  Though the interfacial tractor beam experiment supports the increase of
photon momentum (i.e., Minkowski momentum), it is still a matter of
investigation whether, inside matter, the photon momentum always increases.
Considering the inhomogeneous or heterogeneous background, we have demonstrated
that if the background and the half-immersed object are both non-absorbing, the
transferred photon momentum to the object can be considered as the one of
Minkowski exactly at the interface. In contrast, the presence of loss inside
matter, either in the half-immersed object (i.e., plasmonic or lossy
dielectric) or in the background, changes the whole situation. For such cases,
our several demonstrations and proposed thought experiments have strongly
supported the decrease of photon momentum instead of the usual perception of
its increase. Although almost all the major radiation pressure experiments have
so far supported the linear increase of photon momentum, our proposed simple
experimental set-ups may introduce a novel way to observe and verify the
exactly opposite proposal: the Abraham momentum of photon. Finally, as an
interesting sidewalk, based on several parameters, a machine learning based
system has been developed to predict the transferred momentum of photon within
a very short time avoiding time-consuming full simulation.
