The moon has aroused the fascination of humanity since the human being began to look at the sky. Its cycles were key to establishing the calendar of ancient societies , even the date of some modern festivities, such as Easter, are still governed by the phases of the moon.
In certain cultures, the influence of the moon has been carried over to astrological mysticism , in the belief that the position of the moon in the sky at the time of birth can determine important aspects of a person’s life, or that the phase of the moon and its position in the sky can provide people with different benefits or harms. Of course, astrology has no scientific value and there is no proof that these influences are real. In addition, there are other ways in which the moon is assumed to influence people’s lives.
mysticisms of the moon
Traditionally, the moon has been associated with women. One of the most widespread beliefs surrounding the activity of the moon is that it is synchronized with the menstrual cycle . In fact, the term comes from the Latin menstrualis , which contains the word mensis , and which refers to the ‘month’ in its conception of ‘lunar cycle’.
Another well-established idea relates the full and new moon phases to the increase in childbirth ; This belief is maintained even by the professionals who attend births.
Both beliefs are false. When the number of births is analyzed—excluding induced labor and cesarean sections—and compared to the phases of the moon, no increase is observed during the full moon or during any other phase; it seems that it is only a myth fueled by confirmation bias .
Regarding the synchronization of the menstrual cycle, although some studies try to link it, the truth is that none have been able to provide a possible causal relationship between the influence of the moon on the earth —basically gravity and luminosity— and the menstrual cycle. In fact, when analyzed in detail, we find that menstrual cycles change, not only from woman to woman, but also with age throughout your life. This means that a woman who is in sync with the moon at a given moment may become out of sync after a while.
The lunar cycle has an average duration of 29 days and 12 hours, and if we assume that the full moon lasts three days -from the day before to the day after the moment of maximum brightness-, a woman with a stable menstrual cycle that lasts only one day more than the lunar cycle it will be synchronized for three cycles, but on the fourth it will lose synchrony and will fall behind, to be synchronized again after 26 menstrual cycles (and 27 lunar ones). That is more than two years.
That is, for a woman to maintain synchronization with the moon in the long term, it is necessary that her cycle is identical to that of the moon, or that if it suffers small variations at a given moment, they are corrected in the following cycles to return to the same value. average. It seems that any appearance of synchronization is nothing more than a biased observation of punctual coincident events. Even a stopped clock gives the correct time twice a day .
The influence of the tides
However, the fact that the moon has no influence on human biological activity does not mean that it does not have influence on other living beings. There are two phenomena that change depending on the phases of the moon: the luminosity during the night and the tides .
The moon is about two-thirds important in tide formation—the other third is the sun’s business. During the full moon and new moon phases, the solar and lunar gravitational influence align causing spring tides , while in the first quarter and last quarter phases, the position of the moon and sun centered on the earth form a right angle which reduces the gravitational effect, causing neap tides .
This tidal influence is extraordinarily important in coastal biodiversity. Large numbers of animals, plants, and microorganisms live in the intertidal zone , the part of the shoreline that is flooded at high tide and exposed to the atmosphere at low tide.
During spring tides, high tides are higher and low tides are lower; At high tide, the sea carries more volume of water and more nutrients to this region, and when the tide is low, the area is more exposed to the atmosphere. Consequently, the intertidal zone is much wider, which provides more territory to distribute to the living beings that inhabit these regions. Hence, the life cycle of a large number of fish, crustaceans, molluscs, corals, algae and microorganisms that inhabit these regions is closely linked to the phases of the moon.
The moon as a source of light
It is well known that the moon does not emit its own light, but rather its light gray surface reflects sunlight very effectively. However, this light source may be relevant to the dynamics of living beings and their relationship with light: the light that reaches the earth during a night with a new moon and a night with a full moon is very different.
This illuminating effect of the moon also has biological effects on certain living beings, especially nocturnal animals and plants.
Nocturnal predators that rely on sight, such as nocturnal raptors or small mammals, are more successful in hunting when there is some light that allows them to see, even in the dim light of a full moon night; That is why during these nights they have more activity. This is not observed in other animals that prioritize other senses, such as bats. Other animals, such as opossums, on the other hand, avoid full moon nights, probably to avoid predation on them. Nocturnal insects also change their behaviors depending on the light that comes from the moon.
Regarding plants, their biological cycles are very dependent on the duration of daylight, which is called photoperiod . Plants ‘perceive’ the season they are in depending on whether the photoperiod is getting longer —in spring— or shorter —in autumn—. However, the light of the moon can produce certain disturbances that ‘confuse’ the plant, making it act as if it were in a time when it is not. However, many plants present evolutionary adaptations that avoid these problems, by means of leaf movements that reduce the intensity of light received from the moon to values between 20% and 5%.
References:
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Bünning, E. et al. 1969. Interference of moonlight with the photoperiodic measurement of time by plants, and their adaptive reaction. Proceedings ofthe National Academy of Sciences, 62(4), 1018-1022. DOI: 10.1073/pnas.62.4.1018
Ilias, I. et al. 2013. Do lunar phases influence menstruation? A year-long retrospective study. Endocrine Regulations, 47(3), 121-122. DOI: 10.4149/endo_2013_03_121
Julien-Laferriere, D. 1997. The Influence of Moonlight on Activity of Woolly Opossums (Caluromys philander). Journal of Mammalogy, 78(1), 251-255. DOI: 10.2307/1382659
Ramos, J. a. A. et al. 2011. Influence of moon phase on fish assemblages in estuarine mangrove tidal creeks. Journal of Fish Biology, 78(1), 344-354. DOI: 10.1111/j.1095-8649.2010.02851.x
Williams, C. B. et al. 1936. IX – The influence of moonlight on the activity of certain nocturnal insects, particularly of the family Noctuidae, as indicated by a light trap. Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences, 226(537), 357-389. DOI: 10.1098/rstb.1936.0010
