Obsidian debates -1

[Darth InSidious]

Well, some of you chaps seem to be stuck on this notion that an 'illusion' means something automatically bad, which is a circular argument. Is bad bad? etc.

 

Replace 'illusion' with 'working simplification' and what do we get?

 

this made me wonder if the whole point is that we don't naturally perceive time most of the er... time. I mean how often are you actually aware of your finite ration trickling away? I've done it a few times in the last few years and it drove me almost mental. It's not healthy.

 

I still favour Doctor Who's "Timey-Wimey-Stuff" explanation.

That's not Doctor Who, it's raped childhood served up in a bap.

[Humodour]

You're being a tool. The maths (and fit with experimental data) is as sound as that of the probabilistic interpretations, therefore it is as valid as them until new data allows us to rule one or more interpretations out.

 

It's basic science.

 

You're missing the point - it itself is not much more than a baseless, untestable "what-if." The math "what if" doesn't directly conflict with the equations that describe quantum mechanics, but it is still baseless and untestable.

 

It's akin to the belief in a god who decides how nature's random number generator works - there's no way to disprove it, it doesn't directly conflict with the equations, but it is ultimately meaningless. The fact is that the equations are all probabilistic.

 

@Krezack - appeals to authority mean nothing. I can dig up some creationists who've been at very prestigious colleges, yet that would do nothing to validate creationism.

 

You don't understand this.

 

Deterministic QM is not a 'what if' - it is a part of the set of currently valid interpretations of QM. IT IS PART OF QM. WE CAN NOT YET SAY OR PROVE THAT ANY OF THE CURRENT INTERPRETATIONS IS MORE CORRECT THAN THE OTHERS. And that is exactly why they are all part of QM. THERE IS NO CURRENT WAY TO PROVE THAT ANY OF THEM IS MORE CORRECT THAN THE OTHERS. So anybody claiming that they know one of them actually is more correct (i.e. predictive) should be looked upon with a great deal of scepticism indeed.

 

That's not to say it won't be possible to eliminate interpretations in the (possibly near) future. There are facets of all the interpretations which are physically testable, including Bohmian mechanics.

 

It's akin to the belief in a god who decides how nature's random number generator works - there's no way to disprove it, it doesn't directly conflict with the equations, but it is ultimately meaningless.

 

I like this quote because it could so easily be applied to probabilistic quantum mechanics as well. Did you never bother to ask yourself the question "where does the randomness come from?"? Frankly I see a deterministic universe as a lot more self-contained and logically consistent than one which requires 'randomness' to come from 'somewhere'.

 

The fact is that the equations are all probabilistic.

 

Why? How? In what way is this 'a fact'? Do you have some evidence to prove it?

 

You're claiming that the equations are all probabilistic without any knowledge of the deeper mechanics of the universe. You can't do that. You can say that the equations we use to model the universe are probabilistic. You can say that the universe appears to be probabilistic to humans. Neither of these is relevant to whether the universe is actually probabilistic, or whether modelling the universe probabilistically is even the most accurate means of doing so (it's certainly probably the most efficient at least until we have quantum supercomputers (so not just quantum computers, but super-fast ones even by quantum computing standards), which are able to quickly model physical systems on a particulate level).

[Humodour]

Thread is tl;dr so I'll just say this:

 

Spacetime isn't something that is believed in or not; that's the premise of religion, not science. Spacetime is real, but not necessarily in the sense that the table I'm writing this on is: it can't be seen, or felt. It merely is. We can measure it, and its effects- if that's an illusion, then your monk's right, but as far as I'm concerned he's wrong.

 

As for the probabilistic/deterministic debate, we simply don't know enough about wavefunction-collapse yet to say anything definite. I personally think the notion of a probabilistic universe is a little far-fetched, but **** it, even if the universe is probabilistic, quantum effects go away on the macro scale, so its not all that unrealistic. Bohm (and for that matter, EPR [even if their math doesn't quite work, I'm talking about the idea here]) can't be ignored because Bohr said so- the math itself simply describes probabilities; it doesn't say absolutely that there is no way to determine which outcome will occur given knowledge of initial conditions. Remember, QM describes things as waves which in some sense can be described merely in terms of first-order derivatives and initial positions.

