worse than the problem with CI.

Observer, or emitter, or absorber are not well defined and magic

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In any case, TI is a collapse interpretation, which saves the realism at cost of assuming actions backward in time.

Regarding the collapse it has the same problems as CI. For example, a mirror or a lense is not considered to be an 'absorber' even photon iteracts with atoms of the glass, while our retina is considered to be an absorber.

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MWI on the other hand is an abomination - the most extreme violation of Ockham's Razor one can imagine and I can't see how it solves anything as there still has to be some kind of a "collapse." Something has to determine which possibility happens to each observer since there is at least one special observer - the one in which my conscious resides - and this special observer is only experiencing one possibility and not the other so there has to be a "collapse" to determine which one it is.

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1

MWI on the other hand is an abomination - the most extreme violation of Ockham's Razor one can imagine and

2

I can't see how it solves anything as there still has to be some kind of a "collapse."

3

Something has to determine which possibility happens to each observer since there is at least one special observer - the one in which my conscious resides - and this special observer is only experiencing one possibility and not the other so there has to be a "collapse" to determine which one it is.

1 No, it is minimalistic. It had been discussed many times. MWI does not introduce additional postulated hence it is minimalistic

2 Quantum Decoherence

3 How do you know that your consiousness resides in only one branch?

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1 No, it is minimalistic. It had been discussed many times. MWI does not introduce additional postulated hence it is minimalistic

2 Quantum Decoherence

3 How do you know that your consiousness resides in only one branch?

1. It postulates existence of immense/infinite number of additional unobservable universes whose number is constantly growing and which are being created out of nothing.

3. Experience, there is always only one possible outcome available to my consciousness.

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firstto be able to calculate on its own, 6 and a half days a week, while not closing one's eye on alternative interpretations on the basis of philosophical prejudice, but only do it on spare time. The vast majority of working physicists is not working on foundations, and they mostly "shut up and calculate". As far as I can tell, I have seen too often, on this very forum, people arguing about such interpretation while not being able to calculate, and I think it is vain.

Agree 100%. I am also a fan of "Shut up and Calculate" and if you cannot Calculate then you should Shut Up. In the past I thought that it was quite fun and harmless to debate interpretations but now with so much quantum babble going around I am not so sure any more.

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1. It postulates existence of immense/infinite number of additional unobservable universes whose number is constantly growing and which are being created out of nothing.

3. Experience, there is always only one possible outcome available to my consciousness.

1. It does not postulate the existence of such universes! This is a very common misconception.

2. So, how does it deny the MWI view? As branches loses an ability to communicate after very short period of time, both "you" in 2 branches are claiming that "there is always only one possible outcome available to my consciousness"

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1. It does not postulate the existence of such universes! This is a very common misconception.

2. So, how does it deny the MWI view? As branches loses an ability to communicate after very short period of time, both "you" in 2 branches are claiming that "there is always only one possible outcome available to my consciousness"

1. How does it not postulate them? Maybe not explicitly but that doesn't matter. Compare for example ensemble or Copenhagen interpretation and MWI, observable physics is exactly the same yet one has an immense number of unobservable parallel universes which are constantly being created and the others do not, where does the difference come from if not from postulates of the MWI interpretation?

2. It does not deny it, it shows that it suffers from a certain indeterminism somewhat similar to standard measurement problem. To understand my point you have to realize that there is at least one special conscious observer - in your case it is yourself, in my case it is myself. My consciousness is confined to one branch only making this branch special to me. Even if I assume there are "copies" of me in parallel universes right now (and new ones constantly branch off) those copies are not really me since I can never control them or experience what they do, what's more their history differs from mine. So now the problem is when a measurement occurs what determines which outcome happens in my branch? From my perspective the outcome is indeterministic.

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This is exactly what GR predicts (if universe is open) - an infinite number of unobservable Hubble voulmes, and more and more expension!

This is a pure psycological thing: it is very easy to accept the SPACIAL infinity (the existence of infinite number of worlds far away from our) but difficult to accept the same infinity of worlds which are in the same place spacialy but which do not communicate.

