The earliest telescopes used by astronomers were:
A) reflectors
B) refractors
C) radio telescopes
D) about the aperture of the telescope on Mount Palomar
E) used late at night to look into the neighbors' windows

Question

Quizplus · Accepted Answer

The earliest telescopes used by astronomers were refractors, which used lenses to bend and focus light, such as the one used by Galileo in the early 1600s. Reflectors, which use mirrors instead of lenses, came later and were invented by Isaac Newton in the late 1600s. Radio telescopes, which detect radio waves instead of visible light, were not invented until the 1930s. The question of the aperture of the telescope on Mount Palomar is unrelated to the history of the earliest telescopes. The last option is inappropriate.

The Earliest Telescopes Used by Astronomers Were