 

Also, since GR correctly describes a larger group of situations [that we know absolutely have come to pass- i.e. star formation] it inherently ought to be given a deep, deep consideration.

 

Indeed. GR was proven to accurately describe the structure of spacetime around around the Earth by Gravity Probe B just this year. Specifically it confirmed the existence of frame-dragging and the geodetic efffect. That said, you know, it's still possible (probable if we give humans enough time) a theory with even more accurate predictive power will come along and knock it over (c.f. Relativity and Newtonian mechanics). One day.

[I want teh kotor 3]

Indeed. GR was proven to accurately describe the structure of spacetime around around the Earth by Gravity Probe B just this year. Specifically it confirmed the existence of frame-dragging and the geodetic efffect. That said, you know, it's still possible (probable if we give humans enough time) a theory with even more accurate predictive power will come along and knock it over (c.f. Relativity and Newtonian mechanics). One day.

 

Definitely. The thing is, though, that its sure as hell NOT QM, so since GR requires determinism, I think those interpretations that fit in to that framework ought to be given special consideration.

[Oblarg]

Why? How? In what way is this 'a fact'? Do you have some evidence to prove it?

 

Uh, yes - the equations themselves. They deal with probabilities. That's rather the entire point of the uncertainty principle.

 

I don't know about you, but when I see a system which is defined in terms of probabilities, I call it probabilistic. I do not think that there's some imaginary "guiding function" secretly working behind the probabilities, because that's a meaningless proposition.

Edited May 18, 2011 by Oblarg

[Humodour]

Ah, really. And where does this randomness come from Oblarg? 'It just is', perhaps? Charming.

[Oblarg]

Ah, really. And where does this randomness come from Oblarg? 'It just is', perhaps? Charming.

 

Yes, it just is. You may as well ask "why does everything exist." You won't get an answer, because it's not an answerable question.

[Pidesco]

http://en.wikipedia.org/wiki/Interpretatio...antum_mechanics

[Humodour]

Ah, really. And where does this randomness come from Oblarg? 'It just is', perhaps? Charming.

 

Yes, it just is. You may as well ask "why does everything exist." You won't get an answer, because it's not an answerable question.

 

*sigh* Then probabilistic QM is no more intuitively useful for describing the universe than deterministic QM, now is it? So I'll say again, until there is some valid reason to rule out interpretations - don't.

[Humodour]

http://en.wikipedia.org/wiki/Interpretatio...antum_mechanics

 

Specifically this: http://en.wikipedia.org/wiki/Interpretatio...nics#Comparison

 

Oblarg, note the column 'deterministic'? Note how many interpretations are?

[Oblarg]

http://en.wikipedia.org/wiki/Interpretatio...antum_mechanics

 

Specifically this: http://en.wikipedia.org/wiki/Interpretatio...nics#Comparison

 

Oblarg, note the column 'deterministic'? Note how many interpretations are?

 

Does nothing to change the fact that quantum mechanics describes the world in terms of probabilities.

[Pidesco]

It should be noted, by the way, that the Copenhagen Interpretation sees the wave function, and hence the probabilities, as a mathematical device without any real existence.

[Humodour]

http://en.wikipedia.org/wiki/Interpretatio...antum_mechanics

 

Specifically this: http://en.wikipedia.org/wiki/Interpretatio...nics#Comparison

 

Oblarg, note the column 'deterministic'? Note how many interpretations are?

 

Does nothing to change the fact that quantum mechanics describes the world in terms of probabilities.

 

That is incorrect. Quantum mechanics only describes the world in terms of probabilities for maybe a third of the main interpretations. Bohmian mechanics for example, the interpretation we've been discussing throughout this thread, does not drescribe the world probabilistically and is one of the main interpretations.

