Yes­ter­day’s lack­lus­ter Acad­e­my Awards cer­e­mo­ny may have afford­ed you some unex­pect­ed time for con­tem­plat­ing life’s more urgent ques­tions, such as the one British come­di­an Alan Davies pur­sues above:  How long is a piece of string? Watch Davies, who is also a fre­quent pan­elist on the pop­u­lar Stephen Fry-host­ed quiz show Quite Inter­est­ing, explore the rid­dle’s philo­soph­i­cal impli­ca­tions and inevitable con­nec­tion to string the­o­ry with the help of physics, quan­tum mechan­ics, and final­ly a vis­it with math­e­mati­cian Mar­cus de Sautoy. Fans of the Davies/du Sautoy inter­ac­tion may also want to check out Du Sautoy’s TED talk on Sym­me­try, as well as the debates in that video’s com­ments sec­tion. More docs can be found in our col­lec­tion of 200+ Free Doc­u­men­taries, part of our larg­er col­lec­tion, 4,000+ Free Movies Online: Great Clas­sics, Indies, Noir, West­erns, Doc­u­men­taries & More.