June 22, 1633 – Galileo Recants his Heliocentric Theory

On this day in engineering history, the Holy Office in Rome forced Galileo Galilei to recant his scientific view that the Sun, not the Earth, is the center of the universe. The heliocentric theory of the solar system was first forumalted by Nicolaus Copernicus, a Polish astronomer who refuted the geocentric models of Greek scholars Ptolemy and Aristotle.

Galileo Galilei first argued for the Copernican, sun-centric view of the universe in 1610 after observing the moons of Jupiter. At the time, the dominant view was still an earth-centric, Ptolemaic and Aristotelian theory. In 1612, opposition grew for a heliocentric view of the solar system. Two years later, Galileo was denounced by a Catholic priest who described his beliefs as dangerous and close to heresy. Galileo went to Rome to defend himself, but was warned never to teach nor advocate Copernican theory again.

In October of 1632, Galileo Galilei published Dialogue Concerning the Two Chief World Systems, a work which compared the Copernican system to the traditional Ptolemaic system. Upon publication, Galileo was ordered to appear before the Holy Office in Rome. In 1633, he was ordered to stand trial on suspicion of heresy. On the morning of June 22, the Inquisition, a Church tribunal which suppressed heresy, delivered its public sentence in three essential parts:

• Galileo was required to recant his sun-centric ideas
• He was ordered to be imprisoned
• His offending Dialogue was banned.

Galileo Galilei died from natural causes on January 8, 1642 while under house arrest. Although an unannounced part of his sentence prohibited the publication of his past or future works, he dedicated his final years to one of his finest works, Two New Sciences, a book which later earned him the title of "father of modern physics."

Resources:

http://www.law.umkc.edu/faculty/projects/ftrials/galileo/galileoaccount.html

http://en.wikipedia.org/wiki/Galileo_Galilei