Severian Posted August 25, 2005 Posted August 25, 2005 Very often people come to these fora with a belief that our current theories of physics, such as the Standard Model or relativity, are flawed and present some alternative of their own. On the whole, this is a fine attitude to take - we should always be skeptical, and it is good if people can think a little 'out of the box' and generate ideas which more standard thinkers may not have come up with. I have always thought that genius was not an ability to think 'better' than everyone else - it is an ability to think differently from everyone else. However, when coming up with a new theory it is important that it should be better than the old one. Therefore the first step of coming up with a new theory is a sufficient understanding of the old one. You have to make sure that your new theory does everything at least as well as the old theory, otherwise the old theory remains more attractive. This is very difficult mainly because our current theories are so spectacularly good in their predictions. Let me give an example: the magnetic moment of the electron. If we look at the energy (Hamiltonian) of an electron in an electromagnetic field, we find that there is a contribution from the interaction of the electron's angular momentum and the magnetic field. For an orbital angular momentum [math]L[/math], this is [math]\vec{\mu}_L \cdot \vec{B}[/math] with a magnetic moment [math]\vec{\mu}_L = - \frac{e \hbar}{2mc} \vec{L}[/math] (The charge of an electron is [math]-e[/math] and its mass is [math]m[/math].) However, if the particle has 'spin' (intrinsic angular momentum) [math]\vec{s}[/math], we also have a contribution to the magnetic moment of [math]\vec{\mu}_s = - g \frac{e \hbar}{2mc} \vec{s}[/math] [math]g[/math] is known as the gyromagnetic ratio, and its value depends on the theory. Since this can be measured in experiment very accurately, it is a good test of a theory to check if it predicts the correct gyromagnetic ratio. For example, simple QM (the Dirac equation in an em field) predicts a gyromagnetic ratio [math]g=2[/math]. Experiments shows that [math]g[/math] is very close to 2, so this is good news, but since experiment shows that it is not quite 2, the Dirac equation cannot be the whole answer. Quantum Field Theory, in the form of the Standard Model, predicts a deviation from 2. It is usual to write down the prediction for this deviation from 2 rather than the gyromagnetic ratio itself. For the SM this is: [math]\frac{g_{\rm th}-2}{2} = 1159652140(28) \times 10^{-12}[/math] The experimantal result is: [math]\frac{g_{\rm exp}-2}{2} = 1159652186.9(4.1) \times 10^{-12}[/math] (A note on errors: the numbers in brackets denote the error on the prediction/measurement at the same precision to which the value is specified. For example [math]1159652140(28)[/math] means [math]1159652140 \pm 28[/math] and [math]1159652186.9(4.1)[/math] means [math]1159652186.9 \pm 4.1[/math].) You can see that the theory predicts the correct experimental value to incredible precision (although the experimental error is still better than the theory one). If you want to persuade scientists that the Standard Model is wrong, then you have to explain why this is a coincidence or show that your new theory predicts [math]g-2[/math] to at least this accuracy. 1
Jacques Posted August 25, 2005 Posted August 25, 2005 I was wondering if the Standard Model was able to predict the instability of the neutron ? Is it able to predict 15 minutes life of the neutron ? If yes what are the equations and parameters used to achive that ?
Severian Posted August 25, 2005 Author Posted August 25, 2005 I was wondering if the Standard Model was able to predict the instability of the neutron ? Is it able to predict 15 minutes life of the neutron ?If yes what are the equations and parameters used to achive that ? Yes it does. This is a weak decay. The neutron is made up of three quarks: one 'up' quark and two 'down' quarks. One of the down quarks decays to an up quark by emitting a 'W-boson' (which then decays to lepton and a neutrino). Since the proton is two up quarks and a down quarks, the neutron has decayed into a proton. The actual calculation is a bit beyond the scope of a web forum though....
