tag:twitter.com,2013:795734470418661376_favorited_by_771583225466531840
John Carlos Baez
https://twitter.com/ChrisAldrich/status/795734470418661376#favorited-by-771583225466531840
tag:twitter.com,2013:795734470418661376_favorited_by_771583225466531840
John Carlos Baez
https://twitter.com/ChrisAldrich/status/795734470418661376#favorited-by-771583225466531840