Tin foil, also spelled tinfoil, is a thin foil made of tin. Actual tin foil was superseded by cheaper and more durable aluminium foil after World War II, and aluminium foil is sometimes confused with “tin foil” because of its similarity to the former material.
Which lends itself to,
A tin foil hat is a piece of headgear made from one or more sheets of aluminium foil or similar material. Alternatively it may be a conventional hat lined with foil. One may wear the hat in the belief that it shields the brain from electromagnetic fields; to prevent mind control and/or mind reading; or to limit the transmission of voices directly into the brain.
Thus we arrive at the conclusion of the matter,
There’s been discussion of Limbaugh’s demented accusation that the crafty masterminds of Team Obama somehow, retroactively to 1993, managed to brand this summer’s Batman-movie supervillain with a name to invoke dark resonances against the GOP contender. Professional media speculation seems divided as to whether Rush is demented enough to believe this tosh, or if he’s just feeding garbage to his deluded listeners.
Yes, it’s the Schrödinger’s cat of political commentary.