from previous post, that the spacetime is actially a massless or smallest state of mass possible.clearly energy field. if a mass has centre 'O'. the energy distribution towards outward from 'O' to 'X' .i.e. max to min. X being last boundary of gravity field. the velocity also differs from 'X' to 'O' .i.e. minimum to max. so any object moving should change their direction towards 'O' since as per feynman shortest distance from 'X' to 'O', principle of least action. i also think photon must have mass since the photon has more energy than empty or vacuum space. more the energy it has in space more easier it is to travel through it. hope this makes sense please discuss.