Mechanics, Planetary Motion and the Modern Science Revolution 51
that he left behind. It was his observations as we shall see later that
served as the experimental basis of Kepler’s great work.
The Contribution of Galileo Galilei
The importance of Brahe’s observational work cannot be under-
estimated. But it is to Galileo Galilei that we owe our greatest debt of
appreciation for the development of the experimental technique, which
so revolutionized physics. Various influences have been suggested to
explain this development by Galileo. Among these the art of alchemy is
often cited. There is little doubt of its influence in the development of
experimental technique particularly in the field of chemistry. It is also
claimed that artists, who, like Leonardo da Vinci, were scientifically
oriented, provided stimulus to the development of experimental
technique. Artists used experimental methods in developing the technical
aspects of their art such as the manufacture of their pigments. Perhaps
more important was the development of perspective by the painters of
the Renaissance. Their approach to this problem was experimental in
a true fashion and, no doubt, provided a model for physics. Perhaps
the greatest influence of all was the widespread interest during the
Renaissance for technical and mechanical devices. Galileo, an inventor,
developed a number of these devices himself. Some of these such as the
geometric and military compass, the pulsilogium, a device to measure
the human pulse, the magnetic compass and the pendulum regulator of a
clock work were developed for practical applications, whereas others
served as instruments in his experimental work such as the telescope, the
microscope, the pendulum, the thermoscope (a thermometer without
a scale) and the giovilabio, a device which computed distances and
periods of Jupiter’s satellites.
Galileo did a number of experiments investigating the nature
of motion by using pendulums and inclined planes. Through his
experimentation he discovered that aside from air resistance all bodies
accelerate uniformly when falling to Earth. Apparently the famous story
that he made this discovery by dropping objects from the Leaning Tower
of Pisa is a myth. The actual discovery was made by rolling objects down
an inclined plane. His investigation of the pendulum is said to have
begun with his observation of a chandelier swinging back and forth in
church one morning. He was fascinated by the regularity of the motion,
which, he saw, could be used as the regulator of a clockwork.