On 23 Sep 2011, at 21:09, Jouni Valkonen wrote: > 2011/9/23 Dr Josef Karthauser <j...@tao.org.uk>: >> >> There's no other evidence for anything other than a 3+1 dimensional universe. > > If this observation about neutrinos is true, then we do not have > anymore even 3+1 dimensions, but only three dimensions. FTL falsifies > the concept of space-time, therefore we cannot no longer consider time > as fourth dimension.
Really? I'm not sure that it does that. At least, I doubt that that's going to be the first thing that theoreticians give up to explain this. :) > I would say that if we need to resort extra dimensions to save the > relativity, then it is just bye bye relativity. No, not at all. G/R is compatible with extra dimensions. That's the entire premise behind compactification and how it's possible to take seriously any notion of super-gravity. (Not that supersymmetry is looking healthy these days). > And it goes without saying, that if relativity fails, everything about > string theory also fails. But quantum mechanics will prevail. I think > that quantum mechanics should have falsified relativity in 1930's when > Einstein find out about the entanglement. Einstein was correct IMHO, > entanglement is really spooky action at a distance. I don't think that we need to worry about string theory being healthy. It's not being invoked to explain anything yet; as far as I know we're still solving the landscape problem, and have no experimental way of verifying that string theory is true or not. And, currently, there's no other local evidence that suggests that G/R is incorrect. Quite the opposite in fact, isn't it? The gravity probe B results have tested it to pretty high precision. So, it's not so much that Q/M is right, and G/R is wrong. It's more the other way around. Even although we believe that Q/M provides a true formalism with which to describe the fields and interactions of nature, our best attempt to use it yields a single wave function containing all the known particle and field interactions but containing 18 free parameters which need to be fine-tuned by experimental results in order for the equations to be predictive. So, yes, Q/M is exactly the right theory and has not been shown yet to say anything other than the truth. But, until we have a theory that constrains the free parameters, at best we can say that we have an effective theory, which happens to model what we observe in experiment, without explaining why. What we've got to remember here about neutrinos, is that we currently don't have a very good model of them at all. At first we thought that they were massless and more recently we've discovered that they change flavours as they travel through space/time, the so-called neutrino-oscillations, and that requires us to accept that they're not massless at all. So we've tweaked the standard model to incorporate this by adding a flavour changing matrix into the symmetries, but we've got no theory which predicts why the flavours change. It's just been added by hand, introducing another 7 free parameters that also have to be fine-tuned. I don't think anyone can put their hand on their hearts anymore and say that they understand why the symmetries in the standard model have to be the way that they are. That's why so much work has been put into string theory, and super-symmetry. They're wild stabs at finding some mathematical structure which would incorporate all the symmetries that we find in nature, and constraining the free parameters (or at least reducing the quantity of them!) And, let's not talk about the Higgs! (Until that's found, then all bets are off that the standard model is "the one true model"). So, whatever your take on extra-(spacial)dimensions are, if you believe that quantum field theory is the entire theory, and that the standard model is the true expression of nature encapsulated in it, then the universe is just a single solution to a 25 parameter equation. How do you feel about those 21 extra dimensions? And, don't get me started about dark energy and dark matter, which are another manifestation of extra symmetries in nature that we don't understand. :) Are you still sure of Q/M? To my mind, I think that we've got a confusion in the way that we think about nature. We shouldn't be partitioning it into the quantum mechanics of the small, and the general relativity of the big. Instead we should be partitioning it into the parts that exhibit continuity and the parts that exhibit discontinuity. I don't believe we'll be able to fully comprehend what's really going on until we do. Regards, Joe