Watches & clocks[1]

The time is an important factor in our lives.

The first clocks were (if it can be so called) sundials which displayed the shadow of the stylus, who changed due to the rotation of the Earth and so gave the time. Through a sand timer and all kinds of other mechanisms at last the mechanical pendulum clock was invented.

The invention of the mechanical clock is attributed to the Frenchman Gerbert (later Pope Sylvester II), who lived around the 10th century. Up to the new time was a clock the most complex machine that one could make.

At sea is a pendulum clock unusable. Only after the invention of the unrest could also be accurately measured the time, what the accuracy of the navigation. The solar stand depends along with the time and position at sea.

Clocks with a sling and with a comparable accuracy are in turmoil. A derogation of one minute per week is possible.

Even more accurate is the use of a quartz crystal, operating by piezo-electricity, distortion as a result of an electrical voltage and vice versa. An error of less than 1 second per week for a quartz clockwork feasible.

The most accurate clocks are atomic clocks, which are directly on the definition of the second are based.

In addition to the Sundial, there are also modern clocks that get the time from an external source, e.g. radio clocks. Very special are the watches that operate on solar energy.