On the matter of a rock falling down a hill

When a rock falls down a hill, there's only one question that needs to be asked in order to determine whether or not we could feasibly predict its path and final destination. And that question is:-

Does the rock obey the laws of physics?

If the answer is "yes", then our ability to predict its path relies solely on our ability to recreate the environment perfectly. If we can, then we can predict the rock's path.

And when I say "perfectly" I really do mean perfectly. If we had a model of the hill at a molecular level, allowing for humidity, air convection and every other item that is controlled by the laws of physics... there is no feasible reason why we couldn't then predict everything that then happens.

If we can't do that, then there is a problem with our method of recording the details, or our computational model.

We could always simplify everything, predicting the path of a dropped ball down a level ramp in an airless chamber. If your argument is one of complexity, then I'd inquire just when (exactly) determinism fails.

If you don't accept all of the above, then I have a simple question for you:-

What is governing the direction of the rock/ball other than the laws of physics? The gentle blowing of a deity? An angel gently flapping its wings? A leprechaun farting?

Just what, exactly, are you proposing if not the material world and (with enough knowledge and computational skills) predictable mechanisms?



"Any sufficiently advanced technology is indistinguishable from magic." - Arthur C. Clarke (third law of prediction)

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Oh, and you'd best be careful when using the word "random". Do you know how difficult a concept randomness is? Do you know how a computer generates a random number? Hint: it isn't random.

(July 11, 2013 at 8:37 am)bennyboy Wrote: The BOP hot-potato game is a cop-out. So is the red-herring of dubbing opposing opinions "extraordinary claims." There's nothing extraordinary in supposing that since many systems cannot be calculated, either they are not deterministic, or at least cannot be proven so.

Particularly annoying (and wrong) is the following logic:
Determinist: I can predict what time the sun will come up. This gives at least some evidential support for determinism.
Non-determinist: Okay, predict where the sun's spots will be this time next year.
D: I could, if I knew the states of all the particles in the sun, and had a powerful enough computer.
ND: That represents a statement of faith, and is probably not knowable even theoretically.
D: That's an argument from ignorance. What evidence have YOU got? BOP on you, since I've at least provided SOME kind of evidence for my position.

The problem with this is that D is arguing a GENERAL theory with specific examples that don't generalize well; in other words, they are anecdotal. There's no reason to think that predicting the sun's rising time has any relationship to predicting market trends 10 years from now, or where the sun's spots will be. Or how a person's decision processes (which seem fairly deterministic in the short term) will arrive at a certain state of being a few years (or even a few days) from now.

Nor is there any reason to believe that it is physically POSSIBLE to achieve a computer that will have the power to calculate such complex systems. The only computer theoretically capable of calculating all the influences of ALL the particles in the universe (gravity, anyone?) on each other is the universe itself.

Physicists, question for you: is it possible to predict exactly when/where particles pop into existence from "empty" space, and what their attributes will be when they do so?

Most likely, determinism is like entropy. Entropy can never decreases but there are locations where it does decrease. Earth is a perfect example. But taking the universe as the whole system, entropy doesn't decrease. Determinism seems to follow the same pattern. On the whole, the universe is deterministic, but there are pockets here and there that aren't. For example, the stock market.

Note: Science presupposes that the universe is deterministic. If it wasn't, we wouldn't not be successful at studying it in a scientific way. That's why the Einstein quote is so important. It goes at the core of what science is all about.

It sounds to me like there are several different concepts of emergent in play, including complex, unpredictible, irreducible, and chaotic.

I rather tire of people who don't understand specifically what they mean by the term substituting the word 'emergent' for whatever it is they do mean as a one-size-fits-all obfuscator. I'm not even sure that emergence is a valid concept, myself, but that discussion can await another day.



