Whenever you look at a map, be it on the web, on your mobile or on your wall there's a compromise. The compromise is the map's projection. Or to put it another way, the way in which the roughly spherical lump of rock we live on can be unwrapped and displayed in a flat, two dimensional manner.

There's lots of way of doing this and the ways come with wonderful, almost eccentric sounding names. There's the pseudo-cylindrical projections; Sanson-Flamsteed, Luximuthal or Kavrayskiy's Fifth Projection (no idea what happened to the first four). There's the conic projections; Lambert's Conformal or War Office Polyconic. There's the pseudo-conic projections; Stabius-Werner and Bonne. Or there's the modified azimuthal projections; Wiechel's or Winkel's Tripel Projection.

There's just so many ways of projecting the Earth onto a map. But there's also the one we're all familiar with. It's Gerardus Mercator's Projection and we've been using it, probably without knowing it, since 1569 and it's showing no sign of going away.