Galilean Advances to 16th-17th Century Science


Galileo Galilei, an astronomer, physicist, and philosopher of the 16th and 17th centuries is credited with the discovery of several scientific instruments and phenomena that contribute further to the understanding of modern science. At the time in Italy, even when religion was dominant, he was one of the primary proponents of scientific innovation over religion. The Church regularly questions his motives and his findings, especially those regarding heliocentrism as opposed to geocentrism. Towards the latter part of his life, Galileo was forced to stay silent about his scientific theories, to allow the Church to remain dominant. The church under the emperor\’s tutelage learned to serve by formulating their faith for the masses. Hence, great councils of early Christianity.

Invention of the Telescope:

In 1609, Galileo set out to improve primitive versions of the telescope in order to examine planets and stars with further accuracy. Galileo manufactured this telescope by using two lenses, one to create the shape of a distant object, and another to make that object look larger to the human eye. As a result of the reflection of light across each lens, the image appears to be upside down when viewed on the Galilean telescope. Galileo went on to use this telescope to discover various moons of Jupiter and the phases of Venus, being one of the initial pioneers in this field. Further improvements were made to this rudimentary telescope in order to allow for a greater focus, higher clarity, and the ability to see objects at a greater distance.

Fig. 1: A diagram displaying how light reflects through each lens and eventually to the eye in a Galilean telescope.


Nicholas Copernicus was the first to propose the heliocentric model of the solar system, where the sun is in the center and all the planets revolve around it, and Galileo was a vocal proponent of this model.[5] At the time (the early 17th century), however, the Church believed in the Aristotalian geocentric model of the solar system, where all celestial bodies revolve around the Earth. Corroborating Copernicus’s findings with his telescope, Galileo wrote a letter to a friend named Bendetto Castelli in 1613 which stated that religious and scientific matters should be separated.[5] As word of Galileo’s stance against the Church spread, and the publishing of a book about Heliocentrism by Galileo, he was called into question by the Church.[5] Unfortunately, the Church convicted Galileo of heresy following a trial, banned his book, and later sentenced him to house arrest.[5] Much of Galileo’s stance on the subject of heliocentrism was revealed by the letter he wrote to Castelli, and more about this is still being investigated today.[5]


However controversial Galileo Galilei seemed to be in Italy during the 16th-17th centuries, today he is considered one of the greatest scientific minds at the time. The discovery of the telescope and his contributions to the theory of heliocentrism are vital in modern day astronomy and physics, and have led scientists to further discoveries in the solar system. In addition, his opposition of the Church displayed his sheer confidence in his findings and in science, which is another aspect that persists for several scientists in the modern day.


  1. Machamer, Peter. \”Galileo Galilei.\” Stanford Encyclopedia of Philosophy. May 10, 2017. Accessed February 13, 2021.
  2. Royal Museums Greenwich. \”What Did Galileo Discover?\” Royal Museums Greenwich. August 27, 2020. Accessed February 13, 2021.
  3. Hurley, Steve. \”Galileo and the Telescope.\” Explaining Science. November 22, 2020. Accessed February 13, 2021.
  4. Nave, C. R. \”The Astronomical Telescope.\” Refractive Telescopes. 2016. Accessed February 13, 2021.
  5. Abbott, Alison. \”Discovery of Galileo\’s Long-lost Letter Shows He Edited His Heretical Ideas to Fool the Inquisition.\” Nature News. September 21, 2018. Accessed February 13, 2021.

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