why is north up?

why do our maps show north as being at the top of the map, and south down?

why did this happen?

when did it happen?

what is dumb luck, a huuuuge government conspiracy or did the aliens have something to do with it (the ones who showed the egyptians how to build pyramids)?

Hemispherical chauvinism. All those European countries and the US, Mexico, and Canada, not to mentioon Japan, are north of the equator. This pisses off the Australians. I’ve seen Aussie “joke maps” that have the South Pole at the top, but there’s no reason why it couldn’t be that way.

This has come up on the SDMB before, and people have pointed out that in the old days East was often at the top, and Jerusalem at the center.

In principle, there’s no reason not to place the equator vertical, or to do a Mercator projection around, say, the Greenwich meriidien. But tradition has us stuck this way.

I have no idea exactly when this started, but I suspect it got a big boost during the era of discovery (15th to 17th centuries). I’ve seen a lot of North-top maps from then, and few maps of any quality before then.

This is something I’ve always wondered myself. I’m not entirely sure, but I assume its a cultural bias. I’ve seen maps put out by South American states that essentially flipped the world “upside down”.

The location of the “center” of the world map is a cultural thing too. If you look at some Japanese maps you’ll see Japan in the center of the map. I saw this in a book once and now every time I see an old japanese movie I look for the map and thats usually how it is.

I have frequently heard the explanataion that Jerusalem has to be in the center, and that a map would look better with Rome north-west of it. But I’m not quite buying it.
There must however be some strong symbolism at work, because the only ‘rational’ orientation (pardon the pun) has to be South up!
The ordinary thing that is most assuredly ‘above’ has to be the Sun - which is mainly in the South. Therefore I would probably put South up if I was to draw a map.

It’s probably the fault of an ancient Egyptian.

Thus saith the Master.

North hasn’t always been “up”. In the middle ages, many maps of the world, focused on the mediterranian, placed East at the top, as that was the direction of Jerusalem from Europe (where these maps were made).

North moved to the top of maps with the advent of large-scale ocean-going exploration in the Renaissance, aided greatly by the lodestone (magnetite), which was used as a compass. Since it lined up North-South, it made a North-oriented map more intuitive (or a South-oriented one, for that matter). North won out, in part, due to the process of discovery: Europe was known, and mapped, and Asia extened to the East…the coast of north Africa had been mapped for ages…with a long east-west axis, the north/south choice for the top of the map was not important to a tidy layout. As the African continent was found to extend further and further south, the world view had to become drawn out to the poles, forcing a decision as to what would be at the top. Since the mapmakers lived where they lived, they put home at the top and center, with the central meridian through either Jerusalem or their capitol city (a determination that, in my opinion, is more imortant and indicative of bias than “who’s on top?”)

I type too slow…

by the way. my desktop image is a 1887 map of TX, AR, LA, and OK (“Indian Territory”), which shows longitude west of Greenwich and Washington, D.C…

Cecil has the answer here.