I was aware of Archemedis’ mirror based death ray from antiquity (and the @MythBusters replication), but TIL that solar mirrors were commercially used in the 15th century for soldering. From @WalterIsaacson’s Leonardo:
用了 #Leonardo# 和 #Lexica# 测试七彩画,关键字 iridescent drawing,prompt:A captivating iridescent portrait of a chameleon, showcasing its ability to change colors and blend into its environment,iridescent drawing