The most accurate clockwork planetarium-tellurium
of its kind
The Watch Quote™ - August 28th, 2007
Of the Planetarium-Tellurium.
The Richard Mille Planetarium is a rare and unique object of its kind, 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 8 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.
Description of the Richard Mille Planetarium-Tellurium movement
Despite its enormous complexity, the Richard Mille Planetarium-Tellurium is designed to be:
- easy to understand
- easy and practical in use
- precise and reliable
This means that for the first time, an object of this type will be able to be operated by someone who is not 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 winding spring is a Tensator type spring, and provides a more consistent torque, which is a vital element in the performance.
Représentations and indications
Astronomic representations (R) and indications (I)
- 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)
Rotation of the earth on its axis (R)
One rotation on its axis in 24 hours. Error: +1° in 7.7 years
Rotation of the earth around the sun (R)
One rotation in 1 year. Error: -1° in 2 million years. This rotation is used as the basis for indicating the seasons, the equinoxes, solstices and zodiac signs, represented in their respective windows.
Obliquity of the earth (R)
Exact rotation, the tilt of the earth’s axis between the two poles: 23.5°. This tilt towards the sun provides a perfect understanding of the phenomenon of the seasons.
Rotation of the moon on its axis and rotation of the moon around the earth (R)
The calculation of the rotation is based on a synodic month of 29.53058912 days (time interval between two new moons). Error : +1° in 168 years.
Phases of the moon (I)
The phases of the moon are represented on the moon itself with a surrounding ring that represents the area visible from the earth.
Equation of time (I)
The equation of time is represented by a fuel gauge liek dial divided into sectors on the front part of the planetarium. The hand represents in + or – the minutes that must be added or subtracted from the mean time in order to obtain the true solar time.
Associated with the equation of time, it represents the true time in relation to the sun. This indication is connected to the planetary mechanism and is on the dial.
Representation of Mercury performing a rotation around the sun in 87.9 days. Mercury does not rotate around its axis.
Representation of Venus performing a rotation around the sun in 224.7 days. Venus does not rotate around its axis.
Static representation of the sun in the centre of the planetarium-tellurium.
- Time zones
- Date (Perpetual calendar)
- Day (Perpetual calendar)
- Month (Perpetual calendar)
- Year, decade (Perpetual calendar)
- Leap year
- Power reserve
- Seasons, equinoxes, solstices, Zodiac signs
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