There are many interpretations of the human energy system and even more labels within those variations. We will work with a form describing seven major chakras or energy centers along a central axis. This central axis is an energy channel residing in the core of the body along the front of the spine. Intrinsic to and extending past the body are seven layers or levels of an energy field that work in concert with the chakras. This energy field is what is usually referred to as the aura.
The seven major charkas connect into the central channel at different latitudes on the body. Each chakra relates to a different area of the body and different aspects of our experience in life. The "domain" of each chakra corresponds with the "domain" of each level of the energy field. Each progressive level both encompasses the preceding level and extends past that level. The quality of energy becomes finer as it moves further away from the body. The levels or layers of the energy field have different qualities on alternating levels. The first, third, fifth and seventh levels are a structured energy grid composed of lines of energy. The second, fourth and sixth levels are composed of fluid plasma-like energy.
The energy in the central channel functions at another dimension that is deeper to our experience of the energy of the chakras and the levels of the field. Whereas the energies moving in and out of the chakras and through the levels of the energy field are dynamic and capable of constant change just as our thoughts and emotions change, the energy along the central channel relates more to our core, that which is eternal and unchanging. Our obscurations of the central channel are related to ignorance.
On either side of the central channel (sushumna nadi) are two other major energy channels (ida-left and pingala-right). They originate at the central channel four finger widths below the navel. These two channels are generally described as traveling upwards in the configuration of a double helix, much like DNA. The energy of the two channels coincides with the energies that we associate with masculine and feminine. The channel that originates on the left terminates at the left nostril after arcing upward into the left hemisphere of the brain. While the channel that originates on the right terminates at the right nostril after arcing upward into the right hemisphere of the brain. The right channel, known as the solar channel, is associated with masculine energies of action, individuality and expression and the obscurations of anger, aggression and separation. While the left channel, known as the lunar channel, is associated with feminine energies of reflection, receptivity and creativity and the obscurations of desire, attachment and jealousy.
Hatha yoga, virtually all of the forms that we know as yoga in the west, is literally named for the solar and lunar channels. The hatha yoga practice of moving the body into postures is designed to balance the energies of masculine and feminine, solar and lunar, action and reception, doing and being. A balanced yoga practice will illuminate obscuration to these oppositional energies and create harmony within the energy system. We become clearer and in balance in our bodies and minds. This in itself is not the goal of yoga. As we sustain harmony between these seemingly oppositional ways of being, we have access to the central channel. And that is about having access to wisdom.
“A Current of Luminous Compassion creates and sustains the entire gross and manifest realm, a current known by many, many names--the Holy Ghost, the Sambhogakaya, saguna Grahman, Arwah or divine luminosity, Keter, the subtle body--but a Current that, in all events, is simply the sound of the beating of your Heart keeping rhythm to the pulsing of the world.”
Ken Wilber, The Simple Feeling of Being