Spenser

I got the following from Here which ironically enough was written by a diarist who chose the name Jesus Christ!

I thought it quite good! :notworthy

ex-xian

Oh, I agree. I didn't mean to imply that science is the exclusive province of the scientists. I believe quite the opposite. However, when I post in the evolution forums I wouldn't try to discuss the implications of what I may think evolution means without talking to people who specialize in it. I'm a big fan of popularizing science; but I think that I agree with Sagan who said that a good popularization of QM doesn't exist and probably never will.

Also, I don't want to give off a false impression. I'm only an undergrad (although only for one more year!); and I've only had about a year's worth of QM. So I'm by no means anything near a expert. As a matter of fact, the more I learn about QM, the less I think I know about it.....does that make sense?

BTW, you're a physicist...what do you think about all this?

I also added the missing "think" in my other post. Thanks for pointing it out.

Quantum Ninja

Hello, this is my first post here. Please be gentle... I don't claim to be an expert in QM.

Isn't there a fallacy of composition here? Just because the consituent elements exhibit indeterministic behavior, that doesn't necessarily mean that composite objects can't exhibit deterministic properties. Or is the argument the other way around? Are you saying that because we observe that macroscopic objects interact with each other deterministically, that the constituent elements must also behave in a deterministic manner? That's a fallacy of division.

Just check out this link below:
http://www.creighton.edu/~csc107/Labs/flips.html

In the text box labeled "Desired flip pattern", enter H. Enter a large number for the number of flips (I usually do about 50,000) and then press the "Simulate" button. Take note of the percentage of matches. Wash, rinse, repeat ad nauseam.

After doing several trials of this (using 50,000), the outcome looks pretty damn deterministic to me. I've never had a result fall anywhere out of the range 49-51. Sure, the element of randomness is still apparent at this level, but as you increase the number of flips, it becomes less and less noticeable. Eventually, with a large enough number of flips, you won't start noticing any effects of randomness until, say, the 25th decimal spot. In a real world setting, most minute discrepancies like this are usually beyond the limits of the accuracy of our measuring instruments at the macroscopic level. In which case, we are unable to observe the inherent randomness of quantum mechanics and say that the outcome is regular enough to be called determinisitic. But that's essentially what probability does... it retains the unpredictably of each individual outcome, but it allows for deterministic behavior to emerge at a large enough number of trials.

And who knows, there's always the possibility that macroscopic interactions are 100% deterministic, and that the limits of unpredictability of QM are governed by this deterministic behavior. For instance, every time I flip 1000 coins, 500 will flip up heads every single time. That's absolute determistic behavior at the macroscopic level. The randomness at the constituent level is that I can't accurately predict which 500 coins will land on heads. Perhaps our own world works in a similar way. I'm not a scientist (yet...), so this is all groundless conjecture, of course.

Obviously QM is a lot more complicated than flipping coins, but I think it serves as a good analogy.

haverbob

You know, I hear stuff like this on this board all the time. Events or whatever are caused by one thing or force mixing with or operating on another thing or force. After that it seems that we can put the reason, cause or origin stuff to bed, right? Well I can't. What is the reason, origin or cause of the things or forces that operate with other forces in a "random fashion"? It seems to me that people like to bring up the "black hole" stuff like that is some sort of final explanation that has no reason, cause or origin. If it doesn't, then please tell me why scientists are still trying to figure out a reason for black holes. Why didn't they just drop it and say "that's it, we found something with no reason, cause or origin, we're done". Actually, what discovery WILL scientists make that they will not question it's reason, cause or origin?

Shadowy Man

I wasn't trying to deride the people who talk about QM here, or trying to act superior. I was just pointing out that a lot of people here talk about it as if they really, really know it and argue the fine points of its implications etc.

I was trying to give the sense of my agreement with you on the idea that without really using the theories, and seeing how it meshes together with observations, etc. etc. one only has an incomplete knowledge of the subject. One of the main reasons I went into physics/astronomy as a career was because I wasn't satisfied with the "popular" presentation of the subject. I wanted to know more and I wanted to understand the subject(s) more fully.

As far as what I think, I tend to reserve judgement on some of the underlying issues, like if things are truly random or not. In fact, you'll probably note that I don't post much on those issues. I know that I don't fully understand the philosophical implications of QM. There is certainly so much more for us to learn about the universe. Remember that QM is a theory... all physics is a model. And, if the past has taught us anything, we need to be careful how much we assume our models are true representations of reality.

I do know, however, that QM is an insanely accurate model - I don't think any of my work would be possible if it weren't. It has been proven to me to be a good theory repeatably, reliably, and convincingly.

contracycle

I don't really understand haverbobs last post. We are exploring to know new stuff, find out how it works. We are curious apes. Finding outbstuff is useful - when we found out about penicillin, we could save peoples lives. Is that what you were asking?

ComestibleVenom

I think the primary issue that was being discussed was in essence a defense of using different ways of describing a system. It takes very little education, really only a bit of critical thought, to learn that terms borrowed from deterministic theory can easily be used as a heuristic to describe an indeterministic system.

Normal

Sorry for the late reply all, I'm on vacation

Semantics.

