PDA

View Full Version : Why does the Earth always look the same?



WhyNot??
2006-Mar-15, 07:40 PM
Why does every photo, picture, image etc. of the Earth always dipict the North Pole as the "top" of the planet? When we know the planet is a sphere floating in space. Why do satellite pictures always have the Northern part of countries as the top of the image? Is this because the north pole is believed to be the top of the Earth floating around in space? Surely satellite cameras are not all capturing images from the same prespective? What if you took a photo, rotated the satellite 180 Degrees, then took another, would the image not develop the other way around? So are all satellites launched in the same manner?

grant hutchison
2006-Mar-15, 07:47 PM
I think you need to look at some more Earth photographs (http://eol.jsc.nasa.gov/sseop/clickmap/). They come in all orientations. Books and magazines often reorientate them so that north is at the top, because that orientation makes the landforms more immediately recognizable to people familiar with maps from atlases and wall charts.

Grant Hutchison

WhyNot??
2006-Mar-15, 07:50 PM
yeah, probably do. So why north at the top? Were the first people to depict the earth living in the northern hemisphere?

grant hutchison
2006-Mar-15, 08:06 PM
Were the first people to depict the earth living in the northern hemisphere?They were, but I don't think that's the whole reason: a lot of early maps have east at the top. (Related to the phrase to "orientate" yourself. Same word as "Orient", meaning the east.)

I wonder if the north-at-the-top convention started when people began to navigate using the magnetic compass: you want a map you can read when it's pointing the same way as the compass needle. But compass needles were thought to point north (rather than south) because people were already used to navigating by the Pole Star, and that's something you can only do in the northern hemisphere.
so maybe if map-makers had first started work in the southern hemisphere, we'd think that compass needles pointed south, and would have south at the top of our maps.

Grant Hutchison

01101001
2006-Mar-15, 08:07 PM
It's an arbitrary convention, followed by most.

The Upsidedown Map Page (http://www.flourish.org/upsidedownmap/)


Arabia (Ancient): They put south at the top. [...]

Arctic/Antarctic: A natural map of the poles has either south or north at the top and at the bottom - indeed, in all directions. [...]

Biblical Times: There is evidence from the Torah that east was at the top of maps. [...]

Medieval Europe: Jerusalem was on top because that was the Holy Land. [...]

China (Ancient): The Chinese were the first to invent the compass, which they always thought of as pointing south. [...]

Egypt (Ancient): [...] However, they also thought that "up" was south because of the northwards flow of the Nile; rivers must flow "downwards". [...]

India (Ancient): [...] Presumably this indicates that they used maps with East at the top. [...]

New Zealand: Upsidedown or "corrected" maps are becoming more popular, especially with tourists.

Wikipedia: North (http://en.wikipedia.org/wiki/North)


The notion that north should always be up and east at the right was established by the Egyptian astronomer Ptolemy (90-168 AD).

Disinfo Agent
2006-Mar-15, 08:12 PM
I thought they all showed Israel on top (http://www.bautforum.com/showthread.php?t=3218)...

WhyNot??
2006-Mar-15, 08:26 PM
ok, maybe i watch too many science fiction films then. Or the school i went to could only afford the maps of the world that are all the same, and text books etc. with the earth always with North on top. Perhaps in your school they taught that there was no top of the earth but in mine they didnt. (So that says alot about australian education systems then dont it?)

five_distinct
2006-Mar-17, 03:37 PM
I always assumed that it was because of the first explorers..... But also there's more land in the north, so doesn't it make more sense to have it at the top?

hhEb09'1
2006-Mar-17, 04:04 PM
Perhaps in your school they taught that there was no top of the earth but in mine they didnt. (So that says alot about australian education systems then dont it?)Probably spent most of the school budget to keep the system from falling off the earth. :)

The_Radiation_Specialist
2006-Mar-17, 04:06 PM
I go to an australian (international) school...
in the library there is a big map of the world up-side-down.