What Are the Next VU Experiments

Since the question of a possible relationship between asymmetry at the elementary particle level and chirality at the biomolecular level (a) remains unanswered until today and (b) is clearly of outstanding interest with regard to the question of the origin of life, I would like to urge others to extend earlier experiments and to develop new ones having a bearing on the matter. A strategy for a successful experiment might be to adapt experimental parameters to interstellar-like conditions in which amino acid structures had recently been identified (Bernstein et al. 2002; Munoz Caro et al. 2002). In particular, the experimental study of asymmetric synthesis and radiolysis reactions of a-methyl-a-amino acids with the P+-radiator 26Al might have the potential to offer important results. Various a-methyl-a-amino acids were identified in meteorites showing considerable enantiomeric excesses (see Chap. 8) and these amino acids are stable against radioracemization (Bonner 1984). The 26Al emitter of spin-polarized ('homochiral') positrons (van House et al. 1984) has largely contributed to the early thermal evolution of comets and small icy bodies (Meiring 1987; see also Chap. 9), in which amino acid structures were identified as well. Here, the experimentalist should take into consideration that positrons obtained by the P+-decay show opposite handedness (right-polarization) compared to left-polarized P-electrons (Conte 1985). The P+-radiator 26Al should therefore induce the opposite handedness into organic molecules such as amino acids compared to a P~ -radiator as e.g. 32P. Furthermore, longitudinally polarized protons (Bonner et al. 1982) or supplementary and hitherto overlooked particles acting as external chiral driving forces might be examined carefully in future times.

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