Galileo Galilei  (1564-1642) of Pisa, Italy,  he was one of the greatest astronomers in the world, he was born in  the same year as William Shakespeare  (1564-1616) It was also the same year in which Michelangelo (1475-1564) died. 

Galileo was the first person to use a telescope to look at the universe and publish his work.

In July 1609 was heard about Lippershey travel to Venice to sell his invention, the history don’t say if he bought one from Lippershey or only get the idea, but he never talk about the name of Lippershey anymore.

Galileo was an excellent experimentalist, he made several telescopes, learned to grind his own lenses and improved the Lippershey instrument multiplying its magnification, making demonstrations of the instrument, which he called a “ Perspicillum” to the Venice government showing ships far out the sea and remarking the military potential of the invention.

Galileo’s telescopic discoveries were publishing in the book  “Sidereus Nuncius”, published in Venice in 1610. The book instantly made Galileo a European celebrity.

The telescope popularized by Galileo continued to dominate the field and it became known as a Galilean telescope or Galilean refractor, He was the first to make the new device widely known.

The Galilean telescope with 5 or 6 feet in length, could be used for terrestrial and celestial purposes, later, by the middle of the century, the Galilean telescope was improved for terrestrial purposes using four convex lenses objective, ocular, erector lens, and a field lens to get enlarged the field of view, for astronomical purposes size increased with 20 or 25 feet , to minimize chromatic aberration and increase magnifications in a single-element objective.

The multi-element objective, invented in 1733, allowed the construction of telescopes of large aperture.

Galileo most remarkable astronomical discoveries was the mountains on the Moon, Jupiter’s moons, sunspots, the rings of Saturn, phases de Venus, and discovered many other important phenomena.

In December of 1613, the Church clergy from the Vatican said that his observations could be true, since they would contradict the Bible, in reference a passage in Joshua where God causes the Sun to stand still and lengthen the day, how could this mean anything other than that the Sun went around the Earth?  And accused Galileo of heresy.

In 1600, a man named Giordano Bruno was convicted for believing that the earth moves around the Sun, Bruno was burnt to death, this time Galileo was found innocent of all charges, but this matter still o rest of his life, years later in 22nd day of June of the year 1633 the tribunal of the Supreme Inquisition that investigated cases would contradict the Bible against Galileo Galilei given a show a degree of ignorance on the part of the church, ended with could not possibly the Earth rotate around the Sun and formally accused Galileo again of heresy.

He was old and sick, threatened with torture; he public ally confessed that he had been wrong to say that the Earth moves around the Sun.

Saving his life, he was allowed to live under house arrest, he continued to investigate other areas of science even published a book on force and motion until his death in on January 8, 1642, in Arcetri, near Florence.

Centuries later the Church finally accepted that Galileo might be right, It wasn’t until 1981 that the Vatican ordered a Pontifical Commission to look into Galileo’s case, and after 11 years, In October 1992, 350 years after Galileo’s death, the commission acknowledged the “errors” of Galileo’s judges, the Pope John Paul II reviewing the commission’s report, proclaimed that the Roman Catholic Church erred in condemning Galileo, who spent the last years of his life under house arrest.

Galileo Galilei was a great astronomer and scientist.