why can't this (three polarizers) be explained classically? googling turns up this explanation, for example http://van.physics.illinois.edu/qa/listing.php?id=1

why can't this (three polarizers) be explained classically? googling turns up this explanation, for example http://van.physics.illinois.edu/qa/listing.php?id=16544 http://van.physics.illinois.edu/qa/listing.php?id=16544 or this one http://www.lhup.edu/~dsimanek/14/polaroid.htm http://www.lhup.edu/~dsimanek/14/polaroid.htm