2. This is circular. You assume the collapse saying "My consciousness is confined to one branch only making this branch special to me". I dont assume it.

So, there are 2 branches. MWI predicts that both copies are equally conscious, share the same memory and are not aware of each other because of the decoherence. So each copy will say: "Only MY branch is real! But the choice of a branch was RANDOM" This is exactly what MWI predicts and this is exactly what happens. There is no indetermminism at all.

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Fredrik

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The difference between ensemble/copenhagen* and the MWI is that the former assumes that QM *doesn't* tell us what actually happens, while the MWI assumes that QM *does* tell us what actually happens. That makes it the minimal *realist* interpretation, because it doesn't contain additional axioms which serve no other purpose than to get rid of the many worlds (like the version of Copenhagen that asserts that there's a mysterious physical process called "wavefunction collapse" that replaces a superposition with an eigenstate).

(I recently questioned the assertion that the MWI requires*no* additional axioms here, but due to too many distractions I haven't really thought it through yet, so I'm still not sure about this).

Decoherence isn't a problem for the MWI. Quite the opposite. It just singles out the worlds in which a system's environment can contain stable records of the state of the system. A memory about a result of a measurement in a physicist's brain is such a stable record, so only the worlds that are singled out by decoherence theory can contain conscious observers.

*) See this thread for a discussion about those terms.

By the way, I also think the claim that the number of worlds is growing is incorrect. The claim that they're being "created out of nothing" is definitely incorrect.

(I recently questioned the assertion that the MWI requires

Decoherence isn't a problem for the MWI. Quite the opposite. It just singles out the worlds in which a system's environment can contain stable records of the state of the system. A memory about a result of a measurement in a physicist's brain is such a stable record, so only the worlds that are singled out by decoherence theory can contain conscious observers.

*) See this thread for a discussion about those terms.

By the way, I also think the claim that the number of worlds is growing is incorrect. The claim that they're being "created out of nothing" is definitely incorrect.

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It postulates existence of immense/infinite number of additional unobservable universes whose number is constantly growing and which are being created out of nothing(c) PMT19

This is exactly what GR predicts (if universe is open) - an infinite number of unobservable Hubble voulmes, and more and more expension!

This is a pure psycological thing: it is very easy to accept the SPACIAL infinity (the existence of infinite number of worlds far away from our) but difficult to accept the same infinity of worlds which are in the same place spacialy but which do not communicate.

2. This is circular. You assume the collapse saying "My consciousness is confined to one branch only making this branch special to me". I dont assume it.

So, there are 2 branches. MWI predicts that both copies are equally conscious, share the same memory and are not aware of each other because of the decoherence. So each copy will say: "Only MY branch is real! But the choice of a branch was RANDOM" This is exactly what MWI predicts and this is exactly what happens. There is no indetermminism at all.

1. Your comparison is not valid since GR is the best description of experimental results while MWI doesn't offer any additional predictive power over other interpretations. If some alternative theory existed which gave exactly the same experimental predictions as GR but didn't require singularities or event horizons it would of course be preferable.

2. It is not circular, and I do not assume collapse, if you agree with "I think therefore I am." then it follows from there - you are special due to your consciousness and that there is at least only one such observer.

Or to put in a different way - one can explain anything one wants by postulating parallel universes in which other possibilities take place making distributions normal or explaining otherwise unexplainable phenomena but this is not physics since it has no predictive power and is not falsifiable.

For example why matter dominates? It doesn't! We are just in a universe where it happens to be more abundant but there are other parallel universes where antimatter is more abundant and on average they are equally likely to dominate.

Does it solve the problem? Is such a solution satisfactory to you?

To me it doesn't solve anything since we want to know what made it dominate in *our* universe, we don't care about parallel unobservable universes. The fact that matter dominates here means that there was some process in our universe which lead to it and the problem will only be solved when we understand that process.

Or another example why do particles decay when they do? They decay when a particle in a parallel universe comes through exactly the same location they occupy in our universe! So particle decay is deterministic after all, and there is nothing to worry about.

A similar explanation can be invented for anything you want, is this physics?

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