hi, i encountered this term in julian barbour webpage and i will like it if someone can tell me more about them?
loop quantum gravity said:hi, i encountered this term in julian barbour webpage and i will like it if someone can tell me more about them?
jeff said:I couldn't find this term on barbour's site or by googling.
well let's see if we are speaking about the same page.jeff said:I couldn't find this term on barbour's site or by googling. But knowing what he works on, by a "stratified" space he may have meant what is more commonly referred to as a "foliated" space, which roughly speaking is a space that has been expressed as a union of disjoint hypersurfaces, very much like a salami as a union of slices. In the context of the physics of spacetime, these hypersurfaces represent surfaces of simulteneity, with different observer's seeing the universe as being sliced up - foliated - in different ways. If this turns out not to be what he meant by "stratified", never mind.
I also plan to post on this website a paper explaining the rather brief remarks on p. 344 of my The End of Time about stratified manifolds, which are models of my central notion of Platonia (as explained in that book). Stratified manifolds occur widely in theoretical physics, and a question that has long interested me is the effect, if any, that the strata of these manifolds exert on classical dynamical trajectories and quantum wave functions defined on such manifolds.