Climate: getting concrete in Beijing

On Tuesday, President Obama and his Chinese counterpart Hu Jintao agreed to cooperate on climate change and other important matters. Anchor Jeb Sharp talks with David Biello, the associate editor for environment and energy at Scientific American magazine.

Arts, Culture & Media

"Horses and Bayonets"

The most tweeted line of the debate was President Obama's zinger that the military has fewer horses and bayonets. So where are bayonets from? Anchor Marco Werman gets the answer, plus the history of bayonets from Chris Woolf.