Galileo Galilei, The Phases
of the Moon
1609 Galileo Galilei, a professor of mathematics
at Padua, heard reports of an exciting new
instrument, the telescope. He soon made a
much improved model and turned it toward
the heavens. What he saw there amazed the
world and changed it forever. The Starry
Messenger (Sidereus Nuncius),
a slim volume published in March 1610, reported "great
and marvellous sights": "the lofty
mountains and deep valleys" of the moon;
a Milky Way revealed to be no dusty haze
of light but "a mass of innumerable
stars" that had never been seen distinctly
before; and most astonishing of all, four
satellites of Jupiter.
Copernicus had been right about the solar
system. The challenge to the fixed-earth
doctrine of the church provoked Pope Urban
VIII; eventually Galileo was tried and imprisoned
by the Inquisition, which forced him to recant.
But the revolution in the heavens continued.
In the late 1660s, Isaac Newton greatly improved
the telescope by substituting concave mirrors
for lenses; his six-inch-long reflecting
telescope could magnify forty times, surpassing
a six-foot-long refractor. With the help
of such instruments, Edmond Halley was able
to predict the return of the comet that bears
his name, and William Herschel discovered
Uranus in 1781.
James Thomson, from The
Many amateurs also enjoyed
the pleasures of gazing through a telescope
at the night sky. It was a theme of which
eighteenth-century British poets never
tired, as in James Thomson's appeal
to Nature in his poem The Seasons (1730).
From Autumn (lines 1354–59)
|Snatch me to heaven; thy rolling wonders
World beyond world, in infinite extent
Profusely scattered o'er the blue immense,
Show me; their motions, periods, and their laws
Give me to scan; through the disclosing deep
Light my blind way.