The hard part about opening a hole in the proof of the Poincaré conjecture is that Grigori Perelman will come out of retirement to try to fix it by drawing a loop around the hole and contracting it to a point.
Special 10th anniversary edition of WHAT IF?—revised and annotated with brand-new illustrations and answers to important questions you never thought to ask—coming from November 2024. Preorder here!
