Galileo Galilei: A Career in Free Fall

Galileo’s career started in a monastery in Florence; but his father saw a doctor in him. Defying his father, he studied mathematics instead and made his first invention at 22. At 25, he was lecturing at the University of Pisa and building high class musical instruments.

This still left him time to do experiments galore. He invented at that time a thermometer, not a very exact one but still a working item. Through his involvement in fortifications and ballistics, he became interested in the movement of bodies and especially in free fall. In the 4th century BC, Aristotle had formulated the theorem that heavy objects fall to earth faster than light ones. Like many other Aristotelian theories, this one was made an irrevocable law by the Christians without trying or proving it, as usual.

Galileo’s experiments show that Aristotle was wrong. As time keeping was out of reach, he did tests on an inclined plane. This allowed him to measure the speed of a slowly accelerating sphere. He was thereby the first to find the distinction between speed and acceleration in modern times. It led to his law of falling bodies in a vacuum which would be improved upon by Isaac Newton. His description of the experiments he conducted is an early guideline on how to communicate experimental settings to make them replicable by others. Something modern ‘science’ has forgotten how to do in favour of monetary greed.

Presenting his results to his colleagues in Pisa meant challenging Aristotle; his presentation was ridiculed by the kindly and outright rejected by most. His welcome in Pisa had come to an end and his contract as a lecturer was not prolonged. In the eyes of the establishment, he had not only committed a scientific solecism, he had committed an outright crime against science and the church.

Meanwhile, Galileo had established himself with several high placed admirers and acquired powerful protectors; he was offered the chair of professor for mathematics in Padua due to their intervention. Giordano Bruno had expected to be called to that post. The pay was definitely better than in Pisa, but Galileo still gave paid exclusive lectures for a select circle of people. He also presented and sold a precursor to the slide rule called a compass. To that end he employed a full time mechanical engineer in production.

In Padua, he started to get interested in astronomy and cosmology. In a letter to Johannes Kepler in 1597, he expressed his tendency towards the heliocentric theory of Nicholas Copernicus. At the same time, he was completely unimpressed by the writings of Tycho Brahe on comets. He missed the point of Brahe’s discovery completely, calling comets ‘ape stars’.