Naked Science Forum
Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: Hannah LS on 13/12/2018 12:01:18
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Ian asks:
A) Why do we view the solar system from the top?
B) Why view orbits counterclockwise? We often 'resist' counter spin because clocks look 'normal'…
C) Did we choose "north" by looking down at our orbit, or are the concepts unrelated?
D) Why did most land masses end up on "top" of a spinning ball...?
Aargh! Google fails miserably on this...
What do you think?
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Why did most land masses end up on "top" of a spinning ball...?
No "end" yet : they're still moving ...
https://youtu.be/uLahVJNnoZ4?t=2m4s (https://youtu.be/uLahVJNnoZ4?t=2m4s)
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Ian asks:
A) Why do we view the solar system from the top?
B) Why view orbits counterclockwise? We often 'resist' counter spin because clocks look 'normal'…
C) Did we choose "north" by looking down at our orbit, or are the concepts unrelated?
D) Why did most land masses end up on "top" of a spinning ball...?
Aargh! Google fails miserably on this...
It started with maps or globes of all Earth, putting North at the top because most of the people lived in the north and didn't appreciate needing to peer at the underside of the globe to see home.
Yes, in Australia, they print maps and produce globes with south at the top, but there are just not enough Australians to make that the standard.
OK, so north being up became the standard, and looking down upon the north pole became the intuitive standard for a polar view of rotating system. My house spins counterclockwise, as do most houses, so counterclockwise became the default way to view spinning things.
It seems wrong to view one's house from below, so they don't print maps that way. Maps are views from above, but star-maps are views from below, so if north is up, east is on the left of a star map.
Clocks move the other way because that's the way shadows move on a northern sundial, the earliest clocks, and the guy that first made clocks with faces and hands was from the north, and set the standard.
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Ian asks:
A) Why do we view the solar system from the top?
B) Why view orbits counterclockwise? We often 'resist' counter spin because clocks look 'normal'…
C) Did we choose "north" by looking down at our orbit, or are the concepts unrelated?
D) Why did most land masses end up on "top" of a spinning ball...?
Aargh! Google fails miserably on this...
What do you think?
A & D: "Top" is a relative term in this case, As far as the continents go, we, we decided what hemisphere was considered on top in part because that is where the majority of the land mass was when our civilization formed. (And as pointed out, on the geological time scale this was not always the case.) As a result, the major contributions made to our modern society came from civilizations that originated in the Northern hemisphere. In the Northern Hemisphere, North is the easiest direction to pin down. (for example, it is the direction of that part of the night sky that stays in one place. This made North an important direction, and we tend to put important things at the top.
B.This basically comes from our above choice, when we draw or look at maps, we are generally holding them looking below our eyes and looking down. That way they align with the ground we are traveling over. Since we have already decided on North being "up", it made sense to make charts of the solar system so that we we looking down at the "top" of the world. This results in the the motion of the planets follow a counter clockwise direction. Halc has already touched on why we picked one particular direction as being "clock-wise". This also leads us to the conclusion that if modern society had risen from a Southern hemisphere civilization, we would still likely view the Solar system as rotating counterclockwise, as while the direction we would perceive the solar system as rotating in would reverse, so would the direction in which a sundial operates, so the direction we define as clockwise would also reverse.
C. North was chosen as stated above because it was the most convenient direction to locate in the hemisphere in which our predecessor civilizations arose. If by some chance a civilization from the other hemisphere would have arisen, we likely would have done things differently.
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...because the big colonial empires of past centuries were the ones making most of the maps
- The Spanish, Dutch, English and French
- they were in the northern hemisphere, so they put themselves at the top
- More modern colonial empires of the space age were also in the northern hemisphere
- The Russians, USA and now China
- so they put themselves at the top, where they can be seen
- Both are effects of the current distribution of continents
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Actually old China seems to have placed 'North' at the bottom of their maps, if I remember right. And I would suspect the reason for why continents 'floats' above magma etc is buoyancy and density, possibly also connected to heat? I don't think it's the centrifugal force.The planet would then be of a greater density at its surface than inside after a while? Then again, who knows? Maybe such planets exist, maybe Earth is one.
Naah :)
http://www.bbc.com/future/story/20160614-maps-have-north-at-the-top-but-it-couldve-been-different
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Damn, it was the opposite. It was us placing it at the bottom of the map for a while, whilst China had their own emper(or)ic reasons for doing the opposite. My memory told me they did it opposite for a while and that's what got me fooled. I better be prepared for someone showing me that it is the centrifugal force doing it too :) And that plates are of the highest density, which may be possible considering the heat factor. As a excuse I will have to admit that I never really learnt the compass rose, so I always translate it into left and right :) I'll keep trusting in buoyancy though, I think?
Anyone?