The ancient Taoist "cosmic scientists" discovered through their highly developed insight that there is essentially one primal cosmic energy. In the stillness of the unmanifest aspect of the universe, the primal cosmic energy expresses a state of oneness. As it extends itself in the process of creation, its movement causes the polarization of the one primal energy, giving birth to duality. The polar aspects of the effects thus created were designated as yin and yang. Yin and yang have many translations, such as the two sides of positive and negative, expansion and contraction, construction and destruction, masculine and feminine. Yin and yang are not two separate energies or activities. The activity of one is inherently contained within and created by the other. For example, a symphony is composed not only of musical sounds, but the silent pauses between the sounds are also intrinsic aspects of the composition. In the English language, the contradictory sense of positive and negative is strong. But in the Chinese way of thinking yin and yang unite themselves, and through this union the existence of all things is made possible. If one side is excessive, its state of balance is lost, thereby creating the possibility of destruction.
Nature is energy. The entire world is composed of formed and unformed energy. Even space is made up of different kinds of energy. Energy is simply all there is. Although conceptually we talk about fields of energy, capacities of energy and forms of energy, classifying and categorizing them as different matters, in reality the entirety of nature is one energy, one life. We are small lives. This is the basic understanding of the ancient developed ones.
In the physics of the worlds, ether or functional energy is the senior and most subtle of the gross elements, which also include solid, liquid, fiery, and gaseous substances (the ancient esoteric elements of earth, water, fire, and air). Ether, the most subtle state of gross or material appearance, is the all-pervading element of the physical universe, analogous to space itself. The etheric dimension of force or manifest light pervades and surrounds our universe and every physical body. It is the field of energy, magnetism, and space in which the lower or grosser elements function. Thus, your "etheric body" is the specific concentration of force associated with and surrounding-permeating your physical body. It serves as a conduit for the forces of universal light and energy to the physical body.
In practical terms of daily experience, the etheric aspect of the being is our emotional-sexual, feeling nature. The etheric body functions through and corresponds to the nervous system. Functioning as a medium between the conscious mind and the physical being, it controls the distribution and use of energy and emotion. It is the dimension of vitality or Life-Force. We feel the etheric dimension of life not only as vital energy and power and magnetic-gravitational forces, but also as the endless play of emotional polarization, positive and negative, to others, objects, the world itself, everything that arises.
"Prana" is a Sanskrit term meaning "life-energy" or life-force. In yogic esoteric teachings, "prana" is also a specific technical name for one of a number of forms of etheric energy in the bodily being. The term here more generally, in reference to the whole dimension of living energy that pervades and sustains the physical and vital processes of Man. Thus, "prana" is the manifest life-energy. It is an aspect of the Transcendental Current of Life, which is All-Pervading, but also Eternal - but manifest or "pranic" energies are only temporary phenomena of the Realm of Nature.
The whole universe is a big nuclear reaction furnace in which energy transformations are constantly taking place. Non-being becomes being. Being becomes non-being. This results from the constant transformation, sublimation, evolution, or devolution of energy. Through objective understanding, one can see that it is necessary to make subjective effort to consciously adjust oneself in order to achieve and maintain harmony, balance and progressive evolution. The whole human body, like the universe, is also like an alchemical furnace in which energy changes and transformations are continually taking place.
We can make our body into a small workshop of the universal process of energy transformation by subtly adjusting our own internal energies. In this way, we may gain the self-mastery necessary to dissolve our apparent physical bondage. When certain terms and environmental conditions are present, specific results must appear. This is the basis of all experimental science. As far as the human external form is concerned, since it is already completely formed, we are limited in our ability to change and improve it. However, everyday, even every minute, the inside of the body is constantly working and changing.