A "Logic".
A household appliance predicted in a 1947 short story (later dramatized on the radio in 1953)that every household in the future will feel the need to have.
Hard to describe a "logic".
Imagine a TV set, but with a typewriter keyboard attached.Just ask it anything - type in the question- and it hooks you up to a world wide network to answer your question.
Is that a CRAZY prediction, or what?