Introduction
Several hundred years ago, the vision of the universe in the scientific community was completely different. The current view of the Solar system was seen as impossible, while the idea that everything revolved around the Earth was considered accurate. However, for people in the sixteenth century, the debate over the correct planetary model was one of the most heated conflicts in the research and religious worlds. [The Ascent of Man 1974: 11:40].
Galileo Galilei’s experiments significantly contributed to this discussion, and his findings expanded on Copernicus’ predictions. Galileo’s commitment to supporting and improving upon the Copernican heliocentric model yielded much tension among scientists and the Church, and his views of religion, mathematics, and nature were revolutionary.
Convincing Observations
The Aristotelian view of the objects in the cosmos described them as perfect – the Moon, Sun, and other planets were heavenly, having no blemishes and revolving around the Earth. Galileo challenged this opinion by documenting cavities, ridges, and spots on the Moon, bringing up “the old Pythagorean opinion that the moon is like another earth.” [Galileo, The Starry Messenger, quoted from Drake 1610: 34] Galileo’s observations of the Medicean planets also opposed the idea that all bodies revolved around the Earth.
Looking at Jupiter, Galileo noted that its moons “sometimes follow and sometimes precede Jupiter by the same intervals… accompanying that planet in both its retrograde and direct movements.” [Galileo, The Starry Messenger, quoted from Drake 1610: 56‒57] Thus, not all objects moved around the Earth, as some revolved around other planets. Galileo likened this finding to the patterns of the Earth and the Moon, believing that “both [planets] run through a great orbit around the sun” [Galileo, The Starry Messenger, quoted from Drake 1610: 57]. Galileo deemed these findings convincing to support the heliocentric model of the planetary system.
Other significant discoveries included the illumination of Venus and sunspots. Looking at Venus through the telescope at different times, Galileo saw that the planet displayed different phases during its rotation. According to the geocentric model, Venus was always positioned between the Sun and the Earth, thus never wholly lighted. However, Galileo observed a fully illuminated Venus, meaning it could appear behind and before the Sun. This observation supported the idea that the Sun was at the center of the universe.
Similarly, Galileo discovered dark areas on the surface of the Sun. Galileo wrote that “the spots circled about” the Sun and noted the star’s movement around its axis. [Galileo, Letters on Sunspots, quoted from Drake 1613: 91] These points brought the Aristotelian view of heavenly bodies into question and later became a foundation for Galileo’s belief that the Sun’s movement related to the rotation of other planets.
Apart from his interest in the Solar system, Galileo also expressed great passion for exploring the Earth. In The Assayer, a discussion about the comets and a response to Orazio Grassi, he wrote that the book of nature was “written in the language of mathematics, and its characters are triangles, circles, and other geometric figures without which it is humanly impossible to understand a single word of it; without these, one wanders about in a dark labyrinth.” [Galileo, The Assayer, quoted from Drake 1623: 238] This statement implied that nature had a specific structure – a language – and understanding it could be a key to uncovering its secrets. Using mathematics, Galileo later studied such phenomena as the motion of objects and the velocity of the free-falling bodies. His experiments represented that mathematics allowed people to decode the concepts of nature.
Science and Religion
The traditional view of the Earth and its position on other bodies was primarily based on the Bible. Religious beliefs were that God created the world and the Earth was the center of all life. Therefore, one may understand why the heliocentric theory and similar discoveries were regarded as heresy. Statements that questioned the role of humans in the universe opposed contemporary Christian values and morals. However, Galileo’s vision did not disregard or criticize God’s presence and excellence.
In contrast, Galileo believed strongly that “God [was] the source of all things good.” [Galileo, The Starry Messenger, quoted from Drake 1610: 25] The sciences were “blessings which are sent to you not so much from the stars as from God, their Maker, and their Governor.” [Galileo, The Starry Messenger, quoted from Drake 1610: 26] In Galileo’s works, one can see that he regarded the world as God’s creation.
Based on his beliefs, Galileo could not think that science disagreed with religion. In The Assayer, he wrote about his respect for Nature and God, “I do not wish to be counted as an ignoramus and an ingrate toward Nature and God.” [Galileo, The Assayer, quoted from Drake 1623: 272] In his letter to Christina, a Grand Duchess interested in astronomy, Galileo argued against scientific discovery being an affront to God.
For instance, he suggested that the phrase from the Bible, “He had not yet made the earth, the rivers, and the hinges of the terrestrial orb,” could refer to the rotation of the Earth. [Galileo, Letter to the Grand Duchess Christina, quoted from Drake 1615: 216] Galileo’s perceptions of religion and science were not imbalanced, and his interpretation of the Bible supported his findings.
Letter to the Grand Duchess Christina
Galileo’s debates were known among those in power, some of whom wanted to know more about astronomy. One of them was the Great Dutchess Christina, to whom Galileo addressed his writing about the planetary system. Although many of Galileo’s opponents used Bible-based arguments, some of the philosophical and science-based opinions could be presented in a response letter:
Dear Grand Duchess Christina,
The claims made by Galileo Galilei object to the fundamental beliefs held by astronomers of today. Most educated people understand that the position of the Earth is in the center of the planetary system, while heavenly bodies revolve around it. The Earth is not made of aether; its surface is rugged and made of stone and water. Thus, it cannot stand in line with other perfect bodies and move around the Sun. The Earth takes its natural place in the geocentric model and is the center of gravity. Galileo’s writings fail to explain why each object dropped to the ground lands on Earth in the same spot. It does not float away toward the Sun or move through the air, thus disproving the rotation of the Earth and establishing it as the center of the universe.
Conclusion
Galileo’s experiments supporting the Copernican model presented a significant danger to the Roman Catholic Church as they challenged its authority over its interpretation of the Bible. His writings were not as dangerous as his use of telescopes and other equipment proving his hypotheses. Despite the arguments made by those who opposed Galileo, the world eventually moved forward toward the heliocentric model of the solar system.
As new technology was designed, people gained the ability to see the Solar system and discovered the vast universe beyond it. The Scientific Revolution was based on the developments and criticism of old knowledge. With time, the information about the planets overwhelmed the geocentric side’s arguments and supported the heliocentric theory in the following centuries.
References
Drake, Stillman, ed. Discoveries and Opinions of Galileo. New York, NY: Anchor Books, 1957.
Galilei, Galileo. The Assayer (1623). Quoted from [Drake1957: 229‒280].
—.Letter to the Grand Duchess Christina (1615). Quoted from[Drake 1957: 173‒216].
—.Letters on Sunspots (1613).” Quoted from [Drake 1957:87‒144].
—.The Starry Messenger (1610). Quoted from [Drake 1957:21‒58].
The Ascent of Man: 6 — The Starry Messenger. Directed by Adrian Malone. 1974. London: BBC-TV. 2023. Web.