Galileo Galilei (15 February 1564 – 8 January 1642) was an Italian physicist, mathematician, astronomer, and philosopher who played a major role in the Scientific Revolution. His achievements include improvements to the telescope and consequent astronomical observations, and support for Copernicanism. The motion of uniformly accelerated objects, taught in nearly all high school and introductory college physics courses, was studied by Galileo as the subject of kinematics. His contributions to observational astronomy include the telescopic confirmation of the phases of Venus, the discovery of the four largest satellites of Jupiter, named the Galilean moons in his honour, and the observation and analysis of sunspots. Galileo also worked in applied science and technology, improving compass design.
Galileo's championing of Copernicanism (within the pages of Dialogue Concerning the Two Chief World Systems) was controversial within his lifetime. The geocentric view had been dominant since the time of Aristotle, and the controversy engendered by Galileo's presentation of heliocentrism as proven fact resulted in the Catholic Church's prohibiting its advocacy as empirically proven fact, because it was not empirically proven at the time and was contrary to the literal meaning of Scripture. Galileo was eventually forced to recant his heliocentrism and spent the last years of his life under house arrest on orders of the Roman Inquisition.
Galileo Galilei in A World of Difference
With the help of his telescope, Galileo Galilei produced the first detailed map of Minerva. This was reckoned among the main achievements of Galileo's career, and was considered as the beginning of scientific research of this planet.
Galileo Galilei in "But It Does Move"
In 1633 Galileo Galilei was a prisoner of the Inquisition in Rome. Although he'd been investigated by the Inquisition in his native Florence, Pope Urban VIII decided that more thorough investigations should be done in Rome. Galileo had been interrogated by ten different cardinals before he was sent before Cardinal Sigismondo Gioioso, who questioned him using a different approach that he called "an analysis".
Galileo had been quite proud of his Dialogue Concerning the Two Chief World Systems, and had gone out of his way to make sure he had the approval of the Inquisition before publishing it. Unfortunately, Galileo did not present a balanced examination of the Copernican and Ptolemaic views. His protests to the contrary, Galileo, based on his observations via telescope, concluded that the Copernican view was correct, and made that conclusion plain in the Dialogue. Thus, in 1633 Galileo was summoned to Rome for investigation.
Cardinal Gioioso's approach puzzled Galileo. The Cardinal shared wine and cakes with Galileo before their first meeting, and allowed Galileo to lay on a couch while answering questions. After some brief discussion of the Dialogue, Gioioso questioned Galileo about his mother and his father, and suggested that Galileo resented his father's initial attempts to steer him away from music and mathematics. Galileo denied such anger. He also denied that in his youth he'd wished his father had been removed so as to have the full attention of his mother. At the end of the first session, the Cardinal gave Galileo the choice of continuing their conversations. While Galileo realized that Gioioso was being sincere in giving him the choice, Galileo felt that the Inquisition really left him no choice. At the very minimum, participating in "analysis" with Gioioso would insure that the Inquisition could not inflict harm upon Galileo, so he agreed to continue.
The Cardinal's questions brought forth several memories from Galileo's youth. Gioioso explained that this was necessary to get at the heart of Galileo's decision-making processes as an adult, particularly his decision to produce the Dialogue. To further pursue the analysis, Galileo agreed to a stipulation that he was a "hypothetical" supporter of the Copernican view. As Gioioso presented the agreement in writing, Galileo felt comfortable with this line of thought.
With this task done, Giosioso asked Galileo why the Copernican method was important to him. Galileo explained that the Copernican view better and more accurately explained observable astronomical events. For example, the difference in time each system reckoned the rise of the Sun and Moon was in fact two minutes. Gioioso was horrified that Galileo was ready to overturn the Church for a mere two-minutes, but Galileo assured Gioioso that improvements in technology (such as clocks) would reveal the error soon enough. Gioioso asked Galileo if the usefulness of the Copernican method would be worth the chaos its adoption would create in the Church and the world at large. Galileo reluctantly admitted that he had not thought of that. The session concluded after Gioioso harkened back to Adam and Eve, and the consequences of their thoughtless action.
The next day, the stipulation still in force, Galileo explained how the Copernican model actually accounted for the movements of the planet Venus. Gioioso was quick to point out that Galileo's observations were made possible by improvements in the telescope. He lamented how Catholicism (and indeed all religions) would now be vulnerable. When Gioioso refused an explanation as to why the Copernican method even explained the events of the Book of Joshua (wherein the Sun stopped in the sky) as a layman's interference, Galileo angrily decried the Church's interference in his business as an astronomer. To Galileo's surprise, the Cardinal was not angry, but intently questioned Galilieo why he was angry. Realizing that Gioioso viewed him in the same way he viewed astronomical bodies, Galileo admitted that the Church's actions were similar to those of his father's, which he described as "stubborn, wrong-headed" interference.
Gioioso then asked how Galileo was any less stubborn. When Galileo angrily stated that he'd been pushed by the Church all along, Gioioso instead suggested that Galileo had pushed first in his effort to retaliate against his father, that he was projecting his feelings for his late father onto the Church. Galileo conceded he had some disdain for his father, but it was still the Church who had summoned him and subjected him to investigation.
Gioioso then tried a different tact. He asked Galileo if he expected the Inquisition to react as it had. Galileo acknowledged he expected a response, but as he had had the Church's imprimatur before he published the Dialogue, he certainly did not expect the response he got. The Cardinal suggested that Galileo's actions were consistent with someone who wanted the Church's response. Galileo could not accept this, as he did not consciously want the Church to respond as it had. Gioioso replied that subconscious desire did exist, and all men wanted attention.
Galileo once again lamented the Church's interference in astronomy, but praised Gioioso's own explorations of the human spirit. He also found himself lamenting the fact that, despite the observations he'd made, and the works he'd published, he received nothing but criticism. Gioioso again suggested that the Dialogue was an act of defiance and projection, and pleaded with Galileo to realize the damage he was doing to the Church. Galileo acknowledged Gioioso's point, and the session ended.
Galileo returned the following day, and further discussed with Gioioso why he preferred the Copernican model. He cited the example of the moons of Jupiter. That they existed at all showed that the earth could not be the center of the universe. Again, Gioioso asked whether Galileo's pursuit of "truth" was worth the chaos it created when it conflicted with Scripture. Gioioso referred to the immense upheaval that the continent had seen just from the Protestant Reformation. Gioioso argued that to the average person, Venus's orbit and the moons of Jupiter were irrelevant, as he could not see them when all was said and done. But Galileo's insistence in pointing out these "facts" had the consequence of eroding faith in the Church. Pointedly, Gioioso asked if Galileo had honestly been working towards peace and unity when he published the Dialogue. Looking within himself, Galileo conceded he had not been.
Galileo was sentenced by Cardinal Guido Bentivoglio. However, Galileo accepted his sentence, which included abjuration. While Galileo was prepared to abjure all along, he did so with more faith and sincerity after meeting with Gioioso. While he did state "But it does move" to himself, he readily responded "But so what?"
- References to Historical Figures in Turtledove's Work for minor references.
- Galileo Galilei at the Eric Flint Wiki
- Nicolaus Copernicus, a 16th-century astronomer who inspired much of Galileo's research.
- Unnamed Helmandi astronomer, a character in Noninterference who makes similar discoveries about her planet's sun.
- A World of Difference, p. 4.