Lobstrosity

yguy is just incorrectly arguing from intuition like usual (as in "I just know, it's obvious to me--I can't prove it, I just know"). Unfortunately, he seems oblivious to the fact that intuition plays no part in our understanding of the microscopic world. Intuition is based on our experiences, on the observations we make with regards to the world around us. Intuition tells us that time is not relative, that velocities simply add (e.g. if I'm walking on a train at four miles an hour and the train is moving seventy miles an hour, I'm moving seventy-four miles an hour), that massive particles aren't waves but are instead point-like entities. Intuition told Einstein that there really were hidden variables, however it also told Einstein that the universe was static, causing him to make what he later deemed the greatest mistake of his life (creating a cosmological constant to prevent his equations from predicting an expanding universe). Misguided intuition prevented Einstein from predicting the Big Bang. Aspect's experiments, it seems, further demonstrate that misguided intuition gave Einstein a faulty view of quantum mechanics.

What yguy needs to realize is that intuition is only applicable to what we as humans interact with on a daily basis, not to realms of physics with which we have no practical experience. yguy has no intuition with regards to the physics of the microscopic world and yet he is willing to ignorantly assert how things must be. Because he simply does this by making ignorant and unfounded assertion after assertion, he brings absolutely nothing of intellectual interest to the table, especially when one notes that he seems perfectly happy to neglect the logical self-consistency of the current probabilistic theories we have.

yguy

You don't understand. I haven't yet addressed the issue of causality in this thread. If you know the coin will come up heads, do you say it has 50% probability of being heads? No, because you know. Thus, some degree of ignorance is implicit in the idea that an event is determined by probability. In the case of any event in which the possible outcomes are infinite, that degree is essentially infinite. Therefore, to say that an event is determined by probability is to say it is determined by ignorance.

What I'm hearing is that there are a bunch of unproven interpretations of QM which suggest that a particle can be other than "exactly somewhere". This casts doubt on whether we actually know what these particles are - and here we are back again in the land of esoteric ignorance. In fact, your post there is full of physicists saying they don't know what the hell is going on.

You, as a scientist, observe a phenomenon. Its cause is not immediately apparent. In order to formulate a testable theory to explain it, you start with an assumption. You have two choices that I'm aware of:

1. Assume the phenomenon has a cause.
2. Assume the phenomenon has no cause.

If you can tell me with a straight face that 2 is more reasonable than 1, we have no grounds for further communication on the matter.

yguy

From Jesse's post in the God and uncertainty thread:

As the great physicist Richard Feynman said, "Nobody understands quantum mechanics…do not keep saying to yourself, if you can possibly avoid it, 'But how can it be like that?' because you will go 'down the drain' into a blind alley from which nobody has yet escaped. Nobody knows how it can be like that."

In light of this quote, tell me, lob: just what understanding would that be?


in·tu·i·tion
n.
The act or faculty of knowing or sensing without the use of rational processes; immediate cognition.
Knowledge gained by the use of this faculty; a perceptive insight.

Intuition doesn't tell us any of those things. Intuition tells us, if we have never considered the problems before, that we don't know whether you're moving 74 mph, and that we don't know anything about particles.

What makes you think Einstein was excercising intuition here?

Misguided intuition prevented Einstein from predicting the emergence of a yet unproven theory?

The jury is still out on that.

What unfounded assertion have I made?

I'm supposed to be impressed that any particular theory is internally self-consistent and ignore its unacknowledged assumptions?

ex-xian

I don't think that's been said in this thread. Only that QM events are governed by probablity.
Some degree of ignorance in exactly what we have in QM. There really are not an infinite number of outcomes; the probablity of a partictle being located outside the classical limits decays exponetially to zero as the position approaches infinity.

How much mathematics and physics exactly have you had, yguy? Which books/papers have you read on the topic? I'm giving you the benefit of the doubt, since I don't recall ever discussing anything with you, that you actually have reasons for what you're saying about the microscopic world. And we are talking about the microscopic world, btw. Macroscopic events have too high energy for QM rules to apply.

