Can Quantum Weirdness Be Logically Predicted?

[David Sklansky]

One of the reasons I and many others reject the "just look around you" argument of Not Ready and others as some type of evidence for a superior being, is that we know that (aside from possibly human consciousness)the seeming magnificence of the Earth is mainly a simple consequence of Newton's laws and fractal geometry.

Furthermore, there is no reason to claim that Newton's Laws were created by this superior being. Because they are basically pure logical common sense. The Inverse Square law, the Law of the Lever, d=gtsquared, F= ma. All these experimental results are not the least bit surprising if you use logical thought. Even much of Einstein's stuff, I believe is a pretty straightforward deduction from the fact that the speed of light is constant.

What I would like to know however is if the strange things about particles that our experiments show, is a logical consequence of anything that makes common sense. I know the equations of quantum theory predict these results. But is their some underlying logical basis for them? In other words was there any way to logically guess that light would behave as a particle when observed but not otherwise or that a radioctive particle would have a 50% chance of decaying in x years regardless of how long it has already gone without decaying. Do results like these follow straighjtforwardly from any assumptions that are commonsensically reasonable? (For example might quantum randumness be necessary for humans to have free will?)

[halt i am reptar]

[ QUOTE ]
Furthermore, there is no reason to claim that Newton's Laws were created by this superior being. Because they are basically pure logical common sense. The Inverse Square law, the Law of the Lever, d=gtsquared, F= ma. All these experimental results are not the least bit surprising if you use logical thought

[/ QUOTE ]

I see it as the inverse. Those laws have always been constant to us, before we even knew conscious reasoning, and thus it is now "common sense."

[David Sklansky]

I don't want to get into a religious debate about whether God created the laws of logic. My question is about quantum theory. If in fact it doesn't follow logically from anything reasonable, you could use that fact much more forcefully in any god exists arguments, than simply asserting that he created math and logic.

[halt i am reptar]

You're right. And I definitely did not mean to imply that I am saying God made logic/order, and I am not trying to spark another religious debate. I'm sorry to have taken away from the question at hand.

My guess is that a logical conclusion of these properties exists, just has not yet been found. Dipping into another thread, these underlying causes give great moment to studying extremely advanced physical sciences before we even fully grasp them. I think that these studies are just so young that we don't see an easy deduction yet. What were people thinking 500 years ago when gravity was first being explored and defined (differing masses falling at the same rate!)? Unbeknownst to the people of the times, the mass of the earth is so immense, that the relative mass of the other bodies was negligible (ha, I think, right?). I feel like we'll fall into that category once we have unveiled more completely what governs quantum physics.

[LuckOfTheDraw]

David,

What I believe (and what I think reptar was trying to say) is that the actual physics of our macro world are the basis for both scientific laws (ie Newton's and Einstein's laws) and human common sense. In other words, our scientific observations and henceforth laws of physics are consistent with logical common sense because they are both dervied from what surrounds us and is obvious.

On the other hand, most modern physicists agree that the governing phsycical rules of the quantum world are radically different than the rules of our macro world. So, to answer your question, while I think there should be reasoning to quantum mechanics, it probably won't coincide with our notions of logic and common sense.

[LuckOfTheDraw]

[ QUOTE ]
What were people thinking 500 years ago when gravity was first being explored and defined (differing masses falling at the same rate!)? Unbeknownst to the people of the times, the mass of the earth is so immense, that the relative mass of the other bodies was negligible (ha, I think, right?

[/ QUOTE ]

Actually, no.
F=ma
F(of gravity on falling object) = m(of falling object) a(acceleration of falling object)

F(of gravity on falling object) = g(gravitational constant)*M(of earth)*m(of falling object)/d(distance between center of gravities)^2

set F = F

g*M*m/d^2 = ma

m = mass of the falling object is on both sides of the equation and cancels itself out.

[halt i am reptar]

check.

[JMAnon]

[ QUOTE ]
Furthermore, there is no reason to claim that Newton's Laws were created by this superior being. Because they are basically pure logical common sense. The Inverse Square law, the Law of the Lever, d=gtsquared, F= ma. All these experimental results are not the least bit surprising if you use logical thought.

[/ QUOTE ]

I know this isn't the thrust of your post, but I don't follow your point. Newton's laws can't be derived from pure logic; they are the result of logic applied to sensory experience. Newton's laws work to describe what we observe in our physical universe. But there is no logical reason why the universe couldn't have different physical properties.

For example, why is gravity "common sense?" I can imagine a universe in which massive objects repel each other at a distance rather than attract each other. I can also imagine a universe in which massive objects have no effect on each other from a distance. Maybe intelligent beings could not exist in such universes, but there is no logical reason why the universes themselves couldn't exist. We don't know why gravity exists in this universe; we just know that it does. In other words, pure logic does not tell us that there must be gravity in our universe, only that there is gravity based on what we see happening around us. If you think about it, gravity is quite wierd. Why do massive objects affect each other at a distance, even with a vacuum in between? Gravity only seems like common sense because we learned of it as children and it comports with our experiences.

Quantum wierdness is no different than gravity, in my view. We just have less experience with it. We have had the technological capability to observe tiny particles for only a relatively short time. As we continue to apply logic to our experiences with tiny particles, our understanding will grow, and their behavior will begin to seem every bit as much "common sense" as gravity seems to us now.

[GMontag]

[ QUOTE ]
[ QUOTE ]
What were people thinking 500 years ago when gravity was first being explored and defined (differing masses falling at the same rate!)? Unbeknownst to the people of the times, the mass of the earth is so immense, that the relative mass of the other bodies was negligible (ha, I think, right?

[/ QUOTE ]

Actually, no.
F=ma
F(of gravity on falling object) = m(of falling object) a(acceleration of falling object)

F(of gravity on falling object) = g(gravitational constant)*M(of earth)*m(of falling object)/d(distance between center of gravities)^2

set F = F

g*M*m/d^2 = ma

m = mass of the falling object is on both sides of the equation and cancels itself out.

[/ QUOTE ]

The OP was right. Your equations only work when one object is much smaller than the other and can ignore the acceleration of the larger object (i.e the Earth). Otherwise you have to add in the acceleration of the Earth from the gravity of the object.

The equation ends up being G(M+m)/d^2 = a, where a is the acceleration of one object as seen from the surface of the other object.

[Matt R.]

Meh. I was hoping someone would respond to David's questions about QM, as I've been wondering this myself for quite some time. I made a post sometime back positing this:

"(For example might quantum randumness be necessary for humans to have free will?)"

but got no reply. Well, I got 2 replies, but they seemed to think that the reverse was true -- the weirdness of QM negates free will. There was no discussion and I don't understand how they came to this conclusion. I find the topic fascinating and I hope someone can address this.

I think it has been posted on here (I didn't actually read the paper that was linked) that a lot of the non-deterministic nature of quantum mechanics isn't due to some fundamental property of nature, but rather a consequence of our measurements. I think the gist of it was that if we could somehow perfectly measure everything about a quantum system, it would be fundamentally deterministic just like the macroscopic world that we observe. I think Metric was the first person to bring this up on here. Of course this is one of many interpretations of QM, and I haven't studied the subject in depth so I can't give an opinion on which I think is right.

Actually, I would speculate that we would need some sort of accurate unified field theory before we can truly speculate on whether quantum mechanics can be derived logically, or it just "is". From my perspective, it seems to be more of the latter; it just seems too weird to me, and I would think that you cannot "look deeper" than fundamental particles to somehow predict how they should act. Basically, you have to start your assumptions about physical law from somewhere, and elementary particle physics would seem to be the logical choice. I'm definitely rambling right now though, and I don't really know enough on the subject to give any definite opinion.

