... The sun's disk is brilliant, however, and the transparency of the earth'satmosphere is both imperfect and variable; these factors make accurate determination of the solar diameter by this kind of observation difficult. ...
... group at the University of Chicago in the late 1940s who were studying the effects of cosmic rays on the Earth'satmosphere and it led to the idea of age determination using radiocarbon (see Libby 1965); Libby subsequently received a Nobel prize for this ...
... near-collisions with Mars, the earth's spin axis shifted with respect to the crust ... Pole was once near the point on the earth's crust that is now at latitude 70-N and ...
... If magma erupted, completely degassed and crystallised in equilibrium with the atmosphere the initially trapped argon in all minerals must have an isotopic composition, which is identical to those of the atmosphere. ...
... The greatest lead emissions to the atmosphere all over Europe occurred between 1950 ... 1996), total anthropogenic lead emissions to the atmosphere make up 332!10 9 g/year ...
... of stars greatly depends on the state of atmosphere height of the sun and solar ... well as his understanding of the variations of the Earth's spin is far from clarity ... Historical Eclipses and Earth's Rotation, Cambridge University Press, 1997 ...