31.12.2009 - Einstein Podolsky Rosen Paradox II

Arisia Vita: Hi Stim

Gilles Kuhn: hello Stim welcome

Stim Morane: Hi :0

Stim Morane: finally

Arisia Vita: welcome Birric

Gilles Kuhn: hello Birric

Dali Waverider: En garde, Birric!

Gilles Kuhn: so as always i will begin with the official prayers

Birric Forcella: Hi all

Gilles Kuhn: all will be logged not by Gaya that cannot attend today but by me and published so all you write will be published

Arisia Vita: Hi Cosmo

Gilles Kuhn: secondly sorry for last week my internet has gone done seemingly storms and mobile internet does not commute ...;-)

Gilles Kuhn: ok so lets begin

Gilles Kuhn: first thanks Birric for your interesting note please send it too to the attendee that are here

Arisia Vita: I have it

Dali Waverider: got mine

Melchizedek Blauvelt: I have it too

Gilles Kuhn: well we have seen that the paper has two basis "postulate "

Cosmo Fenwitch: I would like to see it.

Gilles Kuhn: a physical theory need to be complete and need to be correct

Gilles Kuhn: by complete it means that all the element of the physical reality must have a counter part in the theory

Gilles Kuhn: by physical reality the authors specify that if we can measure something in a system with certainty without disturbing it then the something has a physical reality

Gilles Kuhn: ok then everybody remember what i s a wave function has described by Schrodinger equation?

Gilles Kuhn: by this equation you can describe the evolution of the value of a certain number of parameter of a elementary particle these parameters describe fully the state of the particle following qm theory

Gilles Kuhn: namely these are position, speed (momentum) direction, spin (magnetic momentum ) the mass and the electrical charge are constant so out of the problem (please anyone remember me if i have forget something)

Gilles Kuhn: the first argument of the epr article describe how you can characterize a parameter of a particle with a single degree of freedom by the an operator A inside Schrodinger equation

Gilles Kuhn: the author show mathematically that you can determine the value of the parameter without disturbing the system and so that it had an intrinsic value and thus a physical reality

Gilles Kuhn: but and its the first great but it show too that if you can determine it you CANNOT determine in the same way another parameter according to qm theory (in the case of our example following heisenberg inequality as we have full determination of momentum we have no possibility to know about the position )

Gilles Kuhn: so if we take back the two basis postulate :

Gilles Kuhn: as we have a parameter that is part of the physical reality but that we cannot determine that can mean two things :

Gilles Kuhn: first qm is incomplete

Gilles Kuhn: second the second parameter has no physical reality at all if we know the first more generally for two non commuting operators if one is determined the second has no physical reality due to the determination of the first !!!!

Gilles Kuhn: ok question remark critics etc so far has that is the resume of the first part of the article which was my target for this week

TR Amat: Doesn't this suggest that you need a better theory?

Gilles Kuhn: yes indeed and the conclusion of the paper point to that

Vertigo Ethaniel: hi everyone

TR Amat: Hi Vertigo

Gilles Kuhn: but the problem is that qm work empirically perfectly i e all experiment thus far confirm it and we have no others theories

Dali Waverider: I've always taken this to mean that there is a limit to what we can observe....that the methodologies for observation necessarily interfere with the phenomenon, and so there are limits to what we can know.

TR Amat: Isn't the other implication that you are trying to use the wrong parameters to characterise reality?

Gilles Kuhn: too the idea of the hidden variable i e the idea that qm forget "something " was showed impossible inside qm so yes another theory but none so far available

Birric Forcella: Can I please make a quick interjection: The math only states that the second parameter has DIMINISHING physical reality as the first gains harder and harder physical reality. While it is generally assumed that the first parameter (like location) can be measured with perfect exactness, I don't really understand how that could be coherently done. However, in case it would be done, the second parameter could be ANYTHING at all and loses all physical meaning - that is right.

Gilles Kuhn: very good and interesting point Birric

Gilles Kuhn: indeed podolsky use only the full determination of one and so the full indetermination of the other

Dali Waverider: Birric, further, it's my understanding that to satisfy the inequality you can have some approiximate information about both parameters

Birric Forcella: Yes, in real life, we all the time talk about both

Gilles Kuhn: which correspond btw at his thought experiment because at the time of the paper that was only a thought experiment we need to wait for aspect experiences to have it implemented

Birric Forcella: And even within QM, things are rarely measured with such exactness that one of the parameters completely disappears

Gilles Kuhn: but the problem is all included in the full postulate of defining physical reality by the total measure of a parameter when in qm the rule is partial and statistic measure

Gilles Kuhn: indeed Birric

Gilles Kuhn: and as we have already noted the assumption of the definition of physical reality by podolsky is a ontological realist profession of faith....