Edited May 19, 2011 by Krezack

[Oblarg]

That is incorrect. Quantum mechanics only describes the world in terms of probabilities for maybe a third of the main interpretations. Bohmian mechanics for example, the interpretation we've been discussing throughout this thread, does not drescribe the world probabilistically and is one of the main interpretations.

 

The "interpretations" do nothing to change the equations themselves, which deal with probabilities.

 

You want a really simply example? Consider radioactive decay.

Edited May 19, 2011 by Oblarg

[Humodour]

That is incorrect. Quantum mechanics only describes the world in terms of probabilities for maybe a third of the main interpretations. Bohmian mechanics for example, the interpretation we've been discussing throughout this thread, does not drescribe the world probabilistically and is one of the main interpretations.

 

The "interpretations" do nothing to change the equations themselves, which deal with probabilities.

 

You want a really simply example? Consider radioactive decay.

 

Poor example. We do not actually know whether radioactive decay is random or not. Lots of people suspect it might be chaotic and subject to the environment, not random (without even getting into QM). Humans have a long history of looking at things, struggling to find a pattern, and then declaring them random, only to be later proven wrong.

 

After all, as we don't know which interpretation of QM is correct, we have no reason to believe it should be random.

 

Oblarg, you're suffering from the problem of trying to prove QM is random by pointing to things which are random in the probabilistic interpretations of QM (but deterministic in deterministic interpretations). Essentially, it's circular reasoning.

Edited May 19, 2011 by Krezack

[Oblarg]

Humans have a long history of looking at things, struggling to find a pattern, and then declaring them random, only to be later proven wrong.

 

Actually, you have it backwards. The human brain is great at seeing patterns when there are none, not the other way around. Any basic psychology class could teach you that.

 

You don't seem to understand the math behind quantum mechanics. That's alright - take some physics classes, and you'll say things which are less silly.

[Humodour]

Humans have a long history of looking at things, struggling to find a pattern, and then declaring them random, only to be later proven wrong.

 

Actually, you have it backwards. The human brain is great at seeing patterns when there are none, not the other way around. Any basic psychology class could teach you that.

 

You don't seem to understand the math behind quantum mechanics. That's alright - take some physics classes, and you'll say things which are less silly.

 

What kind of a response is this man? You can't respond to logic so you throw out baseless personal insults?

 

Come on, if you're smart enough to understand a bit about one of QM's interpetations (Copenhagen it would seem), then you should easily be smart enough to understand why it is still just an interpretation. There are deterministic interpretations out there which are mathematically rigorous and consistent with the basis of QM (insomuch as, say, Copenhagen is). In those interpretations, radioactive decay is not random, it is chaotic.

 

Your response to this is "nuh-ah, you can't do maths, you're silly!"

[Oblarg]

Humans have a long history of looking at things, struggling to find a pattern, and then declaring them random, only to be later proven wrong.

 

Actually, you have it backwards. The human brain is great at seeing patterns when there are none, not the other way around. Any basic psychology class could teach you that.

 

You don't seem to understand the math behind quantum mechanics. That's alright - take some physics classes, and you'll say things which are less silly.

 

What kind of a response is this man? You can't respond to logic so you throw out baseless personal insults?

 

Come on, if you're smart enough to understand a bit about one of QM's interpetations (Copenhagen it would seem), then you should easily be smart enough to understand why it is still just an interpretation. There are deterministic interpretations out there which are mathematically rigorous and consistent with the basis of QM (insomuch as, say, Copenhagen is). In those interpretations, radioactive decay is not random, it is chaotic.

 

Your response to this is "nuh-ah, you can't do maths, you're silly!"

 

You're splitting hairs. Radioactive decay on the scale of one atom cannot be predicted. It is defined in terms of probabilities on the scale of multiple atoms. Do you honestly not know this? It's easily observable. No amount of interpretation changes that fact - the behavior of radioactive decay is described by probabilities, hence the term, "probabilistic." Speculating as to hidden functions working behind what is observable is silly and changes nothing.

Edited May 20, 2011 by Oblarg