Galileo and his Telescopes – 23rd October 2008

This evening’s main talk on “Galileo and his Telescopes“ was given by Steve Ringwood. He began by setting the historical context. Italy consisted of a number of City States, James I was dealing with the after efects of the Gunpowder Plot, Luther and the Reformation were stirring the Church, and Shakespeare was publishing his Sonnets. Galileo, who was teaching physics in Padua, got news of a device being used in the Netherlands, and, having heard a very brief description of its constituent parts, was able to construct a small working telescope. He quickly improved the design, and was able to sell a number of them. It was several months before he thought to turn his telescope on the heavens, but once he did he made a number of interesting observations, and soon published a book of them. Much of Galileo’s story is tied up with the Church and the conflict between the Copernican and Ptolemaic descriptions of the known universe. His telescopic observations supported Copernicus’ explanation, and the Inquisition eventually managed to bring him to trial. It’s likely they doctored the evidence in order to convict him and force him to recant his support for Copernicus, but even when he was under house arrest Galileo continued to make observations, and to continue work on materials and motion. A book he published at this time was one which later influenced Newton. Galileo did not invent the telescope, but he was able to make better ones than many of his contemporaries, and his astronomical observations did much to lay the foundations for modern physics and astronomy.