Ah yes that's much clearer thanks. It wasnt really linguistic confusion on my part. Just plain confusion : )
I'm curious about this: how does the existence of this "surface" layer jive with Relativity's idea that there is no absolute "present"? Wouldn't that mean different observers would disagree on how the "heap" has grown?I suspect that to conceive of the consequences of Loop and such QG one has to think more deeply than what I see in MTd2's opening post.
Just to give an example of what I mean, here is a conceptual exploration: suppose that geometry consists of events--geometric interactions occurring in a present. (see Gambini&Pullin http://arxiv.org/abs/1502.03410 http://arxiv.org/abs/1502.03831 )
Suppose, as Rovelli Vidotto http://arxiv.org/abs/1502.00278 suggested, that the presence of a smallest measurable angle, or equivalently, a cosmological curvature constant Λ,
causes spatial and temporal geometric interactions to be discrete occurring in small quantum hops shakes spasms or repercussions to speak figuratively.
This then affects how we think of spacetime--the habitat of other quantum fields---as a growing heap of events where only the surface is interactive and actual---the past events can no longer be interacted with and so no longer exist. Gambini and Pullin estimate the thickness of the live layer for us.
So then the consequence is simply that we have to rebuild the theory of quantum fields in this new spacetime geometry residence. In terms of interaction events that so to speak inhabit the geometric ones. In this world there are only events and fields describing which are possible. No little pebbles.
In my view it certainly does. The "evolving surface layer" is a quantum version of a 3+1 foliation in GR, associated with a class of observers.I'm curious about this: how does the existence of this "surface" layer jive with Relativity's idea that there is no absolute "present"? Wouldn't that mean different observers would disagree on how the "heap" has grown?