Galileo Galilei

Galileo Galilei

Galileo Galilei was born at Pisa on the

18th of February in 1564. His father, Vincenzo Galilei, belonged to a noble
family and had gained some distinction as a musician and a mathematician.

At an early age, Galileo manifested his ability to learn both mathematical
and mechanical types of things, but his parents, wishing to turn him aside
from studies which promised no substantial return, steered him toward some
sort of medical profession. But this had no effect on Galileo. During his
youth he was allowed to follow the path that he wished to.

Although in the popular mind Galileo is
remembered chiefly as an astronomer, however, the science of mechanics
and dynamics pretty much owe their existence to his findings. Before he
was twenty, observation of the oscillations of a swinging lamp in the cathedral
of Pisa led him to the discovery of the isochronism of the pendulum, which
theory he utilized fifty years later in the construction of an astronomical
clock. In 1588, an essay on the center of gravity in solids obtained for
him the title of the Archimedes of his time, and secured him a teaching
spot in the University of Pisa. During the years immediately following,
taking advantage of the celebrated leaning tower, he laid the foundation
experimentally of the theory of falling bodies and demonstrated the falsity
of the peripatetic maxim, which is that an objects rate of descent is proportional
to its weight. When he challenged this it made all of the followers of

Aristotle extremely angry, they would not except the fact that their leader
could have been wrong. Galileo, in result of this and other troubles, found
it prudent to quit Pisa and move to Florence, the original home of his
family. In Florence he was nominated by the Venetian Senate in 1592 to
the chair of mathematics in the University of Padua, which he occupied
for eighteen years, with ever-increasing fame. After that he was appointed
philosopher and mathematician to the Grand Duke of Tuscany. During the
whole of this period, and to the close of his life, his investigation of

Nature, in all her fields, was never stopped. Following up his experiments
at Pisa with others upon inclined planes, Galileo established the laws
of falling bodies as they are still formulated. He likewise demonstrated
the laws of projectiles, and largely anticipated the laws of motion as
finally established by Newton. In statics, he gave the first direct and
satisfactory demonstration of the laws of equilibrium and the principle
of virtual velocities. In hydrostatics, he set forth the true principle
of flotation. He invented a thermometer, though a defective one, but he
did not, as is sometimes claimed for him, invent the microscope.

Though, as has been said, it is by his
astronomical discoveries that he is most widely remembered, it is not these
that constitute his most substantial title to fame. In this connection,
his greatest achievement was undoubtedly his virtual invention of the telescope.

Hearing early in 1609 that a Dutch optician, named Lippershey, had produced
an instrument by which the apparent size of remote objects was magnified,

Galileo at once realized the principle by which such a result could alone
be attained, and, after a single night devoted to consideration of the
laws of refraction, he succeeded in constructing a telescope which magnified
three times, its magnifying power being soon increased to thirty-two. This
instrument being provided and turned towards the heavens, the discoveries,
which have made Galileo famous, were bound at once to follow, though undoubtedly
he was quick to grasp their full significance. The moon was shown not to
be, as the old astronomy taught, a smooth and perfect sphere, of different
nature to the earth, but to possess hills and valleys and other features
resembling those of our own globe. The planet Jupiter was found to have
satellites, thus displaying a solar system in miniature, and supporting
the doctrine of Copernicus. It had been argued against the said system
that, if it were true, the inferior planets, Venus and Mercury, between
the earth and the sun, should in the course of their revolution exhibit
phases like those of the moon, and, these being invisible to the naked
eye, Copernicus had to change the false explanation that these planets
were transparent and the sun\'s rays passed through them. But with his telescope

Galileo found that Venus did actually exhibit the desired phases, and the
objection was thus turned into an argument for Copernicanism.

Galileo was tried by the Inquisition for
his writings discussing the Ptolemaic and Copernican systems. In June 1633,

Galileo was condemned to life imprisonment for heresy. His