[LuckOfTheDraw]

[ QUOTE ]
[ QUOTE ]
[ QUOTE ]
What were people thinking 500 years ago when gravity was first being explored and defined (differing masses falling at the same rate!)? Unbeknownst to the people of the times, the mass of the earth is so immense, that the relative mass of the other bodies was negligible (ha, I think, right?

[/ QUOTE ]

Actually, no.
F=ma
F(of gravity on falling object) = m(of falling object) a(acceleration of falling object)

F(of gravity on falling object) = g(gravitational constant)*M(of earth)*m(of falling object)/d(distance between center of gravities)^2

set F = F

g*M*m/d^2 = ma

m = mass of the falling object is on both sides of the equation and cancels itself out.

[/ QUOTE ]

The OP was right. Your equations only work when one object is much smaller than the other and can ignore the acceleration of the larger object (i.e the Earth). Otherwise you have to add in the acceleration of the Earth from the gravity of the object.

The equation ends up being G(M+m)/d^2 = a, where a is the acceleration of one object as seen from the surface of the other object.

[/ QUOTE ]

You're correct. My equations only work when the acceleration of the Earth is neglected. I actually misinterpreted the meaning behind the OP's statement. I basically just repeated what he said. Sorry reptar.

[Metric]

I tend to disagree that the condition of the universe is logically inevitable (even given the specific dynamical laws), but the most relevant passage I am aware of regarding your specific question is a paragraph from a paper by Christoph Adami called "The Physics of Information." (Google will take you to the paper, if you are interested in more details)

"This nonseparability of a quantum system and the device measuring it is at the heart of all quantum mysteries. Indeed, it is at the heart of quantum randomness, the puzzling emergence of unpredictability in a theory that is unitary, i.e., where all probabilities are conserved. What is being asked here of the measurement device, namely to describe the system Q, is logically impossible because after entanglement the system has grown to QA. Thus, the detector is being asked to describe a system that is larger (as measured by the possible number of states) than the detector, and that includes the detector itself. This is precisely the same predicament that befalls a computer program that is asked to determine its own halting probability, in Turing’s famous Halting Problem analogue of Godel’s Incompleteness Theorem. Chaitin showed that the selfreferential nature of the question that is posed to the program gives rise to randomness in pure Mathematics. A quantum measurement is self-referential in the same manner, since the detector is asked to describe its own state, which is logically impossiblek. Thus we see that quantum randomness has mathematical (or rather logical) randomness at its very heart."

[Nielsio]

To answer your question: no, you cannot prove 'uncausality'. But to get to the real matter: there is no theory of 'god'. Religion has nothing to do with knowledge. Belief is a complex as a means to survive trauma. http://www.freedomainradio.com/Traffic_Jams/how_to_control_a_human_soul.mp3 .

[uDevil]

[ QUOTE ]
Even much of Einstein's stuff, I believe is a pretty straightforward deduction from the fact that the speed of light is constant.

[/ QUOTE ]

They are deductions from the ASSUMPTION that the speed of light is constant. It may be a common sense assumption, but there is also evidence that it is wrong-- the speed of light and other physical constants may have changed over time.

If you demand that nature follow common sense, you're headed down a very dark road.

[Jordan Olsommer]

[ QUOTE ]
For example might quantum randumness be necessary for humans to have free will?

[/ QUOTE ]

Yes, in the sense that violating the known laws of physics in some way is necessary for human beings to have free will.

The argument that free will is located in the quantum world is logically equivalent to the supernatural argument. God gives us free will = quantum spookiness gives us free will. Neither argument is supported by evidence, and even then the "quantum free will" argument seems worse; I can imagine a world in which a supernatural being has given humans free will, but I can't imagine one in which we control every seemingly random blip of every subatomic particle and yet somehow manage to get billions and billions of them to coordinate in such a way as to make certain neurons fire in certain patterns.

And even if we could control quantum spookiness (very doubtful) and even if we could use that control to control neurons (more doubtful still), why only certain groups of neurons? If you control quantum spookiness within your own head, why wouldnt you be able to precisely control things like your heart rate, your disposition, or your level of self-esteem? Why on earth would some people with certain neurological maladies be born with what any reasonable person would describe as "less" free will than others if the free will were "out there" in the world of quantum mechanics and not simply a construct or post-hoc confabulation in the brain itself?

Free will is a wonderful model that helps us go about living our lives and keeps us from despair (believing that our lives have meaning and thus implictly rejecting what Camus called "the absurd" is another one), but that's all it is as far as empirical science is concerned.

Again, it's the exact same thing as the God gives us free will argument - sure, it's possible, but to the best of my knowledge it has no basis in fact.

[Piers]

I suspect that you’re chasing a red herring.

The elegance of Newtonian and Eienstinean Physics and the weirdness of Quantum Mechanics are in my opinion a consequence of the way the relevant theories were developed.

Newtonian Mechanics is elegant, not because nature is, but because we like to create elegant deductive models of the universe. These theories are designed to fit us.

I take it as established that we will never understand the full nature of the universe, so any pretensions to do so are futile. Giving the imposable is beyond us; we might as well fit our scientific theories to suit us, which is what we do. Nice deductive theories that create fairly accurate models from a few basic assumptions are the sort of thing that we find easy to accept. So it’s not surprising that that is what we usually end up with.

Quantum theory seems to break this pattern. It’s kind of an admission of failure, an inductive theory rather than a deductive theory.

We cannot see a simple pattern that can be deduced form a few simple assumptions and explain the phenomena Quantum Mechanics seeks to explain. Instead we have to pragmatically take what we can observe from experiments and tie the results into a model that allows for predictive theories that can be tested.

Its not surprising that quantum mechanics feels unnatural, because unlike most other scientific theories it has not been designed with the intention of feeling natural.

There is also I think a big trap with Quantum Mechanics. A lot of quantum mechanics is scaffolding rather than the real thing; a consequence of the way the model was developed, by taking the results of experiments and combining them into a model, rather than something inherited from what’s really?!? happening.

[ QUOTE ]
… Do results like these follow straighjtforwardly from any assumptions that are commonsensically reasonable?

[/ QUOTE ]

I see no reason why they should. Human intuition was not designed for understanding the intricate depths of the universe. So beyond a certain point, I doubt what ‘seems reasonable’ to us has much bearing.

[ QUOTE ]
For example might quantum randumness be necessary for humans to have free will?

[/ QUOTE ]

No. You are confusing levels of thinking and ending up with nonsense. Microscopic and Macroscopic.

Free will exists at the level of human experience; Patterns of thought in the brain creating the sensation of free will. Quantum Mechanics is a red herring.

[Nielsio]

[ QUOTE ]
I suspect that you’re chasing a red herring.

The elegance of Newtonian and Eienstinean Physics and the weirdness of Quantum Mechanics are in my opinion a consequence of the way the relevant theories were developed.

Newtonian Mechanics is elegant, not because nature is, but because we like to create elegant deductive models of the universe. These theories are designed to fit us.

I take it as established that we will never understand the full nature of the universe, so any pretensions to do so are futile. Giving the imposable is beyond us; we might as well fit our scientific theories to suit us, which is what we do. Nice deductive theories that create fairly accurate models from a few basic assumptions are the sort of thing that we find easy to accept. So it’s not surprising that that is what we usually end up with.

Quantum theory seems to break this pattern. It’s kind of an admission of failure, an inductive theory rather than a deductive theory.

We cannot see a simple pattern that can be deduced form a few simple assumptions and explain the phenomena Quantum Mechanics seeks to explain. Instead we have to pragmatically take what we can observe from experiments and tie the results into a model that allows for predictive theories that can be tested.

Its not surprising that quantum mechanics feels unnatural, because unlike most other scientific theories it has not been designed with the intention of feeling natural.

