In chemistry, the path length is defined as the distance that light (UV/VIS) travels through a sample in an analytical cell. Typically, a sample cell is made of quartz, glass, or a plastic rhombic cuvette with a volume typically ranging from 0.1 mL to 10 mL or larger used in a spectrophotometer. For the purposes of spectrophotometry (i.e. when making calculations using the Beer-Lambert law) the path length is measured in centimeters (rather than in meters).
In a computer network, the path length is one of many possible router metrics used by a router to help determine the best route among multiple routes to a destination. It consists of the end-to-end hop count from a source to a destination over the network.
More simply, in general computer terminology, it can mean simply the total number of instructions executed from point A to point B in a program - Instruction path length.
In physics, the path length is defined as the total distance an object travels. Unlike displacement, which is the total distance an object travels from a starting point, path length is the total distance travelled, regardless of where it travelled.
Famous quotes containing the words path and/or length:
“Often on bare rocky carries the trail was so indistinct that I repeatedly lost it, but when I walked behind him I observed that he could keep it almost like a hound, and rarely hesitated, or, if he paused a moment on a bare rock, his eye immediately detected some sign which would have escaped me. Frequently we found no path at all at these places, and were to him unaccountably delayed. He would only say it was “ver strange.””
—Henry David Thoreau (1817–1862)
“Baltimore lay very near the immense protein factory of Chesapeake Bay, and out of the bay it ate divinely. I well recall the time when prime hard crabs of the channel species, blue in color, at least eight inches in length along the shell, and with snow-white meat almost as firm as soap, were hawked in Hollins Street of Summer mornings at ten cents a dozen.”
—H.L. (Henry Lewis)