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:
“I own I never really warmed
To the reformer or reformed.
And yet conversion has its place
Not halfway down the scale of grace.”
—Robert Frost (1874–1963)
“I don’t pity any man who does hard work worth doing. I admire him. I pity the creature who does not work, at whichever end of the social scale he may regard himself as being.”
—Theodore Roosevelt (1858–1919)
“Every man needs slaves like he needs clean air. To rule is to breathe, is it not? And even the most disenfranchised get to breathe. The lowest on the social scale have their spouses or their children.”
—Albert Camus (1913–1960)