Wikipedia:Reference desk/Archives/Miscellaneous/2016 October 14

= October 14 =

World Map
A flat "World Map" is sought with the capability of zooming (in and out) along with "time zone" and other sort of valuable information. -- 103.230.105.25 (talk) 19:31, 14 October 2016 (UTC)


 * This is the first Google result I get for "zoomable time zone map" - other similar sites are available. If it doesn't contain the information you need, let us know what that information is, and we should be able to find something suitable. Tevildo (talk) 20:00, 14 October 2016 (UTC)


 * Note that any "flat map" of the world will be badly distorted. The exact type of distortions depends on the map projection used.  One of the biggest advantages to a map on a computer is that it can be truly spherical, eliminating all distortion, and yet zoomable, unlike a physical globe. StuRat (talk) 01:29, 15 October 2016 (UTC)


 * Computer screens are flat.  How does this affect the resolution? 2A02:C7F:A14:AA00:B9C1:49D7:605B:A265 (talk) 10:52, 15 October 2016 (UTC)


 * Your meaning is a little unclear. Computer screens are flat (or flat-ish), but it's the projection of the map itself that is the issue. When you load up, say, Google Earth it presents you with a globe, not a projected map, so the material is not distorted apart from glitches and the areas of incomplete data. But when you load up Google Maps in your browser and zoom out you will see it is a variant of the Mercator projection and it is very much distorted, particularly at the poles - you'll see that Iceland (~100,000 km²) is about the size of Texas (~700,000 km²). Same computer screen, but different projections make for different distortions. In this context, your use of resolution is unclear; resolution would only affect the amount of detail presented on the screen and wouldn't directly change the distortion either way (although seeing more of a projection at once would make it easier to see the distortion). See display resolution and optical resolution for details. Matt Deres (talk) 12:56, 15 October 2016 (UTC)


 * So it's a globe viewed through a flat screen.  How is that different from a stereographic projection? 86.147.209.235 (talk) 13:34, 15 October 2016 (UTC)


 * An image on a screen is not 'projected' in the sense used by map makers. A stereographic projection is just another kind of map projection, one that (from the lead of that article) preserves angles, but not distances or areas. You'll note that an image of the earth made using stereographic projection looks nothing like a globe. Matt Deres (talk) 15:09, 15 October 2016 (UTC)


 * It's true that viewing the entire world at once on a flat screen would necessarily mean it is badly distorted. However, flat maps of small areas are only slightly distorted, whether on paper of a flat computer screen.  The difference between a single flat map and a computer screen is that a computer can automatically "reproject" it as you zoom in, to give a projection more appropriate for that location and zoom level (perhaps even asking which projection you want).  You can get a similar effect with flat maps, but only if you have an entire book of world maps, such as with polar projections at the poles, and you still can't zoom in very far, except perhaps in a few special points of interest, or the number of paper maps would quickly exceed what would fit in a book.


 * Also note that there are curved computer screens. However, they are generally only curved in one direction (cylindrical) instead of two (spherical) and being unable to change the curvature means it doesn't adjust as you zoom in and out, but flexible screens can fix that.  One interesting note is that the curvature of the screen means you are looking at the map as if you are inside the Earth looking out, but that works out just fine.   StuRat (talk) 16:06, 15 October 2016 (UTC)