In earlier papers I have argued that the unique 260-day sacred
almanac which was used
throughout pre-Columbian Mesoamerica traces its origin to the
interval between zenithal sun
passages over the Formative site of Izapa in southernmost Mexico. I
have argued further that,
by employing the Goodman-Martínez-Thompson correlation, it is
possible to date the beginning
of that count very precisely to August 13, -1358 (or 1359 B.C.).
(Because the present Gregorian
calendar was not used in the Christian world before A.D. 1582, the
equivalent date in the Julian
calendar was August 26, -1358.) As I have also pointed out, each year
the southward passage of the
zenithal sun over Izapa is heralded by the Perseid meteor shower on
the two preceding evenings, but
on that specific morning in 1359 B C. another astronomical event of
significance took place of which
the Zoque priest who formulated the sacred almanac must surely have
taken notice. That was the
heliacal rising of the planet Venus (at 2:48 A.M. local time) over
Volcán Tajumulco, the highest
mountain in Central America.
We know from the later records of such peoples as the Maya and the
Aztecs that the heliacal
rising of Venus was attended with great awe, if not apprehension. Of
course we can only speculate
that the priest who set in motion the sacred almanac at Izapa was
actually aware that this event would
take place on this auspicious morning, for, if he wasn't, it
certainly was a most fortuitous coincidence.
We likewise know that, despite Venus's mysterious "disappearances
into the underworld" as it
alternated between being a morning star and an evening star, the
Mesoamericans managed to fix the
length of its complete cycle as 584 days. In doing so, they must have
also been intrigued to discover
that with the completion of each cycle, the day-number of the sacred
almanac decreased by one
whereas the day-name advanced by four.
(See Table 1. Please note that Maya day names are used in the absence of their Zoque equivalents.)
Julian Date |
Maya Date |
Time |
Azimuth |
|
August 26, -1358 |
1 Imix |
2:48 |
66º 35' |
|
April 1, -1356 |
13 Chicchan |
3:52 |
107º |
|
November 5, -1355 |
12 Muluc |
3:15 |
83º |
|
June 12, -1355 |
11 Ben |
3:04 |
82º |
|
January 17, -1353 |
10 Caban |
3:37 |
109º |
|
August 23, -1350 |
9 Imix |
2:46 |
66º 48' |
|
March 30, -1348 |
8 Chicchan |
3:52 |
108º |
|
November 3, -1347 |
7 Muluc |
3:13 |
83º |
|
June 10, -1345 |
6 Ben |
3:06 |
83º |
|
January 15, -1343 |
5 Caban |
3:35 |
109º |
|
August 21, -1342 |
4 Imix |
2:46 |
66º 43' |
From the above table, the calendrical regularity of Venus'
heliacal rising is readily apparent,
as is also the fact that with every fifth completion of its cycle
Venus once more rises in the vicinity of
the Volcán Tajumulco. Nevertheless, even within the time-span
examined in Table 1 it must have
been clear to the priests in Izapa that the heliacal rising of Venus
was getting out of phase with the
zenithal passage of the sun, for in the year -1350 the latter did not
pass overhead at Izapa until two
days later (on 11 Akbal according to their count), and in -1342 its
zenithal passage occurred five days
later (on 8 Chicchan).
As we have seen, assigning a length of 584 days to the cycle of
Venus allowed for a very convenient
way to calibrate it calendrically. Although every fifth time its
heliacal rise once again took place over
Tajumulco, the interval between it and the zenithal passage of the
sun steadily continued to widen.
Had the priest chosen an interval of 584.4 days for the duration of
the Venus cycle, the two events
would have remained in phase with one another, but the fact that he
did not strongly suggests
that he was unable to conceive of any temporal unit shorter than an
entire day -- in other words,
mathematically he was able to think in integers but not in fractions.
On the other hand, it must have been tempting for the priest to
have believed that, because of
the calendrical regularity of the Venus count, the real problem of
calibrating the two events lay in
defining the interval between the zenithal passages of the sun. In
effect, he was recognizing that
although the sun spent 260 days south of Izapa and 105 days north of
it, these two values did not
equate to the length of its total cycle -- in other words, to the
true length of the solar year. This
problem was far more serious than the growing discrepancy between the
heliacal rising of Venus and
the zenithal passage of the sun, for already within four years a lack
of calendrical regularity began to
manifest itself. Rather than passing overhead at Izapa on 1 Imix, the
sun now passed overhead on
6 Ik instead, and in four more years its passage occurred on 11
Akbal, and so on. Clearly, if the
original intent of his time-count had been to help define the
beginning of the rainy season, for
example, then the 260-day sacred almanac was already quickly becoming
less and less useful.
To redefine the length of the solar year required a new and
hopefully more precise starting point
than the zenithal passage of the sun. Through continued observations
of its movements it
gradually became apparent that, as viewed from Soconusco, the sun
reached its northernmost
turning point in the sky (i.e., the summer solstice) somewhere behind
the great wall of volcanoes
that loomed up on the northeastern horizon. Therefore, by careful
planning it should be possible
to find a site where the zenithal passage of the sun on August 13 and
the June 22 sunrise over
the highest mountain in Central America could both be calibrated at
the same place. As I have
explained in earlier writings, it was this fortuitous combination of
circumstances that was
responsible for the choice of Izapa's location.
With the priest now thinking in terms of the summer solstice and
the Volcán Tajumulco, it
was perhaps only natural that the earlier correspondence of the
heliacal rising of Venus over the
mountain and the zenithal sun passage should once again come to mind.
In previous papers I
have demonstrated that the internal structure of the 365-day secular
calendar strongly suggests that
it came into use during the period between -1324 and -1321, and that
it may in fact have been the
product of the same mind which had developed the sacred almanac just
over thirty years earlier.
By employing the Goodman-Martínez-Thompson correlation, we
find that the summer solstice
(June 22 in the Gregorian calendar, or July 3 in the Julian calendar)
coincided with the date of 0 Pop
during only those four years. It is also interesting that there were
heliacal risings of Venus in two of
those years -- one at 4:12 A.M. in -1324 when the planet rose at an
azimuth of 67º 35', or nearly
over Tajumulco, and one at 3:10 A,M. in -1321 when its rise took
place at an azimuth of 72º. The
date of the first occurrence according to the sacred almanac was 4
Manik and of the second, 7 Ik.
One is tempted to conclude, therefore, that of the two possible dates
for the secular calendar's
beginning it was the former on which it was set in motion. Indeed, it
may have been that the choice
of 4 Manik for the initiation of the 365-day secular count gave rise
to the notion held by later peoples,
such as the Aztecs, that previous creations of the world likewise
occurred on days numbered 4 and
that our present world shall also end on a day numbered 4.
(It may be of interest to note that the next heliacal rising of
Venus on August 13th will take
place in the year 2001 at 3:15 A.M. On that occasion, its azimuth
will be 67º 21', or still very close
to Volcán Tajumulco. In the year 2003 a heliacal rising of
Venus will occur on the summer solstice
(June 22) at 4:37 A.M. closer yet to Volcán Tajumulco, namely
at an azimuth of 67º 02'.)
(Note that references for this and the other papers are found on the 'home page' of this article.)