THEORY OF EARTH'S GROWTH

Evening Star, Issue 19559, 18 May 1927, Page 9

THEORY OF EARTH'S GROWTH

New conclusions resulting from more than a score of years of study to learn the secret of how continents and oceans were formed are reported by Dr Thomas C. Chamberlain, professor emeritus of geology and paleontology at the University of Chicago. The studies were based on his hypothesis that the earth was never in a molten condition, but grew up slowly in a solid state, with a core composed mainly of metallic and stony material. Professor Chamberlain’s latest announcement (writes the Chicago correspondent of the ‘ Christian Science Monitor ’) is that at lust tiie earth was unable to hold rn atmosphere, but when one had been collected and had developed dry and burr'd areas a new method of growth was attained. Star dust camo down and tell more abundantly on humid regions than on dry places,' because the moisture added weight to the particles and brougnt them down more rapidly, says Professor Chamberlain. In this way humid tracts grow faster,_ and they became continents. But in the dry regions growth was slower, and planetssunal dust that finally reached eartli must have been heavier and yielded more to gravity, and hence basins were termed for bodies of water. “ Professor Chamberlain’s planetesimal hypothesis,” says a statement from the university, “ started with the assumption that a star approached our sun near enough to stimulate by tidal action the ao'ar eruptivity sufficient to cause it uO i ioject small masses of sun substances so far toward the passing _ star' that ’.t drew them in the direction of its own motion, and gave them reyolutional motion about the sun. His recent studies have made it clear that these projections would rotate on their own axes, much as does a shell from the rifling in a cannon. This rotation would aid in the dispersion of the bolts into scattered little bodies, revolving about the sun like planets, leaving only a small residue of the heaviest and slowest of the bolt-material still under the control of its own gravity. The scattering not only involved the cooling of the dispersed matter,- but gave it orbital state. Practically all gases were dispersed because the molecules would be too light and too swift to be held under control by the bolt or its residue. Professor Chamberlain’s conclusion is that the re-collection of these small bodies in orbits .-would bo too slow to heat the earth to a molten condition. The earth would, therefore, grow up slowly in a solid state, aud sp the offects of the growth would :be permanent, except as such ■ solid structures would modify themselves as they grew. This conclusion of Professor Chamberlain’s is the key point to this theory, for, if the globe were liquid, the difference would disappear, and the whole globe would be symmetrical and free from peculiarities.”