Alternate zones (and their interactions) of differing densities as in a vortex. For instance water floats on oil because water is less dense than oil. A container filled with low density air is considerably less dense than high density water so the container will float on the water while resisting being under the water. Densities will seek their level of density (or tenuity) in proportion to the difference in densities. For instance, low density air released under high density water will rise until it finds equation of density at its own level of density in the atmosphere. [see specific gravity, striation, Vortex]
Keely
"Light is an etheric evolution propagated by "sympathetic conflict" between the "celestial" and "terrestrial" outflows: solar tensions against terrestrial condensations and true luminosity is induced in no other way. Progressive molecular and intermolecular disintegration reproduces light in Nature's manner on a small scale. In this regard Keely says "All such experiments invariably resulted in vortex motion, whether induced sympathetically or otherwise. All corpuscular action in Nature is vortex motion. The undulatory theory of light is only hypothetical. The conditions of electro-magnetic radiation, on the same plane of matter as light, disprove the undulatory theory in many particulars. The vortex action induced by differential conflict between the low and high tensions shows conditions analogous to those in the molecular dissociation of water into hydrogen and oxygen in other words, vortex action of the highest order but peripheral only. Were it otherwise, the ether could not be held suspended or enclosed in the molecular or atomic envelopes." [Light - Snell]
See Also
Bernoulli Equation
Figure 13.21 - Differential Pressure Zones in Antagonism cause Rotation
Gravity
Mass
specific gravity
Stria
Vortex
Weight
2.7 - Differential Densities
3.6 - Differential Densities Begin to Form
16.13 - Differential Densities