19
no significant new ideas in astronomy
in this tradition for nearly 1,400
years. Independently, great cultures
in China, India, and the Islamic
world developed their own traditions
through the centuries when
astronomy in Europe made littleprogress. Chinese, Arab, and
Japanese astronomers recorded
the 1054 supernova in the
constellation Taurus, which
made the famous Crab nebula.
Although it was much brighter
than Venus, there is no record of its
appearance being noted in Europe.The spread of learning
Ultimately, Greek science returned
to Europe via a roundabout route.
From 740 ce, Baghdad became a
great center of learning for the
Islamic world. Ptolemy’s great
compendium was translated into
Arabic, and became known as the
Almagest, from its Arabic title.
In the 12th century, many texts in
Arabic were translated into Latin, so
the legacy of the Greek philosophers,
as well as the writings of the Islamic
scholars, reached Western Europe.The invention of the printing
press in the mid-15th century
widened access to books. Nicolaus
Copernicus, who was born in 1473,
collected books throughout his life,
including the works of Ptolemy. To
Copernicus, Ptolemy’s geometrical
constructions failed to do what
the original Greek philosophers
saw as their objective: describe
nature by finding simple underlying
principles. Copernicus intuitively
understood that a sun-centered
method could produce a much
simpler system, but in the end
his reluctance to abandon circular
motion meant that real success
eluded him. Nevertheless, his
message that physical reality
should underpin astronomical
thinking arrived at a pivotal
moment to set the scene for the
telescopic revolution. ■FROM MYTH TO SCIENCE
499 CE
1025
C.118 0
1279
1437
1543
Italian scholar Gerard of
Cremona makes Arabic texts,
including Ptolemy’s Almagest,
accessible in Europe by
translating them into Latin.Chinese astronomer
Guo Shoujing produces an
accurate measurement of the
length of the solar year.Mongol ruler Ulugh Beg
corrects many of the
postions of stars
found in the Almagest.Arab scholar Ibn
al-Haytham produces
a work that criticizes
the Ptolomaic model
of the universe for
its complexity.In the Aryabhatiya,
Indian astronomer
Aryabhata suggests
that the stars move
across the sky because
Earth is rotating.
Nicolaus Copernicus’s
book De revolutionibus
orbium coelestium is
published, outlining a
sun-centered cosmos.It is the duty of an astronomer
to compose the history of the
celestial motions through
careful and expert study.
Nicolaus Copernicus