De Hypothesibus Motuum Coelestium a se Constitutis Commentariolus
(A Commentary on the Theories of the Motions of Heavenly Objects from Their
born in Torun, Poland, in 1473
studied first at the University of Cracow.
then went to the University of Bologna to study canon law
fell under the influence of the mathematician and astronomer
Domenica Maria de Novara.
failed to complete his canon law studies
began (but did not complete) the study of medicine at the
University of Padua
finally completed legal studies at the University of Ferrara.
returned to Frauenberg in 1503 to position as a canon of
the Cathedral, where he remained for the last 40 years of his life.
1510, unpublished (until 19th century)
short essay but gained wide, private circulation
by 1515, Copernicus was a famous astronomerpresented
seven postulates: foundation of a new, heliocentric cosmology
Copernicus' seven principles reversed the places of the Earth and Sun and
eliminated Aristotle's two worlds --- the terrestrial realm of earth, air,
fire and water and the celestial realm of aether --- in favor of a unified
world described by the same physics everywhere.
There is not a single center for all the celestial orbs
or spheres [the Sun is one center of motion, for the planets; the Earth
is another, for the Moon]
The center of the Earth is not the center of the world
Sun is the center of the world], but only of the heavy bodies and of
the lunar orb [rocks fall toward the center of the Earth and the moon
circles the Earth]
All the orbs encompass the sun which is, so to speak,
in the middle of them all, for the center of the world is near the sun
[the planets have orbits or spheres centered on the Sun]
The distance from the sun to the earth is insensible [so
small as to be not measurable] in relation to the height of the firmament
stars are much, much more distant than the Sun]
Every motion that seems to belong to the firmament does
not arise from it, but from the Earth. ... the firmament, or
last heaven, remains motionless. [This is Oresme's idea:
the Earth turns while the stars remain still.]
The motions that seem to us proper to the Sun do not arise
from it, but from the Earth and our orb, with which we revolve around the
sun like any other planet. In consequence, the earth
is carried along with several motions. [The Sun
is still. The Earth experiences two fundamental motions: rotation
on its axis, which gives us day and night, and revolution around the Sun,
which gives us the year and the seasons. An additional motion, known as
precession, accounts for the 26,000 year period discovered by Hipparcus
. The Earth is treated "like any other planet."]
The retrograde and direct motions which appear in the
case of the planets are not caused by them, but by the Earth. The
motion of the Earth alone is sufficient to explain a wealth of apparent
irregularities in the heavens. [Retrograde motion
occurs when the Earth " laps" an outer planet or an inner planet
"laps" the Earth. The planets do not actually slow down, stop, and reverse
directions when they are seen to go retrograde.]
In 1543, he would publish the book De Revolutionibus
Orbium Celestium [The Revolutions of the Celestial Orbs]
Advantages of the Copernican system:
Earth is one of six planets, just like any other planet.
"By making the Earth just another planet, Nicholas Copernicus, in 1543,
hurled an imiplicit challenge to the concept of incorruptibility.
As a planet, the heretofore imperfect earth was as perfect as other planets;
or conversely, the previously perfect planets were now as impoerfect as
the earth." [Grant, from Planets, Stars, and Orbs] --- thus
this directly challenges Aristotle's two-part universe, including his laws
of physics (why do objects fall down or rise up, if Aristotle is wrong?)
there are no celestial spheres; without them, how do the
planets stay in their orbits?
the stars are incredibly far away; how far away? what is
The Sun is no longer a planet
The Sun is the center (presumably of the universe)
closest planets to Sun orbit fastest
lots of empty space exists between the planets --- this
is forbidden by Aristotle
moon orbits the Earth
the Earth moves (double motion) --- how does the Earth
stay in motion? why don't we fall off a moving Earth?
