What other notable achievements must European society have reached even to make this exchange of letters possible?

What other notable achievements must European society have reached even to make this exchange of letters possible?

What does the correspondence between Galileo and Kepler reveal about an emerging spirit of scientific inquiry?

What other notable achievements must European society have reached even to make this exchange of letters possible?

What aspects of European material culture made the work of these scientists easier?

What language were these letters written in?