True and false chirality and absolute enantioselection

Abstract

The discrete symmetries of parity P, time reversal T, and charge conjugation C are used to characterize the properties of chiral systems. The concepts of true chirality (time-invariant enantiomorphism) and false chirality (time-noninvariant enantiomorphism) that emerge provide an extension of Lord Kelvin’s original definition of chirality to situations where motion is an essential ingredient thereby clarifying, inter alia, the nature of physical influences able to induce absolute enantioselection. Only a truly chiral influence lifts the degeneracy of chiral enantiomers and so may induce absolute enantioselection in all circumstances. Chiral enantiomers remain strictly degenerate under a falsely chiral influence, which may therefore not induce absolute enantioselection in a process that has reached thermodynamic equilibrium, but may do so in far-from-equilibrium processes via a breakdown in microscopic reversibility analogous to that observed in elementary particle processes under the influence of CP violation. Parity violation and CP violation are suggested to be manifestations of true and false cosmic chirality, respectively, and their possible roles in abiotic enantioselection discussed.