what is the "density" exactly means?

[zenmaster]

Correct, but were you addressing any particular point?

Yes, this one.

I would think the opposite: they would start out disoriented, because most of the initial access would be the 3rd-density societal mind, then gradually form a 4d Social Memory Complex, as more and more of that mind could be accessed.

Third density societal mind will be gone long before a fourth density societal memory complex is formed; close to fifteen million years gone.

We were talking about the 4D graduates. Again, initially the dual-activated people will be accessing 3rd-density societal mind - being mostly wanderers, esp initially, they will be confused due to coming from different logos. There will be a lot of odd people around - like L.A.
Presumably, once yellow-ray is gone, 3D societal mind is gone. What's left? 4D societal mind then on to 4D SMC. I don't see why the emphasis on 3D being 15 million years gone.