Instead of accepting ideas as true based upon authority or revelation, in 1609 he used a telescope to observe the Moon's surface.
(he; used; a telescope; to observe the Moon's surface; T:in 1609) Context(he used,List([79, 86))):(he; used a telescope to observe; the Moon's surface)
he used,List([79, 86))
he he
used used a telescope to observe
a telescope to observe the Moon's surface T:in 1609
the Moon's surface