Frank, Thanks for the puzzle. I think that these instructions might work if you ventured to the antarctic circle during the southern winter and then trecked to a position such that your latitude is greater than 90-Dec (so that the midnight sun is visible) but less than 90. The shadow of the stake would then be longest and point to true north at true solar midnight.
Geoff On 28 October 2016 at 06:58, Frank King <f...@cl.cam.ac.uk> wrote: > Dear All, > > I have been looking at new U.K. educational > website which has a whole category devoted > to sundials. Early on, there is section > "Finding True North". See: > > http://wiki.dtonline.org/index.php/Finding_True_North > > This is what it asserts: > > The Sun can be used to find True North > quite simply by placing a vertical stake > in the ground and noting which direction > the longest shadow points to. > > You may now take a two-minute break while > you recover from rolling on the floor in > a state of helpless laughter. > > When you have recovered, ponder this puzzle: > > Where on the planet would you have to > be, and at what time of year, for these > instructions to give the correct result? > > Moral: > > It is better to learn from other people's > mistakes than from your own. > > Frank King > Cambridge, U.K. > > P.S. The home page of the website is: > > http://wiki.dtonline.org/index.php/Category:Sundials > > It won't take long before you notice other > erroneous assertions :-) > > --------------------------------------------------- > https://lists.uni-koeln.de/mailman/listinfo/sundial > >
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