The omni-present computer-like device in TheLastQuestion by IsaacAsimov, which is able to come up with unique and non-trivial solutions to problems.  It (the various incarnations of it through the ages of the universe) is continually asked a question to the effect of "Can entropy be reversed, or is it all winding down?", to which it continually replies to the effect of "I don't have enough information to answer you yet".

''Nope. Univac was a genuine line of MainframeComputer''''''s. Asimov named his fictional computers Multivac. In either case, I smile at the thought of vacuum tubes. -- ElizabethWiethoff''