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Old 2008-09-10, 11:16   #36
S485122's Avatar
Sep 2006
Brussels, Belgium

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Originally Posted by xilman View Post
The phrase "travels one mile due east" means "travel one mile towards the longitude of Greenwich while maintaining a constant distance from the north pole (or equator or south pole)".

The North American plate is subject to continental drift. Not only is it heading westwards on average, it is also rotating. Pick a spot such that the combination of continental drift and rotation combines such that after drifting west one mile that spot is due south of the starting point. Walk very slowly on the eastward leg of the journey.
I would disqualify this type of solution on the ground that all travelling in the original puzzle refers to ground distances : the reference point for the travel is not some coordinate but the base camp which will travel with the ground all the traveling is done on.

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