Author: José Carlos
Date: 01:50:39 08/07/02
Go up one level in this thread
On August 07, 2002 at 03:57:30, Sune Fischer wrote: >On August 06, 2002 at 21:09:20, José Carlos wrote: >>>The theory has worked wonders for 70 years, passed all test, pridicted endless >>>amounts of results (it has pridicted new particles, explained alpa and >>>beta-radiation etc etc...), it's been one long success story from the very >>>beginning, it's possibly the greatest achievement of the human race in the 20th >>>century. >> >> General Relativity is more impressing to me. Hard to believe we live in a non >>euclidean space... > >Not to me. General relativity is almost obvious once you realize the newtonian >laws are inadequite. Every problem seems obvious once you have (and understand) the solution. GR is, IMO, a great intellectual achievement. >>>...but you don't believe it! >>> >>>-S. >> >> Don't get me wrong, I don't say it's bad. I'm not qualified to make such >>statement. I only say I don't believe what the theory relies on, specially >>non-determinism. > >It's the building block of quantum mechanichs, if you take that away there is >nothing left. >How will you describe the wavefunction for an electron _without_ this, and what >do you put instead of the Scrõdinger equation? The whole thing collapses >instantly. I'm afraid I didn't express myself very well. There're mathematical models (theories) and there's and undelying "real" structure of the universe. QM is good (as a whole, including UP) as a mathematical model that allows good predictions. But how can we know it describes the exact underlying structure of the universe? One example of what I mean: Newton laws allowed humanity to make good predictions about gravitation. As a mathematical model, it worked well enough for time. But the universe it described was telling to people that two bodies atract each other according to some parameters. But why? There was no reason beyond that. Then Einstein figured a curved four-dimension space that provided (among other things) what Newton couldn't provide: an explanation of "what is behind" the equations, a physical meaning. Is Einstein description "correct"? Who knows, all we know is that it works well from a mathematical point of view. >> There's no way to prove a theory, either right or wrong. A theory (in physics) >>is just a mathematical model of the world. > >I don't care much for that argument. This is obviously wrong once >you understand that a physical proof is different from a mathematical >proof. If the apple falls to the ground _always_, There's no physical proof, only physical clues. The only way to know that the apple falls always is to sit there along eternity wathing the apple fall again and again under every possible condition. But what if the earth chagens it path along space and start falling to the sun? At some point, the apple wont fall to the earth, but to the sun. Even Descartes made a big mistake when he built his reasoning from his starting point "cogito ergo sum". He used God to proove God existence in a non obvious but true circular reasoning... >then a we conclude there is a force of gravity - We _guess_ there's a force of gravity, until someone comes up with a better description of the event. What about gravitons? >by measurement, by emperical data. How should one *prove* this otherwise? >Is it a matter of religion whether or not gravity exists? No, it's physics >and it is based on observations. I disagree. We observe and then try to create mathematical models about the observations. But it's only inductive inference, we don't know what is really behind the observations. The whole universe could very well be ruled by a single equation, or by a million. We'll never know, I'm afraid. >>Using maths, we guess what's the >>reason for events and predict how nature will behave. A theory is as good as >>it's predictions are. So quantum mechanics is a good theory, no doubt. But: a) >>it's incomplete (it fails about gravitation); > >The quantum theory is more or less complete and it doesn't fail without the >gravity part IMO. Quantum theory doesn't describe _everything_ but in the areas >where it does work it fits perfectly. That's what I meant. It doesn't describe everything. We still lack a theory that describes the whole universe. QM in incomplete in that sense. >>b) it needs strange (anti-natural) >>statements (measure problem, non locality); > >Nature is strange, sorry if that is inconvinient to you ;) >My pet theory is that laws of nature is infinitely complex, and that >any attempt to look for pretty solutions is bound to fail. And you could be right here, of course. But can you figure out a way to be sure about that? There isn't such a way, because we only have our (stupid?) minds and our senses to observe the universe. How can we know we "see" everything? >Natures was not made so that humans would find it simple or easy to understand, >its *creator* had no such concerns, so why run around and expect it to be >simple? Creator? So you need a religion element for your physical argument? ;) >>c) doesn't make perfect predictions >>(you can't predict the behaviour of a single particle); > >It makes predictions that falls within the uncertainty principle, did >you expect it to contradict itself? As I said before, I don't. It works well as a whole, mathematically... >Youd _can_ calculate the probability for the presence of the particle, namely >its wavefunction. > >>d) it's just another >>model, we'll never know how the "real" (if such a thing exists) structure >>of the universe is. > >I fear you could be right. We still need a theory to tell us the physics of a >black hole singularity, for instance. >Doesn't mean that the rest is wrong :) >The problem lies in the difficulty of running experiments, we learn by >observing, when that is impossible progress becomes hard. Hawking has a theory where no singularity is needed outside a black hole, but it doesn't seem to be generally accepted, AFAIK. >> Non determinism is, IMO, a contradiction itself. If the same cause doesn't >>always yield the same effect (causality principle violation) any further >>reasoning is void. Note that every reasoning _needs_ the causality principle to >>make sense. Reasoning is going from a premise to a conclusion using inference >>rules. Same premises -> same conclusions, A is true _because_ B is false, etc... > >I don't see a problem, you _can't_ make the same premises, you can never setup >the same experiment twice at the quantum level so where is the problem? The problem is that reasoning is about making conclusions from premises. Non determinism means same premises may lead to different conclusions if we repeat the experiment. So reasoning process becomes absurd. >Do the lottery numbers come out the same every time, even when the >experiment is the same over and over? The numbers depends on the balls. The balls follow gravitation laws (and/or whatever other laws) so, IMO, if we repeat the experiment with the same initial conditions (balls in the same positions, same exact time moving them, same force applied, etc) the same numbers will come out. >> So non determinism as an inherent property of the universe is not acceptable >>for me, unless we immediately conclude we can't conclude anything, not >>even this conclusion! > >Einstein never 'converted' either, I think if you are not open minded you will >fail in this area of science, the subatomic world is alien to us. The clues are >in the experiments :) You said it: The clues! Yes, clues, not proofs. I'm not a physicist, so my opinion is not important to science world, it's just a personal feeling, but I don't think I will convert :) On the other hand, Einstein himself, even not accepting the background of QM, was the expert who named Heisemberg and Schroedinger for the Nobel prize, giving credit that way to their fantastic work, so I guess Einstein accepted the mathematical beauty of QM, and it's usefullness as a good source of predictions. >> This said, I have much respect for quantum theory and the brilliant scientists >>who developed it (Heisemberg, Schroedinger, Bohr, Dirac, Pauli, De Broglie, >>Fermi, ... even Planck and Einstein contributed!). >> But I still believe we are nothing but deterministic machines :( > >Pop quiz: how do your alternative theory explain alpha-decay? I don't remember what alpha-decay is :( I'll try to read it somewhere and answer your question, I case I can :) José C. >-S. > >> José C.
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