Gilles Kuhn: for the Copenhagen interpretation and Bohr point of view the very basis epistemological postulate of Podolsky is wrong

Gilles Kuhn: well if you wish we can cover too the second part of the paper so we can discuss the whole of it ?

TR Amat: Sounds interesting...

Gilles Kuhn: ok i will try to resume it

Birric Forcella: I think you need to bring this out a bit more clearly - why it is merely a profession of faith - and why it is wrong - after all, it's the basis of all the physics known to most of us

Gilles Kuhn: in the second part we consider two systems that after an interaction can be described by the rule of qm by a single wave ;;;;;;;;; k Birric i will address that first

Birric Forcella: okay

Gilles Kuhn: so the idea of ontological realism that is assumed by Podolsky Einstein and Rosen

Gilles Kuhn: is that a physical theory if it is a correct one describe the reality as it is and fully i e ontologically in simple word describe what the world is even without an observer or an interpretation

Gilles Kuhn: this position is very common in scientist but its a position that is attacked by a lot of philosophers and even of physicist

Gilles Kuhn: and indeed its what lurk behind the veil in our present theme

Gilles Kuhn: actually i wanted to introduce this debate by the epr because is a direct and real problematic consequence of a epistemological debate in science and worst ;-) in the allegedly queen of science s ie physics

Gilles Kuhn: Einstein and Bohr disagreed not so much for qm but in fact about that Bohr was instrumentalist and so limited the scope of what a scientific theory can offer us epistematicaly

Gilles Kuhn: but i think Birric could express the realist position better than me as i am of the other side....

Birric Forcella: Well, no, I am perfectly convinced of the rightness of QM - and I am not a realist by a long shot. However, besides Bohr, there are a number of interpretations of QM which ALL are equally physically valid. Like Heisenberg, or Quantum Logic, or, what you probably all have heard of, the "Many Worlds Interpretation."

Gilles Kuhn: yes but as you well say they are interpretations and fundamentally in all the interpretation s the maths and so the model of the theory is the same so you can perfectly well use qm without interpretation as a model that work even if it seems not to give "sense" intuitively (ok thats a kind of interpretation too even if minimal)

Birric Forcella: I think my view is more basic - since all these interpretations preserve the contradictions I have outlined in my short notecard. Bohr's interpretation tackles the quantum problems by taking the whole of the experiment as one - that includes the experimenter. I fully agree. In fact, I agree with most QM interpretations, I only have doubt about 'Many Worlds" - while it is internally consistent, it just looks like an awful lot of efforts on the side of reality to create QM effects.

Stim Morane: :)

Birric Forcella: Yes, most physicists use QM without any interpretation - the interpretations are strictly philosophy

Gilles Kuhn: well the many world make my occamian mind howls indeed

Vertigo Ethaniel: lol

Arisia Vita: welcome Arch

Gilles Kuhn: so shall i proceed to the second part of the argument? (well time a bit short for that perhaps better to let the ground more to the other participants )

Birric Forcella: Well, to make it simple - Bohr basically cashiers all reality below the Planck constant. I think we need to look more closely at the two-slit experiment in order to understand WHY the experimenter is crucial for the outcome of the experiment.

Gilles Kuhn: please questions even naive one nor Birric nor me would eat you here at least ;-)

Birric Forcella: But first, proceed, Gilles

Birric Forcella: Well, I would like to remark here, that I am always a bit puzzled by QM presentations where the people sit around and nod their heads - in truth, if they understood REALLY what it's about, their first reaction should be to run screaming into the street and rip out their hair. ..

Cosmo Fenwitch: It does seem like magic.

Dali Waverider: can't our heads hurt quietly?

Archmage Atlantis: It is magic

Gilles Kuhn: yes Birric indeed the problem and that's very important for understanding what will follow when we will go further with bell inequalities Bohr objection and worst aspect experiment ;-) is to understand that when you make a measure what you do is to make interact two systems the measurement apparatus and the measurzers have too a wave function

Archmage Atlantis: Magic is science not yet accepted, understood, or bounded

Gilles Kuhn: so when you measure a particle in qm point of view you disturb its wave function because it interact with another one

Arisia Vita: May I ask if the Bohemian interpretation is still considered valid?

