I Cartan's Understanding of Einstein Field Equation

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Cartan's geometric interpretation of the Einstein Field Equation suggests that the equation relates the sum of moments of rotation within a 3-cube to the energy-momentum contained in that space. This interpretation is primarily discussed in John Wheeler's works, particularly in "Gravitation" (MTW), while other popular texts like Wald do not cover it. Wheeler is credited with bringing Cartan's ideas to broader attention, highlighting the significance of his coordinate-free differential geometry. The lack of adoption of Cartan's viewpoint may stem from its complexity and the sophistication required to understand it. Overall, Cartan's insights offer a unique perspective on the relationship between geometry and physics in the context of general relativity.
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Cartan and general relativity
About a week ago I was reading about Cartan's geometric interpretation of the Einstein Field Equation

Gij + Λgij = κTij

According to Cartan, this equation expresses the idea

(sum of moments of rotation for the faces of a little 3-cube) = 8π * (amount of energy-momentum within that 3-cube)

As far as I can tell, it is only in John Wheeler's various books (MTW, but also his other books) where this idea of Cartan is explained. None of the other popular books like Wald discuss this. Apparently, it was Wheeler who dug it out of Cartan's papers and made it widely known. If anyone on this forum has a good understanding of this, I would appreciate it if you can share/explain this. Also, why don't more people and books adopt this viewpoint? Is it because Cartan's coordinate free differential geometry is too sophisticated?
 
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Frankly I don't know why...Btw MTW has also a section for the Cartan's geometric interpretation of Newton spacetime (basically the Poisson equation).
 

Thread 'Physical Interpretation of Frame Field'

Moderator's note: Spin-off from another thread due to topic change. In the second link referenced, there is a claim about a physical interpretation of frame field. Consider a family of observers whose worldlines fill a region of spacetime. Each of them carries a clock and a set of mutually orthogonal rulers. Each observer points in the (timelike) direction defined by its worldline's tangent at any given event along it. What about the rulers each of them carries ? My interpretation: each...
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