Sundial - Wikipedia
网页The term sundial can refer to any device that uses the Sun's altitude or azimuth (or both) to show the time. Sundials are valued as decorative objects, metaphors, and objects of intrigue and mathematical study.
Sundial | Definition, History, Types, & Facts | Britannica
网页2024年8月27日 · Sundial, the earliest type of timekeeping device, which indicates the time of day by the position of the shadow of some object exposed to the sun’s rays. As the day progresses, the sun moves across the sky, causing the shadow of the object to move and indicating the passage of time.
How a Sundial Works (And Why You Need One in Your Backyard)
网页2024年2月19日 · A sundial is a device used to tell time using the Sun and the movement of a specific shadow during the day. How do sundials work? The Sun casts a shadow over a carefully calibrated rod, known as the gnomon.
How to Read a Sundial: 11 Steps (with Pictures) - wikiHow
网页2024年9月29日 · To read a sundial, first place the sundial on a flat surface in a sunny spot. Rotate the sundial so the gnomon, or the pin on the sundial that casts a shadow, is pointing north if you’re in the northern hemisphere or south if you’re in the southern hemisphere.
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History of sundials - Wikipedia
网页A sundial is a device that indicates time by using a light spot or shadow cast by the position of the Sun on a reference scale. [ 4 ] . As the Earth turns on its polar axis, the sun appears to cross the sky from east to west, rising at sun-rise from beneath the horizon to a zenith at mid-day and falling again behind the horizon at sunset.
(2a) The Sundial - NASA
网页Instructions and explanations for constructing a paper sundial; part of educational site on space, astronomy and mechanics
Sundial S
网页You can find sundials everywhere: on homes, in gardens, on the walls of public buildings, and there is even a Sundial Park with 28 dials by Vinzenz Philippi a sundialist from the Saarland region and 5 other dials from other dialists. The Birkenau Sundial Society offers tours of the village sundials in German or English.
How does a sundial work? - EAAE
网页A sundial is a device that measures time by the position of the Sun. In common designs such as the horizontal sundial, the Sun casts a shadow from the gnomon, which is a thin rod straight edge, onto a flat surface marked with lines indicating the hours of the day.
How do sundials work? - Yale Scientific Magazine
网页A sundial contains a gnomon, or a thin rod, that casts a shadow onto a platform etched with different times. As the sun changes relative positions over the course of a day, the rod’s shadows change as well, thus reflecting the change in time.
How Do Sundials Work? - The Wonder of Science
网页2018年5月3日 · How Do Sundials Work? Description: The simplest sundial consists of two parts: a flat plate and a gnomon (or stick) that casts a shadow on the plate. When the sundial is properly aligned it will tell the local solar time.