houghtonlib: Galileo didn’t know it at the time, but his observations of sunspot activity in
Galileo didn’t know it at the time, but his observations of sunspot activity in 1612 were tailor-made for the animated GIF! He demonstrated that sunspots can be tracked across the disk of the sun as it rotates–look for the cluster labeled R moving from top left to lower right.
Galilei, Galileo, 1564-1642. Istoria e dimostrazioni intorno alle macchie solari e loro accidenti, 1613.
Houghton Library, Harvard University
Wed, 20 Apr 2016 09:40:36
