A Vertical Sundial


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This applet was made together with Tey Meng Khoon and Frederick H. Willeboordse of CITA (Centre for Information Technology and Applications) for the course Heavenly Mathematics: Cultural Astronomy.

Video Clip

I have recorded a video clip that explains this applet. It's available in several formats.

If you can't get any sound in the QuickTime file, you may need to download the latest version of QuickTime.


This Java applet shows a vertical sundial. It shows the shadow, and also traces out the path of the tip of the shadow.

Helmer Aslaksen
Department of Mathematics
National University of Singapore