Greetings to all
We all know that the atomic clock has the highest possible resolution, while
for sundials 2 to 1 minute seems to be the best achievement. I have a
feeling 1 second could be obtained considering what follows. ( I consider a
second ideal as one can feel it, I mean it is a timespan well related to the
human body, one second you live, the next you may be dead; it is also
somewhat
related to the heartbeat)
Consider a horizontal sundial whith the 15 degrees hour lines; it is
impossible to trace minute lines when keeping usual dimensions for the dial.
However, if we go far away from the base point of the gnomon, the portion of
the arc between 2 hours, becomes larger; so imagine we go to where 60 lines
can be drawn between two adjacent minute lines and we keep only the top part
of the line 11h59m59s and try to draw it on the ground related to a very
accurate positioning of the local meridian. These data allow also to
calculate the height of the gnomon tip. If both dimensions are feasable to
realise, we would have the desired accuracy of one second; of course the
positioning of the meridian is of paramount importance and probably the most
difficult to materialise. ( is this a nice subject for a university ?) Of
some important influence is the width of the gnomon. The indication of noon
time is never accurate because of this width, while the shadow cast for the
earlier hours, may be considered as a hairline and is thus more accurate,
which means that the morning part of the dial is more accurate if the shadow
hairline is taken into account for determination of the meridian. So in
fact, sundials should have a gap at noon corresponding to the width of the
gnomon, and the afternoon part should be calculated in function of the right
hairline shadow
related to a second parallel meridian.
Very interested to read your comments
Walter
