In art, science can identify fakes and forgeries, but has limitations in authenticating a work. For example, if a chemist shows that the paint and canvas used for an advertised ‘1660s Rembrandt oil painting’ is from the 1800s, that proves beyond a doubt that the pasinting is a fake. However, if science shows the canvas and paint is from the 1660s, that doesn’t prove the painting is by Rembrandt. It could have been by a student or admirer of Rembrandt copying his style. The chemist’s finding is clearly useful towards determining a Rembrandt’s authenticity, but the authentication also requires art historians assessment of the painting’s style, quality and other non-scientific aspects.