what is the "density" exactly means?

[unity100]

Probably not. I was still deducing the properties of 2D (vs 1D), in order to answer the question of what a 'density' was.

yes that might be a fertile direction.

Since we do not really understand the electrical properties of 1D, let alone 2D, I'm not sure how we can really determine the nature of incompatibility between 3D and 4D.

we can go from analogies and similar patterns, to determine approximate nature of the interaction in between densities. that might help shape a broad picture, which then can be completed with details.

What's confusing further is that the 'dual-activated' entities have 4D and 3D bodies which are compatible with each other.

it seems that these dual activated bodies, are activated in some ways which will allow them to 'appreciate' (ra says) certain qualities of 4th vibration.