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An array of experimental findings suggest that the simple molecules required for the origin of life may have been available on the primitive Earth. The well-known Miller-Urey electric discharge experiment [...]

Earth probably accreted in two stages corresponding to conditions before and after the removal of gas from the nebular disk. Helium and neon in the mantle primarily record a solarlike component likely incorporated during the first stage by solution into a magma ocean blanketed under a massive protoatmosphere of molecular hydrogen and helium. The heavier noble gases primarily reflect a meteoritic (planetary) component trapped in accreted planetesimals. This model provides a possible explanation for the reduced and oxidized accretion stages inferred from siderophile elements and may explain why the present mantle appears to be too oxidized to be in equilibrium with the core., Planets form from material left behind in residual accretion disks once infall of the collapsing source clouds is complete. Such disks experience a two-stage history involving the separation of minor [...]

Origins The subject of 'Origins' was suggested to me for this talk I suppose because this topic has always attracted the curiosity of scientists, and indeed of everyone else. It [...]

At first sight, there seem to be remarkably few probes of the early Universe. The expansion of the Universe was first discovered by Edwin Hubble. Together with the 2.7-K blackbody [...]