f5fb/1245684879-duchamp23.jpgThe legend goes like this.

On Easter Day in 1916, the artist Marcel Duchamp—the man who invented the readymade (or is "invented" the right word?)—gave his friend Walter Arensberg a ball of nautical twine and asked Arensberg to insert an object into the center of the ball. Duchamp asked Arensberg not to tell him what was in the center of his own artwork. He sandwiched the ball between two brass plates held together by four screws, and titled the sculpture With Hidden Noise because when you shake it, the secret contents make a rattling sound.

Duchamp's sculpture is a surrealist exercise in collaboration and symbolism, but it's also a critique of the author's role in creating art. There is always something at the heart of the work, Duchamp insists, that even the artist doesn't know and certainly doesn't control.

According to lore, Arensberg didn't die with the secret. He passed it on to another one of Duchamp's friends, Walter Hopps.

But Hopps died in 2005, and (because I am a total nerd) I've been dying to know: Did Hopps spill the beans before his death? Is there somebody out there now who knows what's inside that ball of twine?

The other day I asked Adelina Vlas, assistant curator of modern and contemporary art at Philadelphia Museum of Art, which owns With Hidden Noise. (An artist's proof is at LACMA, made in 1964, 10 years after Arensberg died, presumably with the collaboration of Hopps.)

"Hopps didn't tell anyone," Vlas told me, "or if he did, that person didn't come forward. Conservators go into the work, and they do know. But curators aren't told the secret. We can't know."

The legend lives.