LucidDreamer Posted August 25, 2005 Posted August 25, 2005 But going to the trouble to really understand a current scientific theory isn't as much fun as learning just a tiny bit and then coming up with my own crazy theory that appears to be better than the original because of my lack of understanding. 1
Royston Posted August 25, 2005 Posted August 25, 2005 But going to the trouble to really understand a current scientific theory isn't as much fun as learning just a tiny bit and then coming up with my own crazy theory that appears to be better than the original because of my lack of understanding. Perhaps you should start another thread, this one's for the experts...which I'm clearly not either, but it won't stop me reading and researching the terminology used and trying to get a slight understanding of the subjects raised...that also can be fun. I think Severian deserves a break from advising people like me all the time. 1
Jacques Posted August 25, 2005 Posted August 25, 2005 Thanks Severian So the standard model can compute the life time (or should I say the half-life time ?) of the neutron! I asked because the only thing I saw on the standard model is little table with the "fundamental particle" and some Feynman diagram . What would be a good start to go deeper than that ? What level of math is necesary ? Therefore the first step of coming up with a new theory is a sufficient understanding of the old one. I completly agree and I am at that step. 1
Severian Posted August 25, 2005 Author Posted August 25, 2005 To really understand the Standard Model, you really need to understand Quantum Field Theory. The best book on QFT that I have seen is called "An Indtroduction to Quantum Field Theory" by Peskin and Schroeder. It starts off quite advanced though. What level are you at? Would you understand this: http://www.phys.ualberta.ca/~gingrich/phys512/latex2html/node1.html or is that too advanced?
Jacques Posted August 25, 2005 Posted August 25, 2005 Thanks for the link ! It will be a lot of work for me to understand, but with the help of Wikipedia I think I will be able to grasp the essentials things. My goal is not to do any calculations, but to understand the basic principle (more than the usual analogy).
bascule Posted August 25, 2005 Posted August 25, 2005 So does this mean thefinaltheory.com is wrong? *gasp*
nameta9 Posted August 25, 2005 Posted August 25, 2005 Severian, you seem to have some knowledge of modern physics. I have some too, but not very technical. My question is actually how on earth can any normal person hope to completely understand and calculate things as hard as quantum electrodynamics ? The theory is hard, the calculations are harder and in many cases very few scientists can even cross check many results, you need a supercomputer and need to work at CERN or with an equipe. At this point how much can we really trust the results that are being given to us since it becomes increasingly difficult to REALLY control them ? How many years of studying tensors and integrals and all are necessary ? How smart in the technical sense must a person really be ? It has always been a question in the back of my mind. Thanks for any clue.
MetaFrizzics Posted August 25, 2005 Posted August 25, 2005 How many years of studying tensors and integrals and all are necessary ? How smart in the technical sense must a person really be ? It has always been a question in the back of my mind. Thanks for any clue. Actually there is now hope for almost anyone to quickly pick up and more deeply understand the basic concepts of modern physics than ever before: Would you like to begin the study of Newtonian mechanics using NO vectors and NO (F = ma)? How about starting Quantum Mechanics with NO complex numbers and NO Schroedinger equation? Would you and your students enjoy exploring General Relativity deeply and widely with NO tensors and NO field equations? Suppose further, that along the way your students learn concepts and methods central to contemporary physics research. Finally, what if particle motions described by Newtonian mechanics, quantum mechanics, and general relativity were summarized in three brief commands of Nature that turn out to be variations of the same command? Physics is already being taught this way, and students respond with enthusiasm and understanding. The theoretical background for this curriculum has been around for a long time and is well developed and deeply understood by the physics and math communities. MIT (Manchester Institute of Technology Advanced Learning) Here are some links: E.F. Taylor Edu. Lagrange
nameta9 Posted August 25, 2005 Posted August 25, 2005 OK, I know you can learn it and all, and I know some of it. I mean how hard is it to really understand and calculate feynman diagrams and cross check the results knowing exactly what you are doing ? I guess I am suggesting at the PHD level where you review peer papers regarding new results and corss checking all the old ones. It can be done and all but I have the impression that you really have to gifted to be able to start calculating these things seriously.
J.C.MacSwell Posted August 26, 2005 Posted August 26, 2005 But going to the trouble to really understand a current scientific theory isn't as much fun as learning just a tiny bit and then coming up with my own crazy theory that appears to be better than the original because of my lack of understanding. LOL, as much as I agree with Sevarian, I agree with this more! My problem is with "other people's" crazy theories.
