This Colloquium is about the development of new ideas in molecular physics which could not have occurred without my close acquaintance and collaboration with Donald S. Gemmell. It revolves around the experimental efforts to make sense of quantum handedness in molecules. The story starts with Don's Coulomb-Explosion-Imaging (CEI) technique as a new direction in molecular structure. The significance of using CEI for absolute handedness measurements of molecules in the gas phase and its modern accomplishment is then told. Lastly, the measure of handedness without absolute configuration is presented.

Argonne Physics Division Colloquium Schedule