There is also I think a big trap with Quantum Mechanics. A lot of quantum mechanics is scaffolding rather than the real thing; a consequence of the way the model was developed, by taking the results of experiments and combining them into a model, rather than something inherited from what’s really?!? happening.

[ QUOTE ]
… Do results like these follow straighjtforwardly from any assumptions that are commonsensically reasonable?

[/ QUOTE ]

I see no reason why they should. Human intuition was not designed for understanding the intricate depths of the universe. So beyond a certain point, I doubt what ‘seems reasonable’ to us has much bearing.

[ QUOTE ]
For example might quantum randumness be necessary for humans to have free will?

[/ QUOTE ]

No. You are confusing levels of thinking and ending up with nonsense. Microscopic and Macroscopic.

Free will exists at the level of human experience; Patterns of thought in the brain creating the sensation of free will. Quantum Mechanics is a red herring.

[/ QUOTE ]

Good post.

We have some 'free will' discussion going on here:
http://www.freedomainradio.com/board/forums/

Wanna join in?

[bunny]

[ QUOTE ]
Furthermore, there is no reason to claim that Newton's Laws were created by this superior being. Because they are basically pure logical common sense. The Inverse Square law, the Law of the Lever, d=gtsquared, F= ma. All these experimental results are not the least bit surprising if you use logical thought. Even much of Einstein's stuff, I believe is a pretty straightforward deduction from the fact that the speed of light is constant.

[/ QUOTE ]
I dont see how they arent surprising - you cant derive the inverse square law (unless you bring in the anthropic principle which doesnt seem to be what you are talking about) it is a brute fact about the world. Similarly, you cant derive quantum weirdness - it just is.

I think the only difference is we've had a few hundred years to get used to "action at a distance" so it seems common sense to us, I dont think there is anything inherently sensible or logical about it.

[guesswest]

It's intellectually irresistable to take the position that 'quantum weirdness' will be explained and predicted when we come to understand it better. But the idea that we can explain x can never be proved wrong, it can only be proved right - we can never know if an occurence is simply inexplicable, or whether we just haven't found the explanation yet. Looking for explanation and causal sequence everywhere is probably a good idea as a general intellectual strategy, but it shouldn't be accompanied by a dogmatic assumption that such explanations must exist.

And quantum randomness as a necessary condition of free will? That's a huge can or worms tucked away as an aside. Can you explain that please?

[bluesbassman]

[ QUOTE ]

What I would like to know however is if the strange things about particles that our experiments show, is a logical consequence of anything that makes common sense. I know the equations of quantum theory predict these results. But is their some underlying logical basis for them? In other words was there any way to logically guess that light would behave as a particle when observed but not otherwise or that a radioctive particle would have a 50% chance of decaying in x years regardless of how long it has already gone without decaying. Do results like these follow straighjtforwardly from any assumptions that are commonsensically reasonable? (For example might quantum randumness be necessary for humans to have free will?)

[/ QUOTE ]

I think I understand what you are getting at...

There is a saying in quantum mechanics which goes something like, "That which is not strictly forbidden, is inevitable." So, for example, when an electron travels from point A to B unobserved, it will follow "all possible" paths. That is, if a quantum state is possible, it is inevitably achieved in a statistical sense.

On the macroscopic level, I have sometimes wondered whether this feature of quantum mechanics is the "raw material" which induces the incredible complexity of the universe (including life), which to many people seems teleological. For example, it was inevitable that self-replicating molecules were synthesized on the early Earth, since it's chemically possible. And that early life forms "found" mutations which increased their fitness and morphological complexity, etc.

By contrast, if the Laplacian dream of a completely deterministic, predictable universe were true, one might expect the universe to quickly reach a much "simpler," homogenous equilibrium state.

I guess I'm trying to hypothesize that the (subjective) richness or seemingly teleological complexity of the universe is a "logical" consequence of the quantum weirdness which indicates particles will achieve all possible states.

[David Sklansky]

"dont see how they arent surprising - you cant derive the inverse square law (unless you bring in the anthropic principle which doesnt seem to be what you are talking about) it is a brute fact about the world. Similarly, you cant derive quantum weirdness - it just is."

The inverse square law isn't obvious to you?

[Max Raker]

[ QUOTE ]
[ QUOTE ]
[ QUOTE ]
What were people thinking 500 years ago when gravity was first being explored and defined (differing masses falling at the same rate!)? Unbeknownst to the people of the times, the mass of the earth is so immense, that the relative mass of the other bodies was negligible (ha, I think, right?

[/ QUOTE ]

Actually, no.
F=ma
F(of gravity on falling object) = m(of falling object) a(acceleration of falling object)

F(of gravity on falling object) = g(gravitational constant)*M(of earth)*m(of falling object)/d(distance between center of gravities)^2

set F = F

g*M*m/d^2 = ma

m = mass of the falling object is on both sides of the equation and cancels itself out.

[/ QUOTE ]

The OP was right. Your equations only work when one object is much smaller than the other and can ignore the acceleration of the larger object (i.e the Earth). Otherwise you have to add in the acceleration of the Earth from the gravity of the object.

The equation ends up being G(M+m)/d^2 = a, where a is the acceleration of one object as seen from the surface of the other object.

[/ QUOTE ]

Nope the OP is wrong. The mass of the Earth dosen't matter.
There is really no such thing as "acceleration of one object as seen from the surface of the other object." You can measure acceleration locally and it is absolute. An object is or isn't accelerating, it dosen't matter where you look from. This is the opposite of velocity in which you need to specify the frame where you measure from.

[bunny]

No moreso than heisenberg's uncertainty principle.

I am assuming that by being obvious you mean it must be that way (is that your intention? Or do you mean it's easy to see?)

For the former - I can imagine a world where gravity is proportional to the cube of the distance, for example so I dont see why the strength of gravity being inversely proportional to the square is obvious in this sense.

In the second meaning - I dont think it is easy to see just by looking, you need to do experiments and calculations (and even these will give the "wrong" answers due to measuring error, friction, etc - you have to follow a process of abstraction to get to the law). This doesnt seem any different to quantum results, they are just newer imo.

[Max Raker]

[ QUOTE ]
"dont see how they arent surprising - you cant derive the inverse square law (unless you bring in the anthropic principle which doesnt seem to be what you are talking about) it is a brute fact about the world. Similarly, you cant derive quantum weirdness - it just is."

The inverse square law isn't obvious to you?

[/ QUOTE ]

I dont think you can call the inverse square law obvious. It's a very good guess based on geometry. But, in Newtonian physics, you can on paper come up with other possibilities. Ironically, when you say that Newtonian physics is obvious, I think you are wrong. Newtonian physics is based on many arbitrary concepts. (Why not F=ma^2 or something else). Things like F=ma where almost purely experiement. In that sense I think your question is flawed because quantum mechanics is really MORE "obvious" and predictable than Newtonian physics.

[tsrcess]

i think i will wade a little into these waters. although everything appears to be very regular at a distance, EVERYTHING up close is VERY weird. consider, for example, any event or any observation at all (i.e. the jfk assaination or the position of any particle) that has been studied in great detail. the conclusion is ALWAYS the same. the event or observation is weird and does not make sense. why is this? well, my theory is that our (human) perception of reality is really an illusion on a grand scale. we observe our surrondings and we attempt to logically define them. but, our notions of logic are not truely consistent with our surroundings. if i'm correct (as i'm sure i am), there are no particular implications for the average life. afterall, millions (billions) have lived and died with no good understanding of existence. what does it matter? it matters only to those who want to know the truth. i don't think the knowledge has any practical consequences...

[chezlaw]

Not sure this is what your looking for but maybe something like quantum wierdness follows from the assumption the universe is efficient plus some other bits.

Calculating positions/momentums/polarisations/spins etc etc is costly and often unnecessary (in some sense). Why not only calculate them when a value is needed - something like QM then follows as quantumn wierdness is equivalent to just in time computation.

