Einstein's framework for his theory of gravity, for example, is incompatible with quantum theory, which explains how nature works at an atomic and subatomic level.

WSJ: Einstein Proved Right on Gravity��Again

Some things which seem obvious now could not have been found without maps: that Brazil's bulge fits neatly into West Africa's dent, and so to the theory of plate tectonics, for example.

ECONOMIST: Modern man knows where he stands. His map tells him

So the prohibition won't in theory prevent hedge funds and other investors short-selling French and Italian banks, for example, through offshore exchanges.

BBC: Can a ban on speculation strengthen Europe's banks?

For example, if productivity falls, current returns decline, says the theory, so workers and firms choose to work less and take more leisure.

ECONOMIST: The causes of booms and busts