When the news of Lipperhey’s invention reached Galileo Galilei (1564-1642), an Italian scholar, the latter built his own instrument. According to one report, Galileo completed the construction of his telescope in 1608 itself. He is also reported to have effectively prevented Lipperhey from gaining a foothold in Venice and won the support of the Venetian senate for his own ‘spy glasses.’ As lipperhey gave a telescope to his princes, Galileo fashioned his own tube and presented it to his ruler, Leonardo Dona of Venice .initially, Galileo demonstrated how distant objects on land appeared closer. Soon he made his first effective use of the telescope to look at the sky in 1609.
The United Nations declared 2009 as the International Year of Astronomy (IYA) to celebrate the first astronomical use of the telescope by Galileo.
Galileo: An Icon of Experimental Science
Though Galileo did not invent the telescope, he developed one without actually looking at any model. he is reported to have made 100 telescopes, ten of which were quite good. some of his instruments could magnify objects 30 times. It was a boon to traders, who could then spot their ships of merchandise, hours before their arrival. in a brilliant act of public relations, he named Jupiter’s moons after the Medici family, as he had applied for a position of a mathematician to their court.
His instrument, now known as the Refractor telescope, was 98 cm long and had two lenses. A primary convex spherical lens collected and concentrated the light and a concave eyepiece made the rays parallel again. he used his knowledge of mathematics to calculate the correct distance between the lenses, he found that the magnification in his telescope was proportional to the ratio of the power of the concave (more distant) lens.however, the spherical lens the used caused chromatic aberrations, as different colors of light focused at different points while going through a glass lens .nevertheless, it was a historic achievement.
Using his telescope, Galileo saw the craters of the moon , sun spots, solar rotation, the moons of Jupiter, Saturn’s rings and the phases of Venus. he demonstrated that the Milky Way is composed of stars. (an Englishman, Thomas Harriot reportedly sketched a lunar map, a few months ahead of Galileo, using a telescope ,but did not publish it.) in a pamphlet entitled Siderius Nuncios (starry messenger) written for the common people in Italian rather than Latin. Galileo described the shadows cast by lunar mountains and craters. The pamphlet, written in 1610, triggered an onslaught on the feudal order of the old universe with a new weapon of discovery: the telescope .it was a novelty that demolished the Aristotle’s geo-centric concept of the universe.
It is the interesting to recall that even before he used a telescope, Galileo was attracted to the heliocentric theory of Copernicus .in 1597 ,when he was only 33, Galileo wrote to Kepler,” many years ago I become a convert to the opinions of Copernicus , our teacher of immortal fame to some, through rejected by many”, in 1613, Galileo wrote in support of Copernicus. The Italian professor was warned by the inquisitors in Rome not to defend Copernicus but after years of observation and calculation, he wrote his masterpiece, Dialogue on the Two World System only to conclude that Copernicus was logically superior .
The Italian astronomer famously stated that the church could preach to people on how to go to heaven, but pleaded that he be allowed to describe how the heavens moved! The church would have none of it even though he was aided by telescopes. He was called to Rome in 1633 to face the inquisition for the second time.
He was found guilty of heresy and disobedience and sentenced to life imprisonment. Even after he recanted his views, he is reported to have murmured, ”And still it (the earth) moves”!
In view of his old age, he was put under house arrest. However, he continued his scientific studies and produced yet another master piece, this time on the theory of motion. he eventually went blind. Twenty years after his death, he was given the unique honor of a burial in the famous Basilica di Santa Croce in Florence. a beautiful statue in the basilica brings out his scholarly look, despite being blind.
Shortly after Galileo was found guilty of heresy, a famous artist, Bernhard stoozi showed his opposition (in 1635) to the church by painting Eratosthenes, the Greek scholar, teaching in Alexandria. Erasosthences, admired for his amazingly accurate measurement of the earth’s circumference, inspired Copernicus. The painting (now in a Canadian museum) is a celebration of reason prevailing over prejudice, frozen in brilliant colours for ever.
It is only in recent years that the church revised its view on Galileo. In 1979, Pope John Paul II declared that the church had made a mistake in condemning Galileo and appointed a commission of inquiry. In 1992, the Pope endorsed the finding of the commission that the church had indeed committed a mistake in condemning Galileo.
Galileo’s middle finger of his right hand, taken out after his death, has been preserved and kept on display at the Museo Di Storia Del la Scienza in Florence along with his instruments, as if pointing a finger at the blind orthodoxy that still prevails in the world. There are still some people even in the so-called advanced countries, who do not think that the earth around the sun!