Date: December 11, 2010

Title: The Mother of Love Imitates Cynthia’s Shapes

Podcaster: Mark Thompson

Description: Another glimpse into the past– 400 years ago Galileo began sending alphabet puzzles in the form of confusing anagrams to announce his telescope discoveries. This one, sent 400 years ago to the day, to Johannes Kepler announces for the first time that Venus has phases, which we can see very clearly in the morning hours this December.

Bio: Galileo 1610 is a living history production; a dramatic, musical and comical odyssey back to the life and times of Galileo Galilei, the famous 17th century Italian scientist and philosopher. It commemorates the 400th anniversary of Galileo’s discoveries with his telescope in 1610.

Today’s sponsor: This episode of “365 Days of Astronomy” is sponsored by Lorenzo Rota on behalf of his wife Lynette Rota. Happy Birthday Netty! This is for all the times that you call every month’s full moon the Harvest moon, …and for giggling with me every time we hear the theme song for this podcast.

Transcript:

If you are an early riser and can bear the chill of winter, step outside at dawn and look well above the southeastern horizon. Be dazzled by the immensely bright Venus at magnitude -4.9. If you happen to have a telescope, even the lowest power will reveal Venus’s widening crescent shape as it moves toward its greatest elongation from the Sun next month. You might find it interesting to know that four hundred years ago, nearly to the day, Galileo Galilei sent a letter from Italy, in Latin, to his contemporary Johannes Kepler in Germany, in which he revealed a very strange message about the planet Venus in the form of an anagram that read:

“Haec immatura a me jam frustra leguntur oy”

Which may have sounded to Kepler something like: “this was already tried by me in vain too early.” How true. Indeed, Kepler was still reeling from Galileo’s earlier similarly indecipherable message about Saturn, received just a few months before, which read something like: ”Be greeted, double knob, children of Mars”—which really meant: “ I have observed the highest of the planets three-formed”—which would certainly be confusing to us as well, since we have the benefit of knowing that Saturn, to the contrary, is not three-bodied, but ringed—but Galileo didn’t know this. His fledgling perspicillum could never resolve those rings.

Nevertheless, whether out of caution, vanity or fear of jealousy, Galileo had the infuriating habit of not announcing his discoveries openly and clearly. Rather he disguised them in alphabetic puzzles. Just a few weeks after Galileo’s revelation that Saturn had appendages which looked like ears, he began to observe Venus in October of 1610 with his 24-power telescope. But then, Venus was in a kind of reverse phase of what we see today, 400 years later. When Galileo first began studying Venus with his telescope, it was round and full, but distant. Then, as it rose in the sky, it grew in size until it began to lose its roundness on the eastern side. And by mid-December, 1610 , Venus had been reduced to a half circle, as it will appear to us at the end of this month.

The phases of Venus are of course well-known to us. But in Galileo’s day—this information was, well, heaven- shattering, and this brings us back to Galileo’s anagram to Kepler which when the letters of the alphabet were properly configured was intended to read:

“Cynthia figures aemulatur mater amorum”—or “The Mother of Love imitates Cynthia’s shapes.” Quite literally, the phases of the moon are imitated by Venus.

And in December, 1610, when Venus was observed as a half-circle, Galileo noted in a letter to his faithful friend Castelli, “In that shape, it has stayed many days, but always growing in size. Now it begins to become sickle-shaped. In the evening, it will continue to thin its little horns until they vanish. But then return in the mornings and be seen with horns thin, turned away from the Sun and will grow toward a half-circle until maximum elongation.”

And this, dear listeners, describes precisely what we shall have as the New Year commences.

Scholars debate whether Galileo, in December 1610, with his observations of Venus was finally convinced that the Copernican doctrine was indeed fact, but there can be no doubt Galileo was finally persuaded that Venus revolved around the sun and not around the earth. And that pretty much nailed the coffin on the 2,000 year-old geocentric theories of Aristotle and Ptolemy.

End of podcast:

365 Days of Astronomy
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