The origin of optical asymmetry on earth

The nature of optical isomerism, and the problem of the origin of optical asymmetry in relation to the origin of life are defined. Developments in particle physics, such as the discovery of parity non-conservation in weak interactions and more recently, of neutral currents, are described. Their significance is that there are a number of possible mechanisms whereby the fundamental asymmetry of matter could be reflected in a preference for one enantiomer over the other, and that, contrary to long-established views, optical isomers do not have identical energy contents: the difference, however, is estimated to be very small. Theories regarding the origin of optical asymmetry are classified in a two-dimensional matrix (origin by chance or due to already existing order; susceptible or not susceptible to experimental test). Recent experimental results and theoretical speculations are reviewed, and proposals are made for further experimental work.