Is the Earth too old? The impact of geochronology on cosmology, 1929–1952

Abstract

AbstractEstimates of the Earth’s age have had significant impacts, not only on geology but also on biology, astronomy and biblical creationism. In the 1930s and 1940s, the age of the universe as estimated from the expanding universe was less than 2000 million years, but the age of the Earth as estimated from radiometric dating was perhaps as great as 3000 million years. Astronomers responded to this contradiction in at least three different ways. Some cosmologists favoured Georges Lemaître’s relativistic model, in which the universe remains about the same size for an indefinite period of time before starting its present stage of expansion. Since theories of the origin of the solar system that were popular in the early 1930s assumed an encounter between the Sun and another star, it seemed plausible that the Earth could have been formed around this epoch of ‘cosmic congestion’. Edwin P. Hubble, generally regarded as the founder of the expanding-universe theory because of his discovery of the redshift-distance law, doubted that redshifts are actually due to velocities, and seemed to prefer a non-expanding model, though he emphasized that the correct interpretation of the redshifts of distant galaxies was still an open question up until the time of his death in 1953. Fred Hoyle, Hermann Bondi and Thomas Gold proposed a ‘steady-state’ cosmology: the universe has always existed, so there is no conflict between its (infinite) age and that of the Earth. The discrepancy was finally resolved in the 1950s when astronomers revised their distance scale and boosted the age of the universe to 10 000 million years or more. The current agreement between geologists and astronomers again leaves creationists with no scientific support at all for their claim that both the Earth and universe were created only about 10 000 years ago.