Register to reply 
String Vibrations Prove Higher Dimension? 
Share this thread: 
#1
Dec1612, 09:13 PM

P: 9

Is it true that strings can vibrate in certain manners in which they cause a "ripple effect" in spacetime, affecting the topology of the higher dimensions, causing these different timelines to occur in which you have changes so minor as to electrons a plank's unit to the right, or so drastic as to you not even being born (which in itself would cause other socalled "ripples")? That was a lot to say, but to question further if this were true, were would the energy needed for these changes in string harmonics come from? Lost energy in wave function collapse, or some mysterious source like dark energy? I know some physicists have been working on things like flop transitions and string harmonics to prove how these higher dimensions could exist. If they could, could someone explain exactly why all this happens/is there any experimental data support it. Thanks!



#2
Dec1712, 12:38 AM

P: 751

Whether there are "different timelines" is an issue of quantum mechanics in general, not string theory in particular, which is just quantum mechanics applied to "strings", i.e. extended vibrating objects.
The practical reality of quantum mechanics is that it involves the use of "wavefunctions" to obtain probabilities for the possible physical events. You only ever see one event at a time, but the wavefunction has to be able to give you a probability for every possibility. The manyworlds idea, that goes back to Everett, is the idea that the wavefunction is not just a calculating device, it is reality itself; the world we see is just one part of it, and the other parts of the wavefunction, that correspond to the other possibilities, are other worlds as real as our own. There is a faction of opinion among physicists that believes in Everett worlds; maybe about 510% of physicists, though it would depend on what area they work in. But the idea has a lot of problems; the main one is that it can't justify the probability rule (which is called the "Born rule" after Max Born, who first figured it out). The wavefunction may contain a branch where the electron turns right (in a given experiment) and another branch where it turns left, but to explain why the electron is seen turning right twice as often (this is a madeup example), you really ought to have twice as many electronturnsright worlds as there are electronturnsleft worlds, and this is precisely what manyworlds theory has failed to explain. The way physicists think about quantum mechanics is not uniform. Some people stick to the original, observationoriented approach, according to which wavefunctions are absolutely not real. This is the original "Copenhagen interpretation" and in technical jargon, it says that the parts of quantum theory that correspond to something real are the "observables" like position and momentum. The particle has a position if we detect it to have a position, wavefunctions gives us the numbers but they aren't a real thing, and we don't ask ourselves what the reality is between observations. Then you have people who do visualize the world between measurements as particles with definite position and momentum, but jumping around randomly; then there are people who talk about wavefunctions as real, but they don't go all the way to Everett's multiple worlds; then there are the people who still believe in deeper deterministic theories, for whom quantum mechanics is just an incomplete theory. All that already applies to quantum theories of particles and force fields. With string theory, you have the vibrations and the higher dimensions that you mention, but it's all still within the quantum framework. There are "observables" like the position and the momentum of the string, and you use wavefunctions to describe the probabilities of how the observables change over time. But the question of, what is a wavefunction really, is logically separate from the specific details of string theory. The cautious Copenhagen attitude is still the straightforward practical way to approach quantum physics, even in string theory: a wavefunction isn't a real thing, so there's no "wavefunction collapse" or "different timelines", there is just the one world, containing vibrating strings which have notquitedeterministic behavior. 


#3
Dec1712, 07:36 AM

P: 9

I have trouble finding validity in the Copenhagen interpretation. Young's Double Slit Experiment clearly outlines the wave function probability of a particle, and has even been mathematically proven with something as simple as the abs. value of ψ^{2}(sorry I don't really know how to LaTeX (can't find abs. value anywhere)). So, presuming wave functions and wave function collapse are all valid things, and if they gave rise to the belief in the multiverse, would the differences in the wave functions as they currently exist give rise to other universes, of which came from the "unused" states of the particle mentioned. If this were the case, then an infinite number of possible universes could arise (although at this point the term uni becomes paradoxical). For the sake of discussion, the alternate would presume that all universes (again presuming more than one exists) arose from some predeterminant state in which one universe was defined and then the others were molded after what the first one was not. I honestly am not sure how this could arise, possibly the Big Bang, but regardless, it seems consistent that wave functions and their collapse are needed to prove different universes. Strings and different vibrational patterns could cause these universes, but then, what determines that two strings are not in accordance with one another? Could Pauli Exclusion somehow be applied to strings, providing validity to a multiverse based on strings so that the different universes do not take the same form? Then again, could Pauli Exclusion be applied to the multiverse at all? If a universe were to differ in the minute terms of a single wavelength, all other factors would be the same, which is not allowed in our current universe, but perhaps the rules of the higher dimensions play differently. 


#4
Dec1712, 07:44 AM

P: 9

String Vibrations Prove Higher Dimension?
I have trouble finding validity in the Copenhagen interpretation. Young's Double Slit Experiment clearly outlines the wave function probability of a particle, and has even been mathematically proven with something as simple as the abs. value of ψ^{2}(sorry I don't really know how to LaTeX (can't find abs. value anywhere)). So, presuming wave functions and wave function collapse are all valid things, and if they gave rise to the belief in the multiverse, would the differences in the wave functions as they currently exist give rise to other universes, of which came from the "unused" states of the particle mentioned. If this were the case, then an infinite number of possible universes could arise (although at this point the term uni becomes paradoxical). For the sake of discussion, the alternate would presume that all universes (again presuming more than one exists) arose from some predeterminant state in which one universe was defined and then the others were molded after what the first one was not. I honestly am not sure how this could arise, possibly the Big Bang, but regardless, it seems consistent that wave functions and their collapse are needed to prove different universes. Strings and different vibrational patterns could cause these universes, but then, what determines that two strings are not in accordance with one another? Could Pauli Exclusion somehow be applied to strings, providing validity to a multiverse based on strings so that the different universes do not take the same form? Then again, could Pauli Exclusion be applied to the multiverse at all? If a universe were to differ in the minute terms of a single wavelength, all other factors would be the same, which is not allowed in our current universe, but perhaps the rules of the higher dimensions play differently. 


Register to reply 
Related Discussions  
LQG in Higher Dimension?  Beyond the Standard Model  11  
Higher dimension Integrals  Calculus & Beyond Homework  16  
String Vibrations  Introductory Physics Homework  1  
Taylor's Formula in Higher Dimension/Higher order Total differentials  Calculus & Beyond Homework  3  
String vibrations  Beyond the Standard Model  1 