Felton Davis offered thousands of strangers a close-up view of the Moon and planets orbiting New York City. Now he’s passing ...

Among his many achievements, English physicist and mathematician Isaac Newton revolutionized the way we look at the cosmos. In 1668, he built the world’s first reflecting telescope, which had ...

Isaac Newton built the world's first reflecting telescope in 1668. Jimmy Sime/Central Press/Hulton Archive/Getty Images The Royal Greenwich Observatory was founded in 1675 by King Charles II.

With this development, Hall proved that Isaac Newton was mistaken in his supposition that color distortion could not be solved using refracting rather than reflecting telescopes.

What exactly are Dobsonian telescopes? We explain their design and why they have such widespread popularity among astronomers.

Newton invented the first practical reflecting telescope, improving upon the existing refracting telescopes of his time.

Later in the same volume (p. 129) we read “I have myself seen the first telescope [Newton's reflecting telescope] … preserved in a city of England … with this are treasured up those prisms ...