Meg, I agree. It is indeed interesting to see diverse answers on such a core issue.
In order to answer you about inviting “Mother Earth” I would like to use a shamanic model of reality.
In the Shamanic traditions the planets are regarded as living beings where the the sun, “Father Sun” help us by being a channel for the universal light. The earth, “Mother Earth” on the other hand help us by being the channel for the universal darkness, the void.
To connect with the universal source of light can be very beautiful and can create an experience of oneness, understanding and can also be mistaken for enlightenment. Done prematurely by opening the crown has been covered enough on the forum. Direct contact with the Void is like accessing the creative potential of the universe, which is experienced as raw and undirected power. Direct access to the void prematurely can be an experience of utter terror as it can be frightening and uncovers psychic garbage we have successfully managed to avoid before. So instead of contacting the void directly it can be done via Mother Earth where she acts as a filter and the experience is then more like a subtle, loving stability. She lovingly acts as a safe channel for us to access the vast potential of the void making it possible to find the stability crucial for major openings.
To be human is to have these two qualities meet in the heart. And to be human is to have them in balance.
Accessing the light is easy and easily perceived, no need get into details. Accessing the void through Mother Earth on the hand is a very subtle experience. It not like an apparent feeling of energy filling the body, no fireworks. The effect of a firm connection to Earth is on the other hand much more apparent. It makes it possible to be able to stay open in hostile environments without losing the balance.
To some people it is a natural condition to be grounded, they never really lost the connection. Most people in the Western “spiritual” communities are not grounded.
Getting back to yoga, in India people in general have the natural grounding, they don’t have to think about it. Grounding was never an issue and grounding practices never had to be included in the yoga sutras, it was taken for granted! So, for most us in the West the yoga system is not complete because it presumes that everyone has the basic ability to stay grounded, which we do not have.
So, what I mean by inviting the energy of Mother Earth to fill my body is to consciously reconnect to the Earth, and this is more like a permanent condition that has to be cultivated. The energy experience is very subtle but the effect is very apparent. When we are out in nature this happens automatically to a level that covers our everyday need. But when working in the yogic system I believe that a much more firm grounding is needed than what we get from forest walks etc.
//lorf