Re: Even more compact dimensions Re: Re: Compact dimensions and orthogonality
On 26 Oct 2012, at 14:00, Roger Clough wrote: Hi Brent, What happens -- or is it even possible -- to collapse the dimensions down to one (which I conjecture might be time), or zero (Platonia or mind). Yes it is more zero, or zero^zero (one). In my favorite working theory. Bruno Roger Clough, rclo...@verizon.net 10/26/2012 Forever is a long time, especially near the end. -Woody Allen - Receiving the following content - From: meekerdb Receiver: everything-list Time: 2012-10-25, 15:27:47 Subject: Re: Compact dimensions and orthogonality On 10/25/2012 11:47 AM, Richard Ruquist wrote: On Thu, Oct 25, 2012 at 2:23 PM, meekerdb wrote: On 10/25/2012 10:49 AM, Richard Ruquist wrote: On Thu, Oct 25, 2012 at 1:43 PM, Stephen P. King wrote: On 10/25/2012 11:52 AM, meekerdb wrote: On 10/25/2012 4:58 AM, Richard Ruquist wrote: Stephan, Since yesterday it occurred to me that you may be thinking of the 10 or more dimensions of string theory as being orthogonal because they were so before the big bang. But the dimensions that curled-up/compactified went out of orthogonality during the big bang according to Cumrun Vafa. I'll look up that reference if you are interested. According to Vafa 2 dimensions compactified for every single space dimension that inflated. In over simplified terms, 2 dimensions (actually in strips of some 10,000 Planck lengths) to be compactified lined up say in the east-west space dimension so that space in an orthogonal direction could expand. So some semblance of orthogonality exists in the compactification process, but it is clear that the compactified dimensions become embedded in 3D space for inflation to occur. It's implicit in the definition of dimensions of a Riemannian manifold that there are as many orthogonal directions as dimensions. Compactified dimensions are just small; they're small, not infinite, because they have closed topology. That property is completely independent of having orthogonal directions. Brent Dear Brent, Compactness and orthogonality are not the same quantities. Yes. But my point is that the compact structures in string theories (super or not) are orthogonal to the dimensions of space-time. Maybe we need all take a remedial math class on linear algebra and geometry! I am still waiting for the explanation of how you know that to be true- that the compact manifolds are orthogonal to space dimensions. Richard If they weren't orthogonal then a vector on them could be represented by by a linear combinations of vectors in 3-space - and then they wouldn't provide the additional degrees of freedom to describe particles and fields. They'd just be part of 3-space. They are just part of 3 space once the extra dimensions are compactified. No, that's incorrect. I don't know much about string theory, but I wrote my dissertation on Kaluza-Klein and the additional dimensions are still additional dimensions. KK is simple because there's only one extra dimension and so compactifying it just means it's a circle, and then (classically) the location around the circle is the phase of the electromagnetic potential; quantized it's photons. Being compact just means they're finite, it doesn't imply they're part of the 3-space. If they were they couldn't function to represent particles 'in' 3-space. I do not know about what happens to the extra degrees of freedom. If you lost them then you'd just have 3-space, possibly with different topology, but you couldn't represent all the particles which was the whole point of string theory. Brent -- You received this message because you are subscribed to the Google Groups Everything List group. To post to this group, send email to everything-list@googlegroups.com. To unsubscribe from this group, send email to everything-list+unsubscr...@googlegroups.com . For more options, visit this group at http://groups.google.com/group/everything-list?hl=en . -- You received this message because you are subscribed to the Google Groups Everything List group. To post to this group, send email to everything-list@googlegroups.com. To unsubscribe from this group, send email to everything-list+unsubscr...@googlegroups.com . For more options, visit this group at http://groups.google.com/group/everything-list?hl=en . http://iridia.ulb.ac.be/~marchal/ -- You received this message because you are subscribed to the Google Groups Everything List group. To post to this group, send email to everything-list@googlegroups.com. To unsubscribe from this group, send email to everything-list+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/everything-list?hl=en.
