Vacheron Constantin: The Birth of the Most Complicated Timepiece

　　2015 9 17, isVacheron Constantinanniversary260, the brand unveiled a timepiece described as the most complicated ever made on that day.

　　According to the brand, this prestigious and elegant double-dial timepiece features the most exceptional mechanical construction and technical innovation to date, for whichVacheron Constantinan exclusive department was formed, bringing together three of the brand's master watchmakers who spent eight years on its design and development. This remarkable project originated from a challenge issued by a world-renowned collector,Vacheron Constantinwho not only accepted this challenge but also delivered a satisfying result.

　　Continuing classic watchmaking traditions while adopting a twenty-first-century mindset, this timepiece is a brand-new, original creation by Vacheron Constantin. This complication features an unprecedented construction, requiring calculations, design, and development from scratch to create a completely new movement. Furthermore, many well-known complicated mechanisms were revised, reinterpreted, and redesigned solely to enhance the overall harmony of the finished timepiece. Conceiving and realising this vision demanded not only extraordinary imagination but also advanced logical mathematical thinking and a deep understanding of craftsmanship. The successful launch of this timepiece demonstrates the brand's new complications in watchmaking while refining much knowledge and technique during the development of its structure, marking another exceptional contribution to mechanical watchmaking technology developed since the 20s20.

　　The exclusive information within my jigsaw puzzle is the equation of time: the equation of time display shows the minute difference between solar time and mean time. Each year, solar time is up to 16 minutes 33 seconds ahead of mean time (around 11 3), and up to 14 minutes 6 seconds behind mean time (around 2 12). There are only four days each year when the durations of solar time and mean time are identical. The movement's hands are controlled by an irregular cam designed according to sidereal time calculation principles, while this sidereal equation of time mechanism also allows the seasons to be displayed via the solar hand. Historically, mastering the equation of time was an essential skill for navigators, who typically used portable mean solar time dials to observe solar altitude and then calculated the specific time difference by comparing it with their home time.

　　There are two main factors causing the equation of time. The first is the intersection angle between the Earth's orbital plane and the equatorial plane. The second is that the Earth's orbit is elliptical rather than circular.

　　The equation of time caused by the obliquity of the ecliptic (i.e. the Earth's axial tilt).

　　If the Earth's axis of rotation were not tilted relative to the orbital plane (i.e. the ecliptic plane), sunlight would shine directly onto the equator along the ecliptic orbit, and the direct solar angle on the equator would remain completely constant over equal time intervals. However, this is not the case; the subsolar point is not distributed in a straight line, but fluctuates up and down along the equator according to time. The solar altitude angle reaches its maximum when the ecliptic plane is parallel to the equatorial plane (i.e. the summer and winter solstices), while it is at its minimum during the vernal and autumnal equinoxes.

　　The equation of time caused by the orbital revolution (i.e. the Earth's elliptical orbit).

　　The Earth's orbit around the Sun is elliptical. The distance between the Earth and the Sun is at its minimum around 12 31, and at its maximum around 7 1. The change in longitude is fastest when the Earth is closest to the Sun. The Sun will pass directly over the meridian at noon on these two days, and the elliptical orbit dictates that the equation of time is zero on these two days. Mean solar days are calculated by astronomers based on the annual average solar time, setting a day as 24 hours for the convenience of daily life. Solar time and mean time have the same duration only four times a year, namely 4 16, 6 14, 9 1, and 12 25. The equation of time is zero on these four days. On the remaining 361 days, the equation of time window must be used to understand the difference between the two times. This difference, along with sunrise and sunset times, self-corrects at noon local time every day. The equation of time is usually represented by the symbol 8, known as the "analemma8", and can be calculated using the following equation: E = 9.87 * sin (2B) – 7.53 * cos (B) – 1.5 * sin (B) where: B = 360 * (N-81) / 365 where: N = number of days, 1 1 = day 1.