The Birla Planetarium of Kolkata is an educational museum building with a dome, within which a planetarium projects the image of the heavenly bodies and their movements in the sky. Birla Planetarium is the largest planetarium in Asia and the second in the world. It was inaugurated in 1963 by the Prime Minister of India Jawaharlal Nehru. A great place for children to learn about the space in a fun, MP Birla Planetarium is the largest of its kind in India. Along with the models of the solar system, has a series of films every day that explains the mysteries of space so children can understand.
The remarkable thing is that this tool is still in working order, and can be visited all year round, so it can be considered the oldest planetarium in the world still in activity. In 1913, Oskar von Miller , engineer, founder in 1903 and first director of the Technical Museum in Monaco, he turned to the firm Zeiss of Jena, specializing in realizations optical, mechanical and electrical, for this study the possibility of building for the Museum planetarium that reproduce not only the starry sky but also the motion of the planets. This idea was suggested to von Miller by Max Wolf, director of the Astronomical Observatory of Heidelberg, but the beginning of World War I interrupted the bud evaluation of the project. This was taken just after the end of the war, around March 1919, by Walter Bauersfeld.
In August of 1923, on the roof of the Zeiss plant in Jena, was completed a hemispherical dome of 16 meters in diameter, where it was installed the first Zeiss projector Model I, the first true modern planetarium. Although the dome was an extremely innovative: its external skeleton was, in fact, the first light metal structure in the world. For the internal part of the dome was used a wooden base, on which it was sprayed a thin layer of cement which, once solidified and painted white, formed a good surface for the projection.
From 2000 onwards, are then entered using the digital planetarium. They are based on three main elements: a set of computers, software can generate a realistic image of the starry sky and a projection system. The digital planetarium allowed epochal evolution in the world of planetary. Compared with a conventional opto-mechanical system, which represents the sky in two dimensions as well as it can be seen from Earth, a digital system allows you to move in three dimensions in space. It is therefore possible, for example, simulate an approach to Mars, or a trip to the stars of our galaxy; and, yet, you can even switch between the different galaxies up to see the large-scale structure of the universe.
This is possible because, in fact, a digital planetarium projection system is in some ways similar to that of a movie theater, with the difference that is full-dome ie covering the entire hemispherical dome of the planetarium room. Thus, the system allows you to project, in addition to the sky, any other type of contribution multimedia: images, animations, entire film. In fact, back in the eighties, the American company Evans & Sutherland which deals with simulation systems for aircraft, ships, etc. Had proposed the forerunner of the digital planetarium, called Digistar.
It was a single projector with a fisheye lens placed in the center of the circular room of the planetarium, capable of reproducing the sky in three dimensions, albeit with a very low resolution. The new digital systems may instead rely on a number of projectors also high 4, 5, 6 up to 12, depending on the diameter of the dome, which generally are not placed at the center of the room but on the edge of the dome projection, that is, the horizon of the observer.
A computer system divides the image to be projected in different projectors; the different pieces then combine to form the final image as a whole. A digital system, therefore, is in fact a projection system with a software dedicated to the simulation of heaven. But is able to project, on the entire dome or in specific areas of it, any type of video contribution: still images, animations, graphics, movies, whole film.
The building has an octagonal plan of the Planetarium and the size of the projection room 19.6 meters in diameter with a capacity of 375 seats makes it currently the largest in India. The structure is very active and popular teaching concerning the astronomy and its related sciences, hosting about 100,000 visitors each year, between schools and the general public.