We all use watches. The creation of modern devices has greatly facilitated human life. Previously, it was also necessary to watch the time, so there were other clocks. And they called them an interesting word "gnomon". From ancient Greek it is translated as "pointer". What were they like, how were they used before? We will talk about this today.
Gnomon - the most accurate indicator of true time
Gnomon is an ancient astronomical instrument that allows you to determine the angular height of the sun by the smallest length of the shadow of its column. Such peculiar watches were created a long time ago, they helped to determine the time on a sunny day. The sun here just plays a key role, more precisely, the shadow from it. In other words, the gnomon is the simplest sundial.
In addition to the column and its shadow, the watch has a dial that allows you to more accurately determine the time and, accordingly, the height of the sun.
In different points of the Earth, the division of the dial will not be the same. It depends on thea specific point where the gnomon is supposed to be installed. In astronomy, such an instrument is designed to determine the height of the sun. During the day, it is located at different points, respectively, the shadow cast by objects also differs. This allows you to know the time. The definition is made in degrees of arc. The azimuth and altitude of the sun is what allows you to determine it accurately. In addition, by the shadow of the gnomon they find out, for example, the day of the equinox, so with any date. These watches may look different. Most often, this is a circle on a plane, with a triangle attached to it. A sundial is easy to tell the time, but how accurate is it?
How is a sundial different from a regular one?
Sundial is always either in a hurry or somewhat behind the present time. Only four times a year they show absolutely correct time, and on other days they do not coincide with it. In fact, a sundial shows the correct time, not a wrist watch invented by people. But still, in order to better navigate in time, they use a special chart, which, as a rule, is placed next to the clock. There are usually two ways to tell the time in a sundial.
Shadow of the gnomon - time indicator
Gnomon is a clock, but to be more precise, it is just a part of it, namely an object that casts a shadow. Most often it is a triangle. The angle of its inclination depends on the geographical latitude. The gnomon is always directed to the north. An accurate watch has two gnomons. One face is a curved path.
It was made in order not to confuse on which of the faces to measure time, but it looks quite aesthetically pleasing. Also, for aesthetic purposes, you can make the gnomon slightly curved. The most important thing is that the edge intended for registering time should be straight.
Variety of sundials
Sometimes watches are created that have three gnomons at once. The first gnomon is the one that measures local time, the second measures zone time, and the third is needed to measure the azimuth of the sun.
Interesting about sundial
A sundial, unlike a wristwatch, shows the real solar time, while the time invented by man is largely simplified. The sundial clearly shows noon. The interval between two noons is called a solar day. A sundial is directly dependent on the sun, and it is almost impossible to design a mechanical unit focused on the luminary. The time invented by man is not only not accurate, but also constant, which excludes this very accuracy.
Thus, the gnomon is one of the main parts of the sundial. It looks like a nice design. Observing the gnomon allows you to find out the exact time depending on the sun, that is, the true one.
