logical adj.
[from the technical term `logical device', wherein a physical
device is referred to by an arbitrary `logical' name] Having the
role of. If a person (say, Les Earnest at SAIL) who had long held
a certain post left and were replaced, the replacement would for
a while be known as the `logical' Les Earnest. (This does not
imply any judgment on the replacement.) Compare virtual.
At Stanford, `logical' compass directions denote a coordinate
system in which `logical north' is toward San Francisco, `logical
west' is toward the ocean, etc., even though logical north varies
between physical (true) north near San Francisco and physical
west near San Jose. (The best rule of thumb here is that, by
definition, El Camino Real always runs logical north-and-south.)
In giving directions, one might say: "To get to Rincon Tarasco
restaurant, get onto El Camino
Bignum going logical north." Using the word `logical'
helps to prevent the recipient from worrying about that the fact
that the sun is setting almost directly in front of him. The
concept is reinforced by North American highways which are
almost, but not quite, consistently labeled with logical rather
than physical directions. A similar situation exists at MIT:
Route 128 (famous for the electronics industry that has grown up
along it) is a 3-quarters circle surrounding Boston at a radius
of 10 miles, terminating near the coastline at each end. It would
be most precise to describe the two directions along this highway
as `clockwise' and `counterclockwise', but the road signs all say
"north" and "south", respectively. A hacker might describe these
directions as `logical north' and `logical south', to indicate
that they are conventional directions not corresponding to the
usual denotation for those words. (If you went logical south
along the entire length of route 128, you would start out going
northwest, curve around to the south, and finish headed due east,
passing along one infamous stretch of pavement that is
simultaneously route 128 south and Interstate 93 north, and is
signed as such!)