Did Einstein Say Light is Massive?

[Anomalocaris]

That somewhat trivializes it.    In common parlance, fillingness and taste are two different properties which objects may possess. It is certainly possible for anyone object to have one but not the other.  The slogan in fact plays off the insinuation that they are usually not both found in the same thing so anything that possesses both is a neat thing.

Wave/particle duality says what in everyday experience are two mutually exclusive states of being in fact not only can simultaneously describe the same thing same, but in principle It is impossible for anything to be one without being the other.

Impossible? Dude! Ok, the wave exists, but you cannot prove the particle. Duality is not commensurability is it? Nothing can be or is, duality! Yet, everything is commensurability--is it not? Or is nature a crack eyed whore?

Duality is commensurable, maybe not in the colloquial languages based on untutored daily experience of the macroscopic world, but then reality does care for its alleged feasibility as inferred from colloquial terms.   In the language of mathematical description of outcomes of rigorous experiments that seeks to discover what really is all about,  it is commensurable.  

I certainly can prove a particle.   Again, science turned out to be smarter a hundred years ago than you are now:

Photo electric effect