Did Galileo Invent The Telescope?

Galileo Galilei

Galileo Galilei, the brilliant Italian scientist from the late 16th and early 17th century is widely believed to be the inventor of the telescope. But we are here to give you an opportunity to dazzle your friends at the next trivia night at your local when the question “Who invented the telescope” rears it’s ugly head. Contrary to popular belief Galileo did not invent the telescope. That distinction is held by a Dutch lensmaker by the name of Hans Lippershay who was the first to apply for a patent on the telescope in 1608. However the first telescopes were very limited, offering only about 3 times magnification. Here is where Galileo comes in.

Paolo Sarpi, a friend of Galileos from his time at Pisa University had heard of the telescope and informed Galileo, who also learned of the arrival in July of a foreigner in Padua who had brought the device to Italy to try and sell it to the Venetian government. After failing to see the device for himself, Galileo quickly set out to make his own, which he quickly succeeded in doing. Meanwhile Paolo Sarti had been asked by the Venetian Government, to assess whether they should purchase the telescope from the foreinger. Galileo sent word of his success in making his own device, then quickly set out to improve on his design. Sarpi discouraged the Venetian government from buying the foreign device and Galileo arrived in Venice in August with his own improved device 3 times more powerful than the foreign device. Needless to say, the Venetian government was thrilled and Galileo was now famous and free of financial difficulty.

Galileo’s Telescope

Galileo continued to develop his telescope throughout 1609, quickly ramping up the power to about 30 times magnification. This turned out to be the maximum for a device of this design, with a Plano convex objective and a Plano concave eyepiece. He turned his improved device toward the skies with explosive results, making a series of groundbreaking discoveries that challenged the prevailing geocentric model of the universe and supported the Copernican heliocentric theory.

In late 1609 his telescope also revealed the Moon's surface was not smooth, as previously thought. Though he was not the first person to view the moon through a telescope, he was the first to deduce the uneven waning of light was caused by mountains, craters, and valleys. This challenged the Aristotelian view of celestial perfection and immutability.

In January 1610, Galileo discovered what he thought to be fixed stars, spread in a line close to Jupiter. Further observations revealed they were four large moons orbiting Jupiter: Io, Europa, Ganymede, and Callisto. This was the first time celestial bodies were observed orbiting another planet.

His observations of Venus revealed a full set of phases similar to the Moon, ranging from crescent to gibbous. This observation was inconsistent with the Ptolemaic geocentric model, which had Venus orbiting entirely on the near face of the sun and would therefore only reveal only crescent and new faces. but aligned with the Copernican heliocentric model, which posited that Venus orbits the Sun.

Galileo observed dark spots on the Sun, known as sunspots, which demonstrated that the Sun's surface was not perfect and unchanging. Their existence raised another difficulty with the suggested unchanging perfection of the heavens in the orthodox Aristotlean view adopted by the church. He also noted that these spots moved, suggesting that the Sun rotated on its axis.

Prior to Galileos observations of the Milky Way, it was believed to be nebulous, a cloud or haze. Galileo’s telescope revealed that the Milky Way was composed of a vast number of individual stars, previously unresolved by the naked eye. He also observed many more stars in the night sky than were visible without a telescope.

His finding were published in his book Sidereus Nuncius bringing him great fame and leading him to become Mathematician and Philosopher to the Grand Duke of Tuscany.

Galileo Faces The Roman Inquisition

As startling as his observations were, they ultimately caused him a great deal of trouble with the Catholic church who endorsed the geocentric model and believed that any attempt to “reinterpret” the bible to reflect the heliocentric model would be considered heresy.  Attacks against Galileo and his followers were appearing in ecclesiastical quarters and Galileo was ultimately required to defend his views in the Roman inquisition. Though he was never formally charged with heresy, he was tried and found "vehemently suspect of heresy" by the Roman inquisition. He was forced to recant his views and spent the remainder of his life under house arrest.

Galileo's work with the telescope revolutionised astronomy and our understanding of the universe. His discoveries demonstrated the power of scientific inquiry and the importance of challenging established beliefs with empirical evidence, an approach that led him to be regarded as the father of observational astronomy, the scientific method, and modern science.
In Series 3 Episode Kennardley finds out about the life of Galileo. Click below to listen.

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