In 1978, Fred Hoyle proposed that interstellar comets carrying several viruses landed on Earth as part of the panspermia hypotheses. With respect to life, the origin of homochirality on Earth has been the greatest mystery because life cannot exist without molecular asymmetry. Many scientists have proposed several possible hypotheses to answer this long-standing L-D question. Previously, Martin Gardner raised the question about mirror symmetry and broken mirror symmetry in terms of the homochirality question in his monographs (1964 and 1990). Possible scenarios for the L-D issue can be categorized into (i) Earth and exoterrestrial origins, (ii) by-chance and necessity mechanisms, and (iii) mirror-symmetrical and non-mirror-symmetrical forces as physical and chemical origins. These scenarios should involve further great amplification mechanisms, enabling a pure L- or D-world.
Subjects
?-strand absolute asymmetric synthesis achiral stationary phase amino acid handedness amino acids assemblies asymmetric autocatalysis asymmetric reaction asymmetric synthesis autocatalysis biological homochirality bioorganic homochirality C1- and C2-symmetric catalysts chiral field (memory) chiral separation chirality chirogenesis circular dichroism circularly polarized light circularly polarized luminescence circularly polarized photon deracemization enantiomer self-disproportionation enantiomorphism enantioselective reaction environmental chirality etch figures genesis of life chirality gravitation heat capacity hidden chirality high dimensional chirality homochiral and heterochiral aggregates homochirality lipid magmatic flow magnetism metal-organic framework multi-point approximation nepheline neutrinos nucleus-molecular coupling origin of life parity violation parity violation in the weak interaction plasma reactor polymer prebiotic precision measurement racemate racemic field replicators Salam hypothesis SDE self-assembly Soai reaction spin polarized electrons spin-polarized lepton super-high-velocity impact supramolecular assembly supramolecular chirality symmetry breaking tilt-chirality triethylenediamine (DABCO) molecules tunneling two-fold helix Viedma ripening effect vortex Wallach's rule weak neutral current Z0 boson