--- Canopus56 <canopus56@yahoo.com> wrote: <snip> In rereading my original post, it would have been clearer to explain that the shadow always runs to the north of the gnomon and not across the gnomon's base, as Norm pointed out. - Canopus56(Kurt)
The equinoxes are the only day of the year that the shadow cast by a gnomon moves in a straight east-west line. Have students go out at one or two hour intervals and mark the location of the shadow of the top of the gnomon on the ground with chalk. The line traced by the shadow will be a straight east-west line. If repeated in few weeks, the line traced by the gnomon's shadow will be curved.
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