Before the J. Paul Getty Museum in Malibu, Calif., paid millions for an ancient Greek statue of a young man, University of California, Davis, geochemist Stanley V. Margolis tested it. Some art historians doubted the statue's authenticity. In December, NOVA, public broadcasting's weekly science show, will look at Margolis' innovative tests on Getty's "Kouros" and three other cases where scientific techniques have been used to detect misattributions and downright forgeries on "The Fine Art of Faking It." In Northern California, the NOVA program will air Dec. 17 on KVIE, Channel 6, at 8 p.m. and midnight; Dec. 18 at 5 a.m.; and Dec. 22 at 5 p.m. In the San Francisco Bay Area, "The Fine Art of Faking It" will be broadcast once Dec. 17 on KQED, Channel 9, at midnight. Applying standard geological techniques to art authentication, Margolis found that the age of the weathered surface of the "Kouros" was about right for marble sculpted in the 6th century B.C. This and other findings persuaded the museum to pay an estimated 7 to 18 million dollars for the 6-foot-8-inch "Kouros." That was in 1985. The controversy still rages. The statue's critics were bolstered by the recent discovery of a very similar statue that is an obvious modern forgery. Research on the "Kouros" continues in Margolis' laboratory.