The molecular building blocks of life are nearly all chiral: They have a definite “handedness” and thus can’t be superimposed on their mirror images. What’s more, everywhere on Earth, biomolecules all have the same chirality, even though their left-handed and right-handed isomers are energetically identical. Somewhere along the line, something must have happened to break the left–right symmetry and induce the dominance of one chiral form over the other.
Inspired by the mystery of biohomochirality, Cristóbal Viedma, a geologist at Complutense University in Madrid, Spain, went looking for ways to break chiral symmetry in the lab. Rather than chiral molecules, his experiments use chiral crystals—achiral atomic and molecular ions arranged into a chiral lattice. He found that a fifty-fifty mix of left- and right-handed crystals of sodium chlorate (NaClO3), suspended in aqueous solution, could be transformed into a single chiral form either by crushing and grinding the crystals...
