Cryptography

The thirty-fourth entry is pós-quântico, and an English reader arrives at it holding an idiom that points the wrong way. « A quantum leap » in ordinary English is an enormous advance, the jump that changes everything, and it is said of a career, a product and a policy without anybody pausing over it. In the physics the word was borrowed from, a quantum is the smallest amount of anything that can exist on its own, and a quantum jump is the smallest change a system can make: the idiom has turned its own source inside out. English keeps the sober reading in the law courts, where the quantum of damages is simply the sum awarded, straight from the Latin quantum, how much. Portuguese built no such figure of its own. O salto quântico exists as a borrowing and is rare outside translated prose, while quântico stayed inside physics; pós-quântico is a flat technical adjective meaning able to survive a quantum computer, said of an algorithm and of nothing else. Read o algoritmo pós-quântico as a promise of a great leap forward and you have imported an English figure of speech into a specification.