Sentence examples for lunation from inspiring English sources
noun
A month of approximately 29.53 days, measured from a lunar phase until the return of that same phase. On average, the number of days between Full Moons is about 29.5306 days. The actual number of days may differ from the average number by more than a half day. From one Full Moon to the next, the number of days in one lunation can vary between 29.272 and 29.833 days.
The first emperor, Shih Huang-ti, of the short-lived Ch'in dynasty (221 206 bc) made the year begin one month earlier—i.e., with the lunation (the period of time between one new moon and the next) before the one in which the winter solstice occurred.
In either case the result was a year of 365 days, a period incompatible with the 29 1/2-day lunation.
Fishing is then postponed for another lunation, which they insert in the lunar calendar, thus having a year of 13 instead of the usual 12 lunations.
In West Africa some tribes used a four-day interval; in central Asia five days was customary; the Assyrians adopted five days and the Egyptians 10 days, whereas the Babylonians attached significance to the days of the lunation that were multiples of seven.
Hipparchus calculated the tropical year to have a length of 365.242 days, which was very close to the present calculation of 365.242199 days; he also computed the precise length of a lunation, using a "great year" of four Callippic cycles.
The month is based on the lunation, that period in which the Moon completes a cycle of its phases.
Metonic cycle, in chronology, a period of 19 years in which there are 235 lunations, or synodic months, after which the Moon's phases recur on the same days of the solar year, or year of the seasons.
If this total of 235 lunations is taken to contain 110 hollow months of 29 days and 125 full months of 30 days, the total comes to (110 × 29) + (125 × 30), or 6,940 days.
Taking a synodic month to be 29.5 days, they then computed the difference between 12 of these lunations and their tropical year, which amounted to 11 days.
This was very close to the total of 99 lunations (99 × 29.5 = 2,920.5 days), so this cycle gave a worthwhile link between lunar and solar calendars.
The large upper dial has a five-turn spiral slot with a moving pointer to show the 235 lunations, or synodic months, in the Metonic cycle.
