Venkatesh Rao@vgrIf you have grand-unified-theory hedgehog aspirations, benchmark against Grothendieck Mansion level, not crank levelthebigquestions.comThe Rising SeaAround 1970, Alexander Grothendieck, the greatest of all modern mathematicians and arguably the greatest mathematician of all time, announced — at the age of 42 — the official end of hi…11:06 PM · Nov 23, 20152 Retweets9 Likes