It's fascinating to learn about the transitional period of the Scientific Revolution and just how all these various advances and changes in thinking actually ha

It's fascinating to learn about the transitional period of the Scientific Revolution and just how all these various advances and changes in thinking actually happened. It's usually a lot more complex than we think of now. The article's mention of optical problems in early telescopes is actually quite an important one when it comes to the history of geocentrism vs heliocentrism and the Galileo affair. One of the objections to heliocentrism is that if the Earth moved then we should expect to see stellar parallax, which was not observed (certainly not with the observation technology at the time). The Copernicans responded by positing that the stars were extremely far away, but you can imagine how such an evidence-lacking response would seem like trying to explain away one hypothesis by adding a new one. But in addition, the geocentrists seemed to have solid observational evidence on their side: the apparent diameter of stars when viewed through the telescope either implied that the stars were close enough that we should be seeing parallax with 1600s-era instruments, or that the stars are far away and all absurdly giant in size. It turned out that the manufacture of the telescopes themselves created an optical illusion now known as an Airy disk ( https://en.wikipedia.org/wiki/Airy_disk https://en.wikipedia.org/wiki/Airy_disk ), which makes the stars look like disks and thus have a misleading apparent diameter. It wasn't until 1835 that this phenomenon was understood! For anyone interested in the long and complex history of geocentrism, helicentrism, Galileo and his contemporaries, I have to strongly recommend reading the nine-part series of posts "The Great Ptolemaic Smackdown" by SF author Michael Flynn. It makes for a wonderful bit of weekend reading, and you'll come out of it with a great appreciation for the slow, methodical process of scientific understanding: Part 1: http://tofspot.blogspot.com/2013/08/the-great-ptolemaic-smackdown.html http://tofspot.blogspot.com/2013/08/the-great-ptolemaic-smac... Table of Contents: http://tofspot.blogspot.com/2013/10/the-great-ptolemaic-smackdown-table-of.html http://tofspot.blogspot.com/2013/10/the-great-ptolemaic-smac...