Settle a quantum mechanics argument.

[CaseS87]

Just fyi neither of us are very educated in QM. (Obviously)

Is it theoretically possible that the moon could "leap" from its original position to the other side of the earth if it was unobserved? MY understanding is that every particle's wave function in the moon extends (at least) to the other side of the earth, and thus has a non 0 chance of appearing in that location when observed. Given these circumstances it would make it possible but EXTREMELY improbable for every particle in the moon to randomly "select" this area of it's wave function and the moon would materialize on the opposite side of the earth from it's original position.

HIS understanding is that due to how massive the moon is, all the the particles' wave functions essentially cancel themselves out making the position of the moon the only position possible. Basically objects of that size follow the laws of classical physics exactly.

So who is right? Are we both wrong?

Thanks.

[madnak]

I don't know QM well either, but I believe there's a variable element to essentially everything. From my understanding particles even pop into and out of existence spontaneously, so it seems like it's definitely possible for "the moon" to pop from one place to another.

But that's a bit of a different subject. It sounds based on what you're saying like your friend is confusing extreme improbability with impossibility. The wave functions will certainly "cancel themselves out," but that's due to the law of large numbers. If you play 8*10^1,000,000,000,000 games of poker and are always much better than your opponents, you'll certainly win money.

But "not that certainly." Obviously it's possible you could be dealt poor hands every single time. I'm not sure if it matters per se, because it's not going to happen. But then again, I think (but can't seem to get solid confirmation) that if you have a system with a limited set of parameters and an infinite time span, along with a significant level of variance, you will "eventually" see the parameters adopt every possible conformation.

[m_the0ry]

If my understanding is correct...

This theoretically could happen, but it would happen in a span of time shorter than a planck time and thus would be impossible to measure the existence of the moon as no probe particle could detect its presence.

Part of the problem with this scenario is the moons orbit is a few light seconds in diameter (rough estimate). If the moon appears on the other side of the earth it would have moved faster than the speed of light, an impossibility. It's my understanding that the upper limit on where you can find a particle is c*(time-since-last-observation) meters away from the position observed at.

Now that isn't to say that the moon couldn't be "re-created" out of virtual particles in vacuum fluctuation. Vacuum fluctuation, in the most simple form, allows for particles to appear out of nothing. So in essence in a very improbable situation the moon could materialize out of nowhere at any given position. The only problem is that vacuum fluctuations must disappear within a planck-time unless they are on the event horizon of a black hole. Meaning that the moon would have to appear and disappear in less than one planck time, which means its presence would be completely immeasurable by any concievable test.

There are also the problems of inertial frame of reference changing instantaneously which as far as I know is infeasible.




Keep in mind this hypothetical comes dangerously close to outright asking what the Grand Unified Theory is because it involves incredibly microscopic and macroscopic events. Essentially, I don't think anyone could give you a good answer right now.

[flipdeadshot22]

[ QUOTE ]
Just fyi neither of us are very educated in QM. (Obviously)

Is it theoretically possible that the moon could "leap" from its original position to the other side of the earth if it was unobserved? MY understanding is that every particle's wave function in the moon extends (at least) to the other side of the earth, and thus has a non 0 chance of appearing in that location when observed. Given these circumstances it would make it possible but EXTREMELY improbable for every particle in the moon to randomly "select" this area of it's wave function and the moon would materialize on the opposite side of the earth from it's original position.

HIS understanding is that due to how massive the moon is, all the the particles' wave functions essentially cancel themselves out making the position of the moon the only position possible. Basically objects of that size follow the laws of classical physics exactly.

So who is right? Are we both wrong?

Thanks.

[/ QUOTE ]

The measurement postulate (that observation of a quantum mechanical system -causes- the system to choose a particular state) is one of the most misunderstood concepts by most laymen (and a large number of scientists in fact.) Whether or not the moon is observed at any time during such an unfeasable process as described in the OP has nothing to do with the measurement postulate. Such an impossibility can be ruled out with classical mechanics alone (the moon is NOT a quantum mechanical system, but rather a classical system), since such a jump made by the moon would imply infinite acceleration, which further implies an infinite force to supply such an acceleration. Whenever an infinity arises in the analysis of a physical process, you can pretty much be assured that the reasoning that leads to such a result as an infinity is flawed.

[MaxWeiss]

It's entirely possible for a whole object to just randomly jump to another point because all of it's subatomic particles do at the same time. The likelihood of this happening is so small that if you started writing zeros at the beginning of the universe, you'd be nowhere close to having enough of them now. To any significant digits, it's not possible.

[Dark Helmet]

If the original post is asking whether the moon could actually do that with non-zero probability, no one can tell you, since it is really outside the realm where QM predications have and reasonabley could be tested, and would require a theory that fully resolves QM/relativity conflicts, which there is non as of yet.

If you are asking whether pure standard QM would allow that, then the answer is yes.

Treating the moon as a classical system, as the above suggests, would be the usual reasonable thing to do, but the formal theory of QM does not draw a boundary between big and small objects, and if you wanted to give a quantum mechanical description of the moon, you should be able to within the bounds of the theory.

