Landmarks: A Thought Experiment - Landmarks: GIScience for Intelligent Services - page 30

2.1.3.1 Adding More Landmarks

Let us assume the walker decides to mark the location where she found the coin with
some chalk on the ground. She also draws a line on the ground from that location to
home. Home is another mark on the ground. These externalized landmarks can now
be found even with fading memories of path integration. The experience of walking
can be repeated, can be communicated easier to others, and can be shared by others.
Further landmark experiences in the environment can be added over time,
and connected to the existing ones. What forms over time is a travel network
between landmarks. The intersections in this network were originally destinations,
or locations of particular (shared) memories or stories. But over time also the edges
in the network get some prominence, since they are commonly experienced by some
embodied locomotion. As the dependent elements (e.g., “the route from home to the
place where we have found the coin”) their prominence may be lower, but we will
argue later in the topic that they will also share some landmarkness. For example,
the walker and her friends can give names to edges (or sequences of edges in this
regard). If over time the stories of the original landmark experiences fade away the
prominence of the named edges may even get stronger (e.g., “the coin route”).
Whatever elements are the primary anchors, either the connected landmark
locations or the dual view of the edges between landmarks, this network enables for
spatial tasks such as orientation and wayfinding. Using landmark orientation would
be maintained either with local landmarks (“I am at the location where the coin was
found”) or with global landmarks (“I am three intersections from home”), and route
planning would be about an appropriate sequence of landmarks (e.g., “From home
to the location where the coin was found, and then right”). Using edge orientation
would be maintained also either locally (“I am on Coin Route”) or globally (“Coin
Route must be in this direction”), and route planning would be about an appropriate
sequence of edges (e.g., “Point Route, then turn right into Serendipity Street”).

2.1.3.2 Adding Directed Light

Alternatively, let us change the settings of the experiment slightly. Instead of diffuse
light imagine there is a point-like light source, mounted several times above body
height. Call it the sun although it will not move in this experiment. This sun
can be observed from any location, and since it is the only marked point in the
environment—a singularity in an otherwise homogeneous empty space—it will
attract attention from walkers. It also provides a reference direction for orientation
and communication. Instead of using solely their locomotion-based orientation,
walkers can now refer to the sun: “Walk towards the sun”. Even on the ground is
now a singular location where the body throws no shadow, which is where the sun
is in zenith. This point can be found by any walker. It is an embodied experience
but also a characteristic of the environment, and thus independent from previous
locomotion. Therefore it can be used as a common, or shared reference point.
Everybody can find it with no further instructions about its distance or direction.