'Radar' is so useful as a metaphor; what did people do before World War II?
It was a snowy December here in Boston, during which one storm seemed to blur in with the next. And having been out of town at a critical juncture, the Night of the Very Long Drives Home, Dec. 13, I somehow lost count of which storm was which after that.
Then one day, when I heard a radio host report that such-and-such storm was "still on the radar," I did a little double take.
I realized he meant it literally. He, or at least someone who was supplying him with information, had an actual radar screen. It was one of those moments when the literal and the figurative were one, in a kind of harmonic convergence.
I, on the other hand, had no such fancy hardware. I had a memory bank, and one that had not been supplied with a completely wonderful wad of data at that.
A radar screen, with its characteristic "sweep," is such a good metaphor for the idea of a comprehensive overview of whatever one is trying to follow that I wonder how people got along without it as a source of metaphor before radar came into wide military use during World War II.
I realize that having, or keeping, things "on the radar screen" is a turn of phrase I often use myself. I picked it up when I was a junior editor in the Monitor's international news department, where we would often speak of something being "on the screen," or occasionally, of its having fallen off it.
It was implicitly a radar screen, albeit a metaphorical one. We had computer screens in those days, but they were single-application terminals. They didn't offer a window on the world, as personal computers do today.
It strikes me as a good metaphor for journalists needing to keep scanning their "fields," whether geographic or thematic, for developing trends, controversies brewing, storm clouds gathering, and such.
Another expression conveying a similar sense of a systematic sweep of an area is . It's French and means literally a tour, or circuit, of the horizon. It's often used to mean a general survey, in a figurative sense, rather than a tour of actual geography. A diplomat departing from a post will give his successor a of the issues in that particular country, for example.