No, it's not that we don't know where the particles are, it's that, before any measurement is taken, they don't exist at any specific point in space. There are "fuzzy." Look into the double slit experiment. And physicists don't know what the hell is going on in the sense of why is happens b/c QM is so counterintuitive. Richard Feynmann, speaking of QM, said that it's no use asking why it's this way, it just is.

Jesse

yguy
You don't understand. I haven't yet addressed the issue of causality in this thread. If you know the coin will come up heads, do you say it has 50% probability of being heads? No, because you know. Thus, some degree of ignorance is implicit in the idea that an event is determined by probability. In the case of any event in which the possible outcomes are infinite, that degree is essentially infinite. Therefore, to say that an event is determined by probability is to say it is determined by ignorance.

"Determined by ignorance?" That phrase doesn't mean anything. It'd be like if I said, "ability to predict the outcome is implicit in our calling a process 'deterministic', therefore to say an event is deterministic is to say it is determined by our ability to predict it." That's obviously nonsense, as is your claim.

And again, surely you must see the fallacy of saying that because we use probabilities to deal with events that are deterministic but too complicated to for us to predict due to ignorance (like a coin flip), that means all use of probabilities implies the phenomenon is deterministic but too complicated to predict due to ignorance. This is nothing more than reasoning-by-analogy! A simple Venn diagram would show the error in this type of reasoning.

yguy:
What I'm hearing is that there are a bunch of unproven interpretations of QM which suggest that a particle can be other than "exactly somewhere".

Apparently you weren't reading very carefully--the whole point of most of these "unproven interpretations" is to restore the idea that the particle is "exactly somewhere", which seems to be contradicted by things like the Aspect experiment. The notion that the particle has exact values for things like position and momentum at all times is called a "hidden variables" theory, and it's been proven that the Aspect experiment is not compatible with local hidden variables (where 'local' means that influences between particles cannot exceed the speed of light).

yguy:
You, as a scientist, observe a phenomenon. Its cause is not immediately apparent. In order to formulate a testable theory to explain it, you start with an assumption. You have two choices that I'm aware of:

1. Assume the phenomenon has a cause.
2. Assume the phenomenon has no cause.

If you can tell me with a straight face that 2 is more reasonable than 1, we have no grounds for further communication on the matter.

Of course you always look for causal explanations, but if none suggest themselves, and the phenomenon meets every criterion for randomness that can be found, one might tentatively conclude it's genuinely random.

But once again you're sidetracking the argument here, which is about the logical possibility that a phenomenon could have a genuine element, not the epistemological question of whether we could ever know if something is genuinely random or has a hidden cause. Based on your strange "determined by ignorance" comment, it appears you're having trouble separating epistemology (what we can know about the world) from ontology (what is actually true about the world).

Unless you can provide a single argument as to why it's impossible a phenomenon could actually be inherently probabilistic (apart from the issue of whether we could ever know it to be inherently probabilistic), I agree that we don't have much reason to continue this discussion, since you'll have confirmed my initial view that you're not capable of going beyond bare assertions of your own opinion on this matter.

yguy

Of course it doesn't. That's the point. Neither does "determined by probability".

But that isn't what I've said here. What I've said is that we are disguising ignorance as knowledge through the self-deceptive semantics.

Then I don't understand why you objected when I said any particle whose position or momentum we don't know is exactly somewhere. If you're saying these interpretations fail to restore the "exactly somewhere" idea, I don't see how that is significant.

Perhaps you could give an example or two of criteria for "genuine randomness".

I accidentally edited your post when I meant to reply, sorry--Jesse

yguy

No doubt, but there are an infinite number of possibilities as to where a particle might be at any particular time.

Call it none.

You are speaking here of a particle as a wave before the wave function collapses under observation, I presume? This begs the question - to me at least - of whether the particle as a wave can be said to have random motion.

I am familiar with the fact that coherent light sources can produce interference patterns which vary according to wavelength and other variables. How is that significant here?

I should take the word of a guy who admits he doesn't know what the hell is going on that there is no use asking why?

Jesse

Jesse:
Determined by ignorance?" That phrase doesn't mean anything.

yguy:
Of course it doesn't. That's the point. Neither does "determined by probability".

Who says "determined by probability"? I agree that's awkward phrasing, but what I've been saying is that it's not meaningless to say an event could be inherently probabilistic--ie there is no hidden cause behind the fact that the outcome is different in some trials than in others.

