I would argue that the gradual improvement of glass as a medium spurred on astronomical progress as much as the ingenuity of astronomers. Since Hellenistic times, glass was all but taken for granted. Sure, it was expensive early on, but it was everywhere. Starting with beads, then mosaic tile and vessels. By the 1st century B.C. The Roman Empire had developed fairly consistent recipes for glass manufacturing. The apex of this was the development of blown glass. More on why this is important later. I could write pages on Roman glass, but I’ll just leave this here: The Portland Vase, layered and hand cut between 5 and 25 A.D. After the Empire collapsed some 300 years later, Europe was losing the ability to manufacture glass. The local masters were dying out, and the Venetians were clamping down hard on their secrets. They had also clamped down on the supply of natron, the flux used in Roman glass making.  They inherited … Continue reading →