The above posters are correct about the wave function tails of every particle in the moon theoretically extending over all space (QM wave functions ignore special relativity and thus locality + causality. Relativistic Quantum field theory attempts to mesh the two, but again I will assume your question was on standard QM and limit my discussion to that). If the wave function tails extend over all space, then any "observation" of a particle in the moon can collapse (localize) it to any location in space, and with some probability the whole moon could collapse to the other side of the earth, since every particle in it must have wave function probability tails extending everywhere in space. The problem is that standard QM theory does not spell out what constitutes an observation of the moon. There is a large body of philosophical literature on this subject, but the fact is most scientists just ignore it, because they are concerned with making experimentally verifiable predictions, and any experiment yielding data surely constitutes an observation, while any system sheltered from the environment (light, particles etc) in-between measurements is unobserved for as long as it is sheltered. Obviously the moon is not sheltered at all, so it is a safe bet to say it is being observed repeatedly at very close intervals, and thus its wave function is often collapsed and relocalized to where we think it is.

The above people who cite the moon exceeding the speed of light in such an event assume that its location is where we think it is to begin with. In fact, no object under standard QM has a definite location, it only has a probability distribution centered on what we would call its location. The uncertainty principle demands that this is so. So standard QM would allow the moon to hop to the otherside of the earth, but this would violate special relativity if you treat the moon as a classical object. That is one example of the conflicts between relativity and QM.

I have no idea why I just spent the time to write this up.

[Kdmck]

I am the other person involved in this debate. What many of you are confusing is that there is no such thing as a system of particles in QM. There is only one wave equation for a system, not a wave equation for every particle which are then added together. The existence of other particles always shift the nature of any single particle( such as photons tend to move toward eachother, the concept that leads to the technology of lasers) and this is indeed why on large scales the random movements of quantum particles in the moon do truly cancel out to make it impossible for it to quantum jump as a massive object. This concept has been a part of science sinse prior to QM and is the basis of all thermomechanical theory and has never been questioned in respect to the random movement of molecules which still follow absolute deterministic laws( such as entorpy). Another misunderstood idea is that quantum motion is inherently different than "classical motion" as if an electron making a jump from a certain energy state to another is different than the moons orbit. In fact QM teaches us all movement everywhere is only of the quantum jump vairety and for this reason if all the particles in the moon happened to begin to select in a single direction toward the other side of the Earth it would necisarily have the effect of the moon actually beginning to collide with the Earth and the effects of inertia and gravity would force the overall average movement of the moon to remain as it has been for quite some time now. The main point to understand here is that we can not consider any particle as a single entity, this is in fact demanded by QM, instead we can only view every particle of the moon as part of a system which indeed does have 0 probability as a whole to move anywhere but along the path described by general relativity. Any single particle will have some probability to appear in many different seemingly bizarre places, but we must remember this does not mean we can ignore their nature as a whole and hypothesis an extremely minute probablity of the moon itself performing a quantum jump.

[madnak]

Molecules don't follow absolute deterministic laws at all. At least, no such laws that we can identify. You're confusing "function according to deterministic laws so often that it's unlikely any human will ever observe an exception" with "follow deterministic laws in the absolute sense," which is typically a fine distinction and is not one worth making in terms of virtually any realistic application, but it's exactly the point most relevant to this debate.

[Kdmck]

You're misunderstanding determinism here madnak. In reality random behaviour of a particle does not in anyway violate determinism.

QM does show us that on scales approaching the planck length determinism breaks down and behaviour becomes random, but random behaviour on a small level does not imply that determinism fails at all levels.

This is more clearly illustrated by knowledge of thermodynamics. Molecules and atoms vibrate in a totally chaotic way and while you are right we can never absolutely determine the behaviour of any atom at a certain time, we can certainly make absolute mathmatical judgements on the nature of heat transfer for large scale systems according to statistical laws.

Also keep in mind that to say nothing definite and therefore deterministic can be said when there is any factor involved that is random implies there is no possible relevant knowledge to a poker hand while some cards have not been shown as their value is still random and basically discounts the importance of this entire website.

[madnak]

I do actually know some things about both determinism and thermodynamics, so this is a much more comfortable subject. Probabilistic determinism isn't remotely the same as classical determinism, and explicitly allows for situations like the one described in the OP. QM has every appearance of violating classical determinism, and thermodynamics is explicitly probabilistic. In thermodynamics there's always a possibility of virtually everything. This extends to other fields as well, and practically defines chemistry. The entire contemporary concept of entropy is that a system is more likely to be stable than unstable, and most reactions happen because the likelihood of different events evens out.

You seem to be misinterpreting statements of scientific fact and mistaking their context. For example, it's frequently stated that the entropy of a closed system always increases. This is directly untrue. For example, it's often described that the proportion of hydrogen ions in an aqueous solution times the proportion of hydroxide ions is always 10^-14, but it's entirely possible for every water molecule to spontaneously dissociate and for that value to be something like .25 instead. Diffusion across a membrane is another relevant example. It is very possible for diffusion to actually increase the gradient. When statements like "particles always diffuse from areas of high concentration to areas of low concentration" are made, they're designed as generalizations that describe solid trends.

In some cases it's actually possible to measure fluctuations. Diffusion occurs, to put it in simplistic terms, because a molecule on the "full" side is more likely to "bounce" into the "empty" side than vice versa. However, part of the equilibrium is that particles from the "empty" side are constantly crossing over to the "full" side. This is simple to demonstrate using a clear model. Imagine there are 11 molecules of a substance in two compartments separated by a thin membrane permeable to the substance. During most of the time there will be 6 molecules on one side and 5 on the other, but from time to time due to randomness there will be 7 on one side and 4 on the other. If we could run the simulation for an infinite span of time, eventually all 11 molecules would end up on one side of the membrane. The same is theoretically true regardless of the number of molecules.