Returning to the epistemology vs. ontology issue, perhaps the problem here is that you are unable to conceive of statements about "probability" as being anything other than epistemological claims about our ability to predict something or determine its causes. But I don't see how there is any problem using "probability" in ontological statements about what the world is really like--if there is one, you certainly haven't been able to point it out.

yguy:
But that isn't what I've said here. What I've said is that we are disguising ignorance as knowledge through the self-deceptive semantics.

But aside from the epistemological issue of whether we can ever be justified in thinking a particular real-world phenomonon (like quantum mechanics) has hidden causes even if we can't find them, it seems you are also making the claim that it is inherently impossible (or meaningless, perhaps) that a phenomenon could "really" be purely probabilistic (an ontological issue). Am I misunderstanding you?

Jesse:
Apparently you weren't reading very carefully--the whole point of most of these "unproven interpretations" is to restore the idea that the particle is "exactly somewhere", which seems to be contradicted by things like the Aspect experiment. The notion that the particle has exact values for things like position and momentum at all times is called a "hidden variables" theory, and it's been proven that the Aspect experiment is not compatible with local hidden variables (where 'local' means that influences between particles cannot exceed the speed of light).

yguy:
Then I don't understand why you objected when I said any particle whose position or momentum we don't know is exactly somewhere. If you're saying these interpretations fail to restore the "exactly somewhere" idea, I don't see how that is significant.

Funny how you've suddenly gone from deriding those "unproven interpretations" in your last post to completely depending on them in this one, now that you understand they're the only way to salvage your preconception that a particle must be "exactly somewhere" at all times.

Anyway, if you read what I originally wrote maybe you'll understand my objection better:

I didn't say it's impossible that hidden-variables theories are true, just that the violation of Bell's inequality deals them a major blow, and that the only way to salvage them is to postulate some other very strange phenomena like faster-than-light conspiracies between particles.

Jesse:
Of course you always look for causal explanations, but if none suggest themselves, and the phenomenon meets every criterion for randomness that can be found, one might tentatively conclude it's genuinely random.

yguy:
Perhaps you could give an example or two of criteria for "genuine randomness".

Same way you'd determine whether a computer's random-number-generator was actually based on a pseudorandom algorithm--look for various types of hidden patterns or correlations. A bunch of such tests are listed here:

http://www.fourmilab.ch/random/

But once again you've brought the debate back to epistemological questions about whether it's possible to know if something is genuinely random or not. I'm not interested in talking about that, I just want to know why you think it's impossible something could be genuinely random (but perhaps the answer is, as I said above, that you're unable to conceive of using words like 'random' or 'probability' in anything other than an epistemological context--if so, please say so).

yguy

That is the problem. I see no difference between saying an event is inherently probablistic and saying it is determined by or based on probability.

Yes.

There isn't, as long as the ignorance (I'm not using the term pejoratively here) implicit in the idea is recognized.

I haven't made that claim here yet, because I don't think it's particularly an arguable point. What I do believe is that the idea that idea that an event has no cause is patently absurd. I'm sure those atheists here who find odious the idea of God as the uncaused first cause can identify.

You lost me. How am I depending on any of those theories for anything? All I said was I don't understand how your objections follow from any of the quoted material.

Or we could just admit we haven't got a clue.

IOW, look for known patterns. What it amounts to is, if you can't see a pattern, you conclude there probably isn't one. See the implicit subjectivity in such methodology?

If the conversations we've had to this point haven't made that plain, it's a waste of time.

Jesse

Jesse:
Who says "determined by probability"? I agree that's awkward phrasing, but what I've been saying is that it's not meaningless to say an event could be inherently probabilistic--ie there is no hidden cause behind the fact that the outcome is different in some trials than in others.

yguy:
That is the problem. I see no difference between saying an event is inherently probablistic and saying it is determined by or based on probability.

If an event is inherently deterministic, would you say it is determined by determinism? Determined by causality? Still seems like awkward phrasing. Perhaps it would be better to say that if an event is "inherently probabilistic", that means the outcome of any particular trial is not determined by anything (ie the outcome is uncaused), but over a large number of trials the ratios of different outcomes will tend to approach the ones in the probability distribution.

