• ZpbkPEcaHhIveqdR@lemmy.world
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    12 days ago

    I don’t think that’s the true size. You’ll find all those countries are actually a lot bigger than presented on that map and scaled down to fit on a screen

  • chiliedogg@lemmy.world
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    13 days ago

    Yes, but blue (Mercator) preserves direction and shape, which were all that really mattered for navigation by sea, so Mercator was a fantastic projection for centuries.

    And we still use it today for smaller scale areas, since it does a remarkably good job at preserving all 4 features (shape, area, distance, and direction) close to the map origin line. Universal Transverse Mercator is a system that has 60 zones of Mercator turned sideways.

    The reason it’s Transverse is because, unlike lattitude depending on a defined equator, longitude has an arbitrary meridian, so by turning the map sideways we can move the distortion point, and any map area that doesn’t stray too far East or West will be very accurate.

    Think of trying to map something like Chile or Florida, where the area of interest is pretty far North to South, but not East to West.

  • Pyr@lemmy.ca
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    12 days ago

    How much do you wanna bet Trump wouldn’t be so gung ho on Greenland if he saw this map? He probably thinks he is going to double the size of America.

  • observes_depths@aussie.zone
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    13 days ago

    I’ll add that we use the mercator projection because it preserves shapes but not scale. There’s other projections that preserve scale but not shapes.

  • BarneyPiccolo@lemmy.today
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    13 days ago

    This is why Trump wants Greenland so bad. He sees it, and says “It’s big, I want it. Get it for me!” and gets all Veruca Salt about it.

    All because he doesn’t understand what a Mercator Projection is, on account of he beat up some nerd to do his homework that day, like every day.

  • Rachel@lemmy.blahaj.zone
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    13 days ago

    How can it be the true size if it’s still a projection on a 2d surface? I thought could only see the true size on a 3d globe.

    • vithigar@lemmy.ca
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      13 days ago

      True size is possible just fine on a 2D surface. For both too large and too small to be even possible there must exist some transitional point where the size is correct.

      You cannot have both the size and shape correct at the same time. Having the correct size means distorting the shape, and vise versa. One or the other can be correct, but never both.

  • BradleyUffner@lemmy.world
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    13 days ago

    Why is the difference only extremely pronounced in the northern hemisphere? If I understand the math behind the projection correctly, the equator should be true scale, and things should vary more the further north AND south you go.

    This image shows the extreme southern latitudes to be almost equal to their true area. Is the image wrong, or am I misunderstanding something about the projection?

    • Lvxferre [he/him]@mander.xyz
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      13 days ago

      This map is clipping a good chunk of the Southern Hemisphere. When you include it, you also notice the same distortion:

      Note how it looks like Antarctica (14*10⁶km²) is 1/4~1/5 of the globe, even if it’s actually smaller than South America (18*10⁶km²).