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Organic chemicals — compounds that contain carbon — are the substance of life and pervade the universe. Is there a connection between comets, which are rich in prebiotic organics, and the origin of life? Current concepts of biomolecular evolution are first reviewed, including the important paradigm of catalytic RNA. At the very least, impacting comets appear to have supplied a substantial fraction of the volatile elements required for life shortly after the Earth formed. Some impacting material may even have survived chemically intact to directly provide necessary complex prebiotic organic chemicals. For life to originate and evolve in comets themselves, liquid H2O would be absolutely required: arguments for and against 26Al radiogenic melting of cometary cores are presented. Cometary panspermia, if theoretically possible, is not necessary to explain the origin of life on Earth. The Halley spacecraft provide evidence against Earth-type microorganisms in this comet’s dust.
Active in the first century BCE, Marcus Vitruvius Pollio wrote his influential architectural treatise in ten books. It remained the standard manual for architects into the medieval period. The topics which Vitruvius considered essential are diverse, including aspects of design as well as geometry and engineering. In the nineteenth century, the English architect and author Joseph Gwilt (1784–1863) won greater acclaim for the books he published than for the buildings he designed. His most celebrated achievement, The Encyclopaedia of Architecture (1842), is also reissued in this series. Gwilt's one-volume translation of Vitruvius's Latin text was first published in 1826. Supplanting previous versions, this work was long regarded as the standard edition in English. It contains a brief life of Vitruvius as well as an annotated list of previous editions since the fifteenth century. A number of detailed illustrative plates accompany the text.