Leaves the question, when is a value needed - maybe something to do with concious experience.

chez

[felson]

David,

This has no bearing on the QM/creator issue. But if, as you say, so much of physics is common sense, it is a cruel accident of history that you were born 500 years too late to be credited with the discovery of Newton's laws and gravitation, and that you were born 100 years too late to be credited with the discovery of relativity.

Would you also say that all the "obvious" discoveries in physics have now been exhausted? Or might there be some remaining?

[Zeno]

There is a very good and article in the recent Skeptical Inquirer Volume 30, No.4 July/August 2006 titled: "Why Quantum Mechanics Is Not So Weird After All", by Paul Quincey. Unforturnely the recent issue of the magazine and article are not yet available on the website Skeptical Inquirer (http://www.csicop.org/si/) but it may be within a few weeks.

Anyway, the article is worth reading and Mr. Quinecy borrows and/or bases some of his arguments from material in Richard Feynman's book, QED: The Strange Theory of Light and Matter.


I haven't the time nor the will go over this article in detail here. Pick up the magazine if you want or wait and see if the article will be one of the ones available on the website. Or contact Paul Quiency, he is a physicist at the National Physical Laboratory, Hampton Road, Teddington, Middlesex, TW11 OLW, United Kingdom. His e-mail is given in the magazine but I don't know if it is appropriate to give it here so I will not do so.


A few excerpts from the article:

"But the triumph of quantum mechanics came with an unexpected problem- when you stepped outside of the mathematics and tried to explain what was going on, it didn't make sense."

" Richard Feynman's "least-action" approach to quantum physics in effect shows that it is just classical physics constrained by a simple mechanism."


The article uses a surveyor’s wheel for measuring action in quantum mechanics where the wheel circumference equals Planck's constant, h.


With that tickle and tease, I leave the rest to the more cerebral minds on this forum.

-Zeno

[MaxWeiss]

It seems to me that the only reason that there is so much "weirdness" is due to a lack of understanding of what is going on. I haven't studied quantum mechaincs much (at all) but I have studied special and general relativity.

Anyway, the who field of probability and statistics is trying to derive something useful from incomplete information. AK against 22 is a toss up because we assign a random (unknown) distribution to the possible cards that come. If we shuffle track and know an ace will hit the flop (which is easy to do in a lot of card rooms) we know AK has a much better chance than 50/50. Similarly, I believe deep down (even with the numerous scince classes I've taken) that we just don't know enough yet, and as the field progresses and we learn more about the particles, we won't say it has a 50-50 chance of decaying---we will be able to analyze more variables than we can currently account for (because we have advanced in that field) and say exactly when it will decay.

Physical law will follow the math equations--becaus we derivded them from observation and use of the scientific method. Those equations call for uncertainty and probabilistic functions. The ONLY reason this is so is because we have not yet input all the variables. We just don't know. And we don't know WHAT we don't know.

We tend to forget that nature doesn't act weird. It simply acts, and we think it's weird because it's not what we think it should be, because we are not fully informed. But, and this is my favorite phrase, everything happens exactly as it should.

[Metric]

[ QUOTE ]
...we will be able to analyze more variables than we can currently account for (because we have advanced in that field) and say exactly when it will decay.

[/ QUOTE ]

This was the view of of many physicists before Bell's inequalities, which basically show that "not taking into account every variable" is not sufficient to account for all of the predictions of QM.

[Darryl_P]

Responding to this question requires knowing your starting point. If your starting point is a completely blank slate, ie. a high IQ being who has zero experience in our universe, then there is absolutely no basis upon which to assume Newton's laws are more logical than the results of the double slit experiment. He would need to acquire some experience first, and even then he would need to make some assumptions.

If OTOH we are talking about a high IQ earthly being who has been indoctrinated into placing a high value on high school mathematics because of all the wonderful applications it has, then maybe such a being will be more comfortable (and therefore view as more logical) a theory which lends itself to analysis via those neat graphs and formulas he knows and loves, where you can just use something cool like "infinity" and pretend it has applications in the real world, and few will point out the gross flaw in this becuase most other intelligent folk have been similarly indoctrinated themselves.

Not trying to be a troll here, but once it is clear that a theory is WRONG, ie. Newton's and Einstein's, and the others which follow introduce more loose ends than they tie together, it's really hard to compare these flawed or grossly incomplete theories on the basis of which is more logical. The older ones are certainly wrong and the newer ones are either almost certainly wrong or don't explain very much. The most logical approach to me is to not spend much time on these and focus on more important things like satisfying our current and future biological needs, say.

[MaxWeiss]

Interesting. I'm out of my field of knowledge, but that statement makes me want to study it. Huh, how fascinating.

[ChrisV]

Hmm. Missed this thread for a while.

I think Piers' reply is the best one in the thread. The way that quantum mechanics was developed inductively means that there are a number of interpretations that can be placed on the basic equations. This stands in contrast to most scientific theories, where the basic idea or model was worked out and then the underlying maths flowed from that. Since there are many interpretations other than the familiar Copenhagen Interpretation that could be the correct model to apply, I don't think your question can be answered at this stage. If it turns out that the transactional interpretation (http://en.wikipedia.org/wiki/Transactional_interpretation) is correct, for example, then all questions of "quantum weirdness" will be moot. To me the transactional interpretation does have the property of being an intuitive, neat theory, but like the Copenhagen Interpretation it is unsupported by evidence at this point. All we know for sure is that the equations work.

[Borodog]

It seems to me that the reason that Newtonian physics makes "common sense" is that we are creatures that operate in the Newtonian regime, and we have evolved for it. If there were (intelligent) creatures that had evolved to operate in the nanoscopic world where quantum mechanics dominates, no doubt its rules would make perfect common sense, as would relativity to intelligent creatures evolved to move near the speed of light in the vicinity of black holes.

The other side of this coin, I believe, is simply no, neither quantum mechanics nor relativity could have been "logically predicted" without experimental evidence by some sufficiently deep thinking contemplating the universe from his armchair.

[chezlaw]

[ QUOTE ]
[ QUOTE ]
...we will be able to analyze more variables than we can currently account for (because we have advanced in that field) and say exactly when it will decay.

[/ QUOTE ]

This was the view of of many physicists before Bell's inequalities, which basically show that "not taking into account every variable" is not sufficient to account for all of the predictions of QM.

[/ QUOTE ]
We seem to revist this regularly but here goes again /images/graemlins/smile.gif

If an experiments could confirm Bells inequality point then it would prove action at a distance (one particle 'knows' about the other one without any information passing between them).

However no finite experiment can tell the difference between action at a distance and information that travels sufficiently fast.

Hence all experimental validation of bells inequalities can do is demonstrate action at a distance or set the a lower bound on the speed at which information is transferred.

Is this confused or plain wrong?

chez

[jason1990]

[ QUOTE ]
Hence all experimental validation of bells inequalities can do is demonstrate action at a distance or set the a lower bound on the speed at which information is transferred.

Is this confused or plain wrong?

[/ QUOTE ]
I don't think it's either. However, I think the situation with Bell's Inequality is more complicated than this. Bell's Inequality is simply a consequence of the mathematical formalism of QM. The overwhelming accuracy of this formalism has been corroborated time and time again by experiment. We struggle with and debate over intepretations of the formalism, but the mathematics seems as solid as it gets. (For now, at least.)

What Bell's Inequality shows us is that this formalism is inconsistent with the mathematics of traditional probability theory; namely, that part of probability which concerns covariance and dependence. In other words, within this formalism, we cannot interpret QM as a statistical description of a conglomeration of many deterministic events. Or, more precisely, if we wish to interpret it this way, we must make drastic changes to our view of the universe.