[ QUOTE ]
does not imply that determinism fails at all levels

[/ QUOTE ]

Nobody is suggesting that determinism fails at all levels for all purposes. The question is whether there is a nonzero chance of a certain occurence, and based on what we know there is. Based on what we know particles appear and disappear at random, which makes virtually anything possible. It's very simple - if all the particles in the universe randomly disappear simultaneously, and then particles of a new universe that fits the specified criteria appear simultaneously, the effect will be achieved.

The usefulness of deterministic thinking is only validated by this fact, as college kid demonstrated in his post.

[ QUOTE ]
we can certainly make absolute mathmatical judgements on the nature of heat transfer for large scale systems according to statistical laws

[/ QUOTE ]

We can reach such conclusions because of the very high probability of certain patterns. If there were no variance statistics wouldn't be relevant - the entire point of statistics as a field is to cope with effective randomness (due either to unknown factors or to true randomness). This is why statistics and probability are frequently taught together.

[ QUOTE ]
Also keep in mind that to say nothing definite and therefore deterministic can be said when there is any factor involved that is random implies there is no possible relevant knowledge to a poker hand while some cards have not been shown as their value is still random and basically discounts the importance of this entire website.

[/ QUOTE ]

This site is based on the fundamental understanding that there is always a nonzero chance of highly unlikely occurences. This is one area where Sklansky is very clear, and it's a concept he emphasizes time and time again. An appropriate approach to poker doesn't typically involve any sense of certainty about which card will show up next (there are obvious exceptions in sets of 1 or possibly 0). The applicable techniques are virtually all based on probabilities - if there is a 39-in-40 chance the gutshot won't come, there is also a 1-in-40 chance that it will. That's how probability works, and you will have to get used to the fact that modern science relies on probability.

[thylacine]

[ QUOTE ]
Just fyi neither of us are very educated in QM. (Obviously)

Is it theoretically possible that the moon could "leap" from its original position to the other side of the earth if it was unobserved? MY understanding is that every particle's wave function in the moon extends (at least) to the other side of the earth, and thus has a non 0 chance of appearing in that location when observed. Given these circumstances it would make it possible but EXTREMELY improbable for every particle in the moon to randomly "select" this area of it's wave function and the moon would materialize on the opposite side of the earth from it's original position.

HIS understanding is that due to how massive the moon is, all the the particles' wave functions essentially cancel themselves out making the position of the moon the only position possible. Basically objects of that size follow the laws of classical physics exactly.

So who is right? Are we both wrong?

Thanks.

[/ QUOTE ]

Define`theoretically possible'.

[arahant]

Looks to me like the only point you guys disagree on is whether 1 in 10^10^10^10^10^10^10^10^10^10^10^10^10^10^10^10^10 ^10^10^10^
10^10^10^10^10^10^10^10^10^10^10^10^10^10^10^10^10 ^10^10^10^
10^10^10^10^10^10^10^10^10^10^10^10^10^10^10^10^10 ^10^10^10^
10^10^10^10^10^10^10^10 = impossible

[GMontag]

[ QUOTE ]
Molecules don't follow absolute deterministic laws at all. At least, no such laws that we can identify.

[/ QUOTE ]

The normal evolution of the quantum wavefunction follows completely deterministic laws. It is only observations that introduce indeterminisms.

[m_the0ry]

[ QUOTE ]
Looks to me like the only point you guys disagree on is whether 1 in 10^10^10^10^10^10^10^10^10^10^10^10^10^10^10^10^10 ^10^10^10^
10^10^10^10^10^10^10^10^10^10^10^10^10^10^10^10^10 ^10^10^10^
10^10^10^10^10^10^10^10^10^10^10^10^10^10^10^10^10 ^10^10^10^
10^10^10^10^10^10^10^10 = impossible

[/ QUOTE ]

It's important to note that in statistics, "impossible" is _defined_ as an event with probability = 0. And as a corrolary, something that is "certain" is _defined_ as having a probability = 1. These numbers are exact. One of the axioms of a quantum system is no event has a probability of 1 or 0.



I also retract my statement about it being impossible on the basis of faster than light information travel. Because each particle is a quantum system entangled with itself, it conveys no information because it is a completely random process (more complicated than stated). This is the same principle as how entangled electron pairs cannot convey FTL information.

[Kdmck]

madnak you are still not understanding what i am intending to say here. The point is not that if a draw is 22-1 it is basically impossible so poker is deterministic, that is nonsense. The idea is that it is totally random what card hits but the probability is exactly 1/23 that the event will occur. While the behaviour for the hand itself is truly indeterminate we can still say that the the +ev of any play can be absolutely determined by understanding the theoretical value of the draw hitting mathematically, represented by the fraction 1/23.

To sum this idea up variance is not contradictory to determinism, rather variance is absolutely required by the determined nature of any system involving probability.

Also to understand the original post it is not true that this event is somewhat possible although unimaginably unlikely. The nature of the moon as an object consisting of so many particles casues overall quantum decoherence, the effect of "observation" described by QM which causes the wave function to remain perpetually collapsed as the moon follows an exact path. Again, any particle considered as an entity in itself will have quite erratic behaviour but once viewed as a part of the system these indeterminincies are not preserved.

