For thousands of years sundials have been used to tell both the time of year and time of day and therefore provide a way of understanding the daily and annual motion of the Sun. Sundials work using a ..
For thousands of years sundials have been used to tell both the time of year and time of day and therefore provide a way of understanding the daily and annual motion of the Sun. Sundials work using a gnomon to cast a shadow onto a surface with hour and seasonal markings. Designing sundials to match ancient models, for example the dials from the Tower of Winds in Athens (from 50 B.C.), is made easier using software to map out hour lines and shadow tracks for walls that deviate from the horizon, also known as reclining sundials. To easily facilitate the transfer of sundial markings to such walls, we have connected a vintage Graphtec plotter/cutter to a PC running Ubuntu Linux and the software Inkscape/InkCut. With this setup we will cut, from vinyl sheets, hour lines and shadow tracks accurate for Daytona Beach. Hour lines radiate as straight lines from the sundial's origin and shadow tracks are described by hyperbolas. We are developing software to take these curves, generated from the sundial equations,and adapt them to a picture file format readable by Inkscape/InkCut. This work will allow us to replicate several sundial styles accounting for different orientations, locations, and gnomon placements.
