photo: Ariefrahman for Wikipedia /_
Tides on earth are due to the sun and moon. During the year, the Sun reaches extreme solsticeThe extreme points of sunrise and sunset in the year. In midwinter the sun is to the south of the celestial equator (the reverse in the southern hemisphere) and in midsummer the sun is north of that equator, which is above the geographical Equator). points and during the lunar month, the phases indicate where the sun is relative to the sun: their configuration relative to one another, leading to stronger or weaker tides.
The tides therefore vary but when the lunar orbit is in phase with the solar eclipticThe path of the Sun through the sky along which eclipses of sun and moon can occur, traditionally divided into the 365¼ parts of the solar year, each part then a DAY in angle rather than time. path, the moon rises above and below that path and the moon becomes more extremely north and south than the solstice sun ever can be. Within a single year, the sun is at winter solstice in midwinter, and summer solstice in midsummer. But the moon takes 18.618 years to reach its maximum standstill, further south and north than the solstice sun.
Ancient cultures were aware of this cycle and sometimes thought to place monuments or burial places on an alignment with maximum moonrise or moonset, occurring north and south of east on the eastern or western horizon.
This demonstrates how astronomy can interpret monuments right into relatively recent times. For example, the focal Islamic monument of Kaaba, in Mecca, has an orientation to maximum moon in the north east at sunrise (see this onsite article or chapter 8 of my latest book Sacred Geometry: Language of the Angels). Since the Kaaba is on an ancient site, then it must have inherited this alignment from millennia before, when people aligned monuments to astronomical phenomena; right back to the megalithic period: but such alignmentsA name special to Carnac's three successive groups of parallel rows of stones, starting above Carnac called Le Menec, Kermario, and Kerlescan and another found near Erdevan. are also seen in “ancient” buildings from the historical periods.
More recently, news media have reported an analysis of satellite imaging that shows correlation in the fluctuation in mangrove canopy cover and the lunar nodal cycle, popularly known as the moon’s wobble over 18.618 years. This wobble is in the precession of the the moon’s angled orbit, relative to the ecliptic, which latter itself appears to wobble over tens of thousands of years (between 25, 720 and 25,920). Depending on the phase of the lunar nodal cycle, there can be “as much as 40cm of difference in the tide range” in places such as the Gulf of Carpentaria, Saintilan said. [The] wobble in the moon’s orbit around Earth affects mangrove cover across Australia and likely contributed to mass tree deaths in the Gulf of Carpentaria, [this] new research suggests.
Wikipedia reports ” The last major lunar standstill was in June 2006, and the next one will be in January 2025.” The lunar maximum finds the moon riding high in the sky or very low at the opposite place in its orbit and, in northern climes, it is near to the horizon to the south, especially where mountainous. It pays to notice this since it will be a significant portion of your life before you will see the like again.
An unusual fact enabled the ancients to count out this wobble, due to the backwards motion of the moon’s orbital nodes, the two places where the moon’s orbit crosses the sun’s path (ecliptic). Lunar eclipses are suring full moons and solar eclipses during new moon at the nodes.
These nodes each take 6800 days to traverse the whole ecliptic/zodiac. Counting systems could exploit the factors of 6800 days as being the prime number 17 times 400. One could count smaller numbers, perhaps hundreds, and keep note of how many of those have passed. And half way through, there is the Minimum Standstill of the moon, where the moon is closest to the celestial equator after exactly 3400 days. Many ancient alignments can also be found for the minimum standstill , for example the Heraion on Samos appeared to let only the minimum moon into the chamber of the goddess Hera. Use the search or tag cloud features to find out more about the nodal cycle and eclipses.
The increasing tidal range due to lunar maximum
might be mistaken for the effects of climate change
given our present expectations of disaster.
Further Reading about the Mangrove dieback can be had on Tallbloke’s TalkShop.