The Makers of Science: IV, Galileo

The Makers of Science

By F.S. Harris, Ph.D., Director Experiment Station, Utah Agricultural College

IV.— Galileo

Galileo Galilei was born in Pisa, Italy, February 18, 1564,

while Michael Angelo lay on his death bed. He lived nearly 79

years and died the day Newton was born. Thus he bridged the

gap between the lives of the great artist and the great scientist,

and was both artist and scientist himself, although it is to his

work in science that he owes his fame. He became an eminent

philosopher and mathematician but his skill as an experimenter

is responsible for most of his contributions to the world's knowl-

edge.

Living as he did at a time when the mediaeval ideas of the

powerful Catholic Church retarded all scientific advancement,

it was particularly fortunate that he was able to demonstrate by

experiment some of the fundamental laws of nature. Previous

advocates of the principles he established as facts had been

burned at the stake and very little impression had been made by

their teachings. After Galileo had made his convincing demon-

strations, however, his ideas gained a foothold that even the per-

secutions of the inquisition could not uproot.

At the age of 17 he was sent to Pisa University where his

father insisted that he study medicine in spite of his inclination

toward mathematics. His first important discovery was not in

the profession chosen by his father but in physics. At Pisa he

observed that a pendulum of a given length swings in a definite

time regardless of the distance of the swing. He used the prin-

ciple in counting the pulse beats and later in making a clock.

He was more interested in subjects of this kind than in learning

the uncertain formula for treating disease, and finally after read-

ing the works of Euclid and Archimedes he lost all interest

in medicine. At 26 he was appointed lecturer in mathematics

at Pisa.

He was very much taken up with the writings of Bruno and

became a convert to the theory of Copernicus which taught that

the sun, and not the earth, is the center around which the

planets revolve. The teaching of this doctrine caused the death

of Bruno in 1600 and led to the relentless persecution of Galileo

30 years later.

Aristotle taught that falling bodies descended at a rate

MAKERS OF SCIENCE 245

proportionate to the weight of the body. That is, a rock weigh-

ing ten pounds would fall ten times as fast as one weighing one

pound. Anyone who questioned this gained the displeasure of

the monks. Galileo experimented from the leaning tower of

Pisa and found that all bodies fall at the same rate if the friction

of the air is eliminated. The announcement of this discovery

made him the subject of the most severe criticism. The spirit of

the times gave more credit to authority than to experiment,

and proof by actual trial could not outweigh the recorded state-

ment of one of the ancients. Through the teaching of his dis-

coveries Galileo became so unpopular at Pisa that he was forced

to leave.

In 1592 he accepted a professorship at the University of

Padua which was in charge of the senate of Venice. He held

this position eighteen years. Soon after going to Padua he in-

vented the thermometer, and later he developed several other in-

struments that made possible his scientific investigations. After

making a study of lenses he invented the telescope in 1609 and

somewhat later the microscope. His telescope attracted a great

deal of attention. The fact that with its aid vessels at sea could

be seen long before they were visible to the naked eye and that

any distant object was much clearer, appealed to people. As a

result of this invention the senate doubled his salary.

The delight with which his astronomical discoveries were

received by the scholars is shown in the following extract of a

letter from Kepler:

"I was sitting at home thinking of you, most excellent

Galileo, and your letters, when the news was brought me of the

discovery of four planets by the help of the double eye-glass.

Wachenfels stopped his carriage at my door to tell me, when

such a fit of wonder seized me at a report which seemed so ab-

surd, and I was thrown into an agitation at seeing an old dispute

between us decided in this way, that between his joy, my col-

ouring, and the laughter of us both, confounded as we were by

such a novelty, we were hardly capable, he of speaking, or I of

listening."

In order to have more time to devote to his researches

Galileo left Padua in 1610 and continued his studies at Florence

under the patronage of a wealthy duke. Six years later he was

called to Rome by Pope Paul V and forced to deny many of his

teachings. At this time he had a friend in Cardinal Barbenno

who afterward became Pope Urban VIII. Encouraged by the

friendship of the new Pope, Galileo continued his studies and

teachings; later he wrote a book which he called Dialogues on

the Ptolemaic and Copernican Systems. This presented his

teachings in such a clear form that it aroused the ire of the

246 IMPROVEMENT ERA

Cardinals who went to the Pope with a story that he was being

made fun of in the book.

