Introduction

Abstract

Time most probably is the oldest element in nature. If only because the word ‘old’ does not have a meaning without the concept of time. With the creation of matter, nature was provided with the first timing references, as the elementary ‘building blocks’ of matter are atoms, consisting of electron clouds swarming around protons. In atoms, many periodical sequences take place, dividing time into more or less equal parts. On a much larger scale, the movement of the planets provides nature with a timing reference. This movement is the cause of the timing references that influence the life of every being: the day-night cycle and the cycle of the seasons. It is thus not surprising that the first timing references, that were more accurate than the movement of the planets, were meant to study this movement. The need for these accurate timing references emerged during the renaissance both for use in astronomy and, being a close relative of astronomy, in navigation. As Holland was the largest naval power in that time, it is also not surprising that the first to fulfill the desire for more accurate timing references was a Dutchman. Christiaan Huijgens invented the pendulum clock in 1656, thus paving the way to both safer and longer voyages. The first mathematical descriptions of oscillations were also made by Huijgens. In his Horologium Oscillatoriurn [6], he describes the exact isochronism of cycloidic oscillations, and improvements of the pendulum clock, making it useful for navigation at sea by the introduction of the balance; a mass-spring system that made the clock independent of the gravity field.