joined the household of his uncle, a local
bishop, who saw to Nicolaus’s upbringing
and education. Nicolaus attended the uni-
versity in Krakow, Poland, and then stud-
ied at Bologna and Padua in Italy, taking
up law and mathematics. At the insistence
of his uncle, he also became a trained phy-
sician. His true interest, however, lay in as-
tronomy. While a student in Ferrara, Italy,
he attended lectures given by the astrono-
mer Domenico Maria Novara de Ferrara,
who accepted Copernicus for a time as his
assistant. Copernicus also traveled to
Rome,whereheheldlecturesonas-
tronomy and made observations of a lu-
nar eclipse.
When he returned to Poland, Coperni-
cus was appointed as a canon of the ca-
thedral at Frauenberg, where he earned a
steady income as a church administrator.
From his house, he observed the stars and
planets and worked out a theory contrary
to the notion of the ancient Greeks. Aris-
totle and Ptolemy believed the earth was
the center of the universe; Ptolemy pro-
posed the idea that the stars and planets
moveabouttheearthinaseriesofcon-
centric shells. The Ptolemaic system be-
came the accepted dogma of the Catholic
Church, which during the Renaissance was
still condemning new scientific ideas as
impious heresies.
In the Copernican system, the universe
is heliocentric, with the earth, stars, moon,
and planets all revolving around the sun.
The Copernican system explained the mys-
terious retrograde motion of the planets,
which occasionally seem to move back-
ward in their nightly tracks through the
sky. Astronomers of ancient and medieval
times had to explain retrograde motion
with a series of complex schemes and
mathematical calculations, while the helio-
centric system solved it by pointing out
that the position of planets in different or-
bits about the sun can have irregular posi-
tions to an observer on earth.
Copernicus summarized these ideas in
a treatise, Brief Commentary, that he
passed among friends and colleagues start-
ing in about 1512. He kept a more detailed
work that he entitledOn the Revolutions,
in manuscript form. In the meantime, he
served in his professional capacities as a
church canon, a doctor, and a tax collec-
tor. He produced a useful essay on the
problem of monetary inflation in which
he astutely observed that money will lose
its value as more of it circulates.
Copernicus’s opinions and remedies onA page from Nicolaus Copernicus’s 1543 vol-
ume “De Revolutionbus Orbium Coeles-
tium” that displays the relative positions of
the planets around the sun. HULTONARCHIVE/
GETTYIMAGES.
Copernicus, Nicolaus