Galileo Galilei was a truth seeker.
His quest for truth, though, was to bring
him into conflict with the most powerful institution
of his day – the Roman Catholic Church.
Through such inventions as the telescope,
he revealed truths that landed him in front
of the Holy Roman inquisition, fighting for
his very survival.
Condemned during his life, he is now revered
as a true genius.
In this today’s Biographics, we get the
full story on Galileo Galilei.
Beginnings
Galileo Galilei was born on February 15th,
1564 in Pisa, Italy.
He was the first of six children to Vincenzo
de Bonajuti de Galilei and Giula Galilei.
The Galilee’s were from an ancient, respected
family who originated in Florence.
Vincenzo was a wool trader who also had an
abiding interest in philosophy, science and
music.
At the age of four days, young Galileo was
baptized a Catholic.
He was raised according to the strict tenets
of that faith, as was everyone else in the
region.
From an early age, Galileo showed an intense
interest in making things.
He was constantly making small gadgets that
would amuse his friends and teachers.
These would include wooden animals with moving
arms and legs.
He was fascinated with how machines worked
and would be constantly pulling things apart
and putting them back together.
If he was making a machine and didn’t have
a part, he would improvise.
When Galileo was ten years of age, his father
decided to move the family to Florence.
By now, Vincenzo had developed a reputation
as a learned and wise man.
Despite the demands of business, he had managed
to write several books, the most popular of
which was the Dialogue of Ancient and Modern
Music.
Wealthy people streamed to him to benefit
from his knowledge of Greek and Roman literature
and to hear his musical theories.
He was invited to spend time with Duke Albrecht
of Bavaria, who lived in Munich, Germany,
some 300 miles from Florence.
Vincenzo was also an active member of the
Florentine Camerata, a group of musicians
who were experimenting with musical drama,
the genesis of what would be opera.
Galileo and his siblings were, therefore,
raised in an intellectually stimulating environment.
Vincenzo taught his oldest son how to play
a number of musical instruments, the favorite
of which, for both, was the lute.
Galileo also experimented with drawing and
painting, showing great promise in both areas.
His teenage years coincided with the high
Renaissance period, when Italy was being filled
with the works of the great painters, sculptors,
and architects.
He considered devoting his life to that of
an artist, but his father was keen for his
son to follow him into the wool trade.
Vincenzo had a great passion for the arts,
but he knew that nothing but a solid business
career would secure for his son a stable financial
future.
By the time that Galileo had reached his mid-teens
it was apparent to everyone, including his
father, that his keen mind was destined for
greater things than a life as a wool trader.
Vincenzo saw it as his duty to encourage Galileo
to use his God-given intellectual talents
to the fullest extent.
Through his studies of the works of Aristotle,
Vincenzo had instilled in his son the discipline
of independent study, observation and experimentation.
Rather than being swayed by what others had
already concluded on a matter, he would independently
study the subject for himself and reach his
own conclusions based on those observations.
When he was fifteen years of age, Galileo
attended the Benedictine Monastery of Santa
Maria di Vallombrosa.
From the monks he learned religion and logic.
After a few months, however, he had to return
home due to an eye infection.
Higher Education
When he was 17, Galileo passed the bachelor’s
exam, permitting entry to the University of
Pisa.
Universities in the 16th century were places
attended by members of only the wealthiest
families and were generally reserved for those
with ambitions of being priests, doctors or
professors.
Although Galileo seriously considered the
priesthood as a young man, Galileo, or more
likely Galileo’s father, had decided on
a career in medicine.
In order to achieve it, he first had to obtain
a master’s degree.
Galileo applied himself to his studies and
made excellent progress.
However, several months into the first year
of his medical degree, he happened to overhear
a geometry lecture delivered by a friend of
his father, Ostilio Ricci.
He was immediately attracted to the logic
and beauty of the math that was being applied.
When Ricci heard from Galileo’s father that
the boy was fascinated with his lecture, he
invited him to take his course.
Vincenzo had first made Ricci promise not
to let Galileo know that he had consented
to him taking the geometry paper in case he
saw it as permission to abandon his medical
studies.
