Relics of the Stone Age
Looking in the astronomical calendar, we find in it exhaustive information about the position of the planets in the sky on this or another day, about the upcoming solar and lunar eclipses, about the times of sunrise and sunset and the moon and much more. And, of course, every calendar informs the reader about when spring begins in its hemisphere( summer, autumn, winter), giving the moments of the passage of the Sun through the point of the vernal equinox, etc. The ability to calculate all these phenomena with high accuracy and dozensyears ahead testifies to the high level of astronomical culture that our earthly civilization has already reached.
But many of these questions interested the inhabitants of the Earth three and six thousand years ago, despite the fact that in different parts of it people lived, talked and thought in different ways. For example, it was necessary for the tillers to know whether the warming was accidental or whether it was time to sow: because you are late or, conversely, you start sowing too early, you can remain without bread. If pastoralists in search of fodder foraging decided in early summer to drive their herds for dozens of kilometers to the foothills, then they could not be mistaken when they should return back to the plain. ..
On when this or that season begins( and in general -a new annual cycle), the ancient people could learn from the change in the type of the starry sky throughout the year. The answer to this question could also be obtained by measuring the altitude of the Sun above the horizon at noon or, which is much easier, following the continuous movement of the point of sunrise( and sunset) of the Sun to the north and south relative to some of its average position. And if in some place to establish landmarks indicating the direction to the point of sunrise at the time of the vernal equinox, summer and winter solstice, then in the future for many decades it would be possible to solve the inverse problem: observing the sunrise above one or another landmark, you canwas to establish the beginning of this or that season, the beginning of a new year. The study of cultural monuments of many peoples leads to the conclusion that people used this way in the past quite often.
Define the day of the week, coming on January 1, 1987 Preliminary we find that for this year E = 5. Further for January, Mi = 4, here also P = 1 and D = 1. After substituting these values, we find q = 4 - Thursday.
The break in the course of years "at the turn of the century" deserves attention than the table of monthly coefficients and differs from the same table for the Julian calendar. If the age-old year is simple, then in the 28-year cycle, it can not take place immediately after the 99th. After all, the previous( 100 - 28 =) 72-year was a leap year, and in the transition from February to March in it the coefficient Mi increased by 1. On the other hand, the annual correction( solar epatic) E in the transition from the year 99 toyear, the age-old increases by 1. Therefore, the age-old year is shifted forward by X positions, the value of X being determined from the
relationship, it takes its place immediately after the second leap-day, since X = 6 is an acceptable value for X. In the table, painted for 28 years,the age-old year is about 77 years old. In turn, the 01th year of the new century should be the first before the 4th, leap year. And this means that the effect of the transition from year 00 to year 01 should also increase by 1. From the analogous condition written above, we find the shift of year 01 ahead by the value X = 12: the beginning of the next century corresponds to the same Ki as the year of the 89th centuryprevious. However, in the case when the secular year is a leap year( like the 2000th), this gap will not exist for years.
For example, for April 25, 1983, we have E = 0, for April, Mi = 3, so that q = 0 is Sunday.
According to the above, in the Julian calendar the monthly coefficients Ki = E + Mi are completely repeated after 28 and 700 years. In this case, the chain of years has no discontinuities.