Jesse:
Returning to the epistemology vs. ontology issue, perhaps the problem here is that you are unable to conceive of statements about "probability" as being anything other than epistemological claims about our ability to predict something or determine its causes.

yguy:
Yes.

But you are able to conceive of statements about "causality" being more than merely epistemological claims? "Causality" has an epistemological side too--when we say event A causes event B, we're partly just saying whenever we see event A happening, we always predict B will happen. But I suspect you also think it's also meaningful to make the ontological claim that "A was really the cause of B". So what's the relevant difference? Why can't probability have an ontological side too? Is it solely that you don't believe in uncaused events?

Jesse:
But I don't see how there is any problem using "probability" in ontological statements about what the world is really like--if there is one, you certainly haven't been able to point it out.

yguy:
There isn't, as long as the ignorance (I'm not using the term pejoratively here) implicit in the idea is recognized.

Huh? Ignorance vs. knowledge are completely irrelevant to ontological claims, that's the domain of epistemology. Ontological statements are just about what the world is really like, independent of us; so when I say "using 'probability' in ontological statements about what the world is really like", I'm talking about a statement like "such-and-such an event may really be inherently probabilistic, even if we are can never know this for certain."

Jesse:
But aside from the epistemological issue of whether we can ever be justified in thinking a particular real-world phenomonon (like quantum mechanics) has hidden causes even if we can't find them, it seems you are also making the claim that it is inherently impossible (or meaningless, perhaps) that a phenomenon could "really" be purely probabilistic (an ontological issue). Am I misunderstanding you?

yguy:
I haven't made that claim here yet, because I don't think it's particularly an arguable point. What I do believe is that the idea that idea that an event has no cause is patently absurd. I'm sure those atheists here who find odious the idea of God as the uncaused first cause can identify.

Do you think the idea that "this event had no cause" is just "absurd" and therefore wrong or impossible, or do you think the phrase is meaningless like "green ideas sleep furiously"?

Jesse:
Funny how you've suddenly gone from deriding those "unproven interpretations" in your last post to completely depending on them in this one, now that you understand they're the only way to salvage your preconception that a particle must be "exactly somewhere" at all times.

yguy:
You lost me. How am I depending on any of those theories for anything?

Because without weird ideas like the ones described in those interpretations, there is no way to salvage the idea of "hidden variables", ie the idea that a particle is "exactly somewhere" at all times. You aren't giving up the idea that the particle must be "exactly somewhere", are you? If not, you must depend on these interpretations.

yguy:
All I said was I don't understand how your objections follow from any of the quoted material.

Which part of my objections didn't you understand? My objection was just that theories of local hidden variables have been absolutely ruled out by the Aspect experiment, which only leaves strange non-local hidden variables theories involving things like faster-than-light signalling or the future influencing the past.

Jesse:
I didn't say it's impossible that hidden-variables theories are true, just that the violation of Bell's inequality deals them a major blow, and that the only way to salvage them is to postulate some other very strange phenomena like faster-than-light conspiracies between particles.

yguy:
Or we could just admit we haven't got a clue.

But we do have a clue--we know that the Aspect experiment absolutely rules out local hidden variables theories. There is no room for disagreement on that point.

yguy:
IOW, look for known patterns. What it amounts to is, if you can't see a pattern, you conclude there probably isn't one. See the implicit subjectivity in such methodology?

It's no worse than the subjectivity in saying "if we can't find a phenomenon which violates law of physics X, that means law X is probably true." All attempts to determine the truth about how reality works involve some degree of subjectivity.

Jesse:
But once again you've brought the debate back to epistemological questions about whether it's possible to know if something is genuinely random or not. I'm not interested in talking about that, I just want to know why you think it's impossible something could be genuinely random (but perhaps the answer is, as I said above, that you're unable to conceive of using words like 'random' or 'probability' in anything other than an epistemological context--if so, please say so).

yguy:
If the conversations we've had to this point haven't made that plain, it's a waste of time.

I wasn't thinking enough about the difference between saying "some events could be inherently probabilistic" is impossible and therefore false vs. saying it's meaningless gobbledygook and therefore neither true nor false.