The Mathematics of Sundials

Autor/in	Vincent, Jill
Titel	The Mathematics of Sundials
Quelle	In: Australian Senior Mathematics Journal, 22 (2008) 1, S.13-23 (11 Seiten) PDF als Volltext (1); PDF als Volltext kostenfreie Datei (2) Verfügbarkeit
Sprache	englisch
Dokumenttyp	gedruckt; online; Zeitschriftenaufsatz
ISSN	0819-4564
Schlagwörter	Experiential Learning; Time; Mathematical Concepts; Trigonometry; Mathematics Instruction; Computation; Foreign Countries; Australia + Suchen Sie Ihr Suchwort? Experiental learning; Erfahrungsorientiertes Lernen; Zeit; Trigonometrie; Mathematics lessons; Mathematikunterricht; Ausland; Australien
Abstract	As early as 3500 years ago, shadows of sticks were used as a primitive instrument for indicating the passage of time through the day. The stick came to be called a "gnomon" or "one who knows." Early Babylonian obelisks were designed to determine noon. The development of trigonometry by Greek mathematicians meant that hour lines could be determined arithmetically rather than by geometry, leading to more sophisticated sundials. In the first century CE, the Roman architect and engineer Vitruvius described several types of sundials in his "De Architectura" (Lennox-Boyd, 2006, p. 32), including hemispherical, conical and planar dials. Sundials are often constructed to commemorate special events. The many common designs of sundials, such as vertical, horizontal and analemmatic dials, can all be derived by projections of the basic equatorial dial. In this article, the author shows how trigonometry can be used to calculate the positions of the hour lines for vertical and horizontal sundials, with a particular focus on the mathematics underlying a recently-constructed unique horizontal sundial at Piazza Italia in Melbourne. (Contains 17 figures and 2 tables.) (ERIC).
Anmerkungen	Australian Association of Mathematics Teachers (AAMT). GPO Box 1729, Adelaide 5001, South Australia. Tel: +61-8-8363-0288; Fax: +61-8-8362-9288; e-mail: office@aamt.edu.au; Web site: http://www.aamt.edu.au
Erfasst von	ERIC (Education Resources Information Center), Washington, DC
Update	2017/4/10