Copernican Cosmological Principle: we live in a typical,
not a special, place in the universe
Mars makes a larger retrograde loop than does Jupiter
or Saturn; this is natural in the heliocentric but arbitrary in the geocentric
Mars, Jupiter, and Saturn are largest in appearance at opposition;
this is natural in the heliocentric model
Venus and Mercury never 'leave' the Sun; this is natural
in the heliocentric model
explains accurately the changing size (not phases) of the
eliminates the equant: all circles are truly sun centered
sets out a necessary order to the planets; in Ptolemiac system,
the order was arbitrary
Comparison of Distances of Planets to the Sun
(in Astronomical Units: 1 AU)
||Copernicus' value for distance to planet from Sun
||1142 solar radii
||23,456 solar radii
By the end of the sixteenth century, the total number
of astronomers (Michael Maestlin) and others of influence (Giordano Bruno)
who agreed with Copernicus could be counted on a few fingers (if that many
were needed) of one hand. If heliocentric astronomy was so successful,
why didn't the astronomy community accept heliocentrism immediately?
1515: Copernicus' ideas in circulation throughout Europe
1516: Pope asks Copernicus to reform the calendar
1533: Copernicus has audience with Pope Clement VII
1536: some of Copernicus' friends and associates (including
Cardinal Schoenberg of Frauenborg) began urging him to publish his ideas.
1539: Georg Joachim Rheticus (1514-1574) arrives and becomes
Copernicus' disciple; helps push Copernicus to write his book
1539: Copernicus' live-in, young female friend, Anna Schillings,
who is "in the service of the canon," is ordered to leave by the bishop.
1542, May: Rheticus brings Copernicus' manuscript to Nuremberg
for publication, under supervision of Andreas Osiander (a lutheran theologian)
1542, December: Copernicus has stroke, is paralyzed
1543, May: De Revolutionibus Orbium Celestium
Revolutions of the Celestial Orbs] appears. Has an anonymous preface
(was written by Osiander) asserting that the heliocentric idea is only
an hypothesis to save the appearances. Copernicus never knew of this
preface, probably never saw the final book.
1543, May 24: Copernicus dies.
1545: Council of Trent opens.
1546: Domincan G.M. Tolosani composes refutation of heliocentrism
based on physical, scriptural, and philosphical arguments
1551: Erasmus Reinhold published the Prutenic Tables, using
models and parameters and mathematics of Copernicus; this replaced the
Alphonsine Tables. Reinhold opposed the heliocentric theory but embraced
1572: Pope Gregory agrees to method, proposed by Jesuit astronomer
Christopher Clavius and based on Copernican mathematics, for reforming
the calendar. Institutes Gregorian
calendar in March, 1582.
Council of Trent:
convened from 1545 until 1563 to develop strategies to counter
the Lutheran reformers
April 8, 1546, at the Council of Trent, established the anti-Lutheran
doctrine that no one is allowed to "twist the sense of Holy Scripture
against the meaning which has been and is being held by our Holy Mother
Church whose duty it is to judge of the true sense and interpretation of
the Holy Scriptures, nor shall any one dare to interpret these Scriptures
contrary to the unanimous consensus of the Fathers, even if such interpretations
have never before been brought to light."
This doctrine directly opposed the Lutheran assertion that
each individual was empowered to read and interpret scripture.
Copernicus was challenged by leading Catholic leaders
and Protestant reformers who opposed heliocentrism because it contradicted
several pieces of scripture. The idea that the Earth moved,
that the Earth was not at the center of the universe, was in contradiction
to how these passages had been interpreted by respected Catholic Church
authorities as being consistent with a geocentric cosmos and with how Protestants
(who were more literal in their interpretations than were the Roman Catholics)
Biblical verses that were often cited as proof that Copernicus was wrong
Psalms 104:5: You fixed the earth on its foundation,
never to be moved.
Job 104:7: He stretches out the North over empty space,
and suspends the earth over nothing at all.
1 Chronicles 16:30: Tremble before him, all the earth;
he has made the world firm, not to be moved.
Isaiah 40:12: Who has cupped in his hand the waters
of the sea, and marked off the heavens with a span? Who has held in a measure
the dust of the earth, weighed the mountains in scales and the hills in
Proverbs 27:3: Stone is heavy, and sand a burden,
but a fool's provocation is heavier than both.
