The Renaissance

With the telescope Galileo also ob-
served the phases of Venus, the mountains
and craters of the moon, the individual
stars that make up the Milky Way galaxy,
and the rings of Saturn (although the lim-
ited power of his telescope prevented him
from recognizing their true nature). He
was regarded throughout Italy as a leading
scientist and philosopher of astronomy,
and was appointed as official mathemati-
cian and philosopher to Cosimo de’
Medici, the Duke of Tuscany. His support
of the Copernican system, however,
aroused strong opposition within the
church. Although Copernican astronomy
was widely accepted in Protestant north-
ern Europe, in Catholic Italy a different
philosophy still held sway, one that did
not allow for alternate systems that con-
tradicted the accepted wisdom of the Bible
or of the ancient thinkers Aristotle and
Ptolemy.

From their pulpits, Catholic clergymen
denounced Galileo’s opinions as heresy,
and in 1616 Galileo was officially admon-
ished to cease and desist from advocating
the Copernican system. He held to his be-
liefs, however, and found himself unable
to deny the plain fact of observation and
the confirmation of the Copernican sys-
tem through the use of mathematics. In
1632 he publishedDialogue Concerning the
Two Chief World Systems.In this book, he
disguised the opinions of an ally, Pope Ur-
ban VIII, in support of geocentrism, an
idea that he then discredits with his own
heliocentric views. Although Galileo was
given formal permission to publish the
book, his instructions were not to advo-
cate heliocentrism; worse, the pope was
offended by his thinly disguised portrayal
in theDialogueas a simplistic fool. Galileo
was summoned before the Roman Inquisi-
tion, tried for heresy in 1633, and found

guilty. The Inquisition banned theDia-

logue, required Galileo to give up his he-

liocentric teachings, sentenced him to

house arrest, and banned him from any

future publication.

While living in a country villa near

Florence, he wrote Two New Sciences,a

work about basic physical properties of

various materials and the nature of mo-

tion. Galileo’s other important works are

Dialogues Concerning Two New Sciences,

written toward the end of his life;Starry

Messenger, a book written in 1610 that de-

scribes his many discoveries made through

the telescope; andThe Assayer, in which

he grapples with the strange phenomenon

of comets.

Galileo’s innovations include the use

of the microscope and the refracting tele-

scope, the invention of the thermometer,

an early attempt to calculate the speed of

light, and studies on the phenomenon of

mass, inertia, and the properties of falling

objects, which three centuries later formed

a basis for Einstein’s theory of relativity.

Many of his theories, reached through ex-

tensive and ingenious experimentation,

were later proven by scientists such as Isaac

Newton. Galileo disagreed, however, with

the astronomer Johannes Kepler, who

maintained that the planets moved in el-

liptical orbits and that the gravitational

pull of the moon caused the tides.

SEEALSO: astronomy; Copernicus, Nico-

laus; Kepler, Johannes

Galindo, Beatriz ..............................

(1465–1534)

A Renaissance humanist and professor at

the University of Salamanca, by many ac-

counts the first woman in history to attain

a university chair. She was born in Sala-

manca, Spain, and, under the guidance of

Galindo, Beatriz