Concentric circles appear to be spirals. pic.twitter.com/6CJPkpqTR9 https://t.co/pWE9i4igba — Akiyoshi Kitaoka (@AkiyoshiKitaoka) December 14, 2017
Concentric circles appear to be spirals. pic.twitter.com/6CJPkpqTR9 https://t.co/pWE9i4igba