America 250: How has telescope technology evolved since the dawn of the U.S.?

The past 250 years of optical telescopes have seen revolutionary discoveries and technology that the telescope's inventor, a seventeenth century spectacle-maker by the name of Hans Lippershey, maybe wouldn't have believed possible. When we look back through the annals of telescope history, we find that a significant turning point came, coincidentally, just five years after the United States' Declaration of Independence was christened. It was back in England, in 1781. William Herschel had just made what was possibly the greatest astronomical discovery the world had seen up to that point: a new planet, Uranus . The fact that Herschel had found a seventh planet from the sun was revolutionary in itself. All the other planets, from Mercury to Saturn , had been known since antiquity, obvious in the night sky to the naked eye. Uranus, on the other hand, isn't really visible without optical aid, and its discovery illustrated the power of the telescope to dramatically widen our vistas. Moreover, Herschel found the new planet using a 6.2-inch (157-millimeter) reflecting telescope that he had constructed himself. He was looking through it from the back garden of his home in the Somerset city of Bath. Herschel was a prolific builder of telescopes, polishing and shaping their speculum mirrors. …