While the brain is incredibly complex, unlike physical systems for which Heisenberg's uncertainty principle and the mathematics of chaotic systems apply, there is no obvious reason to consider the behavior of the brain and nervous system as not being predictable in principle. And it is in this latter, scientific sense that it must be considered, not in a philosophical sense, or in the sense of absolute proof. We don't have absolute proof of any natural law according to the standard of perfect predictability; that is not how science works. Science formulates a theory, novel predictions from that theory are made, the predictions are tested, and they either corroborate or fail to corroborate the theory. Uniformitarianism is an assumption, but not one without support. We need not perform the Michelson-Morley experiment millions of times in millions of places to "prove" that there is no ether and the speed of light is independent of momentum. If you have reason to believe that the laws of physics do not apply to a specific phenomena or system under examination, the onus is on you to propose a test which will show this to be the case and then performing it. Nobody is under any obligation to pay any attention to your idiotic warblings if you just toss up your hands and panic, "Oh my great gods! It's all so complex! I just don't understand it! It must be magic!"

(July 11, 2013 at 1:25 pm)apophenia Wrote: I rather tire of people who. . .

We are not amused, wot? Condescension much?

Quote:[. . .] there is no obvious reason to consider the behavior of the brain and nervous system as not being predictable in principle.

You can believe whatever you want in principle. The question is whether you can show it to be true. So go ahead and show it. It's pretty exciting that we can predict some near behaviors based on observations of brain activity. However, going from these primitive calculations to assertions about processes lasting more than a couple days is like going from saying a thunderclap predicts rain, to saying that in principle, we can predict patterns of weather five years from now.

Also, some systems may NOT be provably deterministic, even in theory. I've argued that any predictions which depend on the value of pi are intrinsically imprecise, giving way necessarily, and in all cases, to the butterfly effect. In other words, there is not even theoretically any way to make accurate predictions about some systems, making determinism impossible to verify. Perhaps you should start by showing, in principle, that we can calculate the complete value of pi.

Quote:that is not how science works.

Insisting that all philosophical issues be filtered through the scientific process pretty much defines "begging the question," since as Joe pointed out, science is pretty much founded on physical determinism.

Quote:If you have reason to believe that the laws of physics do not apply to a specific phenomena or system under examination, the onus is on you to propose a test which will show this to be the case and then performing it.

I "rather tire of people" who play the BOP game with philosophical assumptions masquerading as actual science. However, I'm often wrong. Go ahead and link any experiments you can find which prove any given state of the universe can lead only to exactly one other. Then perhaps we will be amused.

I hope that all of the "non-determinists" remember these conversations the next time that they're talking to a creationist who demands that they show them proof of evolution. Not that it is the best explanation, based on all available evidence, mind. Because (apparently) that isn't enough.

They'll either achieve recognition of what they've been doing here... or they'll become hypocrites.

Either/or.

(July 11, 2013 at 5:24 pm)Red Celt Wrote: I hope that all of the "non-determinists" remember these conversations the next time that they're talking to a creationist who demands that they show them proof of evolution. Not that it is the best explanation, based on all available evidence, mind. Because (apparently) that isn't enough.

They'll either achieve recognition of what they've been doing here... or they'll become hypocrites.

Either/or.

Nice try, but just because both determinism and evolution are held by scientists doesn't mean that those who doubt them are following the same process, or have the same reasons, or are using similar kinds of logic. In fact, I'd argue that the scientists are using different processes in arriving at evolution and determinism. Don't believe me? Science can still be done with good confidence if you do not believe that evolution is true, or even if it turns out to be dead wrong. Physical determinism must be true, or the scientific process will be invalidated. See the difference? Only the "conclusion" of determinism begs the question.

(July 11, 2013 at 9:32 pm)bennyboy Wrote: Nice try, but just because both determinism and evolution are held by scientists doesn't mean that those who doubt them are following the same process, or have the same reasons, or are using similar kinds of logic. In fact, I'd argue that the scientists are using different processes in arriving at evolution and determinism. Don't believe me? Science can still be done with good confidence if you do not believe that evolution is true, or even if it turns out to be dead wrong. Physical determinism must be true, or the scientific process will be invalidated. See the difference? Only the "conclusion" of determinism begs the question.

Well. I tried. It's a shocker when someone on the internet fails to admit to being wrong. Because that rarely happens.

Okay, no need say that Bennyboy's just not admitting that he's wrong. I think he's wrong, but I think he's given a reasonably good case for his point, and has in fact pointed out some problems of pro-deterministic arguments some of us have given.

In other words, we simply seem to disagree.

I know. I'm in snarky mode because of the Republic of Ireland.

Lulz, the - wannabe - "Republic of Texas" makes me snarky at times as well. x3