Galileo and the Year of Astronomy

On Jan. 15 the United Nations Educational, Scientific and Cultural Organization officially launched the International Year of Astronomy 2009, in a ceremony at UNESCO headquarters, Paris.

Catherine Cesarsky, president of the International Astronomical Union, predicted that during IYA2009 “the citizens of the world will rediscover their places in the universe, and hear of the wondrous discoveries in the making.” Altogether, 136 countries, including the United States, are celebrating astronomy.

“The sky belongs to everybody,” said Koiichiro Matsuura, director-general of UNESCO, according to an agency web site. “Astronomy is an instrument to promote peace and understanding among nations and as such is at the heart of UNESCO’s mission.”

This year marks the 400th anniversary of Galileo Galilei’s first telescopic studies. The Florentine scientist did not invent the telescope nor did he even make the first scientific observations with the new instrument. An English scientist, Thomas Harriot, sketched the moon through a telescope a few months before Galileo did, but never published his work. Galileo not only published his observations of the moon, Venus, Jupiter, Saturn and sunspots, but he used them to deduce the fact that the planets revolve around the sun, which meant Earth was not the center of the Universe.

It’s ironic that Matsuura says astronomy is an instrument to promote peace and understanding. It was anything but that in Galileo’s day.

In 1616 a panel of theologians, following instructions of Pope Paul V, met to consider the twin pillars of the Copernican theory: that the sun is the center of the world and does not move, and that the Earth is not the center and does move. According to the excellent biography, “Galileo’s Daughter” by Dava Sobel, the panel voted unanimously that the notion that the sun is at the center was a heresy contradicting the Bible. The idea concerning the Earth was merely erroneous in faith, meaning it could lead one astray.

The contrary idea, amounting to official dogma at the time, was Aristotle’s absurd pronouncements that the Earth was the center of the universe and that all the heavenly spheres, including the sun, were perfect and revolved around it.

The moon was anything but an ideal sphere, Galileo discovered when he studied its mountains and valleys. The sun had spots that revolved across its face. The waxing and waning crescent that Venus showed proved it circled the sun. The Galilean satellites that went around Jupiter proved that heavenly bodies orbit each other. Galileo championed these ideas in his book “Dialogue on the Tides” but he was careful to couch the argument in terms of a discussion among proponents of different viewpoints. A character called Simplicius mouthed the official line; his name alone was enough to enrage papal authorities.

Galileo was tried by the Catholic Inquisition in 1633 and convicted of heresy for promoting what he had seen with his eyes and deduced with his mind. Fortunately, rather than being condemned to burn at the stake, he was allowed to repent on his knees, saying he cursed and detested his errors and heresies. He was forced to swear never again to speak or write about these things.

He was sentenced to house arrest for the rest of his life.

My wife Cory and I went to Europe in 2006 to catch a solar eclipse. On March 20 we saw a memorable religious relic.

In the Basilica of St. Anthony in Padua, Italy, the saint’s “vocal apparatus” (as the guide put it) was preserved. St. Anthony was famous for his powerful speaking, so his lower jaw, tongue and vocal cords were on display, still recognizable after 775 years. For believers, they are a treasured reminder of the saint.

Our group stopped the next day in Florence, Galileo’s city, during a heavy downpour. Others hurried off to famous museums like the magnificent Uffizi or to buy fine leather goods, but we had to tour the Science Museum. In its odd, somewhat disordered collections, we found Galileo’s handmade first telescope.

“It was a narrow tube, with a prominent bulge at the front for the objective. That lens was displayed separately, in a separate room, and was in an elaborate mount. Another objective may have been substituted on the telescope,” I noted in my journal. “By bending over beside the narrow case I was able to peer through the telescope, but at that distance only a speck of light came through the center.”

In the Science Museum we came upon a relic of science: Galileo’s preserved middle finger, bone with dark skin. It was inside a glass sphere that stood on a little pillar, protected by a glass case, and it was pointing straight up.

We paid homage to Galileo at the Basilica of Santa Croce in Florence. The fifth largest Franciscan church in the world, it held funerary monuments of Galileo, Dante Alighieri, Michelangelo and Gioacchino Rossini, though Dante is not actually buried there. Each monument had a sepulcher; Galileo is buried in a wall of the church and not in the polished sarcophagus above. The sarcophagus is topped by a beautiful marble statue of him.

I wrote that day, “I paid my respects to Galileo and was touched to see the telescope in his hand, in his portrait bust; I knew it would be there, but it was a different feeling to actually see his representation with the ‘scope.”

And so, this International Year of Astronomy, let us dedicate ourselves to discover the truth and glory of nature, and to take courage from the sacrifices of brave pioneers like Galileo.

May the spark of light that shone through his telescope continue to illuminate our minds.

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