Authors: Thomas Fink and Yong Mao 

Sure, the four-in-hand might be good enough for you, but this book, written by honest-to-god Cambridge physicists, shows you all the different ways you can knot up. The authors went the extra mile to trace the origins of the necktie all the way back to the 17th century, and equate the books title from the fact that they sat down and came up with a formula postulating that every tie knot consists of 6 possible moves—some of which can be switched up. However, out of all 85 possible ways to tie the tie, SPOILER ALERT: they confess that only 13 don't look totally ridiculous.