Even more compact dimensions Re: Re: Compact dimensions and orthogonality
Hi Brent, What happens -- or is it even possible -- to collapse the dimensions down to one (which I conjecture might be time), or zero (Platonia or mind). Roger Clough, rclo...@verizon.net 10/26/2012 Forever is a long time, especially near the end. -Woody Allen - Receiving the following content - From: meekerdb Receiver: everything-list Time: 2012-10-25, 15:27:47 Subject: Re: Compact dimensions and orthogonality On 10/25/2012 11:47 AM, Richard Ruquist wrote: On Thu, Oct 25, 2012 at 2:23 PM, meekerdb wrote: On 10/25/2012 10:49 AM, Richard Ruquist wrote: On Thu, Oct 25, 2012 at 1:43 PM, Stephen P. King wrote: On 10/25/2012 11:52 AM, meekerdb wrote: On 10/25/2012 4:58 AM, Richard Ruquist wrote: Stephan, Since yesterday it occurred to me that you may be thinking of the 10 or more dimensions of string theory as being orthogonal because they were so before the big bang. But the dimensions that curled-up/compactified went out of orthogonality during the big bang according to Cumrun Vafa. I'll look up that reference if you are interested. According to Vafa 2 dimensions compactified for every single space dimension that inflated. In over simplified terms, 2 dimensions (actually in strips of some 10,000 Planck lengths) to be compactified lined up say in the east-west space dimension so that space in an orthogonal direction could expand. So some semblance of orthogonality exists in the compactification process, but it is clear that the compactified dimensions become embedded in 3D space for inflation to occur. It's implicit in the definition of dimensions of a Riemannian manifold that there are as many orthogonal directions as dimensions. Compactified dimensions are just small; they're small, not infinite, because they have closed topology. That property is completely independent of having orthogonal directions. Brent Dear Brent, Compactness and orthogonality are not the same quantities. Yes. But my point is that the compact structures in string theories (super or not) are orthogonal to the dimensions of space-time. Maybe we need all take a remedial math class on linear algebra and geometry! I am still waiting for the explanation of how you know that to be true- that the compact manifolds are orthogonal to space dimensions. Richard If they weren't orthogonal then a vector on them could be represented by by a linear combinations of vectors in 3-space - and then they wouldn't provide the additional degrees of freedom to describe particles and fields. They'd just be part of 3-space. They are just part of 3 space once the extra dimensions are compactified. No, that's incorrect. I don't know much about string theory, but I wrote my dissertation on Kaluza-Klein and the additional dimensions are still additional dimensions. KK is simple because there's only one extra dimension and so compactifying it just means it's a circle, and then (classically) the location around the circle is the phase of the electromagnetic potential; quantized it's photons. Being compact just means they're finite, it doesn't imply they're part of the 3-space. If they were they couldn't function to represent particles 'in' 3-space. I do not know about what happens to the extra degrees of freedom. If you lost them then you'd just have 3-space, possibly with different topology, but you couldn't represent all the particles which was the whole point of string theory. Brent -- You received this message because you are subscribed to the Google Groups Everything List group. To post to this group, send email to everything-list@googlegroups.com. To unsubscribe from this group, send email to everything-list+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/everything-list?hl=en. -- You received this message because you are subscribed to the Google Groups Everything List group. To post to this group, send email to everything-list@googlegroups.com. To unsubscribe from this group, send email to everything-list+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/everything-list?hl=en.
Re: Even more compact dimensions Re: Re: Compact dimensions and orthogonality
On 10/26/2012 5:00 AM, Roger Clough wrote: Hi Brent, What happens -- or is it even possible -- to collapse the dimensions down to one (which I conjecture might be time), or zero (Platonia or mind). I'm not sure what you mean by 'collapse'. Do you mean, Is is possible to invent a theory which has only a one-dimensional Remannian manifold? Sure, but I don't think you can make it agree with physical observations. In my view, these are models we invent to try to understand the world; so we need our model to be understandable. That's one of my objections to a lot of 'everything' theories like Tegmark's; they hypothesize a model that is incomprehensible in order to 'explain' something - it's like God did it and God works in mysterious ways. Brent -- You received this message because you are subscribed to the Google Groups Everything List group. To post to this group, send email to everything-list@googlegroups.com. To unsubscribe from this group, send email to everything-list+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/everything-list?hl=en.