Two new chronobiological studies detail how the phases of the Moon influence us humans even though we live in large cities under the cover of artificial light.
It does not make us hairy beasts, nor do we owe our success or failure in love to the moon, but it may affect our day-to-day lives more than as an inspiration for poets and romantics. Women’s menstrual cycles are temporarily synchronized with lunar cycles, something that affects fertility, and we sleep up to 90 minutes less if the full moon appears in the window. These are the conclusions of two studies published today by Science Advance.
The moon influence us by different factors like our sleep cycle, women fertility and mensuration cycle and other environmental effects.
The lunar cycle refers to the 29.5 days (lunar month) that the Moon uses to orbit the Earth, and the 24.8 hours (lunar day) is the time that it is present in the same geographical point. Throughout these two cycles, the illumination that reaches us from the Moon varies, and the distance at which it is found carries more or less the sea water and causes the tides.
In recent studies on the Earth’s magnetic fields, they have found that the umbrella that defends us from cosmic rays and the threat of particles from the outer universe, would collapse without the presence of the Moon. A piece of information to give us an idea of the magnitude of its influence: The Earth continuously receives 3.7 billion watts of power through the transfer of gravitational energy and the rotation of the Earth-Moon-Sun system. It would seem naive to think the Moon was indifferent to us.
Companion on the journey around the solar system
Every 14.5 days the Moon, the Earth and the Sun are roughly on the same axis and this results in spring tides. The 24.8-hour lunar day produces a 12.4-hour tidal cycle, with high tides when the Moon is placed directly over seawater or at the diametrically opposite point on the other side of the planet. The Moon influence us through these factors directly.
Numerous studies show that these environmental changes caused by the Moon influence affect behavior, physiology, reproduction, etc. of animals and plants.
One of the most fascinating examples is the synchronicity in the spawning of the anthozoans that form the great coral reefs of the world. They all spawn at the same time, simultaneously, on the same day after the full moon. It occurs on the Great Barrier Reef in Western Australia, Hawaii, the Caribbean, and Okinawa. A common land crab in Japan, Sesarma haematocheir, lives in the mountains above the Ogamo River, but adult females have to come down the mountain to release their young into the sea. And they do it the day the Moon lights their way. Eagle owls ( Bubo bubo ) use cues to search for a mate. His calls are more frequent and at a higher pitch on full moon nights. Examples, collected in various scientific studies. They are numerous, however, there is much controversy about whether something similar occurs in our species.
We sleep less the nights before the full moon
Moon influence us with our sleep time. Although moonlight has already been shown to affect the nocturnal activity of many organisms, the question of whether lunar cycles affect nighttime sleep and wakefulness in humans remains controversial. However, in one of the studies published today in Science Advance, they have found that lunar cycles appear to affect sleep patterns both in rural and indigenous communities and in modern cities.
People fall asleep later and sleep less on the nights preceding the full moon, when its light fills the night sky after twilight, according to an analysis of sleep cycles in 98 rural and urban indigenous Argentines and 464 urban university students. from the United States.
The results suggest that human sleep is synchronized with the phases of the moon, regardless of ethnic or cultural differences, and even in places where light pollution dwarfs the moonlight.
For the study, they recorded wake / sleep cycles for 1 or 2 months in three Argentine indigenous communities: an urban community with full access to electricity, a rural community with limited access to electricity, and a rural community without electricity. In all communities, sleep patterns were clearly modulated by the lunar cycle, and each person’s sleep duration varied between 20 and 90 minutes throughout the cycle.
‘Although the true adaptive value of human activity during moonlight nights remains to be determined, our data seem to show that humans – in a variety of environments – are more active and sleep less when the moonlight is at its highest during the first hours of the night ”, write Casiraghi et al. Researchers from the University of Washington who conducted the study.
The Moon influence us and our fertility
An analysis of the long-term menstrual cycle records kept by 22 women up to age 32 shows that those with cycles of more than 27 days were synchronized with the intensity of the moonlight and its gravitational pull.
Previous research suggests that women with menstrual cycles that are closest to lunar cycles are more likely to become pregnant
The researchers hypothesized that human reproductive behavior might have been in sync with the moon during ancient times, but that this changed as modern lifestyles emerged and humans were increasingly exposed to artificial light. Previous research suggests that women with menstrual cycles closest to lunar cycles are more likely to become pregnant, although lunar influence on human reproduction remains a controversial issue.
To address this age-old mystery, Charlotte Helfrich-Förster and her colleagues examined long-term data on the onset of menstrual cycles spanning an average of 15 years, including records of 15 women aged 35 and younger and 17 women over 35 years.
To discover the times when women’s menstrual cycles were in sync with lunar cycles. They found that most women’s menstrual cycles were aligned with the synodic month (the time it takes for the moon to go through all its phases) at certain intervals.
Menstrual cycles were also aligned with the tropical month (the 27.32 days it takes for the moon to pass twice through the same point of the equinox) 13.1% of the time in women 35 years and younger, and 17 7% of the time in women over 35, suggesting that menstruation is also affected by changes in the gravitational forces of the moon.
In addition, the researchers observed a greater synchronization between lunar and menstrual cycles during long winter nights, when women experienced prolonged exposure to moonlight. While the lunar luminescence and gravimetric cycles seemed to weakly affect menstrual cycles separately, the results suggest that these cycles exhibit a stronger effect together, with menstrual cycles more in sync with lunar rhythms when the moon is closer from the earth. The study has been published in Science Advances.