Spirit is a form of energy which has its own frequency wave form. To begins with, human has energy frequency. Once human passed on, energy is released into the environment which this energy may be bonded together rather than dispersed. Another word, if to detect by frequency tester, it should has a reading as the frequency reader will read form of energy. But i guess to conclude which reading belongs to the form of 'spirit' is still unsure. Which i guess therefore in term of science perspective, they recognised as energy and denied as 'spirit', eventually we are talking about the same thing.
Easy money.....la....!!!!!! every time you can hear them said..oh..I see this...oh.. that thing can move, finally, no once see it or caught it to show the world and so on....!! very naive.....!!!