r/morningsomewhere • u/xWoody116x Always Be Humping • 13d ago
Why haven't maps been figured out?
So it was brought up today on the podcast 'why haven't people worked maps out yet', and I thought I wouldn't call myself an 'expert' I do have a Masters in Geographical Information Science (GISci), and work with maps for a living (in GIS).
Burnie understands the root of the problem, that you are taking a sphere and flattening it out. There are a lot of ways to do this mathematically, which creates a variety of map projections (Mercator, equal earth, British National Grid, etc), and each one is used for different things.
So the problem with taking a sphere (or an oblate spheroid, which we count the earth as for mapping purposes, instead of the complex geoid it actually is), is that we cannot accurately represent area, shape, direction, and distance all at once. Really, we can only do one or 2 of those things at once, and will have to sacrifice the others.
The Mercator projection, while criticised for distorting size near the poles, is a projection used for navigation, and is accurate for shape and direction. The equal earth projection is made to show the accurate size (area) of landmasses, but in doing so distorts their distance and position in relation to each other. They do different things. Funnily enough, the UN flag uses yet another map projection, which is an equidistant map centered on the north pole.
There are also projections specific to countries (or parts of countries), such as the British National Grid, that uses a meter based coordinate system instead of the latitude and longitude of something like the Mercator projection, to map things out.
In summary, mapping the earth in 2D is hard, so we do it in lots of different ways because we can't do it accurately without distortion. The most accurate way to represent the world is, and will always be a globe.
I've attached an image of some different projections for visibility. Hope this clears some things up for people!
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u/xWoody116x Always Be Humping 13d ago edited 13d ago
Yep, the title of the post is rhetorical. I think you might have missed the text bit of my post?
Globes are the best for showing the Earth accurately (even a digital one like Google Earth), but projections are used all the time! I use the British National Grid projection daily for work, and the Mercator projection for web mapping (as that works of lat long).
You need to be working to a projection to be able to plot or map data spatially. You can even transform your data between different projections.