In addition to attending Geometry lectures,
Galileo worked one-on-one with Ricci as he
studied the works of Greek mathematician Euclid.
As he become more deeply immersed in the subject,
Galileo became less interested in medicine.
Finally, he confronted his father and asked
him not to stand in the way of his focus on
geometry.
Vincenzo was a realist, knowing that his son
would not prosper as a doctor if his heart
was not in it.
He agreed to support Galileo in his mathematical
pursuits.
Galileo the Mathematician
After switching to mathematics, Galileo brought
his full intellectual rigor to bear on the
subject.
He was an excellent student, but he still
managed to frustrate his professors.
The inclination to question everything that
his father had instilled in him meant that
he would accept nothing as fact.
Established theories were meaningless until
he had personally pulled them apart, studies
them and reached his own conclusions.
It was the Aristotelian scientific method
in action, but it even caused the teenager
to question the theories of Aristotle himself.
One day when he was 19, Galileo happened to
be in the Pisa Cathedral for a mass observance.
After the service he was wandering around
the building when his attention was caught
by a sculpted bronze lamp located in the dome
of the cathedral.
The lamp was swinging back and forth like
a pendulum.
He observed that, regardless of the lessening
arc of the swing, the time that it took for
each swing remained the same.
To check this observation, he timed the swings
with his pulse.
This led him to the realization that the rhythmic
swings of a pendulum were an excellent way
to measure the human pulse.
This was the inspiration for the later invention
of Galileo’s pulsilogium, a machine designed
to take people’s pulses, or a harmonic oscillator.
This was the first example of Galileo not
only observing and testing phenomena but also
finding practical applications of his findings.
Practical Applications
By 1585, the financial strain of supporting
his son’s university studies was too much
for Vincenzo and Galileo had to withdraw from
the University of Pisa.
He hadn’t yet completed his doctoral degree.
But the budding genius was not to be deterred.
He embarked upon his own studies by examining
the works of the great minds of Ancient Rome
and Greece.
After dissecting the works of Archimedes,
he wrote his first scientific dissertation,
in which he described an invention that he
called ‘the little balance’.
This was a hydrostatic scale to measure the
air/water balance.
He also developed a horse-powered pump for
crop irrigation that was inspired by the famous
Archimedes Screw.
Just as his father had a decade earlier with
his muscle talent, Galileo began to impress
important people with his practical application
of science.
He gained a reputation as an up and coming
scientist.
One man who was especially interested in Galileo’s
work was the Marquis Guidobaldo del Monte,
a wealthy patron with an abiding interest
in astronomy, mathematics and architecture.
The Marquis began writing to Galileo and the
two maintained a vigorous correspondence during
which Galileo would explain his latest observations
and applications.
Del Monte encouraged the twenty-two-year-old
Galileo to study the center of gravity in
solid bodies, which led to the publication
of a treatise on the subject.
University Professor
It was through del Monte that Galileo came
to the attention of the Grand Duke of Tuscany,
Ferdinand I de’ Medici.
In 1589, the Grand Duke appointed him as a
professor of mathematics at the University
of Pisa.
This was the position that Galileo had been
hoping to secure even since he had been forced
to quit his studies.
At the time, mathematics was a minor subject
of study at university that was not even seen
as worthy of study by many.
Galileo’s salary was only 60 florins a year,
while philosophy professors earned 600 or
more.
In addition, he was looked down on by them
as a young upstart who dared to question the
teachings of the great Aristotle.
To them this was akin to blasphemy, with the
writings of Aristotle being considered the
final word on all things.
Ironically, Galileo was simply following through
on the teachings of Aristotle himself, who
championed independent study and observation,
well aware that his own theories could well
be overturned as new knowledge was observed.
The most famous example of Galileo not simply
accepting one of Aristotle’s theories because
it was written down on paper had to do with
the speed of falling objects.
Aristotle had contended that two objects of
different weights would fall to the ground
at different speeds, with the heaviest object
falling faster.
As the story goes, Galileo climbed to the
top of the Leaning Tower of Pisa, although
the building thought to have been used may
have been the church tower in Delft, and dropped
two spheres of different masses to the ground
below.
They both hit the ground at the same time,
disproving Aristotle’s theory.