YOur idea that entropy doesn't always increase is directly at odds with Sklansky and all rational thought. To use poker as the easiest example, when AA is against 22 it is always the winning hand. We all recognize that 22 wins on occasion but we understand that this is not a threat to the previous statement that AA is always winning against 22. By analogy we understand that it is indeed absolutely true entropy is always increasing in a closed system and the examples you have given are purely required variance of this process.

In conclusion I must stress the point again that statistics is not an indeterminate science of chance but rather statistics is an exact science of the nature of random events. Random events are in no way threats to determinism unless we believe there is no theoretical mathematical trend that they necisarily follow. In this way Thermodynamics and QM are seen as definitely rescuing science from indeterminism.

[GMontag]

[ QUOTE ]
[ QUOTE ]
Looks to me like the only point you guys disagree on is whether 1 in 10^10^10^10^10^10^10^10^10^10^10^10^10^10^10^10^10 ^10^10^10^
10^10^10^10^10^10^10^10^10^10^10^10^10^10^10^10^10 ^10^10^10^
10^10^10^10^10^10^10^10^10^10^10^10^10^10^10^10^10 ^10^10^10^
10^10^10^10^10^10^10^10 = impossible

[/ QUOTE ]

It's important to note that in statistics, "impossible" is _defined_ as an event with probability = 0. And as a corrolary, something that is "certain" is _defined_ as having a probability = 1. These numbers are exact. One of the axioms of a quantum system is no event has a probability of 1 or 0.

[/ QUOTE ]

I'm not sure where you got that from, but that certainly is not an axiom of QM. The probability of finding a particle at a point where the magnitude of it's wavefunction is 0 (and that's a lot of places) is 0.

[ QUOTE ]
I also retract my statement about it being impossible on the basis of faster than light information travel. Because each particle is a quantum system entangled with itself, it conveys no information because it is a completely random process (more complicated than stated). This is the same principle as how entangled electron pairs cannot convey FTL information.

[/ QUOTE ]

Your original objection was correct. An observation collapses the wavefunction of the observed particle. After that, the wavefunction starts to expand outwards again, but not faster than c.

[CityFan]

[ QUOTE ]
madnak you are still not understanding what i am intending to say here. The point is not that if a draw is 22-1 it is basically impossible so poker is deterministic, that is nonsense. The idea is that it is totally random what card hits but the probability is exactly 1/23 that the event will occur. While the behaviour for the hand itself is truly indeterminate we can still say that the the +ev of any play can be absolutely determined by understanding the theoretical value of the draw hitting mathematically, represented by the fraction 1/23.

To sum this idea up variance is not contradictory to determinism, rather variance is absolutely required by the determined nature of any system involving probability.

Also to understand the original post it is not true that this event is somewhat possible although unimaginably unlikely. The nature of the moon as an object consisting of so many particles casues overall quantum decoherence, the effect of "observation" described by QM which causes the wave function to remain perpetually collapsed as the moon follows an exact path. Again, any particle considered as an entity in itself will have quite erratic behaviour but once viewed as a part of the system these indeterminincies are not preserved.

YOur idea that entropy doesn't always increase is directly at odds with Sklansky and all rational thought. To use poker as the easiest example, when AA is against 22 it is always the winning hand. We all recognize that 22 wins on occasion but we understand that this is not a threat to the previous statement that AA is always winning against 22. By analogy we understand that it is indeed absolutely true entropy is always increasing in a closed system and the examples you have given are purely required variance of this process.

In conclusion I must stress the point again that statistics is not an indeterminate science of chance but rather statistics is an exact science of the nature of random events. Random events are in no way threats to determinism unless we believe there is no theoretical mathematical trend that they necisarily follow. In this way Thermodynamics and QM are seen as definitely rescuing science from indeterminism.

[/ QUOTE ]

Sit down man, you're a tragedy.

[madnak]

[ QUOTE ]
[ QUOTE ]
Molecules don't follow absolute deterministic laws at all. At least, no such laws that we can identify.

[/ QUOTE ]

The normal evolution of the quantum wavefunction follows completely deterministic laws. It is only observations that introduce indeterminisms.

[/ QUOTE ]

You and K are making this claim, but I'm not buying it. Until Metric chimes in, or until your view becomes the majority position here (among those without a vested interest) I'm going to have to assume that what I've been told (by laymen but also some physicists) is correct.

I admit my sample size in terms of actual physicists is small. So, Metric?

[madnak]

[ QUOTE ]
The idea is that it is totally random what card hits but the probability is exactly 1/23 that the event will occur.

[/ QUOTE ]

Again, probabilistic determinism is different from classical determinism. Your position in this thread is that the probability of the moon displacing is exactly 0. That's the relevant question. There's a qualitative different between a "probability of 0" and a "probability so so small we can't express it."

[ QUOTE ]
To sum this idea up variance is not contradictory to determinism, rather variance is absolutely required by the determined nature of any system involving probability.

[/ QUOTE ]

Again, the terms are well-defined (http://en.wikipedia.org/wiki/Determinism). This strikes me as semantic. If you're talking about probabilistic determinism, then I don't see the subject as relevant. If you're talking about classical determinism, then you're wrong.

