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Sky Orientation by Latitude
Name: Peter
Status: student
Grade: other
Country: New Zealand
Date: N/A
Question:
I live in New Zealand (down under), when I look at my country
from space we are indeed facing downward my question is why do I look
up to see the sky, why do I NOT look out sideways to see it? Why, when
your standing at the south pole you still look up to see the sky at the
very bottom of the world as can clearly be seen from space?
Replies:
Regardless of where we stand on the Earth, gravity attracts our body
toward its center. "Our feet are on the ground." Because that is the
"normal" configuration of our bodies with respect to the surface of the
Earth -- more rigorously our center of gravity and the center of gravity of
the Earth. If you lay down, you see the sky "overhead" by looking "straight
ahead". And if you stand on your hands, you have to look "down" (that is,
toward your feet) to see the sky "overhead". To be more precise, you have to
look "over feet" to see the sky. But keep in mind that the stars that you do
see by looking overhead changes with latitude. You see a different group of
stars in the Northern and Southern hemispheres. You also see a different set
of stars at different longitudes, at a given latitude. In common terms we
see stars, planets, the moon etc. "rise" in the east and "set" in the west
from dusk to dawn.
Vince Calder
Dear Peter,
This is a good question. The sky from the south pole is just like
from any other spot, because there is really no up or down in
space. You could observe for 6 months during its long winter
night! But it would be cold.
Sincerely
David H. Levy
Well, the sky is everything out there in the universe. It is all
around us: above, below, ahead, behind, to the right, and to the
left. You don't see it only where the earth is in the way. Since
the earth is below you, you will see the sky above you.
Are you asking why the earth is below you rather than above you, in
the southern hemisphere? It is because "above" and "below" are not
the same everywhere on earth. Your "up" is not the same direction
as my "up." "Up and "down" are determined by the direction of the
force of gravity, which pulls us toward the center of Earth. That
is not the same direction for you and me, but we both consider that
direction to be "down."
Richard E. Barrans Jr., Ph.D., M.Ed.
Department of Physics and Astronomy
University of Wyoming
Hi Peter
When looking at earth from outer space, you see a ball, and what you call the
top of the ball depends on your orientation, or how you are looking at it.
If you look at the ball while standing on your head, then the bottom of the
ball looks like it is the top to you if you can block out all of the other
visual cues telling you that you are standing on your head.
Plus, wherever you are standing on the ball, if you look down you will see
the ground and if you look up you will see the sky. That is because of the
geometry of the sphere.
Sincere regards,
Mike Stewart
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Update: June 2012
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