A physicist who is broadly experienced in using computers to identify consistent patterns in the drip paintings of Jackson Pollock has determined that half a dozen small paintings recently discovered and claimed by their owner to be original Pollocks do not exhibit the same patterns. The finding, by Richard P. Taylor, a physics professor at the University of Oregon, does not prove that Pollock did not paint the works, among a cache of 24 paintings found in 2003 in Wainscott, N.Y., by Alex Matter, whose father, Herbert, and mother, Mercedes, were friends of Pollock. But it casts serious doubt on...