What’s gravity? If you’re guessing that’s the fact that a ball will fall if you drop it, then everything does. Gravity doesn’t really have a working definition, doubting our word? Newton didn’t discover it, neither did Einstein prove it. Truth is, whatever gravity is, it sure does have an influence on us. One of these influences are tides — that’s the gravitational effects of the sun and moon on the Earth. And it seems there’s more going on here than just ocean currents. According to a recent study, gravitational action of the sun and moon influences behavior of plants and animals.
Related media: Tides: Crash Course Astronomy #8
There’s A Tide In All Affairs
There is a close link between Earth’s biosphere and the influence gravity creates by the orbital system of the Sun, Earth, and Moon. And truth is, for somewhat the reason, scientists somehow doubt this as a scientific fact. The recent study was driven by observations of fluctuations in auto-luminescence caused by seed germination in cycles regulated by gravitational tides. It was conducted at the University of Campinas (UNICAMP) in the state of São Paulo, Brazil, and later appeared in an article published in the Journal of Experimental Botany.
“All matter on Earth, both live and inert, experience the effects of the gravitational forces of the Sun and Moon expressed in the form of tides,” Cristiano de Mello Gallep, a researcher at UNICAMP, and led author of the paper, told the Agency for Research Support Foundation of the State of São Paulo (FAPESP). “The periodic oscillations exhibit two daily cycles and are modulated monthly and annually by the motions of these two celestial bodies. All organisms on the planet have evolved in this context.”
This study was both an extensive literature review, and a meta-analysis of data obtained from three prior cases. The gravitational causality of the influence of tides on Earth’s biosphere was not fully explored. These were the aquatic activity of isopods — small shell-less crustaceans from at least 300 million years ago; the reproductive effort in coral; and the growth modulation in sunflower seedlings inferred from auto-luminescence. The researchers analyzed the data from the literature review together with their own results, in the latter case.
“What we sought to show in the article is that gravitational tides are a perceptible and potent force that has always shaped the rhythmic activities of these organisms,” Gallep continues.
Rhythmic Tidal Cycles
Several rhythmic patterns displayed by organisms are well-known and widely studied. These include the circadian rhythm — that’s link to the day-night or light-dark cycle. However, there are other rhythmic cycles that thrive even within the presence of light, even under controlled conditions. And there are several environmental factors that influence these behaviors, albeit weak as compared in many cases.
“The data shows that in the absence of other rhythmic influences such as lighting or temperature, local gravitational tides are sufficient to organize the cyclical behavior of these organisms,” Gallep says. “This evidence questions the validity of so-called free-run experiments, in which several environmental factors are controlled but gravitational oscillations are not taken into consideration. These oscillations continue to exist, and may modulate the behavior of living organisms.”
But the study considered removing some coastal organisms from their natural habitats, among others, and observed whether the persistence of tidal cycles will influence their behavioral patterns.
“These animals modulate their behavior in tune with the ebb and flow of the tides, in a cycle of approximately 12.4 hours that derives from lunisolar dynamics, even when they’re moved to a laboratory with stable and controlled aquatic conditions,” Gallep said. “The pattern persists for several days, matching lunisolar tidal timing at the site where the organisms were collected in nature.”
What Affects Gravitational Cycles
Albeit, the sun and moon constitutes roughly a millionth of Earth’s gravity. However, it is sufficient enough to cause large scale tidal effects in the oceans, and move tectonic plates. By contrast, the Large Hadron Collider (LHC), controlled by the European Organization for Nuclear Research (CERN), is 27 kilometers (17 miles) in circumference, but it is only a millimeter vertically displaced by this gravitational fluctuation. For accurate measurements, scientists would have to adjust their experimental calculations accordingly.
First, these fluctuations were the experiments involved in the auto-luminescence that were linked with seed germination, Gallep noted in Limeira, São Paulo.
“I observed that changes in the signal collected appeared every 12 or 24 hours, but differed in each germination test. When I looked for support in the literature, I found studies pointing to a possible correlation with gravitational tides. We explored this phenomenon in subsequent tests on various types of seed, and also added results obtained in the laboratory by collaborators in Prague, Czech Republic, in Leiden, Netherlands, and in Hamamatsu, Japan,” he said.
Gravitational cycles does not affect simple organisms. Studies show that people in ancient times had their circadian rhythm in sync with the lunar cycle — lasting 24.4-24.8 hours. This was typical with cavemen, who spent long periods out of the day. This affected subtle changes in their sleep and wakefulness, meal times, and other metabolic functions.
As Shakespeare put it, “There is a tide in the affairs of men, [plants, and animals],” after all.
Read more facts like this one in your inbox. Sign up for our daily email here.
The Factionary is ever ready to provide you with more interesting content for your reading pleasure. If you’re amazed by our work, you can support us on Patreon with a donation fee of your choice. Thank you!
Written by: Nana Kwadwo, Tue, Jan 11, 2022.