Actually the reasons for invoking Occam's Razor are not so clear as you would have me convinced. You can use it to eliminate either entities or systems or properties that are unparsimonious. The ability to branch is certainly an unparsimonious property of the universe if all it does is explain the double slit experiment, and especially if it has no other bearing on reality. You might find that proponents of each interpretation swear they're the ones using Occam's Razor correctly.

They cannot be directly verified in such a way that they are unfalsifiable. Most scientific theories I know can be directly verified.

But much like the god hypothesis, they posit untestable claims.

In other words all three interpretations are right, but they have a remarkable ability to incite wonder?

IIRC I don't declare any interpretation to be "out of court". The criticisms I bring against the other interpretations are pretty common.

It seems we are deviating from the real crux of the matter, and that is how an apparently deterministic system can arise from unpredictable components. Your answer is probability, but in reality not even one of the electrons in that cloud can be predicted. Not one. And yet everytime you see that cloud it rains.

Actually science was working with a completely deterministic outlook from the beginning, it works based on the principle that trials are repeatable. It is only recently that proof of indeterminism came forward in the form of quantum mechanics and that is really the basis for my question.

You can change evidence to mean probability all you want, it doesn't answer my question at all. You ultimately have no reason to believe that cloud will rain because it is fundamentally uncaused.

If you didn't mention an apparently deterministic system you didn't do anything to answer my question.

This line of reasoning may be effective if my OP had anything to do with "small changes", but my OP had more to do with causes then "small changes". No matter what you posit the "small change" to be, however, not a single electron's path, which undergoes these "small changes", is predictable. And yet structures composed of arbitrarily large amounts of these unpredictable paths are apparently deterministic. Yes, each electron may follow a model of probability, each with "small changes", but the model of probability doesn't imply determinism, and yet we live in an "apparently deterministic" world.

Also, if you are familiar with chaotic systems, even a small arbitrary change can drastically affect the state of the system. The existence of small change at all does not led to a reason for apparent determinism.

Even when we can't predict where a single one of those electrons can be. Amazing, isn't it?

Was this really necessary? I mean really, if it's not too much too ask to know the "ultimate nature of the orbits of planets", why is it too much to ask about this?

Do you admit uncertainty implies unpredictability?

False analogy. Literally guarding ones flanks is not based on chess, and vice versa.

This is true, it is under investigation, and current evidence suggests it is an illusion.

A non classical interpretation like you are suggesting (based on probability) is not even an appropriate interpretation of the word. There is nothing "causing" those probabilities.

I believe it is the definition "scientists confine themselves to", especially when they claim quantum effects are uncaused.

It is predictable macroscopicly, and unpredictable microscopicly. This is the paradox that is the basis for my question.

So the only path intentionality leads to is god? You may have granted an unfortunate conclusion for atheists.

And at the quantum level, the change in states from "zero" to "one" is unpredictable, and very much uncaused.

The "systematic influence" is unpredictable and random.

My problem is that the "far more accurate" system denies the existence of causes at all. There is no reason for causes to exist at the macroscopic scale. The classical heuristic of newtonian physics is purely an illusion, given evidence at the quantum scale.

But quantum mechanics are the layer underneath newtonian physics, not social relationships.

That wouldn't really be a square, it would be an apparent square. Besides that, this is a false analogy, the dots that make up the square can easily be called partial components of the square. Indeterministic components are making up an apparently deterministic system.

Care to name it?

Straw man, I never suggested throwing away the current system.

If you deny QM events are random then they are caused by something. If you posit they are caused by something you go against current evidence and basically take that on faith. You can do that, but have as much reason to as to believe in god.

Law of excluded middle applies in this case, something is either random, or not random.

Or a consequence of something we are all guilty of.

If you want to say quantum events are non-random, find a cause for them quick, probability is not a cause.

I've taken a course, but the things I'm dealing with are fundamental anyway.

If I have a red fabric, and I isolate a small part of the fabric, I'd expect to find red. If I have an apparently determinisic system, and isolate a small part of it, I'd expect to find a deterministic base.

It's a false analogy. Every apparent cause and effect in the world is at it's base, unpredictable. Even if it does "average out" like the coin flipping, each individual component is unpredictable in the execution of the apparent cause/effect relationship.

Finally to ex-xian:

Having read your other responses in other threads, and your admitted frustrations with dealing with this topic, it is unclear about why you are frustrated with me and my questions? You scorn me for not having an understanding of the underlying mathematical principles of it, and position yourself as the opponent of the language we use as betraying the underlying details of quantum mechanics, but the real issue at the core is that you don't know, no one does.

BTW: If it matters, I'm an undergraduate getting a Bachelor of Mathematics at the University of Waterloo.

My credentials:

Quantum Mechanics 1

We went over Schrodinger's equation, cat and all.

Partial Differential Equations 1

Ordinary Differential Equations 2

Applied Complex Analysis

Chaos

Doesn't really directly apply to QM, but the material went over chaos.

And other first and second year courses.

I'm obviously no expert on Quantum Mechanics, but do you really deny the bizarre philosophical implications of the evidence so far?

ex-xian

So go ask your physics teachers what they think of what you're saying.

Normal

You don't think I have?

I get a variety of answers from "depends on the interpretation", to "unsovled problem", to "not the right question to be asking".