Prana is all the energy that maintains the whole physical body. Prana can be dissipated through selfish thoughts and activities or it can be brought to one particular centre, perhaps ajna chakra or mooladhara chakra. Prana has the power of regeneration, therefore it can be taken to any part of the body which is suffering, for healing purposes. It rejuvenates the decaying limbs and organs and restores lost health. This prana is the body and thus it can be distributed equally throughout all parts of the body or it can be withdrawn to one part of the body. When aroused by yoga, this prana radiates itself out of the body. To the naked eye it is not visible, but the most sensitive photographic system, called Kirlian, enables us to photograph the pranic radiation in each and every animate and inanimate object, from human beings to leaves.
Prana is an inherent force in our life and kundalini yoga is the secret of awakening the super prana shakti. Just as in electricity you have voltage no, then you have 220, then you have 440, go on adding and finally when this ordinary electricity is at a very big voltage, then it is converted into laser waves. Similarly prana can be amplified, modified and transformed to any degree. Of course it is difficult for a normal human being to increase his prana from ordinary voltage to such a voltage where the degeneration taking place in a particular part of the body can be checked. This is the science of prana vidya.
'Prana' means cosmic or vital energy which is inherent in the evolution of human life. 'Vidya' means knowledge. Just as you practice ajapa japa, yoga nidra or antar mouna, there is also a practical technique of prana vidya. By practising for oneself every individual can awaken this prana and conduct it with a little higher voltage to a particular part of the body. The theory and techniques of prana vidya are ancient but I have revised and made them practical for the people of today. For this purpose I have printed the book Prana Vidya, which is now available at Bihar School of Yoga, Monghyr, Bihar, India, and I am presently preparing a more complete edition, Prana and Prana vidya which will be available very soon.