Ecclesiastes 1:5: The sun rises and the sun goes down;
then it presses on to the place where it rises.
Joshua 10:12-13: On this day, when the LORD delivered
up the Amorites to the Israelites, Joshua prayed to the LORD and said in
the presence of Israel: Stand still, O sun, at Gibeon, O moon, in
the valley of Aijalon! And the sun stood still, and the moon stayed, while
the nation took vengeance on its foes. Is this not recorded in the Book
of Jashar? The sun halted in the middle of the sky; not for a whole day
did it resume its swift course.
So Copernicanism had an uphill battle to fight if it were
to gain acceptance.
"The book had to fights its battles without further
help from its author. But for those battles, Copernicus had constructed
an almost ideal weapon. He had made the book unreadable to all but
the erudite astronomers of his day." -- Thomas Kuhn, The Copernican
Armed with literal translations of these verses, Protestant
reformers had all the ammunition they needed to attack Copernicus and his
ideas.Luther (in 1539):
"People gave ear to an upstart astrologer who
strove to show that the earth revolves, not the heavens or the firmament,
the sun and the moon. ... This fool wishes to reverse the entire science
of astronomy; but sacred Scripture tells us [Joshua 10:13] that Joshua
commanded the sun to stand still, and not the earth."
Melanchton (Luther's close collaborator and friend) wrote,
"The eyes are witnesses that the heavens revolve
in the space of twenty-four hours. But certain men, either from the
love of novelty, or to make a display of ingenuity, have concluded that
the earth moves; and they maintain that neither the eighth sphere [the
celestial sphere] nor the sun revolves. ... Now, it is a want of
honesty and decency to assert such notions publicly, and the example is
pernicious. It is the part of a good mind to accept the truth as revealed
by God and to acquiesce in it."
"Who will venture to place the authority of Copernicus
above that of the Holy Spirit?"
Jean Bodin, a political philosopher who opposed Machiavelli's
views, and whose writings were all placed on the Index of banned books
in 1628, wrote:
"No one in his senses, or imbued with the slightest
knowledge of physics, will ever think that the Earth, heavy and unwieldy
from its own weight and mass, staggers up and down around its own center
and that of the Sun; for at the slightest jar of the Earth, we would see
cities and fortresses, towns and mountains thrown down. ... all things
on finding places suitable to their natures, remain there, as Aristotle
writes. Since therefore the Earth has been allotted a place fitting
its nature, it cannot be whirled around by other motion than its own."
By mid-sixteenth century both the Church of Rome and the
leaders of the Protestant movements all agreed, though for different reasons,
that Copernicus' ideas were wrong.
Thomas Kuhn writing in The Copernican Revolution (1957):
"When it was taken seriously, Copernicus' proposal
raised many gigantic problems for the believing Christian. If, for example,
the earth were merely one of six planets, how were the stories of the Fall
and of the Salvation, with their immense bearing on Christian life, to
be preserved? If there were other bodies essentially like the earth, God's
goodness would surely necessitate that they, too, be inhabited. But if
there were men on other planets, how could they be descendants of Adam
and Eve, and how could they have inherited the original sin, which explains
man's otherwise incomprehensible travail on an earth made for him by a
good and omnipotent deity? Again, how could men on other planets know of
the Saviour who opened to them the possibility of eternal life? Or, if
the earth is a planet and therefore a celestial body located away from
the center of the universe, what becomes of man's intermediate but focal
position between the devils and the angels? If the earth, as a planet,
participates in the nature of celestial bodies, it can not be a sink of
iniquity from which man will long to escape to the divine purity of the
heavens. Nor can the heavens be a suitable abode for God if they participate
in the evils and imperfection so clearly visible on a planetary earth.
Worst of all, if the universe is infinite, as many of the later Copernicans
thought, where can God's Throne be located? In an infinite universe, how
is man to find God or God man?
"These questions have answers. But the answers were not
easily achieved; they were not inconsequential; and they helped to alter
the religious experience of the common man. Copernicanism required a transformation
in man's view of his relation to God and of the bases of his morality ..."