If an experiment at a sufficiently high speed or over a sufficiently large distance were to contradict Bell's Inequality, then it would contradict the mathematical formalism of QM itself. Of course this is possible. And, in fact, it may be likely that one day this formalism will be shown to be imperfect. Moreover, it may be fair to say that no finite experiment can completely verify the laws of QM.

But I think what makes the situation with Bell's Inequality more complicated (and more interesting) is something more theoretical than experimental. Namely, if we are to be logically consistent, then we cannot simultaneously believe
<ul type="square">
[1] the (mathematical) laws of QM are valid,
[2] quantum phenomena can be explained by hidden variables, and
[3] the universe is intrinsically local.
[/list]
You are essentially suggesting that [1] might be false. Of course, we must admit that it might be false. And, also, our finite experiments can never prove with certainty that it is true. So what you're saying is right. But I think that, for better or for worse, it's an unusually skeptical position to take on the issue. If one could turn this extreme skepticism into an alternative theory of QM, which is consistent with the current theory in the regime in which we have so far done experiments, and which resolves the "paradox" resulting from Bell's Inequality, that would certainly be a major accomplishment.

[Metric]

Bell's inequalities depend critically on two assumptions:

1) Locality (information not traveling faster than light)

2) Realism (that the outcome of an experiment is determined before the experiment is conducted, though we may not have knowledge of what that outcome will be -- i.e. certain variables may be hidden from us, but the assumption is that they do in fact exist and determine the outcome of the experiment)

Using these assumptions, one can deduce an inequality that must hold in any experiment. One then finds that one can violate the inequality experimentally, and that quantum mechanics correctly predicts the amount by which you can violate it. The conclusion is then that either one or both of the above assumptions is false.

Assumption #1 is essentially a consequence of relativity, but (special) relativity gets along just fine with quantum mechanics -- the combination of the two (quantum field theory) result in the most successful microscopic theory ever devised by mankind. The assumption that information travels no faster than "c" is explicitly taken into account by the theory.

Assumption #2 is therefore usually taken to be the "bad" assumption, and is of course the one that is always assumed by classical mechanics.

In any case, violation of Bell inequalities tells you that classical relativistic hidden-variable theories are not sufficient to describe the world (a point of view held by some physicists prior to Bell showing up on the scene).

Let me know whether or not this clarifies things... You appear very focused on the possibility that assumption #1 is wrong, but relativity is ordinarily the least suspect element in the discussion.

[Metric]

[ QUOTE ]
Bell's Inequality is simply a consequence of the mathematical formalism of QM.

[/ QUOTE ]
A minor nitpick here, but I should mention this lest anyone become additionally confused in an already confusing subject. Bell's inequalities are not a result of QM -- they are classical inequalities. It is the violation of Bell's inequalities that is correctly predicted by QM.

Other than that, I pretty much agree completely...

[chezlaw]

[ QUOTE ]
Bell's inequalities depend critically on two assumptions:

1) Locality (information not traveling faster than light)

2) Realism (that the outcome of an experiment is determined before the experiment is conducted, though we may not have knowledge of what that outcome will be -- i.e. certain variables may be hidden from us, but the assumption is that they do in fact exist and determine the outcome of the experiment)

Using these assumptions, one can deduce an inequality that must hold in any experiment. One then finds that one can violate the inequality experimentally, and that quantum mechanics correctly predicts the amount by which you can violate it. The conclusion is then that either one or both of the above assumptions is false.

Assumption #1 is essentially a consequence of relativity, but (special) relativity gets along just fine with quantum mechanics -- the combination of the two (quantum field theory) result in the most successful microscopic theory ever devised by mankind. The assumption that information travels no faster than "c" is explicitly taken into account by the theory.

Assumption #2 is therefore usually taken to be the "bad" assumption, and is of course the one that is always assumed by classical mechanics.

In any case, violation of Bell inequalities tells you that classical relativistic hidden-variable theories are not sufficient to describe the world (a point of view held by some physicists prior to Bell showing up on the scene).

Let me know whether or not this clarifies things... You appear very focused on the possibility that assumption #1 is wrong, but relativity is ordinarily the least suspect element in the discussion.

[/ QUOTE ]
Thanks, that how I understand it. I'm mainly exercised as you say) about assumption #1 but that's only because it seems to go unstated, leaving claims like Bell's inequalities demonstrate non-realism or demonstrates randomness etc (it took me a while to realise that relativity was being assumed and I assume others don't realise it either).

It doesn't seem at all obvious that one should abandon realism to keep relativity. It seems just as reasonable to claim that Bells inequalities demonstrate something wrong with relativity (not really wrong with it but beyond it).

I don't have a view on which assumption is bad. Apart from the misleading use of Bell by not stating the relativity assumption my main motivation is to see if my limited understanding of QM (which is based on a just in time computation realism model) isn't baloney - don't care if the model is correct or not just that its logically as good as any.

[jason1990 I struggle with the way you put it, if by [3] you basically mean relativity then I think that's the same as Metric's point and I agree - the point remains that its currently arbitary as to whether we should abandon relativity or realism - this is not skepticism in the normal sense. The question is whether to be skeptical about realism or relativity or to suspend judgement in the abscense of any means of telling the difference]

Thanks for the responses

chez

[jason1990]

[ QUOTE ]
[ QUOTE ]
Bell's Inequality is simply a consequence of the mathematical formalism of QM.

[/ QUOTE ]
A minor nitpick here, but I should mention this lest anyone become additionally confused in an already confusing subject. Bell's inequalities are not a result of QM -- they are classical inequalities. It is the violation of Bell's inequalities that is correctly predicted by QM.

Other than that, I pretty much agree completely...

[/ QUOTE ]
Yes, I think you're right. Sorry about that. In the context of a certain class of experiments, classical probability theory produces one inequality, and the mathematical formalism of QM produces the opposite. I had always thought of the latter as Bell's Inequality, but it looks like it is the former which usually bears that name.

[jason1990]

[ QUOTE ]
[jason1990 I struggle with the way you put it, if by [3] you basically mean relativity then I think that's the same as Metric's point and I agree - the point remains that its currently arbitary as to whether we should abandon relativity or realism - this is not skepticism in the normal sense. The question is whether to be skeptical about realism or relativity or to suspend judgement in the abscense of any means of telling the difference]

[/ QUOTE ]
Aha. I think I misunderstood you. Roughly, [3] means the existence of a "speed limit". I thought you were suggesting that [2] holds, that [3] holds (with some speed limit possibly greater than that proposed by relativity), and that [1] might fail, but the failure occurs only outside the realm of speeds and distances in which we are currently able to perform experiments.

[David Steele]

[ QUOTE ]
What I would like to know however is if the strange things about particles that our experiments show, is a logical consequence of anything that makes common sense.

[/ QUOTE ]

One scientist, I forget who, said something like "Particles are not things". The idea that with the very small, properties are not exactly meaurable and have other odd behaviors, has always struck me as sensible.

If quarks were simply small billiard balls, no progress at all would have really been made.

So in one sense it seems very logical that something like
QM follows as compared to classical physics.

This is a far cry from showing that the actual details of QM follow logically ( which others may prove in the rest of the thread GL!).

D.

[prosellis]

Free will exists at the level of human experience; Patterns of thought in the brain creating the sensation of free will. Quantum Mechanics is a red herring.

[/ QUOTE ]

Not in total disagreement, but:
Isn't experience necessary in Quantum Mechanics? Schrodinger's Cat suggests that the act of observation collapses the wave function of a particle or system and therefore defines both the state and coordinates of that thing. My flaw may be in equating observation with experience, but I see them as one in the same in many cases. Without experiencing specific systems through observation they retain their wave function and exist without specific dimension.
I'm not sure that this means that QM is in any way indicative of human free will, but it does account for the necessity of observers to exist.