Gilles Kuhn: well Arisia it work and validity in interpretation that are empirically equivalent is a metaphysical problem at my opinion...

Birric Forcella: Yes, it's valid - all major interpretations are still valid (about 7 distinct ones) - they all completely agree with ALL the data

Archmage Atlantis: Suprise !.......then there is not enough data to reach a conclusion

Birric Forcella: This is why physicists don't like to get into the philosophy of this - it just makes their heads hurt

Gilles Kuhn: but i think the good question would be to ask "is it valid to make interpretation and not to consider only the theories as models?

Birric Forcella: Very good, Arch - you got it

Gilles Kuhn: yes chief magus ! ;-)

Cosmo Fenwitch: If the measurement can affect another measurement made at any time in the future OR THE PAST, the problem seems to go away. So maybe we just need to incorporate a better theory of time into QM .(

TR Amat: Quantum Mysticism can be a bit of a pain...

Birric Forcella: However, the point to Bohr is that for fundamental reasons NO additional data are possible. That is exactly where the classical scheme of representation is broken. Arch is demanding more data exactly to fill this "representational gap," and QM says that that data does not exist.

Gilles Kuhn: well beware the measurement don't affect the past as such

Dali Waverider: By what principal should we assume that physical laws and reality operative at our scale of direct perception should pertain at scales at wide variance? Relativity becomes important at large scales, and quantum effects predominate at very small scales. and there may be more effects as you go into further scales that we will never be able to comprehend. I can live with that degree of incongruence.

Cosmo Fenwitch: Not that we can see anyway.

Archmage Atlantis: I have a file, I carry it with me, of things I cannot understand or explain, and yet, they seem to work

Melchizedek Blauvelt: There are a number of valid interpretations; the notions of "space", "time" or even "you can conclude anything you want from a contradiction" are notions dating back to the iron age

Melchizedek Blauvelt: paraconsistent logic seems to handle the latter quite well, btw

Gilles Kuhn: but can affect a system immediately and a non limited range..... that's the second point of the epr paper that we will consider next week

Archmage Atlantis: Newton only got parts of how the universe works down

Archmage Atlantis: What makes Einstein more special

Gilles Kuhn: Dali about scale one thought experiment by Einstein and a similar by Schrodinger destroy that (the cat )

Vertigo Ethaniel: my friend just rather mischievously labeled quantum mysticism "pub science"

Archmage Atlantis: Better pr

Archmage Atlantis: My cat absolutely refuses to enter that paradox smile

Birric Forcella: I have to insist that QM doesn't just make everything nebulous, like some New Age religion - but QM is actually VERY hard science which creates VERY specific contradictions. It is exactly the specificity of the contradictions that make it the basis of our reality.

Gilles Kuhn: and Melchi the problem is that you need at least for communication the non contradiction principle but that and i agree don't mean you cannot have and use contradictory paradigm for different situation

Cosmo Fenwitch: The concept of simultaneous events depends on the velocity of the observers, so if something an affect a system immediately and a non limited range, to another observer in a different frame, doesn't it affect the system in the past?

Gilles Kuhn: and indeed Birric qm is one of the most successful theories we have it work perfectly the contradiction are only when you try to interpret in habitual terms or make it work with special or worst general relativity

Gilles Kuhn: not necessarily Cosmo in fact if you accept there is no possible hidden variable then no

Archmage Atlantis: Examine the assumptions of your systems of thought

Vertigo Ethaniel: but both special and general relativity are exceptionally successful theories

Gilles Kuhn: well the hour is coming to his end may i ask if anyone need a group invite ?

Birric Forcella: I think for the next time I will prepare a short notecard about the two slip experiment - especially the aspect at which a particle "knows" that a second possible path is either open or closed, even when the decision to close or open that path is make AFTER the particle is already in flight and cannot possibly be influenced by that decision. It demonstrates WHY the experimenter is an integral part of the experiment. Also we need to show how a particle acts as a particle or a wave according to the TOTALITY of the experiment - in fact, the particle knows apparently "psychically" what the total experiment, including the mind of the experimenter, looks like. Unless you get a good understanding of this, all the talk here will go over your head.

Gilles Kuhn: yes vertigo and that's a big part of the problem

Vertigo Ethaniel: therefore, qm must be compatible

Vertigo Ethaniel: else it is a failed theory

Vertigo Ethaniel: yes i wouldn't mind an invite

Gilles Kuhn: yes Birric by all means do so that would be great ! and posit too in the wiki and the Google group !

