The sundial problem from a new angle
| Autor: | R Goyder |
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| Rok vydání: | 2006 |
| Předmět: | |
| Zdroj: | European Journal of Physics. 27:413-428 |
| ISSN: | 1361-6404 0143-0807 |
| DOI: | 10.1088/0143-0807/27/2/023 |
| Popis: | I present the age-old mathematics of the sundial from a new perspective. Standard approaches consider the problem in the Earth frame and focus on spherical geometry. In this work, I apply a more physical approach, based on geometric algebra, to the generalized sundial problem of calculating the position of the tip of the shadow of a gnomon on a flat dial surface, both of which can have arbitrary orientation. This results in both an exact expression for the equation of time and formulae for the shadow tip which reduce to standard results for the special cases of common dial types. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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