Last week's best popular science videos:

Numberphile: what exactly was the mathematical problem Matt Damon solved in Good Will Hunting?

SciShow: cannibalism among animals.

Periodic Videos: Rubidium meets water in slow motion.

TED-Ed: electric cars as a realistic alternative. (somewhat related is this other TED talk, which is one of my favorites, and discusses how energy production, distribution and consumption can be completely reformed in the U.S. by 2050.)

Crash Course!: there's another Crash Course series running in parallel with Chemistry: American history. Its fifth episode is about the Seven Years' War.

FavScientist: Ignaz Semmelweis

SciShow: Richard Feynman

From now you can watch these videos as a playlist too.