Interesting, but nothing to do with whether or not you believe the "spark" you refer to is your spirit. You speak in terms of the physical, what I am asking refers to the non-physical, not anything that one might see but the unseen. If we can leave out science, which denies the spiritual realm, we might be able to explore what is not known or understood. Science itself moves away from attempting to understand what cannot be seen, because science is based upon the physical. But, to give input I will say energy from whatever source can be expended, can one recycle the energy from an atom split? does the energy from a split atom move to reform other atoms? There is much that science will never be able to explain. The atom for example; will science be able to explain what keeps an atom from flying apart, what makes protons and electrons to spin around the nucleus without flying apart? So, let's leave science out of questions about the spirit because science will never acknowledge the spiritual.