Filenews 16 May 2022 - by Giorgos Tzivas
The planetarium in the Tamassos region will be one of the ten best in Europe. With a dome of twenty metres makes it one of the largest in the world. But what is a planetarium? Here's a brief history.
The planetarium is a hall constructed mainly for the presentation of educational and entertaining performances related to astronomy and the night sky, as well as for practicing astronomical shipping. The dominant feature of most planetariums is a large hemispherical screen, on which images of stars (and constellations), planets and other celestial bodies appear and move exactly as in the sky. The planetarium, therefore, in its original and basic function, mainly gives a realistic simulation of the sky. Today, however, it is also used for the screening of spectacular films on scientific subjects. The screen, usually, is identified with the roof of the building that houses the planetarium and has the form of a hemispherical dome.
Planetariums use a variety of technologies, such as special projectors, slide projectors, videos, dome projection systems and lasers. It is possible to represent the positions of the celestial bodies in the firmament at any time of the past or the future, but also as they can be seen from anywhere on Earth.
The term "planetarium" today generally denotes other methods for the representation of celestial bodies, especially the Solar System, such as a planetarium programs or mechanical model.
Planetariums now exist in many places. Most are public, but some are privately owned. Their dimensions vary from diameters of more than 20 to three metres. The last diameter corresponds to inflatable portable planetariums for children, on which the spectators sit on the floor. Such portable planetariums serve educational programs outside the permanent facilities of natural history museums and scientific centres.
Expression content
Most planetariums in the world perform for the general public. Great popularity have themes simply, such as "What's in heaven tonight?" (for the more cloudy countries), or performances associated with local themes, such as a religious holiday (the most classic among them being that of the Christmas Star). The speech can be either live or pre-recorded.
Since the early 1990s, three-dimensional digital planetariums have given an additional degree of freedom to the presenter, because they allow the simulation of the sky as seen from anywhere in space. This new virtual reality feature offers significant educational benefits, as it transmits live the knowledge that the space around the Earth has depth, thus helping the public to abandon the ancient impression that stars are "stuck" inside a giant celestial sphere and to understand the true structure of the Solar System and space beyond it. For example, a planetarium can today "fly" its audience to a well-known constellation such as Orion and reveal to it that the stars that appear to form a certain shape from earth are located at enormous distances from each other and are connected only in human imagination and mythology.
Music is also an important element in complementing the experience gained by the viewer from a good planetarium performance. It often belongs to the genres of space music, space rock or classical music.
From Archimedes to today
Archimedes possessed a primordial device that could show the movements of the Sun, moon, and planets. The discovery of the Antikythera Mechanism proved that such and even more complex devices already existed in antiquity. John Kambanos (1220-1296 AD) described a planetarium in his work "Theorica Planetarum", with instructions for its construction. These devices were small in size. It was only at the end of the 18th century that some teachers attempted to construct larger-scale simulations of the heavens. The efforts of Adam Walker (1730-1821) and his sons are notable for attempting to introduce theatrical illusions into the educational work. Walker's "Eidouranion" was the focus of his public lectures-theatrical presentations. His son describes this mechanism as "20 feet (6 meters) tall, with a diameter of 27 feet (8.2 meters): He stands vertically in front of the spectators and his bullets are so large that they can all be seen from the most remote parts of the theatre. Each planet and satellite seems to hover in space without support, performing their annual and daily orbits without distinguishing the mechanism." Other laymen of astronomy promoted their own devices: Lloyd the "Dioastrodoxon" (Dioastrodoxon) and in 1825 William Kitchener (William Kitchener) the "Ouranologia", which had a diameter of 42 feet (12.8 metres). But these devices probably sacrificed astronomical accuracy for a spectacle that impressed the crowds.
The oldest planetarium still in operation is located in the small Dutch town of Franker. It was constructed by Eise Eisinga (1744-1828) in the living room of his house with seven years of work and was completed in 1781.
In 1905, the German Oscar von Miller (1855-1934) of the Deutsches Museum in Munich ordered increasingly improved models of a mechanical planetarium by M. Sendtner. Later, he collaborated with Franz Mayer, chief engineer at the optics company Carl Zeiss (Chais), in Jena, to construct the largest mechanical planetarium in history, capable of showing both heliocentric and geocentric movement. This was finally demonstrated at the Deutsches Museum in 1924, after construction had been interrupted by World War I. Its planets were moving on rails with the help of electric motors: Saturn's orbit was 11.25 meters in diameter. In addition, 180 stars were projected onto the walls by electric lamps.
Meanwhile, von Miller was working at the Tea factory with the German astronomer, Max Wolff, director of the Observatory of the University of Heidelberg, on a completely new project, influenced by the ideas of Walter Bauersfeld of Tsai. The final design was a planetarium in which all the movements of stars and planets would be produced within a visual projection mechanism, which would be installed in the centre of the room and project their idols onto a hemispherical white surface on the ceiling. In August 1923, Zeiss' first (Model I) planetarium projected images of the night sky onto the plastered surface of a 16-meter concrete hemispherical dome erected on the roof of its factory. The first official public screening took place at the Deutsches Museum in Munich on October 21, 1923.
* Director of the Press Office of the Planetarium of Cyprus