[ QUOTE ]
Also to understand the original post it is not true that this event is somewhat possible although unimaginably unlikely. The nature of the moon as an object consisting of so many particles casues overall quantum decoherence, the effect of "observation" described by QM which causes the wave function to remain perpetually collapsed as the moon follows an exact path. Again, any particle considered as an entity in itself will have quite erratic behaviour but once viewed as a part of the system these indeterminincies are not preserved.

[/ QUOTE ]

I know we have to discard our normal assumptions when looking at fundamental physics. I'm comfortable with the idea that this may even extend to a conception of reality that is not reductionistic, in which the properties of "large" objects can't actually be described in terms of their constituent elements. I know that regarding what I've personally studied (primarily biology) things "make more sense" - the properties of human beings ultimately emerge from the molecules that compose them. If the ideas I've been exposed to aren't analogous to the ideas you're trying to express, you will probably have to explain them at a more basic level before I'll follow you.

[ QUOTE ]
YOur idea that entropy doesn't always increase is directly at odds with Sklansky and all rational thought. To use poker as the easiest example, when AA is against 22 it is always the winning hand. We all recognize that 22 wins on occasion

[/ QUOTE ]

I'm pointing out that the free energy of a closed system may spontaneously increase on occasion. I don't see how this isn't analogous the the statement that 22 wins on occasion. A decrease in entropy is a necessary consequence of such an increase in free energy, so my statement is valid.

[ QUOTE ]
but we understand that this is not a threat to the previous statement that AA is always winning against 22

[/ QUOTE ]

Not if the river has come and the board is 2237K. Am I missing something? I don't think AA is winning here. In fact, I think AA has been losing since the flop.

[Metric]

[ QUOTE ]
[ QUOTE ]
[ QUOTE ]
Molecules don't follow absolute deterministic laws at all. At least, no such laws that we can identify.

[/ QUOTE ]

The normal evolution of the quantum wavefunction follows completely deterministic laws. It is only observations that introduce indeterminisms.

[/ QUOTE ]

You and K are making this claim, but I'm not buying it. Until Metric chimes in, or until your view becomes the majority position here (among those without a vested interest) I'm going to have to assume that what I've been told (by laymen but also some physicists) is correct.

I admit my sample size in terms of actual physicists is small. So, Metric?

[/ QUOTE ]

Yes, evolution of a quantum system is deterministic (unless you model loss of coherence caused by interaction with an unknown environment -- but this is not really the issue here). If you have complete knowledge of the state of a closed quantum system, it will evolve deterministically to one and only one state for each future time.

That is, until you look at it, at which time the system jumps to one of many possible states. At least, this is the standard historical view of quantum mechanics. There are some more modern pictures in which the measurement process is also unitary, and it is only the information gained by the observer which is probabilistic. (I heartily endorse this new information theoretic approach, btw -- it gets rid of a lot of the "weirdness" of quantum theory, and is actually more general than the old formalism)

As for the moon question, the answer depends on the state of the system. It's not at all clear to me that the state of the moon has a nonvanishing component on the other side of the earth. If it did, then yes -- there would be a small probability to observe it there. But I don't know the exact quantum mechanical state of the moon.

[m_the0ry]

[ QUOTE ]
[ QUOTE ]
It's important to note that in statistics, "impossible" is _defined_ as an event with probability = 0. And as a corrolary, something that is "certain" is _defined_ as having a probability = 1. These numbers are exact. One of the axioms of a quantum system is no event has a probability of 1 or 0.

[/ QUOTE ]

I'm not sure where you got that from, but that certainly is not an axiom of QM. The probability of finding a particle at a point where the magnitude of it's wavefunction is 0 (and that's a lot of places) is 0.


[/ QUOTE ]

[/ QUOTE ]

I don't really know what I was trying to say here and I agree it's mostly wrong.

[ QUOTE ]
[ QUOTE ]
I also retract my statement about it being impossible on the basis of faster than light information travel. Because each particle is a quantum system entangled with itself, it conveys no information because it is a completely random process (more complicated than stated). This is the same principle as how entangled electron pairs cannot convey FTL information.

[/ QUOTE ]

Your original objection was correct. An observation collapses the wavefunction of the observed particle. After that, the wavefunction starts to expand outwards again, but not faster than c.

[/ QUOTE ]

Much better way of phrasing what I was saying before, I'm pretty confused on this subject and I can see how my original objection was right.



As for the argument about determinism; classical determinism is the concept that given a set of initial conditions and a perfect model, the entire universe and time in all directions would be dictated exactly by the model. This is why classical determinism is fundamentally a different concept than probabalistic determinism - in the latter the best we can say is "X% of the time one of our systems behaves this way, 1-X% of the time it does something else." This means that for each random element, new models must dictate each possible outcome rather than a single (deterministic) outcome.

[Kdmck]

madnak familiarize yourself with the idea of quantum decoherence because you are missing this concept in your statement that the moon can indeed quantum jump at a non zero probability. The nature of large systems of particles is that their wave functions combine to collapse the probability of the system as a whole to move anywhere other than as defined by general relativity to 0(this is not a conclusion that can be mathematically verified by QM at this time as far as I'm aware but the overwhelming success of GR should allow us to assume that any correct theory of QM would have this result at very large scales, for now our understanding of decoherence is simply that any interaction of a closed system with a relativly complex environment causes wave function collapse). Also understand I do not disagree with your ideas about entropy and other statistics but hope you can grasp that the idea of classical determinism isnt true or false it is meaningless as QM dictates to us probability is the only reality of our universe. Statistical derminism is the only meaningful kind and is absolutely necisary as defined by QM.

