Life force and physical energy are to totally different things.
Energy is the work being done by a force. It is widely understood and can be measured and calculated using widely accepted equations. Any high school physics text can give you the much more information. Energy is conserved and can be transformed to other types of energy. A motor transforms electrical energy into mechanical energy. The engine of your car transforms chemical energy into mechanical energy. The brakes then transform mechancial energy into heat.
Life force isn't widely understood, has no agreed to method of measurement or equations for calculation. Some believe that it exists, can be detected, manipulated and even consumed. Others feel that it is a figment of imagination. Some believe that they can see it as an aura.
Life itself has measurable energies. You body transforms chemical energy into mechanical energy to breath, move etc... The electrical pulses in your nerves and brain can be measured as well as your bodies temperature.
What can't be measure are the things like your mind. What makes up your mind versus your brain? Thoughts can be measured by electrical impluses in your brain, but thoughts are more than that. Some believe in a soul. A soul doesn't have measurable energy in a physical sense. Those that believe they can measure life force, paranormal energy etc.. We see this in things the Ghost Hunters TV show. They use various devices to take measurements, but really don't have any proof that what they are measuring is paranormal. All they show is a value on meter of some type. I'm not arguing the existance of ghosts, just that there is no proof that ghosts can be measured.
The bottom line is that this is't energy in the physical sense. Perhaps we shouldn't even use the term energy to keep from confusing the issue. But, in general, since so many people believe in it, be it a soul, life force or universal energy, the concept should be studied and understood.
