Awol
10-17-2008, 07:24 PM
There is no exact measure of trail distances. A GPS will yield a different number than a measuring wheel, but neither can be said to be objectively accurate. If an ant was to hike the AT, the ant would climb up and over every obstacle. The distance it traveled would most accurately be measured with a string that would drape around every rock, resulting in a trail that is much longer than we accept it to be.
Conversely, a giant would walk a shorter path, because his strides would avoid dips and rises that we must negotiate.
On non-uniform surfaces, a measure-wheel tends to do like an ant does, and a GPS tends to act like a giant.
Even the same person will not travel the same distance twice along a section of trail. Imagine two boulders protruding a foot above the surface of the trail one yard apart. If a hiker strides from one to the other, he will have traveled 36 inches. If he steps down and back up, the distance would be 43 inches.
That's a difference of about 20 percent for a single step. So when guidebooks and maps state walking distances, they are giving approximations, not facts.
Conversely, a giant would walk a shorter path, because his strides would avoid dips and rises that we must negotiate.
On non-uniform surfaces, a measure-wheel tends to do like an ant does, and a GPS tends to act like a giant.
Even the same person will not travel the same distance twice along a section of trail. Imagine two boulders protruding a foot above the surface of the trail one yard apart. If a hiker strides from one to the other, he will have traveled 36 inches. If he steps down and back up, the distance would be 43 inches.
That's a difference of about 20 percent for a single step. So when guidebooks and maps state walking distances, they are giving approximations, not facts.