2007-08-27
In our quest to better understand the world in which we live, planetariums have flourished with it estimated that there is one planetarium per 100,000 population in the US alone. At its simplest, a planetarium is an apparatus or model representing the planetary system - the movements of the sun, earth, moon and planets as well as other types of astronomic occurrences.
From the earliest times of civilization, man has attempted to duplicate the surrounding visible celestial universe. However, the development of the clockwork driven planetarium or tellurium that could show the movements of heavenly bodies automatically - without manual intervention - had to wait until the appearance of newer and more accurate types of escapements that evolved during the course of the 17th century.
Now, Richard Mille has made a contribution to the development of the Planetarium-Tellurium with a rare and unique Planetarium, containing a vast number of extremely precise indications and astronomic representations within the limits of mechanical design. It was developed to be effective and practical in daily use with the possibility of corrections for different time zones and ease of setting, all of which is executed with workmanship of an extraordinarily high level. All these conditions mean that it is an extremely difficult object to create, and thus a rarity. For this reason more than 10 years have been necessary for the development of the Richard Mille Planetarium-Tellurium.
Another unique aspect of the Richard Mille Planetarium-Tellurium is the addition of a perpetual calendar to the astronomic representations in combination with a détente chronometer escapement. The addition of a highly accurate going train and winding barrel of the planetarium to this escapement make this the most accurate clockwork planetarium-tellurium of its kind.
Despite its enormous complexity, the Richard Mille Planetarium- Tellurium is designed to be easy to understand and use, so that it needn't be operated by a specialist.
Understandable visual representation
First of all, the diameter of the earth has for practical and aesthetic reasons been notably enlarged in the Planetarium-Tellurium (in reality, the earth is 109 times smaller than the sun) allowing a good view of the continents and indeed of countries. All the planets can be seen perfectly, although these, as explained above, are not to scale regarding size and distance. The indications (date, equation of time, zodiac) are represented in an easily readable and consistent way, and on a separate area from the layout depicting the rotation of the planets.
Practical in use
The planetarium-tellurium is wound with a lever system, and it has a power reserve of 15 days.
The perpetual calendar, which is for the first time included in a planetarium, is fitted with a rapid corrector that allows it to be corrected either forwards or backwards. The same adjustment can be made to the Planetarium-Tellurium, after it has not been wound for a long period. This synchronisation, seemingly simple yet a true technical feat since it is also linked to the time zone mechanism including local, summer and winter time, is the result of lengthy research into mechanical engineering and of very important developments allowing the object to be quickly restarted. This had previously been impossible, because it required asking the help of a specialist in watchmaking and astronomy.
The movement is fitted with a Stop-Restart balance whose function it is to restart it after having been immobilised (the problem of the failure of the balance starting up during winding of the movement is an inherent feature of the detent escapement).
Precision and reliability of the Richard Mille Planetarium- Tellurium:
The numerous calculations required for this project were executed by a renowned astronomer-physicist. This means that the main consistent error occurs only regarding the earth on its axis, with +1° in approx. 7.7 years. The other figures are as follows: +1° in approx. 168 years for the rotation of the moon around the earth, and -1° in approx. 2 million years for the rotation of the earth around the sun. Given that the value of 1° is below the timing tolerances (+/- 2°) adopted for this planetarium, whilst for the earlier planetariums, the error range was far greater, one realises that the error of the earth on its axis is perfectly acceptable, indeed of no significance.
For the basic movement:
The movement of the Richard Mille Planetarium-Tellurium has a detent escapement which is much more efficient than the lever escapement because it interferes less with the balance wheel.
The adjustment forward and backward is done on the balance wheel with variable inertia, using adjusting screws. This type of balance is highly sophisticated and guarantees greater reliability as well as better chronometric results. The index has thus been left out, which allows for a more precise and repetitive time adjustment.
The Planetarium's astronomic representations (R) and indications (I) are as follows:
- Rotation of the earth on its axis (R)
- Rotation of the earth around the sun (R)
- Obliquity of the earth (R)
- Rotation of the moon on its axis (R)
- Rotation of the moon around the earth (R)
- Phases of the moon (I)
- Equation of time (I)
- Mercury (R)
- Venus (R)
- Sun (R)
Watchluxus' view: fabulous!
