Dr. Irvin Rock, 73, an experimental psychologist...

Dr. Irvin Rock, 73, an experimental psychologist whose work on visual perception helped explain why the moon appears to shrink as it rises in the sky, died Tuesday of pancreatic cancer at his home in Berkeley, Calif.

In 1960, he and Dr. Lloyd Kaufman, a psychologist at Sperry Gyroscope Co., confirmed a hypothesis developed in the second century A.D. by Ptolemy, the Alexandrian astronomer and mathematician, stating that the visual illusion involving the rising moon was caused by differences in perspective. Until their experiments, people attributed the differences to the composition of the atmosphere and the shape of the sky, among other things.


Using mirrors and prisms, Dr. Rock and Dr. Kaufman projected an image of the moon at the horizon and the moon at its zenith while changing its background. They showed that because the horizon moon could be compared with objects in the landscape, unlike the zenith moon floating against a flat sky, viewers perceived the horizon moon as larger.

Dr. Rock received his doctorate in experimental psychology from the New School for Social Research in New York. He taught there and at Yeshiva University in New York, Rutgers University at Newark and New Brunswick, N.J., and the University of California at Berkeley, where he was an adjunct professor of psychology until his death.


Josephine Field Davidson, 74, who joined the Daytona Beach (Fla.) News-Journal as a reporter in 1945 and became its editor, died Tuesday of ovarian cancer. With her husband, Herbert M. "Tippen" Davidson Jr., the paper's co-editor and publisher, she helped shape the daily newspaper and guided its reporters until she was hospitalized last week.

Foster Albert Lane, 92, founder of Lane Aviation Corp. and the Ohio History of Flight Museum, died Tuesday in Columbus, Ohio.

Pasty Ruth Miller, 91, a silent-film actress who played the Gypsy dancing girl, Esmeralda, in the 1923 film "The Hunchback of Notre Dame," died Sunday in Palm Desert, Calif. She performed in more than 70 films. She shifted to writing when her film career ended, winning three O. Henry awards for her short stories.

Ryoichi Sasakawa, 96, a Japanese rightist and one-time war crimes suspect who built a gambling empire and gave millions of dollars to charity, died Tuesday of a heart attack. The native of Osaka was the last living member of a group accused after World War II of the most serious war crimes. After Japan's surrender in 1945, he was imprisoned for four years by U.S. occupation forces but was never convicted.