As regarding to your statement AA loses to 22 in some situations this is of course true but you are failing to grasp the more important connection that despite this when AA gets in preflop against 22 it is always winning by a definite edge at this time. This notion of exact reality despite random future events is what allows us to grasp the definite nature of the motion of the moon despite the complete chaos of all of its particles.

[m_the0ry]

Kdm I don't see how you could make a claim connecting Wave functions to GR because that implies you are certain of some kind of Grand Unified Theory, which as far as I know scientists around the world are still searching frantically for. You acknowledge this in a way but if there is no rigor to the theory then it doesn't lead to any realistic conclusion.

[Kdmck]

my only point is that quantum effects are drowned out by interaction with the environment in a process known as quantum decoherence. As to the exact mathmatecal description of the moon's motion when the total collapsed wave function of all its particles is considered we have no idea but again the success of GR demands that when we are able to understand the path of the moons orbit in a quantum mechanical way it is a very close approximation of the motion predicted by GR, just as classical mechanical laws are easily derived from GR when c is assumed to be infinite.

Edit: to sum my point i simply mean that large scale quantum effects will of course have to be verified by empirical evidence, this evidence is best approximated currently by GR and that is the basis of my statement.

[John21]

[ QUOTE ]
As regarding to your statement AA loses to 22 in some situations this is of course true but you are failing to grasp the more important connection that despite this when AA gets in preflop against 22 it is always winning by a definite edge at this time. This notion of exact reality despite random future events is what allows us to grasp the definite nature of the motion of the moon despite the complete chaos of all of its particles.

[/ QUOTE ]

Effects are deterministic.
Predictions are probabilities.

When you shuffle and cut the deck, only one card can be on top (effect/determinism) however it's possible for one of 52 cards to be on top (prediction/probability). QM is a predictive model, it's not reality.

[Skidoo]

[ QUOTE ]
Effects are deterministic.
Predictions are probabilities.

[/ QUOTE ]

How could you discover that a given effect is deterministic if your only predictions of its outcomes are probabilistic?

[Kdmck]

The major failure to grasp the inherent ideality of probability is dissapointing to me as it should be obvious to anyone familiar with this forum. The notion that an observed state of a particle is more of a "reality" than its probabilistic wave function is very simply a case of being results oriented.

[John21]

[ QUOTE ]
[ QUOTE ]
Effects are deterministic.
Predictions are probabilities.

[/ QUOTE ]

How could you discover that a given effect is deterministic if your only predictions of its outcomes are probabilistic?

[/ QUOTE ]

I get your point, but observation is where the uncertainty lies, not with reality. If we know with certainty, which I claim we could, the state of the deck before it's cut, and know where it's cut - the outcome is completely deterministic. In other words, information depravation necessitates a probability model. But it still remains a model.

[John21]

[ QUOTE ]
The major failure to grasp the inherent ideality of probability is dissapointing to me as it should be obvious to anyone familiar with this forum. The notion that an observed state of a particle is more of a "reality" than its probabilistic wave function is very simply a case of being results oriented.

[/ QUOTE ]

A probabilistic model will never be able to coalesce with an observational model regardless of their inherent correspondence, they're water and oil. That's the problem, or to use your terms, "ideality" is not, "reality".

I understand how your argument plays out, but here's my contention: there is not one observed situation where we have complete knowledge of states, that a non-deterministic outcome results. I'm aware of "uncertainty," however this only applies to dynamic situations, and there are plenty of static situations to observe where uncertainty does not apply (my earlier example of the state of a deck of cards). Obviously, I can't refute randomness, but I really can't understand why determinism isn't acknowledged when there is actual support for the argument, just because it is in conflict with a "model".

I have no problem with someone claiming that, "the ideal is real," my problem is when someone wants to have their cake and eat it too. To me they both exist. We can't come to a knowing of the ideal without the real, and we can't determine the real, without the ideal.

[madnak]

[ QUOTE ]
Yes, evolution of a quantum system is deterministic (unless you model loss of coherence caused by interaction with an unknown environment -- but this is not really the issue here). If you have complete knowledge of the state of a closed quantum system, it will evolve deterministically to one and only one state for each future time.

That is, until you look at it, at which time the system jumps to one of many possible states. At least, this is the standard historical view of quantum mechanics. There are some more modern pictures in which the measurement process is also unitary, and it is only the information gained by the observer which is probabilistic. (I heartily endorse this new information theoretic approach, btw -- it gets rid of a lot of the "weirdness" of quantum theory, and is actually more general than the old formalism)

As for the moon question, the answer depends on the state of the system. It's not at all clear to me that the state of the moon has a nonvanishing component on the other side of the earth. If it did, then yes -- there would be a small probability to observe it there. But I don't know the exact quantum mechanical state of the moon.

[/ QUOTE ]

Thanks for responding, it's always enlightening. It seems like this is the best answer wé'll get regarding the original question.