On a side note:
I know that string theory does not subscribe to the classic wave-particle duality theory, does anyone know how string theorists circumvent this?

[MaxWeiss]

Do you all have any suggestions for introductory books on the subject? I'm not averse to the math, but if you have a layman's guide, that'd be just as well for me.

[Metric]

Volume III of the Feynman Lectures on Physics is a good introduction to quantum ideas with enough math to give you a foothold on things, but not enough to swamp you. As an additional advantage, the lectures can be had on tape/CD, so you can listen to Feynman actually giving the lecture while you're e.g. in the car.

One downside -- he does not discuss Bell's inequalities in these lectures, which are rather profound. However, you should be able to hunt down an intro to this specific topic online without too much trouble.

[Piers]

People keep looking for magic here where there isn’t any.

Would it be clear if I said that the sensation of free will is a biological feature of the human mind?

The position of observers in Quantum mechanics is a consequence of the type of theory Quantum Mechanics is, not of the underlying physics.

Its very easy to get confused about what bits of Quantum Mechanics is inherited from the underlying physics and what bits are just part of the ‘artificial’ structure needed to ‘hold’ the theory.

But here’s a clue, anything about randomness and probably is part of the human constructed mounting not the real thing.

QM and free will might as well compare apples and the French Revolution.

Or at least that’s the way it seems to me.

[Metric]

[ QUOTE ]
On a side note:
I know that string theory does not subscribe to the classic wave-particle duality theory, does anyone know how string theorists circumvent this?

[/ QUOTE ]

Wave/particle duality is emphasized only to get a single point across -- a system's state vector is typically in a superposition of eigenstates of a particular observable. In the case of a particle satisfying the Schroedinger equation, this superposition looks like (has the functional form of) a wave. Superstring theory is a quantum theory, though, so it inherits this same type of "duality," though the observables do not include position operators of a pointlike particle. This is not something fundamentally new -- in quantum field theory one already stops dealing with simple position operators and starts dealing with observables of fields.

[Max Raker]

[ QUOTE ]
People keep looking for magic here where there isn’t any.

Would it be clear if I said that the sensation of free will is a biological feature of the human mind?

The position of observers in Quantum mechanics is a consequence of the type of theory Quantum Mechanics is, not of the underlying physics.

Its very easy to get confused about what bits of Quantum Mechanics is inherited from the underlying physics and what bits are just part of the ‘artificial’ structure needed to ‘hold’ the theory.

But here’s a clue, anything about randomness and probably is part of the human constructed mounting not the real thing.

QM and free will might as well compare apples and the French Revolution.

Or at least that’s the way it seems to me.

[/ QUOTE ]


I disagree with this. The position of observers in QM is 100% the result of the universe and not a by product of the way QM is constructed. And there is a 0% chance that quantum mechanics is "wrong", meaning that the worst that can happen to QM is what happened to Newtonian mechanics, ie it becomes a limiting case of a more encompassing theory.

Also, Bells experiments really told us nothing new. Bohr and Heisenberg knew the results some 30 years or so before it became experimentally possible to test.

[madnak]

[ QUOTE ]
I disagree with this. The position of observers in QM is 100% the result of the universe and not a by product of the way QM is constructed. And there is a 0% chance that quantum mechanics is "wrong", meaning that the worst that can happen to QM is what happened to Newtonian mechanics, ie it becomes a limiting case of a more encompassing theory.

[/ QUOTE ]

Which makes it wrong. I don't think "close enough, given the proper circumstances" really counts in physics.

[Piers]

[ QUOTE ]
I disagree with this. The position of observers in QM is 100% the result of the universe and not a by product of the way QM is constructed.

[/ QUOTE ]

Guess we disagree.

[ QUOTE ]
And there is a 0% chance that quantum mechanics is "wrong", meaning that the worst that can happen to QM is what happened to Newtonian mechanics, ie it becomes a limiting case of a more encompassing theory.

[/ QUOTE ]

You contradict yourself.

Your really keen on these 100%, 0% estimates.

[Max Raker]

[ QUOTE ]

Which makes it wrong. I don't think "close enough, given the proper circumstances" really counts in physics.

[/ QUOTE ]

lol, this is all physics is. We never deal with absolute truths, that is for philosophers.

[Max Raker]

[ QUOTE ]
[ QUOTE ]
I disagree with this. The position of observers in QM is 100% the result of the universe and not a by product of the way QM is constructed.

[/ QUOTE ]

Guess we disagree.

[ QUOTE ]
And there is a 0% chance that quantum mechanics is "wrong", meaning that the worst that can happen to QM is what happened to Newtonian mechanics, ie it becomes a limiting case of a more encompassing theory.

[/ QUOTE ]

You contradict yourself.

Your really keen on these 100%, 0% estimates.

[/ QUOTE ]

The biggest problem with people learning about QM is that they jump to the hardest parts first. I think here you are attacking a precieved weakness in QM without first knowing what it does and why it was created.


Also I don't think I contradicted myself. To me, quantum mechaincs is just a tool, you use it to figure out how particles behave and it works (well actaully it works better than anything else humans have ever thought of).
I said there is 0% chance that QM is wrong because calling QM wrong is like calling a shovel wrong. How can it be wrong, you just use it to dig.

[Max Raker]

[ QUOTE ]
One of the reasons I and many others reject the "just look around you" argument of Not Ready and others as some type of evidence for a superior being, is that we know that (aside from possibly human consciousness)the seeming magnificence of the Earth is mainly a simple consequence of Newton's laws and fractal geometry.

Furthermore, there is no reason to claim that Newton's Laws were created by this superior being. Because they are basically pure logical common sense. The Inverse Square law, the Law of the Lever, d=gtsquared, F= ma. All these experimental results are not the least bit surprising if you use logical thought. Even much of Einstein's stuff, I believe is a pretty straightforward deduction from the fact that the speed of light is constant.

What I would like to know however is if the strange things about particles that our experiments show, is a logical consequence of anything that makes common sense. I know the equations of quantum theory predict these results. But is their some underlying logical basis for them? In other words was there any way to logically guess that light would behave as a particle when observed but not otherwise or that a radioctive particle would have a 50% chance of decaying in x years regardless of how long it has already gone without decaying. Do results like these follow straighjtforwardly from any assumptions that are commonsensically reasonable? (For example might quantum randumness be necessary for humans to have free will?)

[/ QUOTE ]

David,
I have thought about your questions a little bit and I am ready to try to answer some of them. On the wave/particle question, I dont know of a way to explain this without using experimental results. It is clear if you consider the double slit experiment and the photoeletric effect, but I don't know of a way to explain it "on paper".

The particle decay question is not really unique to QM and is just a math problem. Many, non QM based systems follow the same equations.

[madnak]

Not absolute truths, but accurate, reliable patterns. Physics in practice involves a lot of approximation, but physics in theory shouldn't be approximate.

[cambraceres]

[ QUOTE ]
Not absolute truths, but accurate, reliable patterns. Physics in practice involves a lot of approximation, but physics in theory shouldn't be approximate.

[/ QUOTE ]

This is a question of epistemology

[Piers]

[ QUOTE ]
The biggest problem with people learning about QM is that they jump to the hardest parts first. I think here you are attacking a precieved weakness in QM without first knowing what it does and why it was created.

[/ QUOTE ]

/images/graemlins/confused.gif /images/graemlins/confused.gif

[ QUOTE ]
To me, quantum mechaincs is just a tool, you use it to figure out how particles behave and it works (well actaully it works better than anything else humans have ever thought of).

[/ QUOTE ]

Agreed.

[ QUOTE ]
I said there is 0% chance that QM is wrong because calling QM wrong is like calling a shovel wrong. How can it be wrong, you just use it to dig.

[/ QUOTE ]

I agree with the sentiment but don’t like the phraseology.

