Status Updates From A Journey into Gravity and ...

tiene pintaza creo que va a ser impresionante

...This impossibility has been for generations presented as actually due to the complexity of the subject and so unfortunately an almost mystical reverence has grown up around this fuzzy thinking.

Next he has introduced the notion of interval as invariant. Of course his simplistic 2d example only has a union of 2 spatial dimensions, where the interval can correctly be called a distance, but to call it a distance in space-time is highly misleading as the interval is a difference of time and space, not a union of them. It renders an external geometrization not merely hard to visualise, but impossible...

... any possible notion of externalised spacetime. An externalised spacetime union would not have all these complex dynamic features. These only come because we are dealing with a difference, not a union, and it renders us in a position where we have to gather up information and build up a piecemeal spacetime fabric from particular perspectives. This ontological deficit has still not been properly come to terms with.

For if they were it would be realised that what we have here is not some simple "addition" of time, to make the union spacetime. We have an internal creation of a coherent account of time to fit with all the spaces we have information about. Combine this with the fact that there is no true spacetime on micro scale or big scale only on the nebulous "local" scale, and you have a decimation of ..

However, in the next pages, giving a detailed account of how to "add" time, he provides a more messy and real account, with time devices needing to be installed with every event, and with information being gathered everywhere. There not being a true impartial observer who can hold "true" time, of course this is the basic Einstein, relativity of simultaneity insight. But its ramifications are not truly appreciated..

And I think it changes completely how we need to visualise the connection between space and time. It is a much more dynamic thing than a simple union would be, and it is not amenable to a simplistic visualisation of a unified spacetime "out there" in a neutral objective space. and its where many of the later problems come, with paradoxes in general relativity equation solutions, quantum physics etc...

...not just his interpretation. 3) I think I see the basic flaw at the foundation of this whole geometrization of a space-time "out there". He talks and Minkowski talked of a union of space and time. But this is a basic logical mistake. A union would be an addition: Space + Time, what we actually have in the 4D maths is: Space - Time or Time - Space. This is a difference, logically speaking, not a union.

In his attempts to account for how there could be spacetime curvature, he illustrates a few weaknesses in the "mainstream" account. 1) To show sameness of curvature he contracted one spatial dimension, an alternative way to do this is with variable speed of light. 2) A third account places the curvature in our frame of reference, not in something "out there", so we have multiple ways to interpret this scenario...

To my mind it is flowery and misleading language to evoke the idea of having a causal explanation when all you really have is an after the fact approximate mathematical description that you keep adjusting the model of all the time to keep it in close synchrony with reality in order to create the idea of having explained something.

His informational approach is perhaps where this can take you, (with the idea of bearing witness too) but this is still far from currently being a completed coherent project of how to get "It from Bit", it is still very much a work in progress. For how and the grip of spacetime is meant to function when we have no notion of causality to draw upon in this account I do not know.

"A free float frame of reference has a third feature: Being responsive to space right where it is, it bears witness to the grip of space on everything that goes on within it.. Nowhere more simply than in a free-float frame of reference can we see the story of motion of space and time... and spacetime."

This raises many ontological objections. For starters, what does bear witness to the grip of space mean?

Free floating, not free falling. I like it and I'm for it!