1.  A look inside the brain in real time

Neuroscientist and inventor Christopher deCharms demonstrates a new way to use fMRI to show brain activity — thoughts, emotions, pain — while it is happening. In other words, you can actually see how you feel.

2.  Reach into the computer and grab a pixel

The border between our physical world and the digital information surrounding us has been getting thinner and thinner. Designer and engineer Jinha Lee wants to dissolve it altogether. As he demonstrates in this short, gasp-inducing talk, his ideas include a pen that penetrates into a screen to draw 3D models and SpaceTop, a computer desktop prototype that lets you reach through the screen to manipulate digital objects.

3.  Stephen Hawking's zero g flight

X Prize founder Peter Diamandis talks about how he helped Stephen Hawking fulfill his dream of going to space — by flying together into the upper atmosphere and experiencing weightlessness at zero g.

4. Yup, I built a nuclear fusion reactor

Taylor Wilson believes nuclear fusion is a solution to our future energy needs, and that kids can change the world. And he knows something about both of those: When he was 14, he built a working fusion reactor in his parents' garage. Now 17, he takes the TED stage at short notice to tell (the short version of) his story.

5.  How I built a windmill

When he was just 14 years old, Malawian inventor William Kamkwamba built his family an electricity-generating windmill from spare parts, working from rough plans he found in a library book.