In 1950 Immanuel Velikovsky threw down a gauntlet to astronomers in his sensational best-selling book, Worlds in Collision, where he proposed, on the basis of documentary evidence, that gravitation is an electromagnetic phenomenon. Leading American astronomers were enraged and behaved like medieval priests whose sanctified gravitational cosmology was being violated. They pressured Macmillan, the textbook publisher, to burn the best-selling book. The fact neither Newton nor Einstein explained gravity seemed to go unnoticed.<br /><br />In 1979, Velikovsky gave Wal a monograph titled Cosmos Without Gravitation, which he had published in 1946. He noted that in the charged oil drop experiment, “one and the same action is ascribed to two fundamentally different principles,” where the drop is balanced between the gravitational force and the electrical attraction of a charged plate above. This was a return to natural philosophy, which provided the scientific advances that led to the modern age and is essential for progress once more. Velikovsky’s genius was to provide the keys to the solar system’s recent catastrophic history and the astrophysics needed to understand it.