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Post by Progenitor A on Nov 9, 2010 20:43:50 GMT 1
Even if all theories are approximations, some are better aproximations that others. At last, agreement So, to return to classical physics and quantum physics. We can derive classical physics as the limit of quantum physics, but we can't go the other way -- we can't derive quantum physics from classical physics, because classical physics just makes totally different assumptions about reality. How on earth do you think Quantum physics was derived? By a witch doctor doing a rain dance on on the Limpopo? Or by classical physicists poindering new discoveries? Such as the arch-classicist Einstein pondering the photo-electric effect? QM is derived (tortuously) from Classical physics Hence quantum theory is (more) correct than classical physics, and Bells theorem shows just that -- we can't explain quantum results using some hidden underlying classical theory. Any physical theory is 'more correct' than its antecedents - that is in the nature of science to reject older theories as newer 'better fit' theories arise. There is no 'truth' just a gradual , blind fumbling progress toward an approximation to the truth Any physicist that claims to have discovered the 'truth' is second rate
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Post by speakertoanimals on Nov 9, 2010 20:49:51 GMT 1
It wasn't DERIVED -- I was using derived in the mathematcial sense, that you can take quantum theory, and derive the corresponding classical theory as an approximation.
Which is a totally different process to the gradual discovery of quantum theory, through the ad hoc stuff of the Bohr model, through matrix mechanics and the Schrodinger equation, to the Dirac equation and then onto quantum field theory. But this wasn't a derivation...........
The whole point about quantum theory was that people were stuck -- classical physics was just plain wrong, that was it, and where to go next couldn't be derived from what worked previously, something fundamentally new had to be added.
Why you keep pretending to not understand this I don';t know, it's as simple as A fits inside B, but B doesn't fit inside A.
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Post by nickcosmosonde on Nov 9, 2010 22:16:37 GMT 1
Hardly simple. But this is a philosophical question, just the sort of issue you profess to dismiss.
The really interesting, immensely complex, question raised by the "gradual discovery" of quantum theory is the relationship between mathematical formulations and descriptive theory. If you believe this is a simple matter you will have to explain why, for example, Heisenberg and Schrodinger had such radically mutually contradictory theoretical interpretations of their different mathematical formulations - formulations that could indeed be shown to be saying the same thing precisely, mathematically, but which according to their authors represented radically different realities. You have this basic conceptual problem in any interpretation of mathematical formulae - F=ma, special and general relativity, QED, whatever. What do the symbols represent? What is it in the world that the equations fit?
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Post by Progenitor A on Nov 9, 2010 22:16:41 GMT 1
It wasn't DERIVED -- I was using derived in the mathematcial sense, that you can take quantum theory, and derive the corresponding classical theory as an approximation. I did notmean it was directly derived from Classical physics. It was simply a progression of the classic scientific method, where observations were made and hypotheses constructed in an attempt to explain what was observed. That the hypotheses were mathematical hypotheses is neither here nor there - Newtons theories were constructed on mathematics too - he invented a new mathematics to control his Laws of Motion[/quote]
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Post by abacus9900 on Nov 9, 2010 22:55:43 GMT 1
Why anyone would want to think up an 'idea' like this poster is beyond me. Whatever it is, it isn't physics.............. Well, I'm just sorry that my ideas seem too advanced for you to grasp. You are obviously a positivist but please do not assume that positivism is the whole answer. I'm betting that the real answer will be more weird than any of us can imagine. However, I must say that at least you are prepared to discuss things and for that you deserve some respect.
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Post by nickcosmosonde on Nov 10, 2010 1:02:39 GMT 1
I'm not a positivist, particularly, but I confess I don't understand your idea either. Non-tangible I get, but "not-physical"? Are you saying you believe an "idea" has some sort of existence apart from its embodiment in a brain? Res cogitans?
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Post by abacus9900 on Nov 10, 2010 11:06:07 GMT 1
I'm not a positivist, particularly, but I confess I don't understand your idea either. Non-tangible I get, but "not-physical"? Are you saying you believe an "idea" has some sort of existence apart from its embodiment in a brain? Res cogitans? Yes, because when you examine matter at the smallest scales all you find is 'ideas' about it. For example, the famous Schrodinger equation allows us to make statistical predictions about the behaviour of quantum objects, but all this equation deals with are probability 'waves' which are purely mathematical in nature and non-material, in other words an 'idea.' Therefore, matter at its base is essentially an idea. The question then is, where do these ideas originate from if we are all non-material? The answer must be that ideas have to come from some realm not based in what we perceive at the 'material world' but from a dimension that pervades it.
