Absolute "up"?

Question

Whenever I see a representation of the earth, or any body in the solar system (except Uranus), the North Pole is "up", and the south pole is "down", likewise the representations I've seen for the solar system itself, as well as the disk of our galaxy, all seem to be oriented to a uniform "up"

Is there some basis for this, a sort of cosmic structural "up" or is it just convention, and we could just as easily portray the solar system inverted and still be accurate?

Answer 1

It's really just a convention, although there is a historical reason for it.

It evolved this way due to the Earth magnetic pole causing compasses to point to Earths north. The rest evolved from there, but it could have been different had those compasses pointed south!

bye for now!

Answer 2

The arrangement is conventional, but not arbitrary. That is, once you know the convention, no matter what planet, or any other spinning object you consider, everyone will pick the same "north pole" and, hence, the same "up." It is called the "right hand rule." If you stand at one pole or the other of a planet or star, and you curl the fingers of your right hand in the direction of the spin, your thumb will point "up." So, if you are at the south pole, you will have to turn your right hand "over" so the the thumb points at the ground in order for your finger to curl into your palm in the direction the earth appears to turn. The fact that your thumb points at the ground is the clue that you are at the south pole and not the north.

Another way to approach this is that by agreement if you float above t a pole of a spinning object, and the spin appears counter-clockwise, then you are looking "down" on the north pole of the object. This rule determines the north pole of a galaxy, a solar system and a planet.

HTH

Charles

Answer 3

Most of our understanding of the earth came from societies in the northern hemisphere and most of the historical maps show north as up. So today, we still orient the globe that way. Even when we think of the earth from space, we picture north as up because our maps have evolved that way.

The only real reference for up is personal: it is whichever direction goes from your feet to your head. Obviously, up is a different actual direction for people on different parts of the earth. One interesting observation of this is if you move from Canada to southern Argentina. The moon will look mostly upside down, there. That's because *you're* mostly upside down from your previous orientation.

In space, especially when you are weightless, there is no common up or down. You could be sitting at a console in the space station while someone is sitting "above" you and upside down from you. For that person, you would be "above" and upside down. If you're on an EVA, the earth might be above your head or it might be below your feet. You would never feel upside down.

So as you say, it is a matter of convention, where up is personal, but this perception is shared by others in your vicinity who are being pulled by gravity in the same direction that you are.

Answer 4

if you look at pictures of far off galaxies, you will see they face every which way, not just 'up' from our prespective... so no the universe wouldn't have a true 'up' it's just a matter of perspective...

however, your theory does hold some type of merit... most galaxies are flat discs (atleast when you compare the height by the width) from what we've seen, we see generally, 'north' of planets/stars correspond with 'north' of the galaxy....

Answer 5

It is just convention -

Funny fact, when they discovered electricity, they didn't really know which was positive and which was negative. So they just flipped a coin. It just so happens they were wrong. So positive is really negative and visa versa, by we keep it as is out of convention.