Let's see the best popular videos of the last (two) weeks!
Numberphile: after last time's funny story about squaring the circle, here's an explanation of the mathematical problem itself.
Smarter Every Day: amazing slow motion captures of smashing glass drops.
Veritasium: the roundest object in the world, and the history of kilogram.
Sixty Symbols: why is the Higgs boson important?
Mental Floss: 45 fun facts about U.S. presidents.
TEDTalks: architecture and microbiology - how can we engineer ecosystems of microbes surrounding us?
TED-Ed: architect Thomas Heatherwick, who designed the amazing olympic cauldron of the London Olympics, and many other jaw-dropping things.
Vihart: and here's a bonus video for the week long break - poetry!