Indigenous Brazilians made a discovery that Galileo ignored and reached the same conclusion as Issac Newton half a century later: that the moon is the primary cause of tides.

And that the tidal bore, a phenomenon in which a roaring wave several meters high occurs at the mouth of rivers like the Amazon and ascends them. This occurs near the phases of both full and new moons and is described in ancient indigenous myths.

The pioneering astronomy of Indigenous peoples in Brazil was discovered by the astronomer Germano Bruno Afonso, visiting professor at the National Counsel of Scientific and Technological Development (CNPq) at the State University of Mato Grosso do Sul (UEMS). The specialist approached this subject in the 61^st Meeting of the SBPC in Manaus, Amazonas.

 

According to the astronomer, in 1632 Galileo published the book “Dialogue on the two greatest systems in the world: Ptolemaic and Copernican”, in which he states that the primary cause of the tides were the two circular movements of Earth: the rotation on its axis, which occurs each day, and the transit around the sun, which occurs annually, ignoring the influence of the Moon. It was only in 1687 that Issac Newton demonstrated that the cause of the tides is the gravitational attraction of the sun and, primarily the moon on the Earth’s surface.

 

However, prior to publication of the work by Newton, in 1614 the French Capuchin missionary Claude d’Abbeville published the book “History of the mission of the Capuchin fathers on the Isle of Maragnan and the surrounding lands”. In the Paris publication, d’Abbeville narrates his observations in four months lived with the Tupinamba indians, of the Tupi-Guarani family, in Maranhão, near the equator.

 

One of the annotations of the French missionary says that “the Tupinamba attribute the high and low tides to the moon and clearly distinguish the two high tides verified at the full moon and the new moon or a few days later”. This confirms the knowledge of these peoples regarding the tides and lunar phases much earlier than the theories of either Galileo or Newton.

 

Discoveries – At the end of the 1970s, Afonso completed his doctorate in France, where he had access to the book by d’Abbeville, in which the French Capuchin mentions some names of constellations in Tupi, such as “curuça (the southern cross), “seichu” (the Pleiades), “tuibaé” (the old man) and “nhandutin” (the emu). By analyzing them in greater detail, he ascertained that the constellations had Guarani correspondents. Today, although they are separated by distance – more than three thousand kilometers – and by time, nearly four hundred years. Based on this discovery, he began to study them in all regions of Brazil.

 

“In other countries this discipline, ethnoastronomy, is well studied. Much is already known about the Incas, Mayans and Navajo for example. But about the Brazilian indians, no one knows anything. It is only possible to amplify knowledge about them by working in the field, because nothing exists in the libraries”, noted Afonso, who made another great discovery precisely by diving into fieldwork.

 

In 1991, archeologists were working on the banks of the Iguaçu river, in Paraná, where a hydroelectric dam had been built. They found an archeological artifact but did not appreciate its significance. By studying the vertical rock, the researcher identified it as being an instrument for solar observation known as a “gnomon”. “It had four faces chiseled with the cardinal points. I spoke with the Guarani of that region to see if anyone knew what they meant, and indeed they did”, he recalls, “I later found similar instruments in various other places in Brazil”.

 

According to the researcher, one of the first practical objectives of indigenous astronomy was its utilization in agriculture. By means of lunar observation they know, for example, that there are more mosquitoes during the full moon than the new moon. Data such as this can be used by health organizations in Brazil to combat the mosquito Aedes aegypti, the transmitter of dengue fever, determining the best period for extermination.

 

*Elton Alisson, Press Assistant for the SBPC, for the SPBC Agency.

Published before on www.farolcomunitario.com.br/ciencia_000_0056.htm