The wittiest scene in Joel and Ethan Coen's 2001 film The Man Who Wasn't There is one in which a fast-talking defense attorney, Freddy Riedenschneider (marvelously played by Tony Shalhoub), invokes Heisenberg's uncertainty principle as grounds for a not-guilty verdict in a murder case:
We can't know what really happened.... Because the more you look, the less you know. But the beauty of it is, we don't gotta know! We just gotta show that, goddamnit, they don't know. Reasonable doubt. Science. The atom. You explain it to me. Go ahead, try.
At the time, this routine seemed little more than an offhanded parody of the Michael Frayn play Copenhagen, in which Heisenberg and Nils Bohr discourse windily about the inscrutability of their past actions and intents. But the idea recurs more centrally in the Coen brothers' new film, A Serious Man, when a beleaguered physics professor named Larry Gopnik (Michael Stuhlbarg) explains to his students that the uncertainty principle "proves that we can't ever know what's going on." In this case, it is far less clear whether the assertion is intended as satire or corroboration of Frayn's metaphor. Indeed, the movie itself is similarly difficult to pin down: part tragedy, part epistemological inquiry, part Jewish comedy of manners.
The film opens with a prologue, a 19th century ghost story set in Eastern Poland. A poor Jewish farmer returning home to his wife one wintry night brings with him an old traveler who may or may not be a dybbuk--the soul of a dead man sent back from Hell. The scene, played entirely in Yiddish, has no direct connection to what follows and might easily be considered an idle flourish. But it succeeds in establishing the aura of doom--unforeseen but inexorable, deaf to entreaty--that permeates what follows.