Galileo’s experiment at the Tower of Pisa
was believed to have been observed by many
of his students and fellow professors from
the University.
Still, some of the professors refused to acknowledge
that the young man had just overturned one
of Aristotle’ theories.
This stubborn refusal to accept empirical
evidence that overturned long entrenched views
is something that Galileo was to contend with
for the rest of
his life.
Making Enemies
Not long after the Tower experiment, Galileo
was approached by a member of the powerful
Medici family, Giovanni de’ Medici, and
asked to evaluate a machine that he had invented.
The machine was designed to dredge harbor
bottoms of Leghorn to remove the mucky layer
and make them safer for ships to come in.
Galileo carefully studied the machine, only
to conclude that it was badly designed and
was not fit for purpose.
This presented a problem.
Should he be honest and tell the man that
the machine wouldn’t work or should he placate
him with false praise?
The Medici’s were the most powerful clan
in Italy and Galileo was very wary of getting
on the wrong side of any of them.
Still, his loyalty to scientific truth would
not allow him to deceive the inventor.
In a public forum, he spelled out what was
wrong with the machine and assured everyone
present that it would not work.
His opinion was borne out when the machine
proved to be a dismal failure.
Galileo’s honesty had created a powerful
enemy.
The humiliated Medici man was determined to
bring Galileo down and set about getting him
fired from his professorship at the university.
Under the advice of the Marquis Guidobaldo
del Monte, Galileo resigned his position.
Del Monte had opened the door to a new posting,
as the chair of mathematics at the University
of Padua, 130 miles northeast of Pisa.
This was a big step up for Galileo.
He was now making 180 florins a year, three
times his previous income.
No longer did he have to contend with the
ridicule of his fellow professors.
He soon became a very popular lecturer with
his classes being fill to overflowing.
At Padua, he also found the time to work on
his inventions and his writings.
He became an expert at applying science to
military fortifications, designing reinforced
walls for forts and mechanically superior
siege engines.
In 1593, was invited to Venice to give advice
on the ideal positioning of a rowing ship’s
oars to generate maximum use of manpower.
In 1593, Galileo developed an undiagnosed
illness which had kept him in pain, affected
his appetite and robbed him of sleep.
These symptoms would affect him for the rest
of his life.
Despite his sickness he managed to meet his
university obligations.
At the end of his first six-year term at Padua,
he was appointed for a further six years.
By the end of the 1590’s, Galileo had invented
a range of products which were in demand all
over the country.
These included an irrigation pump that require
a single horse to power it and the sector
which was used to measure precise angles.
Lacking the time to produce each piece himself,
he hired a craftsman named Marcantonio Mazzoleni
to make his inventions.
Galileo the Astronomer
It wasn’t until the mid-1590’s that Galileo
took any serious interest in astronomy.
Without studying the issue, he believed in
the Ptolemaic theory that the sun and other
planets revolved around the earth.
When a visiting lecturer spoke on the Copernican
theory, which contended that the earth and
other planets actually revolve around the
sun, Galileo did not attend, considering the
theory to be ridiculous.
Same time later, he was talking with some
of his students who had attended the lecture.
Most of them didn’t accept the new theory
but there was one who did.
It was then that Galileo had a simple but
profound realization – every person who
had abandoned the Ptolemaic theory in favor
of the Copernican theory would be subjected
to ridicule.
They would, therefore, only do so on the basis
of overwhelming evidence.
He was now obsessed with finding what that
evidence was.
The question of whether the sun or the earth
was at the center of the universe would consume
Aristotle for the rest of his life.
Even though he continued to teach the theories
of Ptolemy in his classes, he become more
convinced that Copernicus was right.
In 1597, he established written communication
with German astronomer Johannes Kepler who
was also an advocate of the Copernican theory.
Kepler had published a work supporting Copernicus
and encouraged Galileo to do the same.
However, the Italian was worried that doing
so would bring upon him the anger of the Catholic
church which held that the earth was undoubtedly
the center of the universe.
On a visit to Venice, Galileo met a woman
by the name of Marina Gamba.
A relationship developed, with Marina moving
in with him.
Before long a child was born to the unwed
couple, the first of three, two girls and
a boy.
