Why isn't the best two dimensional global projection just two circles?

[imp_fireball]

Really, I figured I could just draw two circles - one for each hemisphere, and then do the poles at the center. This seems like it'd be the most accurate in terms of being to scale. But most popular projections of earth don't show it that way. Is there any reason anyone here can figure why?

[Mouse]

That kind of projection (azimuthal) only really shows land at the centre accurately. It, and cropped variations of it, are normally used to map the polar ice caps or Antarctica because they distort the land more and more as you get further and further away from the pole.

There are thousands of different map projections - each of them suited to different kinds of map and mapping. Here is a page that Waldronate once showed me, which might help you understand when and why they are used.

http://www.progonos.com/furuti/MapPr...C/cartTOC.html

[imp_fireball]

How is it distorted though, if the world is largest at the equator?

Granted, I don't know the latitudal circumference at every 10 degrees (or however many divisions from 0-90 is desired)...

[Falconius]

It's distorted in two ways when speaking of a 2d surface, one is that the area on as you get to the sides of the globe have to be shown as they would appear visually (theoretically) and they get extremely squished and curved as they head down the globe, the second is that such a projection wouldn't be in true perspective, it'd be an isometric [Edit: I meant orthographic like Walonrate mentioned below] perspective.

There would be no need to have this view centered over the poles, you could choose directly opposite points anywhere on the globe and do the same thing. There are a few old timey maps that do this sort of thing. https://upload.wikimedia.org/wikiped...2C_1664%29.jpg
However he only sort of did what you described. You'll notice the longitudinal lines get wider as they approach the edges, in other words he squished the center down and widened the area on the edges to show the lands there flatter.

[waldronate]

I really do recommend taking a look at the link that Mouse posted. https://en.wikipedia.org/wiki/Map_projection is also a good discussion.

If you're thinking of what a globe looks like from a distance, that's called an Orthographic projection and it has all manner of distortions.

And the world isn't widest at the equator: it's pretty much spherical. Going from that sphere to a plane requires distortions of some sort.

To do the classic kitchen demonstration of projections, go get an orange and peel it. Then push that peel down onto the table to flatten it out. It will break and stretch because a roundish 3D thing can't be flattened out into a plane without distortion. You will notice that at no point does it become two circles.

Map projections let you pick the kinds of distortion to minimize errors in ways that are appropriate for your map.

[Azélor]

I think you are looking at an orthographic projection. Example: https://www.pexels.com/photo/sky-ear...universe-2422/
It's rarely used for maps because the farther you move from the centre, the smaller the objects become despite having the same size in reality.
It's useful to portray 3d objects like whole planets but not that useful for mapping. The objects close to the edge are difficult to recognize.
Google Earth use it but you can move around.

[LordEntrails]

Even simpler than all the technical discussions, take a piece of paper, cut it into a circle and try to wrap it around a ball (or globe if you have one). That should give you a good idea of map projections and distortions pretty quickly.

[DnD4ever]

Because the world you are mapping (presumably) is a sphere, that means it is round in all directions to some degree, but your paper is FLAT. So it will be totally not true but a distortion 'as viewed from the poles.

[imp_fireball]

It actually is widest at the equator if you measure the circumference of circles drawn at areas closer to one side of the sphere or the other. If you measure circumference of the sphere itself, it will of course be largest (that being the equator).

[Mouse]

Ok.

You believe what you want to believe.

Its not like you're hurting anyone

EDIT: My turn to ask a question: Are you a 'Flat Earther' by any chance? (If you are, that would explain the way you see an orthographic map as being accurate to scale)