In the Galileo’s time there were two contradictory models of the universe. The earth-centered universe of Claudius Ptolomias that had been accepted for over 1400 years and the solar-centered model proposed by Nicolaus Copernicus. In the geocentric Ptolomian model the universe rotated around the earth in a calculated fashion,like clockwork. The model Copernicus proposed set the sun in the center with us in orbit.

     The Ptolemaic system was very much reliant of the fact that celestial bodies moved in a mechanical fashion. Part of the mechanics included the motion of Venus being around a circle with the center of this circle always lying in-between the earth and the sun. In the Copernican model Venus orbited the sun. In 1610 Benedetto Castelli, one of Galileo’s former students, proposed that in the Ptolemaic model, Venus would always be lit from the side or behind. Meaning if the model was accurate Venus would always appear crescent-shaped when viewed from earth. In the Copernican model Venus orbits the sun and therefore would go through observable phases much like the moon of “waxing” and “waning”.

     In October of 1610 Galileo was observing Venus in the morning sky and saw that it was in the gibbous phase, or nearly “full” He knew observing the gibbous phase for Venus would be the smoking gun against the Ptolemaic universe model. This was a very exciting time for astronomy with belief shattering discoveries being made everyday.

     Galileo wanted to check his work before publicly declaring something so severe but at the same time wanted assure he was credited for his discoveries before another astronomer made the same observations. He did this with anagrams. Encoding and publishing his findings in letters to colleagues but reserving the right to reveal the meaning later. In December of 1610 Venus entered a half lit or waning phase and Galileo published his results in a letter to Kepler by way of a Latin anagram.

“Haec immatura a me iam frustra leguntur o.y.”

(English meaning) “These are at present too young to be read by me”

On New Years Day of 1611 Venus had moved to the near side of the sun and entered a crescent phase. Galileo unscrambled the anagram.

“Cynthiae figuras aemulatur mater amorum”

(English meaning) “The mother of love imitates the shape of Cynthia”

     The mother of love being Venus (think Aphrodite) and Cynthia referring to the moon. Venus imitating the waxing and waning of the moon must pass both sides of the sun. This finding proved the Ptolemaic system wrong. In years to come Galileo published his findings and attacked the validity of the Ptolemaic system on many fronts, including publishing in Italian rather than Latin. This although seemingly arbitrary to us, was a bold move.  Latin was the language of scholars, Italian was the language of the everyday people. These texts were designed to incite mass change of perspective on the universe rather than acknowledgement of his work by the scientific community.

     The church had long adopted the Ptolemaic universe as part of it’s dogma and was displeased with Galileo rocking the boat. It wasn’t long after that the inquisition charged Galileo with “a vehement suspicion of heresy”.

“Animals, which move, have limbs and muscles; the earth has no limbs or muscles, therefore it does not move. It is angels who make Saturn, Jupiter, the sun, etc., turn round. If the earth revolves, it must also have an angel in the centre to set it in motion; but only devils live there; it would therefore be a devil who would impart motion to the earth…”. -Scipio Chiaramonti, dedicated to Cardinal Barberini

“These writings must be prohibited, because they teach certain principles about the position and motion of the terrestrial globe repugnant to Holy Scripture and to the Catholic interpretation of it, not as hypotheses but as established facts….”- From Anticopernicus Catholicus by Polacco

Under threat of torture Galileo repudiated his work publicly.

“I, Galileo, being in my seventieth year, being a prisoner and on my knees, and before your Eminences, having before my eyes the Holy Gospel, which I touch with my hands, abjure, curse, and detest the error and the heresy of the movement of the earth.”

He spent the last 9 years of his life under house arrest in his Villa near Florence, continuing his work.

He died in 1642.

The Church cleared Galileo’s name in 1983 and issued a formal apology in 1992

“And who can doubt that it will lead to the worst disorders when minds created free by God are compelled to submit slavishly to an outside will? When we are told to deny our senses and subject them to the whim of others? When people devoid of whatsoever competence are made judges over experts and are granted authority to treat them as they please? These are the novelties which are apt to bring about the ruin of commonwealths and the subversion of the state. “ -Galileo, Written in the margin of his own copy of Dialogue on the Great World Systems