Sundial - Wikipedia
A sundial is a horological device that tells the time of day (referred to as civil time in modern usage) when direct sunlight shines by the apparent position of the Sun in the sky. In the narrowest sense of the word, it consists of a flat plate (the dial) and a …
Sundial | Definition, History, Types, & Facts | Britannica
2024年10月12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.
3 Ways to Make a Sundial - wikiHow
2024年10月12日 · A sundial is a device that uses the position of the sun to reflect the time. An upright stick, called a gnomon, is positioned to cast a shadow onto a pre-marked sundial face. As the sun moves across the sky, the shadow also moves. The...
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How to Read a Sundial: 11 Steps (with Pictures) - wikiHow
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
The earliest household clocks known, from the archaeological finds, are the sundials (1500 BCE) in Ancient Egypt and ancient Babylonian astronomy. Ancient analemmatic sundials of the same era (about 1500 BCE) and their prototype have been discovered on …
Telling the time with the Sun - Science Museum
The first came during the 1600s. The development of accurate pendulum clocks meant that clocks could keep their time for weeks, months or even years before without needing to be reset using a sundial.
How a sundial works | Macmillan Hunter Sundials
Sundial and clock hours and the difference between them. Sundials tell the time from the sun. The hour lines on the dial measure the passage of the shadow cast by the gnomon in intervals of one hour at a time.