Why Light/photons behave as both a Particle and a Waveform:

Because they’re traveliing AT the ‘uppermost speed limit’ for Relativistic phenomena, they ‘straddle’ the line between Relativistic and Quantum states simultaneously. They would have to, because they are riding the exact line between the two.
But, it would appear to be more a function of their energy-mass of volume than anything else as they still retain that bi-natured quality when slowed to vasterly slower speeds in an Einsteinian Condensate.

Energy state itself doesn’t matter, as X-rays and other higher energy photons do not exceed the speed limit, thus while the enerfy-state is higher, the function of energy-mass of volume is therefore different in a manner that allows them to exist, possess the bi-natured quality, yet not exceed the C constant of the Universe.

Just my thoughts after tossing some ideas around with hubby…