[madnak]

[ QUOTE ]
The major failure to grasp the inherent ideality of probability is dissapointing to me as it should be obvious to anyone familiar with this forum. The notion that an observed state of a particle is more of a "reality" than its probabilistic wave function is very simply a case of being results oriented.

[/ QUOTE ]

I thought the point you were making was that wave functions don't actually represent probabilities, but just that we can best describe them probabilistically. In a system where one state has a probability of 1 and all others have a probability of 0, is the mechanism really probabilistic? And this is exactly the kind of system you're suggesting the moon represents, correct?

Reading the wiki article on decoherence, it sounds to me as though the wave function itself is a more accurate representation of the (deterministic) nature of reality than the observations we've taken after the collapse of that wave function. Can't it be argued that the universe really is deterministic, and the probabilistic elements of the observable data are deterministically generated (but not predictable)?

It seems like that's what John is saying (correct me if I'm wrong).

[Kdmck]

I'd like to clarify for you John, I am definitely arguing in favor of determinism. In fact determinism and uniformity of nature must be assumed for any scientific investigation and so for a scientific theory to "disprove" determinism is nonsensical.

The fact that there is discontinuity and randomness at the most minute levels is really the less bizarre discovery as the only other possibility is that particles and motion can continue to get smaller "forever", an idea which is absolutely inconceivable.

The main concept I have been trying to convey, which seems to be misunderstood most likely because I am failing to explain it clearly, is that the random chaotic nature of elementary particles is not in anyway necisarily translated into large scale phenomena such as the orbit of the moon. If there is still any confusion as to how totally random elements combine to create non-random definite results it is easier to understand this by studying thermodynamics or poker or any other example of statistics.

The common notion that there is some slight probability that the moon can quantum jump is an intentionally narrow sighted view of QM where we choose to view every particle independently to produce definitely false results to make science seem more bizarre and anyone who does enough research will understand QM in no way allows this.


Also keep in mind that if we are to hypothesis a situation where the moon falls toward the Earth, this would of course happen by way of quantum jumps as this is the only motion we have ever observed in the Universe and the result of this would not be the moon ended up on the other side, it would be a much more unpleasant conclusion for us.

[arahant]

[ QUOTE ]
If there is still any confusion as to how totally random elements combine to create non-random definite results it is easier to understand this by studying thermodynamics

[/ QUOTE ]
I don't understand why you are missing this point. As madnak pointed out, thermodynamics does NOT create definite results. It creates statistical results.

The entropy of a system does NOT always increase, period. There is no known mechanism by which the 'randomness' disappears. It merely gets drowned out. If you believe that there are 'definite' results in thermodynamics, then this is the root of your misunderstanding.

Decoherence in QM is a similar phenomenon. The states of individual particles become entangled with their environment rapidly and randomly, resulting in APPARENT wave-function collapse. All that happens is that the 'quantum' effects become so exceedingly unlikely so quickly, that they are unmeasurable. Mathematically, they remain completely possible, but gagillions of times less likely than the spontaneous ordering of a gas, for example.

[Kdmck]

arahant do not mistake what I'm saying, I completely understand that no particle has definite motion in any thermodynamic system. The more important concept though is that the average rate of heat transfer is a constant. Now yes this is a result only on "average" and does not hold in every instance, but this does not make it non-deterministic or inexact. The average rate of heat transfer is very much an exactly calculated result that is necissarily proved by our theoretical knowledge of atomic motion.

Now this theoretical knowledge does not disprove the correctness of your statement that every atom's motion is totally chaotic, but it does prove it to be short sighted as a complete understanding of heat. But the point where you make an error is when you say quantum mechanics and thermodynamics are indeterminate or inexact sciences, on the contrary these are the very mathematical concepts that enlighten us to what the actual average behaviour of particles or atoms is.

So then there are two ways of viewing the Universe, in ignorance of statistics believing that variance is more real than the proposed theoretical motion, or enlightened by statistics understanding theoretical laws to be the only reality accessible to intelligent beings. The theories of QM Thermodynamics and TwoPlusTwo all belong to this second group which rests completely on the assumption of determinism and uniformity in nature.

[m_the0ry]

[ QUOTE ]
arahant do not mistake what I'm saying, I completely understand that no particle has definite motion in any thermodynamic system. The more important concept though is that the average rate of heat transfer is a constant. Now yes this is a result only on "average" and does not hold in every instance, but this does not make it non-deterministic or inexact. The average rate of heat transfer is very much an exactly calculated result that is necissarily proved by our theoretical knowledge of atomic motion.

[/ QUOTE ]

I see what you're trying to say about how statistical representation is as high resolution as our understanding of physics can get, and I also see that decoherence leads the random degrees of freedom in a macroscopic object is necessarily meaningless.

But that doesn't change the fact that a mean of random variables over any quantized sample size is also a random variable. And in that sense it is completely nondeterministic. For example if we measure mean particle velocity over a discrete period of time but with an infinite number of samples, we will have means that assume every possible concievable value, and for which there is no method to predict which mean will be measured next (as it is necessarily a random variable).

[Skidoo]

[ QUOTE ]
[ QUOTE ]
[ QUOTE ]
Effects are deterministic.
Predictions are probabilities.

[/ QUOTE ]

How could you discover that a given effect is deterministic if your only predictions of its outcomes are probabilistic?

[/ QUOTE ]

I get your point, but observation is where the uncertainty lies, not with reality.

