Networks on Wheels
The yellow lemming vehicle has a slightly more complicated behavior than
that of Dewdney's original species: It moves toward other yellow lights
(other lemmings). When it "sees" no yellow light, it moves forward. The
lemmings were expected to mill around in a group until one, temporarily
staring towards the darkness that lies across the border, would move toward
the border without stopping. The other lemmings would follow en masse over
the non-wrap around border (or over the Nova Scotia cliffs, if you prefer)
and in small numbers they did. When the number of lemmings in the scenario
reaches a critical mass, however, the lemmings exhibit a new group behavior
as described below.
In this demo, 100 lemming vehicles were placed randomly on the field.
The borders do not wrap around.
The Plot Thickens
After a while a group behaviour begins to emerge.
Instead of milling around in an area, the lemmings started to move in
a rounded path. Some moved clockwise and some moved counterclockwise. As
lemmings in the center moved out towards the orbiting lemmings, they would
generally turn at the last minute and join the orbiting lemmings.
The End Game
Eventually every lemming had either joined the group of orbiting lemmings
or had run across the border, never to be heard from again. As the number
of orbiting lemmings increased, so did the radius of the path. Several
times the path grew so large that the path crossed the borders. When that
happened, a number of lemmings would fall out of the simulation, the total
number of lemmings would of course drop and the radius of the path would
Finally the number of lemmings has decreased to the point where the resulting
orbit lies entirely with the borders. Now the lemmings are able to maintain
a stable, perfectly round orbit. Not all simulations end this way, however,
if there are too few lemmings at the start they never start the orbiting
path. In other cases, an orbiting path can cross the border and become
so unstable that the orbiting lemmings do what they were supposed to do
in the first place: run over the border in a line.
December 12, 1988