became an important century for both exploring the heavens and the microworld.
Lenses and how to use them was now being developed. The right type of
lenses used for a telescope, were first invented in Holland
in the early part of the 1600's. In 1609 Galileo Galilei
(1564-1642), an Italian, heard of the invention of spyglasses
or refracting telescope. He used lenses in his
"optic" tube, which allowed him to see objects that were
invisible to the unaided eye. Galileo was able to see stars of the
Milky Way, mountains on the Moon, phases of Venus and many other
important observations that would lead him to the laws of inertia (a
body under no constraint moves in a straight line). Galileo's inquiry
on motion would be used by Sir Isaac Newton to uncover more
mysteries of the Universe. In 1632 Galileo published a book attacking
the current theories of the Earth. He was tried in court and was
forced to deny that the Earth moves. He was put under house arrest for
his remaining years.