Simpleton's view: Particles are just standing waves, so to speak. They are not just an amorphous clay-like lump of matter. They are made of smaller things and

Simpleton's view: Particles are just standing waves, so to speak. They are not just an amorphous clay-like lump of matter. They are made of smaller things and those things are churning around. That in-place churning becomes a wave when the particles move at speeds that approach a significant fraction of c.