Akasha mahabhoota:

According to Ayurved, akasha is anadi and anant i.e. it does not have any origin or end. It is sarvavyapi (omnipresent, ever existent). The only way we can understand akasha is from its apratighatatwa guna, which allows very existence of the matter. If there was no space how could anything ever exist? This fact is true for our own bodies, and for the organs and cells inside it. As the outer space is for our body, our body is for the billions of cells in it. Imagine that we are space for the cells within us. If we stretch our imagination inwards to peep inside our bodies or outwards to fathom the depth of the universe we will appreciate that the outer space is made up of nothing but the inner space and thus proving the sarvavyapakatwa of this basic element akasha. Is this the fact that the "Bhagwatgeeta" is trying to impress upon us while we grasp the concept of "Pinda-Bramhanda Nyaya"?

Shabda (sound) is the sense attribute of akasha. Shabda is nothing but the very basic form of energy, which is also ever existent as akasha. We know now from the theory of Eienstine that, energy can neither be created nor destroyed, but it can be changed from one form to another. Matter is also nothing but a form of energy (E= MC2). Energy cannot exist without matter and vice verse. In the akashamahabhoota energy exists in the form of shabda. According to Hindu philosophy, "Aum" was the first shabda to exist and from this the universe evolved.  Mantra is nothing but a repetition of group of shabda or a specific energy-field. In Ayurved mantra, mani and aushadhi are the basic forms of treatment. Obviously mantra chikitsa is given first preference and is regarded as daiviya (divine) form of treatment. The second being mani chikitsa (gems) and the third, which is most widely used is aushadhi-chikitsa (medicine).