John Shearman, an art historian and scholar who consulted with the Vatican on the restoration of the ceiling of the Sistine Chapel, has died at the age of 72. “Dr. Shearman probably achieved the most fame for his discovery that the vault of the Sistine Chapel was cracked along its length in 1504, four years before Michelangelo began work on it. Because the old decoration — incorporating stars and some geometrical shapes — was ruined, a new ceiling was needed.”