Evolution of Darwinian drift
The evolution of drift with time at a plane normal to the passage of a body from far right to far left is investigated. It is shown that the measurable part of the drift volume as a function of time is uniquely determined, and that the indeterminacy of Darwin's drift integral simply does not matter to the physical world, in which there is a Darwin theorem stating that the drift mass is equal to the added mass. The method for determining the shape of the drift surface is also given.(Received November 7 1996)
1 Professor Chia-Shun Yih died on 25 April 1997 while this paper was being considered for publication in JFM. He was not able to take account of the comments from referees, and the editors have decided therefore to publish the paper as it was originally submitted.