In 1610, Galileo left Padua, taking his two
daughters (both given to the convent eventually
due to their illegitimate births) but leaving
his son, Vincenzo, with Marina.
Years later Marina married another man, but
Galileo remained friendly with her throughout
his lifetime.
Growing Fame
In the first decade of the 1600’s, Galileo
continued to invent new technologies.
In 1604, he observed and discussed Kepler’s
supernova..
His talk was so popular that he had to move
from the overcrowded lecture theater to an
outside forum so that everyone could hear
him.
In 1609, Galileo began working on a machine
that would magnify the night sky.
He used two eyeglass lenses, one concave and
the other convex, placing them at opposite
ends of a long metal tube.
When looking through this ‘Venetian glass’,
later called a telescope, the stars were magnified
several times.
The invention became a hit with prominent
people from all over Italy clambering to get
a look through the amazing machine which allowed
you to see things that were far away.
His telescopes were also a profitable sideline
for Galileo, who sold them to merchants who
found them useful both at sea and as items
of trade.
The invention reflected positively on the
University of Padua, prompting the board to
offer Galileo a lifetime professorship and
increase his salary to 1000 florins.
Before long, Galileo had improved his telescope
until it was able to magnify up to thirty
times.
This enabled him to look through it at the
moon.
He discovered that, rather being perfectly
round and smooth, as Aristotle had written,
it was rough and filled with craters and valleys.
His telescope also enabled Galileo to identify
and observe the moons of other planets.
During the period between January 8 and 14,
1610 he identified that Jupiter actually had
4 moons and are now called Io, Europa, Ganymede,
and Callisto.
Then in July of that same year he became the
first person to identify the rings around
Saturn, though he didn’t quite realize what
they were at the time.
Later that year he identified that Jupiter
and Mars had phases, similar to the moon.
Through the telescope, Galileo was able to
identify that there were many, many more stars
than had originally been thought and, therefore,
that the universe was much larger than previously
thought.
This upset many people who thought that through
his telescope, Galileo was using some form
of trickery to make his new discoveries.
In 1609, he was invited to move to the palace
of the Grand Duke in Florence.
He accepted, moving back to his home region
of Tuscany.
His job now involved giving lectures to princes
and other members of the royal family.
No longer having to lecture, he now had the
freedom to study and write books.
Growing Opposition
By 1615, there was a rising tide of opposition
to Galileo.
Many of his discoveries had flown in the face
of accepted Church doctrine, which was closely
aligned with the teachings of Aristotle.
People began asserting that his findings were
at odds with the scriptures, which were the
revealed word of God.
Galileo responded by writing that the Bible
was not a scientific textbook, but, where
it touched on science, it was, actually in
harmony with his findings.
It was people who had interpreted the scriptures
incorrectly.
The letter that Galileo wrote soon found its
way into the hands of his enemies, particularly
the Dominicans of St. Mark.
They viewed what he had written as heresy
and they made sure that a copy of the letter
got in front of the Pope in Rome.
The pope called for the leading Dominican
to come and give testimony about Galilee.
This man made the most of the opportunity,
telling lies to paint Galileo and his followers
as blasphemers.
Galileo was not cowered.
He considered those who spoke against him
as ignorant fools and set out to defend himself.
To do so, he traveled to the center of the
cauldron itself, Rome.
He appeared before the Holy Office on February
26, 1616 and was ordered to never again teach
that the sun was the center of the universe.
His reasoned argumentation in his defense
fell on deaf ears.
Galileo remained in Rome to argue with his
detractors.
This was not pleasing to his patron back in
the court of Tuscany, who felt that the conflict
could cause a rift between them and Rome.
In June, Galileo finally complied, returning
to Florence.
The stress of defending his reputation had
taken a toll on Galileo.
He was constantly plagued with physical pain
and spent increasing amounts of time bedridden.
In 1617, he moved to a hilltop villa just
out of Florence in order to benefit from the
rural air.
He continued to study the heavens but was
now far more guarded about what he wrote.
Then, in 1618, his ailments worsened.
He was confined to bed for several weeks and
became extremely weak.
