Failsafe

Yesterday's sunrise portends a scorcher: the stars are all gone and only Venus remains, glittering like a diamond in a sapphire sky above a baby-blanket pink band that, in turn, nestles in turn on top of a dusky-blue layer that swaddles the horizon.

In spite of common usage, "Failsafe" doesn't mean something is foolproof and can't fail—it means that when it does fail, it goes into a (relatively) non-damaging state. A satellite, for instance, can be programmed to go into a safe mode when the unexpected happens; it orients itself to keep batteries charged and antennas pointed until further instructions arrive. Likewise when a train's braking system loses air pressure, the brakes are applied; it fails so that the train comes quickly to a stop.

But failing safe is harder to achieve when broken sensors give the wrong information—as comes to mind during my morning commute, traveling along the same section of track where a major accident occurred a month ago, looking at the dawn through the Metro train window ...

^z - 2009-08-05