Yes the distance around the equator is larger than twice the distance
from pole to pole. The flattening of the earth (oblateness) is minor
though. I can find the exact number if you are interested. I write
astronomy software that has to take this into effect.
actually - latitude (contrary to popular misconception) is not measured
as an angle from the centre of the earth, but from the angle from the
celestial equator. This makes a difference because the earth is
flattened as mentioned above.
An interesing side effect is that the latitudes are not equally spaced
on the globe, as one might expect from geometry. The distance of 5
degrees latitude depends on the latitude. I forget offhand if latitude
circles are closer together at the poles or the equator.
I have heard that the high tide is in fact because the earth is being
pulled away from the water on the other side of the earth - a slight
difference which explains why high tides are on opposite sides of the
earth at the same time.
On 2013-04-10 23:23, R Wall ml wrote:
And at the Equator, would the Longitude circle be the biggest circle
of them all, because there is a bulge at the Equator. A bulge because
the mass is forced out due the the Earth spinning? Anyone know the
answer, I don't?
I believe the moon also warps the Longitude circles because that is
why there is a high tide in two places on the Earth at the same time.
The moon's gravity pulls the Earth mass and that also makes a high
tide on the opposite side of the Earth away from the moon. The high
tide on the moon side of the Earth is caused by the moon's gravity
pull on the water.
Looks to me that the Latitude/Longitude circles are all warping and
changing?
Do I have this correct?
Roderick Wall.
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