Galilei was born in Pisa in 1564, the son of Vincenzo Galilei,
well known for his studies of music, and Giulia Ammannati. He studied at Pisa,
where he later held the chair in mathematics from 1589 - 1592. He was then
appointed to the chair of mathematics at the University of Padua, where he
remained until 1610. During these years he carried out studies and experiments
in mechanics, and also built a thermoscope. He
devised and constructed a geometrical and
military compass, and wrote a handbook which describes how to use this
instrument. In 1594 he obtained the patent for a machine to
raise water levels. He invented the microscope, and built a telescope with
which he made celestial observations, the most spectacular of which was his
discovery of the satellites of
Jupiter. In 1610 he was nominated the foremost Mathematician of the
University of Pisa and given the title of mathematician to the Grand Duke of
Tuscany. He studied Saturn and observed the phases of Venus.
In 1611 he went to Rome. He became a member of the Accademia dei
Lincei and observed the sunspots. In 1612
he began to encounter serious opposition to his theory of the motion of the
earth that he taught after Copernicus. In
1614, Father Tommaso Caccini
denounced the opinions of Galileo on the motion of the Earth from the pulpit of
Santa Maria Novella, judging them to be erroneous. Galileo therefore went to
Rome, where he defended himself against charges that had been made against him
but, in 1616, he was admonished by
Cardinal Bellarmino and
told that he could not defend Copernican
astronomy because it went against the doctrine of the Church. In 1622 he
wrote the Saggiatore
(The Assayer) which was approved and published in 1623. In 1630 he
returned to Rome to obtain the right to publish his Dialogue on the two
chief world systems which was eventually published in Florence in 1632.
In October of 1632 he was summoned by the Holy Office to
Rome. The tribunal passed a sentence
condemning him and compelled Galileo to solemnly abjure his
theory. He was sent to exile in Siena and finally, in December of 1633, he was
allowed to retire to his villa in Arcetri, the
Gioiello. His health condition was steadily declining, - by 1638 he was
completely blind, and also by now bereft of the support of his daughter, Sister Maria
Celeste, who died in 1634. Galileo died in Arcetri on 8 January 1642. For
the family of Galileo, see the genealogical
tree. Within the Museo, Sala IV is entirely
dedicated to Galileo and his studies; among other things are preserved the lenses, the inclined plane, the
lodestone, the
model of the
application of the pendulum to the clock, several portraits and a relic.
Galileo GALILEI -Mechanics
The contributions made by Galileo to mechanics remain fundamental,
despite the fact that this field of research met with less interest from the Medici Grand
Dukes than Galileo's astronomical discoveries, perhaps because it was less
spectacular. Galileo's investigations concerned the natural descent of bodies
along planes of
various inclinations, the formulation of the law which
established the relationship between space traversed and time interval in
free-fall, the isochronism of
the oscillations of pendulums of equal lengths and, of particular importance,
the motion of projectiles. At the end of the eighteenth century, from the
necessity of displaying some of the mechanical principles discovered and
demonstrated by Galileo, the Florentine Museum of Physics and
Natural History had experimental devices constructed, such as the model of the inclined
plane, the brachistochrone
descent and the machine for raising
water.
Galileo GALILEI -Astronomy
The observations of the sky which Galileo carried out with his telescope led to
the discovery of the satellites of
Jupiter and to Galileo's increased adherence the Copernican
System. The phenomena which were revealed little by little due to the
increased possibility of larger lenses were described and illustrated by Galileo
in Sidereus
Nuncius. The periods and frequencies of appearances of the satellites of
Jupiter were studied by Galileo in order to develop a method for
determining longitudes at sea.
Galileo GALILEI - The microscope
In the early years of
the seventeenth century Galileo adapted a telescope for the
viewing of extremely small objects. Between 1619 and 1624 he began to produce
microscopes or "occhialini" as he called them. The Galileian microscope is made
up of the tube of a telescope, of reduced size, furnished with two lenses.
Galileo gave his "occhialino" to various people. He sent a letter to Federigo Cesi,
accompanying the instrument, in which he explained the means by which it was
focussed and the arrangement of objects for observation.
Galileo GALILEI - Thermometry
Viviani recounts
that Galileo dedicated himself to research on heat at the end of the 16th
century. The invention of the thermoscope seems,
then, to belong to his Paduan period. This device was used to carry out
experiments on the relationship between changes of temparature and variations of
the level of the liquid. The work of the Accademia del
Cimento which led to the birth of the Florentine thermometer had its origins
in Galileo's early research.
Galileo GALILEI - Magnetism
Between 1600 and 1609
Galileo devoted himself to studying magnetism, inspired by William Gilbert's
De
magnete. He attempted to increase the strength of loadstones by means
of special armatures. One of these (IV.8) was given to
Grand Duke Ferdinand II by
Galileo.
