  Chiral symmetry breaking occurs when a physical or chemical process, with no
preference for the production of one or other enantiomer, spontaneously
generates a large excess of one of the two enantiomers: (L), left-handed or
(D), right handed. Inorganic processes involving chiral products commonly yield
a racemic mixture of both. However life on Earth uses only one type of amino
acids (L) and one type of natural sugars (D). The origin of this selective
chirality has remained a fundamental enigma in the origin of life since the
time of Pasteur, some 140 years ago. Sodium bromate (NaBrO3) and sodium
chlorate (NaClO3) when crystallize from an unstirred solution generates
statistically equal numbers of left-handed (L) and right handed (D) chiral
crystals. But when these two populations of crystals undergo a
dissolution-crystallization phenomenon, they cannot coexist: one of them
disappears in an irreversible competition process that nurtures the other one.
  From the viewpoint of energy, these two enantiomers can exist with an equal
probability, thus the result of this competition in different systems would be
populations of crystals either (L) or (D). But contradicting this theoretical
prediction the handedness of the chiral crystals that win the competition and
remain in solution in the different systems is almost always the same (99.2
percent for NaBrO3). We suggest that these results are the consequence of
Parity-violating energy difference (PVED) between enantiomers and reinforce the
idea of a key role of PVDE theory in the origin of biomolecular chirality on
Earth.
