Art Review MoMA’s Marcel Duchamp show made me long for those simpler times when "eliminating the artist's hand" provided a pathway back to the true self. New York subway commuters passing by an ad for a Marcel Duchamp exhibition at the Museum of Modern Art (all photos Hakim Bishara/ Hyperallergic ) In 1917, Marcel Duchamp turned a urinal on its head and called it art. With that, he earned his place in the canon as the great usurper of artistic norms, the enemy of yesteryear’s tastemakers, the banisher of everything that came before him, and the godfather of art provocateurs.  What is art? After Duchamp, the answer became: It’s whatever you want it to be. A century later, we’ve kissed our attention spans goodbye, welcomed microplastics into our bloodstreams, and surrendered authorship over almost everything to AI — from cake recipes to war target lists. The line between god-made and readymade barely exists anymore.…