Feature Cycle of 23 Years Dominates Heat and Light of Sun Share this: Share via email (Opens in new window) Email Click to share on Facebook (Opens in new window) Facebook Click to share on Reddit (Opens in new window) Reddit Click to share on X (Opens in new window) X Click to print (Opens in new window) Print By Science News Magazine Issue: Vol. 28 No. #750, August 24, 1935 Having trouble viewing this? Open in a new window