Galileo was summoned to Rome and after being subjected

to the terrors of the Inquisition was forced to repeat and sign the

following statement that had been prepared by seven of the ten

Cardinals — three refusing to sign it:

The Abjuration of Galileo

"I, Galileo Galilei, son of the late Vicenzo Galilei, of Florence, aged sev-

enty years, being brought personally to judgment, and kneeling before you

Most Eminent and Most Reverend Lords, Cardinals, General Inquisitors of

the universal Christian republic against heretical depravity, having before

my eyes the Holy Gospels, which I touch with my own hand, swear that I

have always believed and now believe, and with the help of God will in fu-

ture believe, every article which the Holy Catholic and Apostolic Church of

Rome holds, teaches, and preaches. But because I have been enjoind by this

Holy Office altogether to abandon the false opinion which maintains that the

sun is the center and immovable, and forbidden to hold, defend, or teach the

said false doctrine in any manner, and after it hath been signified to me that

the said doctrine is repugnant with the Holy Scripture, I have written and

printed a book, in which I treat of the same doctrine now condemned, and

adduce reasons with great force in support of the same, without giving any

solution, and therefore have been judged grievously suspected of heresy;

that is to say, that I held and believed that the sun is the center of the

universe and is immovable, and that the earth is not the center and is mov-

able; willing, therefore, to remove from the minds of your Eminences, and

of every Catholic Christian, this vehement suspicion rightfully entertained

towards me, with a sincere heart and unfeigned faith, I abjure, curse, and

detest the said errors and heresies, and generally every other error and sect

contrary to the Holy Church ; and I swear that I will never more in future say

or assert anything verbally or in writing, which may give rise to a similar

suspicion of me; but if I shall know any heretic, or any one suspected of

heresy, that I will denounce him to this Holy Office, or to the Inquisitor or

Ordinary of the place where I may be; I swear, moreover, and promise, that

I will fulfil and observe fully, all the penances which have been or shall be

laid on me by this Holy Office. But if it shall happen that I violate any of

my said promises, oaths, and protestations (which God avert), I subject

myself to all the pains and punishments which have been decreed and pro-

mulgated by the sacred canons, and other general and particular constitu-

tions, against delinquents of this description. So may God help me, and his

Holy Gospels which I touch with my own hands. I, the above-named Gili-

leo Galilei, have abjured, sworn, promised, and bound myself as above and

in witness thereof with my own hand have subscribed this present writing

of my abjuration, which I have recited word for word. At Rome, in the

Convent of Minerva, 22nd June, 1633. I Gilileo Galilei, have abjured as

above written with my own hand."

Copies of this statement were sent to all the universities for

public reading. At Florence, his home town, it was read in the

Cathedral, all his friends and adherents being summoned to

hear it.

He was kept in bondage practically the rest of his life.

After a short imprisonment in Rome he was sent to Sienna and

later to Arcetri, but was never allowed to return to Florence.

MAKERS OF SCIENCE 247

He was told not to go out of the house and not to receive visitors,

on penalty of being sent back to Rome and cast into prison.

Broken in spirit and health and lonely, he gradually became

blind, but in this affliction he showed his usual humility and

resignation to the will of God. In a letter to a friend he wrote :

"Alas! your dear friend and servant is totally blind. Hence-

forth this heaven, this universe, which by wonderful obser-

vations I had enlarged a hundred and a thousand times beyond

the conception of former ages, is shrunk for me into the narrow

space which I myself fill in it. So please God; it shall therefore

please me also."

After his blindness came on he was allowed the help of

some of his old students and was permitted to receive visitors

who might get permission from a Jesuit supervisor. Among

his visitors at this time was the poet John Milton, at that time

only 29 years old. This visit to the blind scholar of Italy was

alluded to by Milton in his masterpiece written after he himself

became blind.

In spite of all his persecutions for teaching the principles

he had so completely demonstrated to be true, Galileo held fast

to his belief in God till the end, and he never questioned the

authority of the Pope. He could nevertheless see that even the

Pope could not by a decree change the nature of truth. He

says: "In these and other positions certainly no man doubts

but His Holiness the Pope hath always and absolute power of

admitting or condemning them ; but it is not in any creature to

make them to be true or false, or otherwise than of their Own

nature and in fact they are."

How similar is the latter part of this statement to one made

in modern times, also under the stress of persecution for the sake

of truth:

"Then say, what is truth? 'Tis the last and the first,

For the limits of time it steps o'er,

Though the heavens depart, and the earth's fountains burst,

Truth, the sum of existence, will weather the worst,

Eternal, unchanged, evermore."