You have probably played with Kinect. At the very least, I’m hoping you’ve heard of it. The idea is pretty simple: a special camera looks out from the TV, and tells the XBox about your body position, which allows you to control video games in a way that’s very different from a traditional controller, or even than the Wii. What you mightn’t realize is that only about 5 years ago, most people thought it was impossible to build such a system with the kind of computing power we have today. Many scientists and engineers around the world were working on ways of solving the problem (we called it “markerless human motion capture”), but it looked far off. In a tiny way, it was a bit like all the people working on heavier-than-air flight at the turn of the 20th century—although the Wright brothers get the credit, there were many little steps before they made the first sustained flight. Then, in 2007-2008, several elements came together, and one person at XBox called Alex Kipman suddenly decided it could be done, and gathered a group of people to try to build it. I’ll talk about the steps leading up to this “impossible project”, and how we worked to make it possible. I don’t know what impossible problems the world’s boffins will solve next—invisibilty cloak? anti-gravity? wireless power?—but I hope some of you will one day be involved in changing our future.