[/ QUOTE ]

What reality exists without observation, scientifically speaking?

[m_the0ry]

We're basically discussing localism versus realism which is an epic and unsolvable problem unless you're a physics prodigy.

[Skidoo]

[ QUOTE ]
We're basically discussing localism versus realism which is an epic and unsolvable problem unless you're a physics prodigy.

[/ QUOTE ]

Sorry, are you trying to communicate something beyond the obvious?

[GMontag]

[ QUOTE ]
Can't it be argued that the universe really is deterministic, and the probabilistic elements of the observable data are deterministically generated (but not predictable)?

[/ QUOTE ]

Isn't that a contradiction in terms? Or do you just mean not practically predictable, ala non-linear systems like the weather?

[Duke]

I saw it happen for 1/100000th of a second earlier today. So it's possible, but it's probably not going to happen again before the universe ends.

[John21]

[ QUOTE ]
[ QUOTE ]
[ QUOTE ]
[ QUOTE ]
Effects are deterministic.
Predictions are probabilities.

[/ QUOTE ]

How could you discover that a given effect is deterministic if your only predictions of its outcomes are probabilistic?

[/ QUOTE ]

I get your point, but observation is where the uncertainty lies, not with reality.

[/ QUOTE ]

What reality exists without observation, scientifically speaking?

[/ QUOTE ]

Consciousness?

I took a detour down the Quantum Consciousness road: Penrose, Bohm, Chalmers, et al

Quantum Consciousness - Overview (http://www.quantumconsciousness.org/overview.html) <font color="brown">The boundary between the quantum and classical worlds is unclear, and the transition between the two is commonly described as quantum state reduction, collapse of the wave function, or decoherence. Although quantum effects generally occur at small scales there is no apparent transition or cutoff due to size or scale, no absolute reason why large objects may not be in superposition...

Consciousness is thus a sequence of discrete events, arising from alternating phases of 1) isolated quantum coherent superposition (in which microtubule quantum states are isolated by actin gelation), and 2) classical input/output in which microtubule information communicates with the non-conscious portions of the brain, nervous system and outside world. The alternating phases correspond with brain neurophysiology, e.g. the well known "40 Hz" gamma EEG oscillations.
</font>

Quantum Consciousness? Check your tired old assumptions at the door (Tucson Weekly) (http://www.quantumconsciousness.org/media/quantum.html) <font color="brown"> In the Penrose-Hameroff model, which they call "orchestrated objective reduction" ("Orch OR"), quantum computation occurs in cytoskeletal microtubules within the brain's neurons, and here comes the new and truly weird part links cognition with proto-conscious experience and Platonic values embedded in spacetime geometry.

"The basic idea," Hameroff says, "is that consciousness involves brain activities coupled to self-organizing ripples in fundamental reality."

Or, to put it another way, while the brain simulates reality based on sensory input, maybe it's also intimately connected to that reality at the quantum level remember those photons that seem to communicate without any apparent means of doing so?

</font>

[madnak]

[ QUOTE ]
[ QUOTE ]
Can't it be argued that the universe really is deterministic, and the probabilistic elements of the observable data are deterministically generated (but not predictable)?

[/ QUOTE ]

Isn't that a contradiction in terms? Or do you just mean not practically predictable, ala non-linear systems like the weather?

[/ QUOTE ]

I mean there may be factors involved that we will never be able to observe (or even know about).

[gumpzilla]

[ QUOTE ]


Yes, evolution of a quantum system is deterministic (unless you model loss of coherence caused by interaction with an unknown environment -- but this is not really the issue here).

[/ QUOTE ]

Actually, I think this is the issue. The moon is a large enough object that it's going to lose quantum coherence very rapidly, according to current thinking. Once that happens, it behaves classically, where it's just going to keep on doing its classical dynamics thing. The loss of coherence through interaction with the rest of the world can be thought of, in some sense, as a continuous measuring process.

I know there are some authors who feel that the decoherence argument seems like a giant copout. But, to me, it's a pretty satisfying resolution to the old problem of why macroscopic objects behave classically despite a sea of microscopic constituents that evolve according to QM.

[Metric]

I did not mean to suggest that the moon is not undergoing decoherence -- it certainly is. Even if the moon was in a giant insulating box, its gravitational interaction with the earth alone would cause its state to lose coherence very quickly. The only point I was trying to drive home was that quantum systems do evolve deterministically, unless affected by outside influences over which we have no control -- just as classical systems do.

[Kdmck]

[ QUOTE ]
But that doesn't change the fact that a mean of random variables over any quantized sample size is also a random variable. And in that sense it is completely nondeterministic. For example if we measure mean particle velocity over a discrete period of time but with an infinite number of samples, we will have means that assume every possible concievable value, and for which there is no method to predict which mean will be measured next (as it is necessarily a random variable).

[/ QUOTE ]


I address this issue in my previous post, the mean value is impossibly determined through empirical observation alone. Despite this, it can be exactly determined by mathematical formulas.

If we deal out 100 hands as a 3-1 underdog and with 20 of them we don't decide we were actually a 4-1 underdog, the predicted value always has more reality than the results.

[Skidoo]

[ QUOTE ]
the mean value is impossibly determined through empirical observation alone. Despite this, it can be exactly determined by mathematical formulas.

[/ QUOTE ]

You're describing a theoretical determination without a corresponding experimental result.