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Post by speakertoanimals on Nov 10, 2010 14:36:07 GMT 1
Then you should be MORE CAREFUL in your use of language, given the 'derive' has a very precise meaning in the context of theoretical physics and maths, different to the way you claimed to be using it.
Plus calling something the classic scientific method is also a bad idea! For starters, what other scientific method is there, for you to distinguish the 'classic' one (does it have more chrome?). It also could cause confusion with classical as in classical physics.
All in all, a welter of confusion and possible confusion in what was actually a totally obvious statement -- science progressed from classical physics to quantum physics -- no shit sherlock!
Tell me something I don't know, that has some vague hope of being vaguely interesting.....................
As regards the universe being 'ideas' -- I'll stick to platonism thank you very much..............
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Post by Progenitor A on Nov 10, 2010 14:47:51 GMT 1
Then you should be MORE CAREFUL in your use of language, given the 'derive' has a very precise meaning in the context of theoretical physics and maths, different to the way you claimed to be using it. Plus calling something the classic scientific method is also a bad idea! For starters, what other scientific method is there, for you to distinguish the 'classic' one (does it have more chrome?). It also could cause confusion with classical as in classical physics. All in all, a welter of confusion and possible confusion in what was actually a totally obvious statement -- science progressed from classical physics to quantum physics -- no shit sherlock! Tell me something I don't know, that has some vague hope of being vaguely interesting..................... As regards the universe being 'ideas' -- I'll stick to platonism thank you very much.............. Thank you for your little lecture on taking care in the use of English Something that everyone should take note of, and a dictum that you yourself would be advised to follow.
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Post by Progenitor A on Nov 10, 2010 14:50:03 GMT 1
As regards the universe being 'ideas' -- I'll stick to platonism thank you very much.............. Ho dear! Then you do not fancy a bit of the old rumpty-tumpty in the physics lab storage area?
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Post by carnyx on Nov 10, 2010 15:14:23 GMT 1
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Post by speakertoanimals on Nov 10, 2010 15:29:48 GMT 1
Hardly news to anyone who has read Godel. We leave proff to the mathematcicians, physics proceeds in a slightly different fashion. Anyway, hardly new even on these boards, bringing up the whole Godel thing and then claiming that theoretical physics is in a hole because of it................ Physics doesn't deal in proof, but falsifiability by means of experiment (although proofs can enter in as regards the mathematical structures of theories. So, if we can show mathematcially that classical gravity and quantum theories for other interactions are incompatible, then the result stands, even if we didn't happen to live in a universe that used quantum theory. But since it seems we do, explains why we'd better go looking for quantum gravity, because we can't make classical gravity fit as well.) Has ANYONE out there got anything sensible to say on the subject, or are certain people just going to keep recycling the same ole stock responses.............
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Post by abacus9900 on Nov 10, 2010 17:15:08 GMT 1
Hardly news to anyone who has read Godel. We leave proff to the mathematcicians, physics proceeds in a slightly different fashion. Anyway, hardly new even on these boards, bringing up the whole Godel thing and then claiming that theoretical physics is in a hole because of it................ Physics doesn't deal in proof, but falsifiability by means of experiment (although proofs can enter in as regards the mathematical structures of theories. So, if we can show mathematcially that classical gravity and quantum theories for other interactions are incompatible, then the result stands, even if we didn't happen to live in a universe that used quantum theory. But since it seems we do, explains why we'd better go looking for quantum gravity, because we can't make classical gravity fit as well.) Has ANYONE out there got anything sensible to say on the subject, or are certain people just going to keep recycling the same ole stock responses............. If you can't even rely on the way you measure physical processes then how can you really be in a position to demonstrate what is false and what is not? You are forever bound to keep making mistakes and forever hold a fundamentally erroneous representation of reality.
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Post by speakertoanimals on Nov 10, 2010 17:31:37 GMT 1
Who said anything about not being able to rely on physical measurements?
We take a measurement, and up to ordinary measurement error, we get AN answer. That's it, that WAS the measurement you obtained, and that is what we try to explain.
Where do you think in any of that is anything to say you can't rely on the measurement? Where is the 'mistake'? Or are you just playing word salad with us..............
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Post by abacus9900 on Nov 10, 2010 17:52:59 GMT 1
Who said anything about not being able to rely on physical measurements? We take a measurement, and up to ordinary measurement error, we get AN answer. That's it, that WAS the measurement you obtained, and that is what we try to explain. Where do you think in any of that is anything to say you can't rely on the measurement? Where is the 'mistake'? Or are you just playing word salad with us.............. But Godel showed that any reasonably complex set of mathematical axioms are always incomplete, therefore, what is measured is inevitably misrepresented.
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