The distance from Jacksonville, Florida to Los Angeles, California is about 3888 km. The earth’s circumference is about 40 000 km (source), so the US spans about 10% of that, roughly :)

  • SippyCup
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    2 days ago

    Projection doesn’t matter, distance remains consistent even if it appears longer or shorter than it is in reality.

    That distance does follow the curve of the Earth. It necessarily must. Driving from Jacksonville to LA does not tunnel 3 miles beneath the surface of it earth.

    • Thorry@feddit.org
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      2 days ago

      That’s not what I meant. If the line isn’t a straight as drawn on a sphere, the distance will be longer than it would be when drawn on that sphere. Especially a line like this that follows roads, a squiggly line, can end up much longer than a straight line would be.

      When a straight line is drawn on a mercator projection map, and we then turn that projection back into a sphere, the line would no longer be straight. With the only exception being exactly in the north - south direction, since that is preserved with mercator.

      My point wasn’t that the line is shorter, like you suggest if the line were to tunnel below the surface. Exactly the opposite, the line would appear longer than it actually is, since it wouldn’t be straight if we were to look at that line on a sphere.

      • SippyCup
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        2 days ago

        Sure, and that’s demonstrated pretty well elsewhere here in Australia.

        But that’s reasonably straight for what’s being measured here and not the full breadth of the US. Going from the most extreme points in Maine to California, gives you a distance of 4600 km. Since we’re effectively on a sphere, there’s no particular reason that line needs to follow the latitudinal lines.

        • Thorry@feddit.org
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          2 days ago

          Jup that’s why I mentioned Chili. My point was more that a line that follows a circumference on a sphere, depending on the angle, wouldn’t look like a straight line on a mercator projection. But like I said, the basic fact is still right, it’s just that squiggly line isn’t the best indicator for that. If the line is a fractal it could be infinite length (thinking of coastlines), which isn’t very helpful.