• Xkcd: Gravity https://xkcd.com/2712/ 6 comments 17/12/2022

• xkcd: Gravity Wells http://www.xkcd.com/681/ 8 comments 28/12/2009 reddit.com
• xkcd: Gravity Wells http://xkcd.com/681/ 19 comments 28/12/2009 science
• Development notes from xkcd's "Gravity" and "Escape Speed" https://chromakode.com/post/xkcd-gravity-escape-speed/ 12 comments 16/5/2023 programming