Harold Kroto Harold Kroto Harold Kroto Watercolors by

Harold Kroto

Watercolors by Galileo Galilei, from Sidereus Nuncius, Venice, 1610 Biblioteca Nazionale Centrale, Florence Harold Kroto

Celebrating Galileo in Florence by Judith Harris March 22 nd, 2009 at 10: 39 pm Ottavio Leoni, Portrait of Galileo Galilei, 1624 Drawing in black stone, white lead and red ochre on turquoise paper Marucelliana Library, Florence ROME – 2009 is officially “The Year of Astronomy, ” commemorating Galilei’s first observation of the Moon through his telescope in November of 1609. Born in Pisa, Galileo Galilei worked in Florence, where the fourth centennial of his discovery is being celebrated with a stunning and sophisticated exhibition which took four years to prepare. Galileo, Images of the Universe from Antiquity to the Telescope illustrates the unity of the two cultures, science and art, for millennia. It also shows how astrology acquired a theological cast before evolving into astronomy, even as it bequeathed us the daily newspaper’s horoscope (“love and money await you”). For centuries Venetian glass factories had been grinding lenses “to improve vision, ” to quote Roger Bacon in 1249. By Galileo’s day two low-grade lenses, inserted at either end of a cardboard tube, were being sold as a child’s toy in Venice and elsewhere in Europe. Nevertheless, questions which seemed eternal puzzled people everywhere: What held up the sky? How much does the sky weigh? Harold Kroto

Celebrating Galileo in Florence An answer came close in October of 1608 when a lens maker in the Netherlands named Hans Lipperhey applied for a patent on a spyglass. This had military importance because it could enable enemy ships to be spotted at a distance, allowing more time to prepare a defense, and so foreign envoys sped the news to their home countries throughout Europe. The following year English mathematician Thomas Harriot became probably the first to point such a device, armed with lenses to the power of six, at the Moon and then make drawings of what he saw. Peering into one of the toy devices while visiting Venice in the summer of 1609, Galileo, in his early forties and a little known professor of mathematics, saw that buildings on the horizon were magnified. A Venetian friend, Fra Paolo Sarpi, then told him of Lipperhey’s invention. Grasping the possibilities, Galileo ordered the best quality lenses Venice could offer, only to discover that all those available were inadequate. Even Lipperhey’s spyglass increased the power of the eye by at most three times. Electing to learn to grind and polish the lenses himself, in the course of a scant few months Galileo “bought the appropriate equipment and slowly trained himself, ” according to historian Albert Van Helden of Rice University, in an essay in the excellently translated exhibition catalogue. Harold Kroto

Celebrating Galileo in Florence Galileo’s Telescope Throughout the autumn months Galileo worked at his lenses, first creating one to the power of six and then improving it until he achieved lenses to the power of twenty. At that point in the depths of the winter of 1610 he trained upon the Moon his long and narrow telescope—a telescope covered like the gold-tooled leather souvenir notebooks and bookends sold in Florence today. In so doing he became the first to see the Moon accurately. Watercolors by Galileo Galilei, from Sidereus Nuncius, Venice, 1610 Biblioteca Nazionale Centrale, Florence A talented water-colorist, Galileo painted what he saw of the Moon in its various phases—and then moved on to show the existence of hitherto unknown sunspots as well as moons circling Saturn. While he was at it, he toppled millennia of philosophical and theological speculation, for his research proved that the Earth moved around the Sun rather than the opposite, as was conventional religious teaching. Harold Kroto

Celebrating Galileo in Florence “Galileo was perfectly aware of the epochal implications of the phenomena that he, first among men, had observed on those sleepless nights four centuries ago, ” says Paolo Galluzzi, director of the Florentine Museum of Science History and prime mover of the exhibition. The Church objected, and in 1633 Galileo was put on trial before an Inquisition court that met, incidentally, in a building a few steps from where I am writing this in Rome; the observatory of the Collegio Romano, where he had lectured, is visible from my window. He was forced to abjure and on grounds of “vehement suspicion of heresy” and sentenced to house arrest at Arcetri near Florence for the rest of his life. He was also forbidden to conduct further experiments that could challenge theological status quo. calitreview. com Harold Kroto

image at: galileotelescope. org/ Harold Kroto

image at: www. imss. fi. it/news/eshuttle. html Harold Kroto

http: //www. exo. net/~pauld/workshops/Galileoscope/Galileo. html Harold Kroto

Galileo "It Moves" Introduction Galileo used his telescope to examine the heavens. He recorded his observations as drawings in his notebook. If you own a 25 power telescope like the Galileoscope you can repeat his observations. Let's take a look at what he found, and compare them to more modern images taken by modern telescopes. The Moon Galileo saw that the moon was not a perfect sphere, by looking at the moon at different phases he could use shadows to see that the moon had mountains and the Mare had craters. More recently Lick Observatory used its "Great Refractor" to take images of the moon at first and third quarter, then they stitched the images together to highlight the ruggedness of the moon. The Great Refractor has an objective lens 0. 9 m in diameter, it is 58 feet long, and was built at the end of the 1800 s. Moon through Galileoscope http: //www. youtube. com/watch? v=8 b. PUvsg. CEn. U Moon motion over a month http: //www. astro. washington. edu/IYA/lunar_librations. html You can see the great refractor in a gigapan image here, or drive up to Lick Observatory above San Jose California and take a tour. Jupiter Galileo discovered that Jupiter had 4 moons. The moons obviously orbited Jupiter, this showed that not everything in the heavens orbited the earth. Harold Kroto

Harold Kroto

Jupiter's moons in motion, timelapse video http: //www. youtube. com/watch? v=Ss. WMa. AF 0 km. U The "Great Refractor" was used to discover a fifth moon of Jupiter, Amalthea. Venus Galileo saw that Venus had phases. The phases of Venus can be explained if Venus orbits the sun. At the top left is the drawing of Saturn " a planet with ears" done by Galileo. Sun Don't look at the sun with a telescope! Galileo did look at the sun with a low power, low light collecting telescope at sunset when the earth's atmosphere acted as a filter. He saw sunspots and was not blinded. Let me repeat however, never look at the sun with a telescope. (OK you can look if you know what you are doing and have appropriate solar filters. ) Harold Kroto

Possibly the most compelling argument Galileo made in favor of the Heliocentric Universe of Copernicus was based on the observations of Venus. Galileo observed the phases of Venus throughout the year. At times Venus presented a small but circular disk and at other times a large crescent. Based on these facts as illustrated in his drawings in Sidereus Nuncius, Galileo reasoned that Venus must orbit the Sun; proof of the Copernican Universe. Harold Kroto

http: //www. telescope 1609. com/Galileo. htm Harold Kroto

Above, the Nebula of Orion (left) and the Nebula of Praesepe (right). Below, Galileo's depiction of the stars in the belt and sword of Orion Harold Kroto

History http: //en. wikipedia. org/wiki/File: Phases-of-Venus. svg Diagram of the orbit of Venus in relationship to the Earth. The first known observations of the full planetary phases of Venus were by Galileo at the end of 1610 (though not published until 1613). Using a telescope, Galileo was able to observe Venus going through a full set of phases, something prohibited by the Ptolemaic system (which would never allow Venus to be fully lit from the perspective of the Earth or more than semi-circular). This observation essentially ruled out the Ptolemaic system, and was compatible only with the Copernican system and the Tychonic system and other geoheliocentric models such as the Capellan and Riccioli's extended Capellan model. Harold Kroto

Harold Kroto