Galileo Galilei's Anagram [1]
In the 1610 there were two contradictory models for the universe. The incumbent
model was the earth-centered universe of Claudius Ptolomias that had been accepted and
had run like a complicated clock (with one tune up) for over 1400 years. The challenger
was the sun-centered universe that Nicholas Copernicus proposed in 1543 [2].
One of the details of the machinery of the Ptolemaic system was the motion of
Venus around a circle (epicycle) with the center of this epicycle always lying between the
earth and the sun. In the Copernican model, of course, Venus orbited the sun. In 1610
one of Galileo's former students (Benedetto Castelli) pointed out to him that: in the
Ptolemaic model, Venus was always lighted from the side or behind; and therefore it
should always appear crescent-shaped, as seen from the earth. In the Copernican model,
on the other hand, Venus had a crescent shaped appearance when it was on the near side
of the sun and a exhibited a nearly full (gibbous) phase when it was on the far side of the
sun.
For this reason when Venus came out in the morning sky in Oct. of 1610 Galileo
was waiting with his telescope. When Galileo saw the gibbous phase for Venus he
instantly knew he had in his hands the instrument for the destruction of the Ptolemaic
universe. But Galileo also knew that anyone else with a telescope and the idea to look at
Venus (e.g. Castelli) could scoop him. By Dec. of 1610, Venus had waned to a half lit
phase and he could wait no longer. To gain some extra observing time Galileo published
his results (in a letter to Kepler I believe) in a Latin anagram that he promised to
unscramble later. Galileo's anagram was as follows.
"Haec immatura a me iam frustra leguntur o.y."
or "These are at present too young to be read by me"
By New Years Day of 1611 Venus had moved around to the near side of the sun, it's
crescent phase had begun to emerge, and Galileo unscrambled the anagram.
"Cynthiae figuras aemulatur mater amorum"
or "The mother of love imitates the shape of Cynthia"
In plain words Venus (the mother of love) manifests all the phases that the Moon
(Cynthia) goes through (and hence Venus must pass on both sides of the sun!!!).
Galileo's observation absolutely proved the Ptolemaic system wrong. In
subsequent years he published a full-blown refutation of the Ptolemaic system on many
fronts. The church was not at all happy with this, since it had long adopted the Ptolemaic
universe as part of it's dogma. Moreover, Galileo published in Italian, the language of the
people, rather than Latin, the language of the scholars, thereby presenting an even more
dangerous threat. The inquisition charged Galileo with "a vehement suspicion of heresy".
After being shown the instruments of torture Galileo was forced to recant his work. He
spent the last 9 years of his life under house arrest in his Villa near Florence, during
which time he continued scientific work and received many important visitors.
Galileo died in 1642 and was buried at church of Santa Croce (Florence) next to
Michaelangelo & Machiavelli. The epitaph he had placed on his tombstone was
"eppur Si muove" or "But the Earth does move!"
Galileo had the last word after all !
In 1983 the Church cleared Galileo's name and in 1992 the Church apologizes &
said it was wrong.
Footnotes:
[1] For more details see the "Galileo Affair" by O. Gingerich in Sci. Amer. (about 1981)
[2] Actually the Greek astronomer Aristarchus proposed the sun-centered solar system
about 280 B.C.. This allowed him to propose the explanation of the peculiar retrograde
(backward) motion that the planets appear to execute in the night sky due to the fact that
we are on a planet (earth), which is also in orbit about the sun. He also made estimates
of the relative sizes of and distances between the earth, sun and moon. Copernicus did a
very good job of putting the sun centered solar system together on a firmer quantative
basis, however one must wonder where we might have been if mankind had not taken a
2000 year earth-centered detour.