You create a model and ask what is the chance this model is correct. The natural interpretation of this is that you are asking what is the chance the model has an isomorphism onto reality (whatever that is). Instead you claim you used it to mean something like what is the chance my model of physics is a model of physics. So is a tautology false?

[ QUOTE ]
And there is a 0% chance that quantum mechanics is "wrong", meaning that the worst that can happen to QM is what happened to Newtonian mechanics, ie it becomes a limiting case of a more encompassing theory.

[/ QUOTE ]

I have a street map of London, which was published in 1983. I still use it to travel around London. Is that map of London wrong or not?

[gumpzilla]

[ QUOTE ]

One downside -- he does not discuss Bell's inequalities in these lectures, which are rather profound. However, you should be able to hunt down an intro to this specific topic online without too much trouble.

[/ QUOTE ]

David Mermin wrote a pretty nice article on this; here (http://qt1.tn.tudelft.nl/~lieven/qip/extra/mermin_moon.pdf) is a link. It's very approachable.

[prosellis]

Wave/particle duality is emphasized only to get a single point across -- a system's state vector is typically in a superposition of eigenstates of a particular observable. In the case of a particle satisfying the Schroedinger equation, this superposition looks like (has the functional form of) a wave. Superstring theory is a quantum theory, though, so it inherits this same type of "duality," though the observables do not include position operators of a pointlike particle. This is not something fundamentally new -- in quantum field theory one already stops dealing with simple position operators and starts dealing with observables of fields.

[/ QUOTE ]

Thanks for the response. I have taken a few introductory classes on theoretical physics but am relatively inexperienced with any of the string theories.

You seem to have some knowledge on the subject so I'll try a few more:

In string theories do the string vibration frequencies serve to replace the particle spin rates of classic Quantum Theory or are they in addition to?

Second, do you happen to know how Schwarz resolved the Yang-Mills anomaly that occurs in classic QM? The Clay Math Institute is still offering a Millenium prize for the mathematical proof of the mass-gap, but I've read (without having the background to understand) that Schwarz and Greene resolved this anamoly in the mid-seventies.

Don't mean to hijack the thread, just curious.

And to whoever it was that was curious about books regarding quantum mechanics, I loved David Bohm's "Quantum Theory."

[Metric]

[ QUOTE ]
In string theories do the string vibration frequencies serve to replace the particle spin rates of classic Quantum Theory or are they in addition to?

[/ QUOTE ]

I should say that I am not a string theorist, but I have a little knowledge of the general picture. Basically, spin (and mass) correspond to different excitations of a string -- this is part of what makes the theory attractive to some people. There is no need to postulate spin and mass as external paramenters that simply go into building a theory -- every particle is essentially the same string, merely excited differently.

[ QUOTE ]
Second, do you happen to know how Schwarz resolved the Yang-Mills anomaly that occurs in classic QM? The Clay Math Institute is still offering a Millenium prize for the mathematical proof of the mass-gap, but I've read (without having the background to understand) that Schwarz and Greene resolved this anamoly in the mid-seventies.

[/ QUOTE ]

Schwarz and Green showed that superstring theory was free of anomalies (hence interest in the theory exploded after this discovery). The Yang-Mills mass gap problem is apparently still open, but exists in the setting of quantum field theory. As for the details of Schwarz and Green's proof, I basically don't know anything about it, though you've got me curious about it now -- I may have to look it up.

[MadScientist]

[ QUOTE ]
[ QUOTE ]
[ QUOTE ]
...we will be able to analyze more variables than we can currently account for (because we have advanced in that field) and say exactly when it will decay.

[/ QUOTE ]

This was the view of of many physicists before Bell's inequalities, which basically show that "not taking into account every variable" is not sufficient to account for all of the predictions of QM.

[/ QUOTE ]
We seem to revist this regularly but here goes again /images/graemlins/smile.gif

If an experiments could confirm Bells inequality point then it would prove action at a distance (one particle 'knows' about the other one without any information passing between them).

However no finite experiment can tell the difference between action at a distance and information that travels sufficiently fast.

Hence all experimental validation of bells inequalities can do is demonstrate action at a distance or set the a lower bound on the speed at which information is transferred.

Is this confused or plain wrong?

chez

[/ QUOTE ]

plain wrong.

There is no information transmitted in experiments that show violations of Bell's inequality.
For instance, take a source that emitts two particles whose net spin must be zero. One up. One down.

&lt;- e spin up *source* spin down e-&gt;

However, until measured, whether the leftmost particle has spin up or down is not known, but when it is measured, the rightmost particle's spin must then instantaneously be known.

There is no message sent between particles.

Phase velocities may exceed the speed of light. Only the tranmission of energy (related to the transmission of information), the so called group velocity, can not exceed the speed of light for massive particles.

For those interested in so called quantum weirdness which is just a wrong way to look at quantum mechanics, a well understood and tested part of modern physics, I would refer you to the experiments of Aspect et al., Phys Rev Lett. 49, 91, 1982. He shows by a series of rapidly varying measurement apparatus at a large separation that there can be no "hidden variable" theory at work whereby the orientations of the two particles are predetermined before hand. Rather, he shows that a quantum mechanical theory where the states are determined upon measurement must be correct and that the correlation between states between the two instruments occurs instantaneously.

After reviewing the experimental data, I think you will have a better understanding of QM. It will seem very concrete and indisputable rather than weird.

[MadScientist]

[ QUOTE ]
One of the reasons I and many others reject the "just look around you" argument of Not Ready and others as some type of evidence for a superior being, is that we know that (aside from possibly human consciousness)the seeming magnificence of the Earth is mainly a simple consequence of Newton's laws and fractal geometry.

Furthermore, there is no reason to claim that Newton's Laws were created by this superior being. Because they are basically pure logical common sense. The Inverse Square law, the Law of the Lever, d=gtsquared, F= ma. All these experimental results are not the least bit surprising if you use logical thought. Even much of Einstein's stuff, I believe is a pretty straightforward deduction from the fact that the speed of light is constant.

What I would like to know however is if the strange things about particles that our experiments show, is a logical consequence of anything that makes common sense. I know the equations of quantum theory predict these results. But is their some underlying logical basis for them? In other words was there any way to logically guess that light would behave as a particle when observed but not otherwise or that a radioctive particle would have a 50% chance of decaying in x years regardless of how long it has already gone without decaying. Do results like these follow straighjtforwardly from any assumptions that are commonsensically reasonable? (For example might quantum randumness be necessary for humans to have free will?)

[/ QUOTE ]

David, I would refer you to the textbook that I used in my quantum mechanics class, A Modern Approach to Quantum Mechanics by John Townsend which is very well written. I had the pleasure of taking the class form Townsend himself.
In particular, section 5.5, A Nonquantum Model and the Bell Inequalities, p. 134, will explain the logical underpinnings of quantum effects and what look like violations of relativistic causality (nothing can move faster than the speed of light).

He includes the original data for experiments in the book in order to make things more concrete and clear.

It is accessible for any smart person who has had college level mathematics beyond introductory calculus and who is interested and motivated in learning.

As for your assertion of quantum mechanics being weird, I think this is no different than an ancient philosopher thinking lightning was due to a God's wrath. In both cases, it stems from a lack of understanding of the theory behind the phenomenon AND neglects to understand the elucidating experiments that confirm the physical cause for the phenomenon. Just as experiments using high voltage induced electrical breakdown of air show that lightning can be made in the lab and is electrical in its nature, experiments show that QM is not an attempt to explain a more general theory with hidden variables which would "make sense" and "not be weird".

The basic idea is that probabilities should be used to calculate physical quantities and that there is a wavefunction that describes the state of a particle. The wavefunction's absolute value squared is a probability.
The wavefunction is a logical, simple quantity that evolves by straightforward equations. It changes due to external influences like electric, magnetic, and gravitational fields and produces simple to check results (probabilities, percentage of measurements).

