The path of genius has not always been easy for those who walk it. When the work of the early modern astronomer and physicist Galileo Galilei threatened the very ordering of the cosmos, he made a very powerful enemy in the Catholic Church.
The scientist was deemed heretical by the Inquisition and subject to extended house arrest. But these efforts were unable to stem the tide of heliocentrism: the concept, now common knowledge, that the Earth rotates around the sun at the center of our solar system. With the use of a revolutionary telescope he built himself, Galileo was able to observe celestial bodies in new ways. His work contributed to a
Crafting an Early Telescope
Galileo grew up in Pisa in the Duchy of Florence. At the University of Pisa, he became interested in mathematics and physics. His work on pendulums and his invention of the thermoscope were early achievements. He taught geometry and astronomy to students at the Universities of Pisa and Padua. At this time, the heliocentric view of the universe was in circulation as it was postulated by Nicolaus Copernicus in 1543. This disrupted the long-established Ptolemaic system which was geocentric; however, it was still very much a matter for scientific and religious debate. The revolutionary, even heretical, idea had yet to be proven.
In 1608, Dutch spectacle makers Hans Lippershey and Zacharias Janssen, and Jacob Metius independently
Galileo Perfects His Spyglass
The Dutch versions and Galileo’s first attempt at a telescope possessed only a modest magnification power of 3X. However, by late 1609, Galileo had created a wood and leather
These early models had
Galileo’s telescopes were refracting telescopes. Here’s how they worked: a concave and convex lens were connected by a long tube. A viewing lens eyepiece on the end of the convex lens allowed someone to see the refracted image.
This setup allowed for some shocking discoveries. Peering through his telescope, Galileo discovered that the moon is not a perfect sphere, that Jupiter has moons,
The Church and the Galileo Affair
Refuting geocentrism was still a bold scientific and social move in the early 17th century. Church and science were intimately entwined at the time. Many supporters of geocentrism relied literally on Biblical verses referencing the movement of the sun. However, the church was also a patron of scientific investigation and many learned priests were interested in the heavens, math, and other topics. Galileo, a devout Catholic, was not intending to overthrow religion. However, the period from about 1610 to 1633 came to be known as the
By 1610, Galileo was actively defending heliocentrism in his correspondence and work. In 1615, a Dominican friar wrote to the Roman Inquisition complaining about Galileo’s controversial stance. After an investigation of these charges of heresy, Galileo was not found guilty (yet). However, the Inquisition under Pope Paul V declared that heliocentrism was scientifically and theoretically wrong and prohibited the entire theory. Copernicus’s Revolutions and other books promoting the theory were banned. Galileo himself was personally warned.
When Pope Urban VIII was elected, Galileo was in the papal good books. His work comparing the geocentric and heliocentric models—entitled Dialogue Concerning the Two Chief World Systems—was published in 1632 with papal and Inquisition approval. However, it appears the church did not anticipate the true impact of the work. Presented in contrast, the merits of the two theories were unequal, despite what historians agree was Galileo’s best efforts. Galileo found himself once more in front of the Inquisition which had authorized the book. This time he was found guilty of “suspected heresy” and denying scripture. Galileo, for his part, maintained he had not been a heliocentrist since its banning.
Galileo’s Paradigm-Shifting Legacy
Galileo lived the rest of his life under house arrest, and he worked on kinematics and material science. Meanwhile, his heliocentric theories and use of the telescope—along with the work by contemporaries such as Johannes Kepler—had furthered both the theory and the study of astronomy.
Galileo is considered a father of astronomy to this day. His works