what is the "density" exactly means?

[unity100]

That is correct. Did I suggest otherwise?

it sounded as if you suggested the bodies were activated in order.

OK, you raise a good point. (I understand there is an outstanding question.)

'core vibration' means the photon is based (or intelligently controlled) at a certain discrete level. Each successive layer, transcends but includes the prior layer (subsumes). So the photon can be thought to have an embedded motion.

For 3D, the photon control is 3 levels deep. This photon has the potential freedom to move 'down' to 1D (and to 2D), if the characteristics of the motion of the (vibrating) photon provide for it.

The material you see with your eyeball, and touch, may be based (have a core) at the subtle 3D level. However, that 3D-core vibrational (control centered) photon manifesting (as an atomic-aggregate constituent), in physical form, is at the 'gross' 1D level.

does not compute.

you seem to be just adding an embedded property to the vibration concept. a 'control' aspect, just like how it is customary to take time as a dimension and attach it to physicality.