CPL.Luke Posted August 26, 2005 Posted August 26, 2005 It can be done and all but I have the impression that you really have to gifted to be able to start calculating these things seriously. yep, some people have trouble with math in general, these people probably won't be able to understand the mathmatics of a feynmann diagram without a large amount of effort. Then again it would take me a lifetime of classes to learn how to draw anything more than a stick figure 1
Severian Posted August 26, 2005 Author Posted August 26, 2005 My question is actually how on earth can any normal person hope to completely understand and calculate things as hard as quantum electrodynamics ? The theory is hard' date=' the calculations are harder and in many cases very few scientists can even cross check many results, you need a supercomputer and need to work at CERN or with an equipe. At this point how much can we really trust the results that are being given to us since it becomes increasingly difficult to REALLY control them ?[/quote'] They are not that hard! I do particle physics calculations as part of my job and I have never used a supercomputer. The only need for supercomputers in particle physics is in lattice QCD, where the strong interaction is modeled on a space-time lattice. Most calculations are recalculated by other groups, but even if they aren't there are a lot of checks which can be done. The analytic expressions must have certain properties (like gauge invariance) which would be removed by a careless mistake. Mistakes are made in the literature all the time, but they are corrected quickly and it is rare for mistakes to remain for long. How many years of studying tensors and integrals and all are necessary ? How smart in the technical sense must a person really be ? It has always been a question in the back of my mind. Thanks for any clue. Well, simple Feynman diagrams calculations are done by our final year undergraduates, so it doesn't require that much training to get started. To work in the field and publish papers you really need to do a PhD. To get a permanent faculty job you need to have done a few 2-year postdocs. I think perseverance if more important that hyper-intelligence. No physicist understands everything, so we are all still learning. 1
nameta9 Posted August 26, 2005 Posted August 26, 2005 So then we can be fairly sure that all the theoretical physics results and calculations are cross checked ? I doubt this because most PHDs who are then the ones capable of controlling all the fine details are working on new theories, new results and new papers. I don't think many are cross checking all the old results. Anyways, if new results are built on all the old calculations and math, then I guess we can be pretty sure there are few mistakes.
Severian Posted August 27, 2005 Author Posted August 27, 2005 So then we can be fairly sure that all the theoretical physics results and calculations are cross checked ? I doubt this because most PHDs who are then the ones capable of controlling all the fine details are working on new theories, new results and new papers. Heh - no. A PhD is research done by the superviser under particularly arduous circumstances.
CPL.Luke Posted August 27, 2005 Posted August 27, 2005 severian, do people with phd's ever do research? under normal circumstances
Severian Posted August 27, 2005 Author Posted August 27, 2005 Yes, a PhD is all about research. They do supervised research so that they can learn how to do unsupervised research. I would never trust a grad student's calculation without checking it though (no offense to grad students). Usually if there is a mistake in a calculation it is really obvious - you find an answer with the wrong properties. But even if a mistake goes unnoticed, it doesn't really matter. A false calculation will never agree with the data (unless the mistake is very small) so you will find a discrepancy with data, and the first thing you do (or someone else does!) is check the calculation.
elas Posted September 27, 2005 Posted September 27, 2005 Do you have a new theory? Using the name ‘elas’ I had considerable differences with the administrators of ‘Physics Forums’ on this very issue. Eventually the debate was banned and the rules for ‘Theory Development’ were changed to prevent further debate. At the risk of alienating others I will restate my disagreement with your submission. Very often people come to these fora with a belief that our current theories of physics, such as the Standard Model or relativity, are flawed and present some alternative of their own. The Standard Model is not flawed, it does however, lack a complete interpretation. There are two possible solutions to this shortcoming- a) an addition to the existing theory or, b) a new theory that underpins current theory and allows (or gives rise to) a complete interpretation of ST. This is very difficult mainly because our current theories are so spectacularly good in their predictions. So (a) is unlikely to produce results (there have been many failed attempts) because we do not need more predictive ability, what we do need is to know ‘how’ and ‘why’. For this the most likely solution is to be found following the course set by (b). Using this approach, I set out to test various ideas on ‘PF theory Development’ only to be told this was improper use of the site. Others, and I were told to go for peer review and many sarcastic comments were made some by the administrators, who should have known better. Fortunately, shortly after the rule changes, I was able to produce something suitable for peer review where it has been for the past four months without a decision. Clearly (regardless of the decision) I had something if interest to put forward. So I am disappointed that there is now nowhere for theory developers to discuss their ideas prior to submission for review, unless they are connected to a university. Such prior discussion is essential to development. It is also possible that PF has missed an opportunity to gain a valuable piece of publicity for their site; although, admittedly that remains to be seen. I hope the administrators of physics sites will realise the need for a genuine theory developement site where all the 'nutcases' are allowed a liberal degree of freedom to push their ideas forward.
