This week MIT’s Media Lab is hosting ScratchEd, a conference centered on Scratch. Scratch is a programming language that breaks down code into visual blocks and allows users to animate objects on the screen without using more complex programming languages. When combined with LEGO WeDo sensors and motors it can also be used to animate physical objects. Scratch is incredibly versatile and can be used in conjunction with everything from an xbox Kinect to simple handmade sensors.
Prior to the start of ScratchEd, the MIT Media Lab hosted a variety of different workshops demonstrating the wide range of potential uses of Scratch. I chose to attend Physical-Digital Chain Reaction: WeDo + Scratch. Above is a video of the final run of our collaborative virtual/physical Rube Goldberg machine. You can’t see everything, but as the ball comes around watch the laptop screens and how the digital ball triggers the levers that push the actual balls.
You can view a larger version here.

Each group was responsible for catching the physical ball of the team to their left. When our sensor registered the other team’s ball, it set our virtual (animated ball) in motion. When the virtual ball bounced off the right side of our screen, it triggered a lever, the green and gray LEGO device sticking up behind our computer. This lever set our physical ball in motion, rolling down the ramp and off to the next group.
Take a look at this video for a more straightforward example of a physical-digital chain reaction.