These are terms from the Reciprocal System of physics, to describe the two aspect of First Density (See Densities).

The Material Sector is that sector of the universe which we observe with our physical sense organs, consisting of all matter. It is localized, and inanimate, with sub-luminal speeds.

The Cosmic Sector is that sector of the universe that is non-local, and is identical to the Material Sector except with space and time interchanged. It is also inanimate, as anima or Life, requires a Linkage between the two Sectors. It is called "antimatter" in physics.

Prāṇa is the linkage between the Material and Cosmic Sectors which generates what we know as LIFE. It has the same dimensions as energy, and is also known as Chi.

The Reciprocal System of physical theory was developed by Dewey B. Larson in his 1959 publication, The Structure of the Physical Universe. His premise is that motion, rather than matter, is the fundamental building block of the Universe.

Further research, the RS2 Reevaluation, has redefined motion into a complex quantity that very closely resembles the concepts of the Taiji principles of yin and yang, and has produces some significant results.

Many of the principles put forth by Larson are found in the technology of the Els, such as "motion" being a primary quantity, supra-light speeds being commonplace, and the breakdown into levels of complexity (density) and conjugate sectors of the Universe (physical and metaphysical).