How long can left and right handed life forms coexist?
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چکیده
منابع مشابه
How Long can Left and Right Handed Life Forms Coexist?
Reaction-diffusion equations based on a polymerization model are solved to simulate the spreading of hypothetic left and right-handed life forms on the Earth’s surface. The equations exhibit front-like behavior as is familiar from the theory of the spreading of epidemics. It is shown that the relevant time scale for achieving global homochirality is not, however, the time scale of front propaga...
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Many natural shapes are chiral (or handed). Our hands, for example, have a righthand version and a left-hand version, the two types being mirror images of each other. Molecules are also classi ed according to their chirality, which determines their chemical characteristics. Glucose, for example, is sweet only in one chirality, while it is tasteless in the other. The notion of chirality for two ...
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Although chiral (mirror-symmetric) pairs of molecules are synthesized in equal proportion in laboratory experiments, life is partial to only one molecule of the pair. There have been many experimental and theoretical efforts to explain why living organisms have only L-amino acids in proteins and D-sugars in RNA and DNA, but it still remains an open question. I shall review some of the major eff...
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2 Left-Handed Coordinate Systems 3 2.1 Heading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 2.2 Pitch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 2.3 Bank . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 2.4 Order of Rotations . . . ...
متن کاملEuclidean general relativity from “ left - handed area = right - handed area ”
A classical continuum theory corresponding to Barrett and Crane’s model of Euclidean quantum gravity is presented. The fields in this classical theory are those of SO(4) BF theory, a simple topological theory of an so(4) valued 2-form field, B μν , and an so(4) connection. The left handed (self-dual) and right handed (anti-self-dual) components of B define a left handed and a, generally distinc...
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ژورنال
عنوان ژورنال: International Journal of Astrobiology
سال: 2004
ISSN: 1473-5504,1475-3006
DOI: 10.1017/s1473550404001983