senexa Posted September 27, 2005 Posted September 27, 2005 Amen to that! I quite agree with you that a mistake has been made here in the restrictive nature of this particular forum. But then, the same mistake has been made throughout the history of scientific thought as those whose careers are deeply embedded in existing theories fight against new ideas, i.e., Einstein, Darwin and Galileo. The sad thing is that open discussion on even the wilder ideas could lead everyone to a new understanding and even possibly to exciting discoveries.
Severian Posted September 27, 2005 Author Posted September 27, 2005 The Standard Model is not flawed' date=' it does however, lack a complete interpretation. There are two possible solutions to this shortcoming- a) an addition to the existing theory or, [/quote'] I agree, and I think this is the way forward. The SM makes so many good predictions that we should build on it rather than replace it. b) a new theory that underpins current theory and allows (or gives rise to) a complete interpretation of ST. Presumably ST is 'string theory'. Again, this is holding onto the SM - no string theorists are suggesting that the SM is wrong. They hope to demonstrate that the SM is a low energy limit of string theory. That way, you keep the nice predictive features of the SM, while explaining some of the 'why's with string theory. This is not really any different from (a). So (a) is unlikely to produce results (there have been many failed attempts) because we do not need more predictive ability, what we do need is to know ‘how’ and ‘why’. For this the most likely solution is to be found following the course set by (b). I disgree. There are plenty of new physics theories out there which build on the SM and will be testable soon. A lot of these are actually inspired by string theory's low energy limit in fact. Fortunately, shortly after the rule changes, I was able to produce something suitable for peer review where it has been for the past four months without a decision. If you have something to be peer reviewed then that is great! My post was not to discourage this, but to encourage people to think through their ideas before making a fool of themselves? So before you put yourself up for public ridicule (which is what all new theories are subjected to (Einstein's included)) you have to ask if it makes reasonable predictions for things that have already been tested. For example, if it is a quantum theory, does it describe the motion of electrons correctly? Does it describe electromagnetism? Does it get the correct value for the magnetic moment? (I was being a little tongue in cheek with my first post - I don't expect you to have it calculated to 10 significant figures, but it should agree with 2 to a reasonable approximation.) If it is a theory of gravity, does if have newtonian gravity as its low energy limit? Does it predict the correct perhelion of Mercury? If you have a theory which passes these sort of tests, then we will be very happy to hear aboiut it. If it doesn't pass these tests then surely it is already wrong, and a lot more 'wrong' than the SM. Putting up a theory for peer review which you already know is wrong is asking for public humiliation.
alexross Posted September 27, 2005 Posted September 27, 2005 (edited) Hi Elas, I understand your position. There is a fear that nameta9 broaches upon in that because the current 'theories' = hypotheses are so complicated no-one can question them and if you do you are on your own! Rather than rabbit on about my own theories I will address your points. Please let me rebuke you a little. People are entitled to question you and me for that matter. We all enjoy the intellectual masochistic sparring don't we? Now Complex Quantum Mechanics which I sent away in 1999 does meet all your criteria and more. It resolves the problems of Conventional Quantum Mechanics but unfortunately for me there is not a level playing field. The current theories are NOT good in their predictions. Try and tell me the position of any electron at this moment! Sorry, I sound a little too scolding! Lets return to a placid state. Now how about your comment that: "If we look at the energy (Hamiltonian) of an electron in an electromagnetic field, we find that there is a contribution from the interaction of the electron's angular momentum and the magnetic field. For an orbital angular momentum" Now to be fair I admit I do not know everything not certainly not the specifics you refer to but I can make a comment. Is it proven that these contributions come from the momentum and the field? It is worth bearing in mind that you can interpret mathematics in more ways than one. In 2000 I challenged anyone to prove my theories wrong. In 6 years I have had only 1 criticism and that is that I am being 'too complicated'. Anyone else want to take up the gauntlet? Now I hope you will take this in good spirit perhaps if your question had been worded a bit less like a defence of Conventional Quantum Mechanics I would not sound so disapproving. In fact I have very little to disapprove of and I am just setting out where I stand. Anyone who wants to carry on the discussion. Please write rather than email me or post a thread. Best wishes, Mr Alexander Ross BSc(Hons) AMIMA Dip. Int. Trd. Edited December 12, 2008 by Sayonara³ Personal details removed.
