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Old 06-01-2017, 06:21 AM
Colophon Colophon is offline
Join Date: Sep 2002
Location: Hampshire, England
Posts: 13,368
Originally Posted by Mavic Chen
Instead of playing about with the level, he should have just looked out of the window to see if the Earth is spherical or not.
You really can't see the curvature of the Earth from the height of an airliner. Not with the naked eye anyway.

The diameter of the Earth is almost 42 million feet. An airliner cruises at about 42,000ft maximum, that's only one thousandth of the diameter.

Slight tangent, but of course the horizon is totally flat on a globe. The "curve" you see from higher up isn't the curve of the Earth, it's just the curve of the perimeter of the flat circular horizon: same reason that a round kitchen table has a curved edge, even though it is flat.