Emptiness

Throughout all organized space there are gravity-responding energy currents, power circuits, and ultimatonic activities, as well as organizing electronic energies. Practically speaking, space is not empty. Emptiest space has 100 ultimatons per cubic inch 42:4.6

Emptiness does have its virtue, for it may become experientially filled. 117:2.8

Where it appears

Emptiness is linked in 1 paragraph of the text.