The earth's orbit around the Sun is not a perfect circle. It is an ellipse, albeit not a very flattened one, and this leads to a number of interesting observational effects. One of these is the analemma, the apparent path traced by the Sun in...

In astronomy, an analemma (pronounced /ˌænəˈlɛmə/, Latin for the pedestal of a sundial) is a curve representing the angular offset of a celestial body (usually the Sun) from its mean position on the celestial sphere as viewed from another...

In the era of computers and sophisticated technology many basic principles and concepts inherited from antiquity are sometimes forgotten. In this paper the history of a stick vertically placed in the ground, a gnomon, a shade tool for predicting time, as well as...