Back in the days when Grandpa went to grade school, geography teachers had no trouble explaining how the earth's mountains are formed. The earth is cooling and shrinking, they told the kids; its crust has wrinkled into mountain ranges like the skin of a drying apple. Modern geophysicists, who believe that the earth was cold when it started its career, have abandoned this charmingly simple theory. Trouble is, they have had little luck developing a satisfactory substitute.
Now, Physicist Raymond A. Lyttleton of Cambridge University proposes a return to the wrinkle theory of mountain buildingbut with a difference. The earth...