In a robot lab at TEDGlobal, Raffaello D'Andrea demos his flying quadcopters: robots that think like athletes, solving physical problems with algorithms that help them learn. In a series of nifty demos, D'Andrea show drones that play catch, balance and make decisions together -- and watch out for an I-want-this-now demo of Kinect-controlled quads.

Neuroscientist Greg Gage takes sophisticated equipment used to study the brain out of graduate-level labs and brings them to middle- and high-school classrooms (and, sometimes, to the TED stage.) Prepare to be amazed as he hooks up the Mimosa pudica, a plant whose leaves close when touched, and the Venus flytrap to an EKG to show us how plants use electrical signals to convey information, prompt movement and even count.

View full lesson: http://ed.ted.com/lessons/a-guide-to-the-energy-of-the-earth-joshua-m-sneideman Energy is neither created nor destroyed — and yet the globa...

WATER. It's the most essential and pervasive element of life. Yet, nearly half of humanity will face water scarcity by 2030 due to climate change and populat...

John Witte responds to a question about whether there is a common enough basis among world religions for a human rights declaration.