Cosmo Fenwitch: To say "AFTER the particle is already in flight and cannot possibly be influenced by that decision" implies that the future cannot affect the past.

TR Amat: Does a theory have to be complete to be useful?

Arisia Vita: does it have to be correct to be useful?

Dali Waverider: Newtonian physics proven not to be complete....but perfectly fine for just about everything we do.

Archmage Atlantis: So Birric, it depends on an assumption that a "decision" can be make, am I correct?

Gilles Kuhn: well if you define completeness as Podolsky the history respond no as even the phlogiston was useful....

Stim Morane: thanks, Gilles, Birric, and everyone! I look forward to following the rest of this discussion.

Gilles Kuhn: well i will finish here the official part and yes an important thing there will be no seminar next week exceptionally

Birric Forcella: Well, the decision can be made by computer, Arch

Gilles Kuhn: so i hope to see you all in two weeks

Birric Forcella: it's a question of observer-created reality

Dali Waverider: in a fortnight, then.

Arisia Vita: see you all then

Birric Forcella: Good night all

Cosmo Fenwitch: SO what if on a grand scale, everything has already happened? There is no free will, no "decisions" can be made, and all the experimental observations are fixed. We only need to become aware of them?

Justine Rhapsody: Good night everyone

Archmage Atlantis: Then when Ari's computer invites me, I shall attend again.,......Does your computer have a name I might recognize, Ari?

Melchizedek Blauvelt: Happy 2nd lemmings day all

Dali Waverider: Don't worry Cosmo. You will never achieve that awareness. B-)

Arisia Vita: not that I know of Arch

Arisia Vita: I must name it

Cosmo Fenwitch: True.

TR Amat: I still want to know what tools go in a quantum mechanic's toolbox...

Dali Waverider: particle wrench?

Dali Waverider: wave spanner?

Vertigo Ethaniel: wavy fingers and a stern stare

Birric Forcella: It doesn't actually work like that. While you can make the point that everything has already happened, Cosmo, the fact, according to Einstein, is that you are the oldest part of the universe - so nothing has happened "before" you

Birric Forcella: You can easily prove this by the fact that any clock in the universe is always the fastest clock - so if you had always carried a clock with you - you would ALWAYS have been ahead of all time

Dali Waverider: You are the oldest part of your known universe, Birric?

Birric Forcella: Oldest part in ALL the universe

Dali Waverider: Strong words.

TR Amat: I wanted to know if a Planck meter was required...

Dali Waverider: B-)

Birric Forcella: See, every clock is at rest in relation to itself. So ALL other clocks are either also at rest or moving. According to Einstein, for anything that is moving in relation to you - time passes more slowly. So you are necessarily the oldest part in the universe

TR Amat: Can space-time exist without matter?

Dali Waverider: Maybe the implication is that all clocks are equally old...and that all of the universe is of the same age...consistent with a big bang?

Cosmo Fenwitch: What about tow clocks at different heights in a gravitational field? They can be brought together and will be out of sync.

Vertigo Ethaniel: a better question, can it exist without energy?

Vertigo Ethaniel: matter is essentially energy, after all

TR Amat: Is an empty space-time possible?

Gilles Kuhn: vertigo actually matter is energy

Vertigo Ethaniel: that's what i said

Gilles Kuhn: well following general relativity anyway...

Gilles Kuhn: indeed

Birric Forcella: Actually, Dali, that can't be. Because, by definition, YOUR age, and the age of any spot in the universe is defined by its distance from the edge of the universe. The edge of the universe is exactly as far away from you in light years as it is away numerically in time in real years. So anything that is closer to the edge from you, is necessarily younger than you.

Vertigo Ethaniel: i think a space doesn't necessarily require anything in it at all

Birric Forcella: Since the edge is away from you by the same time in ALL directions, Dali, you have to be the oldest spot in the universe.

Dali Waverider: You mean the edge of the known universe, right?

Birric Forcella: No, the edge of the universe. Outside of time and space nothing exists

Gilles Kuhn: good old space time event cone

Dali Waverider: But aren't you also at the oldest spot, Birric?

Gilles Kuhn: yes its relative o the observer

Vertigo Ethaniel: that concept will never make sense to me

Birric Forcella: Well, no space and time exist outside of space and time - otherwise you would have two ages

Gilles Kuhn: i need to go have fun and see you all in two weeks

TR Amat: Is there still room for tachyons?

Dali Waverider: Bye Gilles.

Vertigo Ethaniel: see ya

Birric Forcella: Bye Gilles

TR Amat: Bye Giles - philosophise well. :)