Our prana changes thoughout the day – with sunrise and sunset etc. Singing, Chanting etc nullifies the negative effects in the environment. Especially chanting Om Namah Shivaya, it nullifies all the negative emotions eg. Anger, hatred etc
There are two branches of knowledge:
A. Vidhya – the spiritual aspect
B. Avidhya – the material / subjective aspect
If you are completely engrossed in avidhya, you are in darkness. If you are completely immersed in vidhya, you are also in darkness – and if you are in neither then you are in greater darkness. Both are essential. Avidhya is divided into 14 branches – ayurveda, astronomy, physics, chemistry etc..
The basis for spiritual knowledge is subjective knowledge. You need to know these first – then know the mind, the memory, the intellect, the ego. These can only be understood if you can understand the self. If someone is only with the experience of vidhya, they can hallucinate. There is no joy in them at all. Too much of anything is not good. Death you overcome through avidhya. Immortality you overcome through Vidhya. Yoga is avidhya, it is not a spiritual science. It is a refinement of the mind. If you are doing something (even pranayamas) it is avidhya. Vidhya is when you do nothing at all. Anyone who is one sided is lost because we are a combination of both – matter and spirit.