Death of Chamberlin

Of a long line of philosophers who have tried to explain the Earth's origin, the best died last week. He was Thomas Chrowder Chamberlin, 85, professor emeritus of geology at the University of Chicago. His death was due to heart disease, made worse by bronchial pneumonia. His theory, the planetesimal, he ex pounded again in a new book published only last month -- The Two Solar Families -- the Sun's Children (University of Chicago Press, $2.50). In brief his theory is this : Eons ago a Star, swished near the Sun and by its gravity, sucked a great, explosive cloud of gases from the gaseous Sun. The cloud twirled out into interstellar space, following the Star for a way, until the Star's gravitational pull on the cloud became less than the Sun's. By that time the particles of the gases--hydrogen, oxygen, helium, iron, etc.--had acquired a gravity of their own. The Sun could not pull them back into its own churning self. Nor could the particles keep shooting away from the Sun. Their gravitational forces and the Sun's gravity balanced themselves; the particles perforce began whirling around the Sun in orbits.

By & by particles bumped into each other and many larger particles. Larger particles kept colliding until planetesimals developed. Planetesimals smashed into each other in such quantities that eventually Sun planets, including the Earth, acquired huge mass and the power to hold great satellites, like the Moon, in their own orbits.