Why don’t we view a world map “upside down” to what we are used to seeing it as? What’s “up” and what’s “down” is all relative… so how did we decide things like which was going to be the “northern hemisphere”?
And how come when we see a working model of the solar system, the planets always go “around” the sun, and never “over” it, or diagonally around it.
The North Star, Polaris, was (and still is to a certain extent) used by travellers in the Northern Hemisphere as a fixed point in the sky by which they could navigate. It is (stop me if this gets too complicated :)) in the north. So you have to imagine the weary Northern Hemisphere traveller, trying to get his/her bearings, facing north to begin with.
Add to this the fact that our modern mapmaking tradition goes back to travellers from this selfsame Northern Hemisphere. Mercator et al. would probably have never thought twice about the convention of facing north to orient oneself to a map or chart.
Well, the people who made the maps lived in the northen hemisphere, so they put their hemisphere on top. This is also related to why clocks go clockwise - they imitate the motion of a shadow on a sundial. If the clock and sundial were invented in the southern hemisphere, they would go the other way.
But none of this reasoning tells why “north” is equated to “up”. They could have looked at the “north” star, called it the “south star”, and said to themselves “let’s travel down towards ‘south star’”
Badtz Maru, your reasoning as to why the northern hemispheree is called the northern hemisphere is non sensical.
“the people who made the maps lived in the northen hemisphere, so they put their hemisphere on top”.
The solar system formed from a cloud of material. This cloud collapsed under its own gravity (and perhaps from some initial cause such as a passing star that disrupted the cloud). As it came together asymmetrically, it had some net resulting spin. Also, due to gravity, friction, and conservation of angular momentum, this cloud came together as a rotating disk*. The material in this disk was mostly in the middle (which collapsed to form the sun). The material in the outer portion of the disk was what collided and stuck together to form the planets. So, all the planets are essentially in the same plane (i.e., they go around the sun instead of “over” or “diagonally” around it).
Here’s the key to your question. Note as the material came together, it began to spin faster due to conservation of angular momentum just like how a figure skaters spin faster when they pull in their arms close to their body. With a faster spin, the bits of material orbiting the center of the mass were flung out into more distant orbits…preferentially in the plane perpendicular to the axis of rotation of the cloud of matter. Gravity and friction (colliding bits of matter) tended to pull everything toward this central plane…the more matter that accumulated in this disk, the stronger the gravity became there to pull more matter into it.
So, after a long billiards game, we ended up with 9 planets and lots of leftover comets/asteroids that are still colliding with planets nowadays…just less frequently than when the solar system was born because there are just fewer of them left.
Damned that cockey Mercator.
I remember at least one print of a map of Blauw where it was turned sideways to fit into an atlas (west was up). I have been told that it wasn’t the only map that was ‘sideways’. I believe the convention was that north was up (for said reasons) though. I don’t know of world-maps that where anything but north-oriented, or Europe oriented for that matter. Ah… those were the days.
I saw a map (which was Astec in origin IIRC) in which west was up. The side note said that west=up was the convention and that this had some sort of religious origin.
However:
This was some time ago,
I’m not sure,
Don’t flame me!
That link answers some of the questions. But the link also states as to why north is up…
“Perhaps this was because the better-known places in his world were in the northern hemisphere”
The earth is a round sphere. There is no reason as to why any half of that sphere can’t be classed as the northern hemisphere. The phrase “Let’s call ourselves the northern hemisphere because that’s the hemisphere we are in” is simply NOT LOGICAL. It would be like saying, before colors were defined, “Let’s call this color red, because that’s the color it is”.
Interesting story as to how the solar system was created, unfortunately doesn’t tell me why we are taught that planets go “around the sun”. You said it’s because “(they orbit) preferentially in the plane perpendicular to the axis of rotation of the cloud of matter”. How do you know that this rotation isn’t just rolling over the top of itself (as opposed to spinning ‘around’), but you just keep looking at it sideways?
Well, if you’re standing out in the middle of a field, and you’re pointing “up” at the North Star and you’re saying to your group, “Let’s go that way”, “that way” is going to be “up”. So “north” eventually gets to be “up”.
Not all maps are faced to the North. At one point they were faced East as Cecil’s column said, but from what I remember from my cart classes was that this is because they believed that the East was where heaven was. Many eastern maps also have East on top.
I’d also say that the reason North us up is because of the lines of longitude run from the poles and the spin of the Earth has something to do with it as well.
OK. There is no preferential “up” and “down” in space. You need to choose a frame of reference. Planets go “around the sun” because for the solar system you use the sun as the reference point. But compared to the plane relative to the center of the Milky Way galaxy, the solar system is indeed skewed (I forget by how much…60 degrees?).
They probably didn’t say that at first. The maps were just of the known regions. They filled in more regions of the world as exploration continued…and of course, they kept “home” at the center & top of the map. Eventually, you can make a globe of your map. By tradition, “home” remained at the top of the world.
Because that is not the definition of “down”. It’s just a word…don’t get stuck on that. The more interesting question is why did the northern hemisphere get to be the “top” of the world on just about every modern map.
As loathe as I am to revisit what has become a middle-school-level debate about etymology, I would be remiss if I didn’t acknowledge that puk makes a valid point. I failed to address it in my earlier post because a compass is not north-specific, it is pole-specific. Since the OP was north-specific (until he devolved the discussion into “why is red red” territory), I thought the Polaris issue was more pertinent. But the compass issue is equally valid from the standpoint of the bigger picture.
Whiskas, you’re being obstinate. Badtz Maru’s explanation that “the people who made the maps lived in the northen hemisphere, so they put their hemisphere on top” does make sense. He’s not addressing what we call our hemisphere, but why maps have North at the top, which is exactly what you asked in the OP.
You’re not listening. If you face the North star, and then orient a map so that it is oriented the direction you’re facing, North will be on top. Your question has been answered several times already.