So I'm going through some old National Geographics tonight, and I ran across an interesting story. Not "Interesting, I've never heard of this before." but rather "Interesting, Human race hadn't known about this then." I find it fascinating when you run across written proof of teaching something for the first time. Sure, a majority of humans believe Gravity exists, but there was a time when humans thought it was invisible glue or some such rot. It must have been very exciting to read Newton's Theory of Gravity for the first time. This National Geographic is from April 1961. A close-up of the Exclusive Article.