Different densities means that simultaneously, in the same spot, several realities can occur. We have spoken of 1st Density through 6th Density, and inferred that there are higher densities humans really need not be concerned with at this time. 1st Density through 3rd Density occupy the same plane, i.e. reside in the same reality together. 1st Density is rock and water, without life. 2nd Density is life without conscious intelligence, such as plants and animals, even such intelligent animals as chimpanzees. 3rd Density is intelligent, conscious, life, such as humans have. 1st and 2nd Density are referred to as densities not because they are truly of differing density states, but because they indicate different levels of spiritual potential. Density is a term that refers not only to the physical state, but to the spiritual. Thus in 1st Density the spiritual potential is nil. In 2nd Density, the spiritual density potential is possible, and in fact at times incarnations into 2nd Density life occurs, as a lesson. In 3rd Density, spiritual potential is realized, etc.
In densities higher than 3rd Density, co-existence can occur. Thus, it occurs that on the planet Earth, where 3rd Density humans are living and walking about, 4th, 5th, and higher Density incarnations are living and moving about, occupying the same space, as it were. This occurs because of a higher vibration rate of the sub-atomic particles. Were one to travel rapidly through the densities occurring in a single spot, one would see first the 3rd Density existence on the 3rd Density Earth, with say a human standing in a field of corn; then, moving to 4th Density existence one might see, for instance, a Zeta standing in a forest, where the forest and the Earth it grows upon are both in 4th Density; then, moving to 5th Density, one might see yet another scene. When we state that the Earth is scheduled to move to 4th Density Service-to-Others, we are describing what is to happen to humans. There will still be a 3rd Density Earth, on the same plane as the future 4th Density home of humans, as a portion of the Earth will be left in 3rd Density.
Much confusion reigns on the issue of density. Humans, for instance, were used to the concept of matter and energy being discrete and separate. Matter could not be energy, and energy could not be matter. Then Einstein shook things up and humans, after much painful denial and agony, allowed their concepts of reality to change. Density understanding is just such a quantum concept leap. In all fairness, the concept of density differences is difficult for even your scientists to deal with. The layman should be excused and granted a little confusion.