If today the geo men know the exact lenght of the Terrestrial Meridiane, or Polar Circumference, (40,007,864 meters), Why not to re-define the base meter to match with the old definition 1 meter = 1/40,000,000 of terrestrial meridiane (and change the today stupid sub-atomic definition)?
The difference, in the practical life, would be unnoticed (the "new" meter should be 0.1966 milimeter more longer than today).
BUT... The Mercator projection has a very useful characteristic: the typical marine and/or aerial travels can be drawn as straight lines, cutting any meridians in the same amount of angles, (which is called: azimuth). So, an straight line in the map from San Francisco to Tokio will show a real travel line (of course, the real line is an special curve called: loxodromical, or something like that).
@hongmin1234 This "equirectangular" projection use equal distance between any paralell from the equator to any poles. Mercator uses a complex equation to increase this distance from the equator to the poles. So, in the Mercator projection all the paralells have different spaces each other. This action creates a great distortion near the poles, and you never will see the poles at all. The "equirectangular" projection shows the poles as a very long straight line (very distorted, of course)
If today the geo men know the exact lenght of the Terrestrial Meridiane, or Polar Circumference, (40,007,864 meters), Why not to re-define the base meter to match with the old definition 1 meter = 1/40,000,000 of terrestrial meridiane (and change the today stupid sub-atomic definition)?
The difference, in the practical life, would be unnoticed (the "new" meter should be 0.1966 milimeter more longer than today).
jotape1960 11 months ago
BUT... The Mercator projection has a very useful characteristic: the typical marine and/or aerial travels can be drawn as straight lines, cutting any meridians in the same amount of angles, (which is called: azimuth). So, an straight line in the map from San Francisco to Tokio will show a real travel line (of course, the real line is an special curve called: loxodromical, or something like that).
jotape1960 11 months ago
Cool!!! I wonder how to distort the cylinder to get the Mercator projection. ???
jotape1960 1 year ago
@jotape1960 I also wonder about this. What's the differences between this and the Mercator?
hongmin1234 11 months ago
@hongmin1234 This "equirectangular" projection use equal distance between any paralell from the equator to any poles. Mercator uses a complex equation to increase this distance from the equator to the poles. So, in the Mercator projection all the paralells have different spaces each other. This action creates a great distortion near the poles, and you never will see the poles at all. The "equirectangular" projection shows the poles as a very long straight line (very distorted, of course)
jotape1960 11 months ago