Qi

Qi is a term in chinese medicine for life energy. Science has yet to validate it's existence, yet it's very real. Think of Qi as the kind of energy your body is always circulating to keep homeostasis. An interaction between conscious observer, sensory data, and electricity from neurons and nerves. In the active or Sympathetic Nervous System mode of processing we tune this out. But when the Parasympathetic Nervous System or relaxed brain is engaged you become aware of a subtle relaxation energy. Qi may be sensed as magnetism, tingling, warmth, or even electric impulse. Qi is that energy that is always there that says "You're alive" that we often don't take time to notice.
              Lets go deeper into it. The Earth and plants and general environment all around us are also performing homeostasis on a larger scale. There is a background life energy running through all forms actually. This energy does exist, but it's up to you whether you let it into yourself.
               One of the goals of Qi exercise practitioners is actually transcending self and attaining the Tao. At this stage you realize you are actually the energy in the earth, the sky, and the plants and only your mind energy made you think you were just the body energy. Of course you are your body, but the process that made your body, environment, life and spirit is part of the immortal workings of the universe. The Tao.