Light is considered as the symbol for all splendour and glory of the spirit. It stands for truth, order, reality, goodness, beauty, intelligence, wisdom, bliss and immortality. Therefore the sun is light and life.
A small part of light of the sun is producing life and energy of all beings. The sun is 1.3 million times bigger than the earth. Sunlight coming to earth represents only about one part in 200 crore of the total amount of energy radiating from the sun, Out of this, 30 % merges in the atmosphere without reaching the earth and only about 1% of the electromagnetic spectrum is thought to be perceived by the eye. Yet this is sufficient to supply our planet with about 4.69 million horsepower per square mile. It is vividly described in the `Taaitryee Araanyyak` how Surya ruling our bodies. Surya is the fountain source of strength and vitality, light and effulgence and so. He naturally rules our heart, spine and constitutions of human body. He causes all respiration and controlling sensory and motor organs and breath. The Sun generates `Vital force` or `Prana shakti` contains five sub vital airs known as `Panch prana` which is inherent in every limb, muscle etc. Our lives, health and well-being are truly dependent upon the Sun.