billy o’callaghan: “galileo’s drawings of our sun’s spots (1612)”

Galileo Galilei drew our Sun’s spots at about the same time each day over the course of 37 days in June and July of 1612 (skipping two days and yielding 35 drawings). He could not look directly at our Sun without significant damage to his eyes. His solution was to use the latest technology – a telescope – to project an image of the Sun onto a piece of prepared paper. Galileo drew a circle with a compass and positioned the paper so that the Sun aligned with the circle, allowing him to draw in the sunspots from a consistent perspective each day. A casual review of these drawings makes evident that our Sun rotates, and at a much slower rate than Earth’s 24-hour cycle. This cascading accordion presents those 35 drawings, side-by-side, in sequence, across 70 pages. This book may be read by by flipping through the pages, like a normal book, or played, like a flip-book crossed with a slinky, to animate one full rotation of our Sun (back and forth).

https://www.printedmatter.org/catalog/59749/

(take a look at this too)