Scale
A globe is the only way to represent the earth with constant scale throughout the entire map in all directions. A map cannot achieve that property for any area, no matter how small. It can, however, achieve constant scale along specific lines.
Some possible properties are:
- The scale depends on location, but not on direction. This is equivalent to preservation of angles, the defining characteristic of a conformal map.
- Scale is constant along any parallel in the direction of the parallel. This applies for any cylindrical or pseudocylindrical projection in normal aspect.
- Combination of the above: the scale depends on latitude only, not on longitude or direction. This applies for the Mercator projection in normal aspect.
- Scale is constant along all straight lines radiating from a particular geographic location. This is the defining characteristic of an equidistant projection such as the Azimuthal equidistant projection. There are also projections (Maurer, Close) where true distances from two points are preserved.
Read more about this topic: Map Projection
Famous quotes containing the word scale:
“It is in vain that we would circumscribe the power of one half of our race, and that half by far the most important and influential. If they exert it not for good, they will for evil; if they advance not knowledge, they will perpetuate ignorance. Let women stand where they may in the scale of improvement, their position decides that of the race.”
—Frances Wright (1795–1852)
“I find it interesting that the meanest life, the poorest existence, is attributed to God’s will, but as human beings become more affluent, as their living standard and style begin to ascend the material scale, God descends the scale of responsibility at a commensurate speed.”
—Maya Angelou (b. 1928)
“That age will be rich indeed when those relics which we call Classics, and the still older and more than classic but even less known Scriptures of the nations, shall have still further accumulated, when the Vaticans shall be filled with Vedas and Zendavestas and Bibles, with Homers and Dantes and Shakespeares, and all the centuries to come shall have successively deposited their trophies in the forum of the world. By such a pile we may hope to scale heaven at last.”
—Henry David Thoreau (1817–1862)