alexross Posted October 6, 2005 Posted October 6, 2005 Very often people come to these fora with a belief that our current theories of physics' date=' such as the Standard Model or relativity, are flawed and present some alternative of their own. On the whole, this is a fine attitude to take - we should always be skeptical, and it is good if people can think a little 'out of the box' and generate ideas which more standard thinkers may not have come up with. I have always thought that genius was not an ability to think 'better' than everyone else - it is an ability to think [i']differently[/i] from everyone else. However, when coming up with a new theory it is important that it should be better than the old one. Therefore the first step of coming up with a new theory is a sufficient understanding of the old one. You have to make sure that your new theory does everything at least as well as the old theory, otherwise the old theory remains more attractive. This is very difficult mainly because our current theories are so spectacularly good in their predictions. Let me give an example: the magnetic moment of the electron. If we look at the energy (Hamiltonian) of an electron in an electromagnetic field, we find that there is a contribution from the interaction of the electron's angular momentum and the magnetic field. For an orbital angular momentum [math]L[/math], this is [math]\vec{\mu}_L \cdot \vec{B}[/math] with a magnetic moment [math]\vec{\mu}_L = - \frac{e \hbar}{2mc} \vec{L}[/math] (The charge of an electron is [math]-e[/math] and its mass is [math]m[/math].) However, if the particle has 'spin' (intrinsic angular momentum) [math]\vec{s}[/math], we also have a contribution to the magnetic moment of [math]\vec{\mu}_s = - g \frac{e \hbar}{2mc} \vec{s}[/math] [math]g[/math] is known as the gyromagnetic ratio, and its value depends on the theory. Since this can be measured in experiment very accurately, it is a good test of a theory to check if it predicts the correct gyromagnetic ratio. For example, simple QM (the Dirac equation in an em field) predicts a gyromagnetic ratio [math]g=2[/math]. Experiments shows that [math]g[/math] is very close to 2, so this is good news, but since experiment shows that it is not quite 2, the Dirac equation cannot be the whole answer. Quantum Field Theory, in the form of the Standard Model, predicts a deviation from 2. It is usual to write down the prediction for this deviation from 2 rather than the gyromagnetic ratio itself. For the SM this is: [math]\frac{g_{\rm th}-2}{2} = 1159652140(28) \times 10^{-12}[/math] The experimantal result is: [math]\frac{g_{\rm exp}-2}{2} = 1159652186.9(4.1) \times 10^{-12}[/math] (A note on errors: the numbers in brackets denote the error on the prediction/measurement at the same precision to which the value is specified. For example [math]1159652140(28)[/math] means [math]1159652140 \pm 28[/math] and [math]1159652186.9(4.1)[/math] means [math]1159652186.9 \pm 4.1[/math].) You can see that the theory predicts the correct experimental value to incredible precision (although the experimental error is still better than the theory one). If you want to persuade scientists that the Standard Model is wrong, then you have to explain why this is a coincidence or show that your new theory predicts [math]g-2[/math] to at least this accuracy. Hi Severian, Thank you for posting your equations I will take a closer look. In the meantime please note you do not use quantum entanglement or such non-classical explanations here. As far as I am concerned that is CQM now and no longer QM. Perhaps I should listen to criticism myself and start a new thread. I will chew that over. regards, Alex
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