To be honest, I am surprised that you think it is "spooky" and weird. To put it in terms that I know you will understand, violation of Bell's equality and a lack of a hidden variable theory means one must trust the results of a probablistic theory. Things would be simpler if we could just know how everything would act ahead of time...

It is similar to a weak poker player trying to put an opponent on a specific card holding and then playing the hand as if he definately has AK, instead of putting him on a range of cards and trusting the result of a probability calculation (even if it is a rough one done at the table) to make the correction action.

-Franklin Grigsby soon to be PhD. Physics

[Metric]

[ QUOTE ]
There is no information transmitted in experiments that show violations of Bell's inequality.

[/ QUOTE ]
I very much sympathize with this "standard" point of view, but some authors have argued that it is the assumption of locality that is at fault in Bell's inequalities. I am aware of no theorem proving that it must be realism that should be abandoned -- all we know for sure is that the combination "local realism" doesn't work. Apparently, chez falls in with the non-locality crowd, which is a bit unusual but by no means ruled out experimentally.

[MadScientist]

[ QUOTE ]
[ QUOTE ]
There is no information transmitted in experiments that show violations of Bell's inequality.

[/ QUOTE ]
I very much sympathize with this "standard" point of view, but some authors have argued that it is the assumption of locality that is at fault in Bell's inequalities. I am aware of no theorem proving that it must be realism that should be abandoned -- all we know for sure is that the combination "local realism" doesn't work. Apparently, chez falls in with the non-locality crowd, which is a bit unusual but by no means ruled out experimentally.

[/ QUOTE ]


Again, only information and energy can not be transmitted at greater than the speed of light, so having effects that occur instantaneously, but do not transmit information are fine with all physical theories.

Bell assumed that info was being transmitted and so causality, events transmitted at the speed of light, (or local realism, which is a silly phrase, as you are calling it) would be violated. However, there is no info, so there is no violation and his assumption is wrong.

[MaxWeiss]

[ QUOTE ]
After reviewing the experimental data, I think you will have a better understanding of QM. It will seem very concrete and indisputable rather than weird.

[/ QUOTE ]

Again, I'm out of my element--and don't take this as insulting. I just recall somewhere I read some famous scientist said that anybody who has studied QM and thinks they have a grasp on it clearly hasn't studied it enough.

[gumpzilla]

[ QUOTE ]

Bell assumed that info was being transmitted and so causality, events transmitted at the speed of light, (or local realism, which is a silly phrase, as you are calling it) would be violated. However, there is no info, so there is no violation and his assumption is wrong.

[/ QUOTE ]

I don't think Bell assumed anything of the sort. The point is that once you've measured the first spin, the outcome of the measurement of the second spin is determined. It is determined even if the measurements are made with such separation and timing that superluminal influences would be necessary. That's the non-locality. I don't think Bell ever claimed that you could use this to transmit information; I would be very surprised to see that he did. Do you have a reference?

Also, "local realism" is pretty much the standard phrase in the literature for describing the situation.

[eastbay]

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One of the reasons I and many others reject the "just look around you" argument of Not Ready and others as some type of evidence for a superior being, is that we know that (aside from possibly human consciousness)the seeming magnificence of the Earth is mainly a simple consequence of Newton's laws and fractal geometry.

Furthermore, there is no reason to claim that Newton's Laws were created by this superior being. Because they are basically pure logical common sense. The Inverse Square law, the Law of the Lever, d=gtsquared, F= ma. All these experimental results are not the least bit surprising if you use logical thought.

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Uh...

They are not the least bit surprising only because your brain was trained by experiences in the macroscopic world consistent with them.

If we lived as subatomic particles, those things would probably seem like "Newtonian Weirdness" in contrast to the obvious, "logical" laws of quantum mechanics.

eastbay

[LadyWrestler]

[ QUOTE ]
[ QUOTE ]
One of the reasons I and many others reject the "just look around you" argument of Not Ready and others as some type of evidence for a superior being, is that we know that (aside from possibly human consciousness)the seeming magnificence of the Earth is mainly a simple consequence of Newton's laws and fractal geometry.

Furthermore, there is no reason to claim that Newton's Laws were created by this superior being. Because they are basically pure logical common sense. The Inverse Square law, the Law of the Lever, d=gtsquared, F= ma. All these experimental results are not the least bit surprising if you use logical thought.

[/ QUOTE ]

Uh...

They are not the least bit surprising only because your brain was trained by experiences in the macroscopic world consistent with them.

If we lived as subatomic particles, those things would probably seem like "Newtonian Weirdness" in contrast to the obvious, "logical" laws of quantum mechanics.

eastbay

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Great Point http://forumserver.twoplustwo.com/images/icons/exclamation.gif

[luckyme]

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If we lived as subatomic particles, those things would probably seem like "Newtonian Weirdness" in contrast to the obvious, "logical" laws of quantum mechanics.

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Are you saying the aussies don't have an accent ??

[Duke]

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"dont see how they arent surprising - you cant derive the inverse square law (unless you bring in the anthropic principle which doesnt seem to be what you are talking about) it is a brute fact about the world. Similarly, you cant derive quantum weirdness - it just is."

The inverse square law isn't obvious to you?

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Is it also obvious why gravity is so much weaker than the other forces? I'd love to enlighten the physics community.

~D

[Duke]

To answer the original question:

I've had the thought running around in my head that "quantum weirdness" could be the result of perfectly predictable behavior in a distinct system, and that our view of it from this spacetime is just a sort of slice of it. Here it's random, but that's because we can't follow the rest of the rules since our system precludes us from even modeling it.

~D

[gumpzilla]

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To answer the original question:

I've had the thought running around in my head that "quantum weirdness" could be the result of perfectly predictable behavior in a distinct system, and that our view of it from this spacetime is just a sort of slice of it. Here it's random, but that's because we can't follow the rest of the rules since our system precludes us from even modeling it.

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As I'm sure somebody has mentioned elsewhere in this thread, Bell's theorem answers questions like this. Your posited "rest of the rules" would be the hidden variables, in Bell's language, and so unless you want your theory to have superluminal influences (making it nonlocal) you're out of luck.

[chezlaw]

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There is no information transmitted in experiments that show violations of Bell's inequality.

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I very much sympathize with this "standard" point of view, but some authors have argued that it is the assumption of locality that is at fault in Bell's inequalities. I am aware of no theorem proving that it must be realism that should be abandoned -- all we know for sure is that the combination "local realism" doesn't work. Apparently, chez falls in with the non-locality crowd, which is a bit unusual but by no means ruled out experimentally.

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Again, only information and energy can not be transmitted at greater than the speed of light, so having effects that occur instantaneously, but do not transmit information are fine with all physical theories.

Bell assumed that info was being transmitted and so causality, events transmitted at the speed of light, (or local realism, which is a silly phrase, as you are calling it) would be violated. However, there is no info, so there is no violation and his assumption is wrong.

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This cannot be correct (well not simply correct in a way that helps me anyway). The question is whether or not info is being transmitted. Concluding that no information is transmitted requires an experiment that can tell the difference between info being transmitted instantaneously and information being transmitted suffucientlty close to instantaeneously. No experiment is needed to know that no experiment can tell the difference, all it can do is place a constraint on what counts as 'sufficiently'

So either you missesd the point about what I said or i'm missing the point about what you're saying.

[metric, I'm not in the non-locality crowd. I'm in the 'it makes no difference crowd' so either way of thinking about it is fine. As far as I can see it's logically impossible to distingish non-locality from non-realism in current science. If I have a bias I suppose its towards non-locality because i think all non-realism models in future science must also have a non-local logical equivalent]

chez