By 1624, there was a new Pope, Urban VIII.
As a cardinal he had expressed admiration
for Galilee, but had never agreed with the
Copernican theory.
A slightly recovered Galileo was convinced
to make a pilgrimage to Rome in order to meet
with the Pope to assess his standing with
the pontiff.
Urban received him well, even presenting a
medal and promising a pension.
Galileo also noticed that church officials
around Rome were far less hostile to him than
they had been.
He felt confident, believing that the new
Pope had eased the pressure on him.
In 1629, Galileo wrote a masterful work, Dialogue
Concerning the Two Chief World Systems which
presented a dialogue between three men on
the merits of the Ptolemaic and Copernican
theories.
Before it could be published, he had to present
it to the chief censor of the press in Rome.
He was forced to make changes that presented
the Ptolemaic theory in the more favorable
light and to state clearly that the ideas
expressed were not facts but simply opinions.
Galileo made the changes, but a series of
delays prevented the book’s publication
until 1632.
Inquisition
The new book brought out the ire of the enemies
of the now 68-year old Galileo.
When Pope Urban got to read it, he became
enraged.
He had convinced himself that one of the three
fictional debaters in the book was based on
himself, and considered this to be the highest
insult imaginable.
In August 1632, all copies of the book sold
in bookshops were seized and the printer was
ordered to cease publication.
Then, in September, Galileo was ordered to
appear before the Holy Roman Inquisition.
After stalling due to ill health, he finally
headed to Rome to face his inquisitors on
January 20, 1633.
He had to wait until April 12th to appear
before the vice-commissioner of the holy office
and two other examiners for preliminary questioning.
It was stated that his book was in direct
violation of the 1616 oath he had taken not
to publicly discuss the teachings of Copernicus.
In his defense, Galileo contended that the
book was simply a dialogue between the two
theories and did not favor the view that the
sun was at the center of the universe.
A second interview was held on April 30th.
This time Galileo was more conciliatory, agreeing
that the arguments in favor of the Corpunican
theory.
. .
come to the ear of the reader with far greater
force and power than should have been imparted
to them by someone who regarded them as inconclusive.
This interview concluded with the examiners
agreeing to give Galileo time to prepare his
full defense.
That hearing was held on June 21st.
Before he could fully develop his defense,
he was asked point blank whether he had ever
held to the Copernican theory.
He answered that he had initially been indifferent
to both theories, but after careful study,
now believed in the wisdom of the Ptolemaic
theory.
This was clearly not true and none of the
examiners believed him.
The following day he was sentenced to a prison
term, to be decided later and his book was
banned.
He was then mde to read a statement of apology
on bended knee.
Pope Urban seemed satisfied with this outcome.
Galileo had been both condemned and humiliated.
The pope decided that the imprisonment to
which Galileo had been sentenced could be
carried out by way of home detention at the
grand duke of Tuscany’s villa near Rome.
However, Galileo was desperate to live out
his last years in his Florence, where his
family were located.
He wrote to the pope begging this indulgence,
which was granted.
He would be confined to the villa of his powerful
friend, Ascanio Piccolomini.
After five months he was permitted to return
to his own villa at Arcetri.
The Last Years
Galileo’s final years were marked by ill-health.
By 1637, he was nearly totally blind.
Before his sight was gone completely, he managed
to complete his last and, in his view, most
outstanding work, entitled Discourses and
Mathematical Demonstrations of Two New Sciences.
Under the rules of his sentence he could not
publish it in Italy and so the manuscript
was smuggled to Amsterdam and published there.
During his last days, the blind genius received
many visitors to his villa at Acetri.
He died on January 8, 1642 at the age of 77.
He had been fighting fever and heart problems
for months.
Nearly a hundred years later, with his brilliance
having finally been recognized, his remains
were removed from the chapel at Santa Croce
and relocated to a much more elaborate mausoleum
inside the church.
During this move, three fingers and a tooth
were removed from his remains.
One of these fingers, the middle finger from
Galileo's right hand, is currently on exhibition
at the Museo Galileo in Florence, Italy.
A monument was also erected with a bust of
Galileo and two figures representing his monumental
achievements in the worlds of astronomy
and geometry.
