Watch - Uses - Using A Watch and The Sun As A Compass

Using A Watch and The Sun As A Compass

An analog watch can be used to locate north and south. The Sun appears to move in the sky over a 24 hour period while the hour hand of a 12-hour clock face takes twelve hours to complete one rotation. In the northern hemisphere, if the watch is rotated so that the hour hand points toward the Sun, the point halfway between the hour hand and 12 o'clock will indicate south. For this method to work in the southern hemisphere, the 12 is pointed toward the Sun and the point halfway between the hour hand and 12 o'clock will indicate north. During daylight saving time, the same method can be employed using 1 o'clock instead of 12.

The method depends on the assumption that the azimuth of the Sun changes at a constant rate during a day. Strictly, this is true only when the observer is at one of the Earth's poles. Seen from moderately high latitudes, say more than 50 degrees North or South, the Sun's azimuth changes at a rate that is sufficiently constant to allow this method to be useful. Seen from lower latitudes, the Sun's azimuth changes much more rapidly around noon than at other times of day. In an extreme case, when the Sun passes directly overhead at noon, its azimuth abruptly changes by 180 degrees, from due East to due West. Obviously, this completely invalidates the use of a watch as a compass. There are also relatively minor inaccuracies due to the difference between local time and zone time, and due to the equation of time.

Read more about this topic:  Watch, Uses

Other articles related to "using a watch and the sun as a compass, watch, sun":

Analog Watch - Using A Watch and The Sun As A Compass
... An analog watch can be used to locate north and south ... The Sun appears to move in the sky over a 24 hour period while the hour hand of a 12-hour clock face takes twelve hours to complete one rotation ... In the northern hemisphere, if the watch is rotated so that the hour hand points toward the Sun, the point halfway between the hour hand and 12 o'clock will ...

Famous quotes containing the words compass, watch and/or sun:

    Constancy in love is a perpetual inconstancy which fixes our hearts successively to all the qualities of the person loved—sometimes admiring one and sometimes another above all the rest—so that this constancy roves as far as it can, and is no better than inconstancy, confined within the compass of one person.
    François, Duc De La Rochefoucauld (1613–1680)

    The eyes of the LORD are in every place, keeping watch on the evil and the good.
    Bible: Hebrew, Proverbs 15:3.

    That the sun will not rise to-morrow is no less intelligible a proposition, and implies no more contradiction, than the affirmation, that it will rise.
    David Hume (1711–1776)