It's not magic or hidden strings keeping this metal ball suspended in midair. It's science.
Created by Jinah Lee and colleagues out of MIT's tangible media group ZeroN is an "interface element that can be levitated and moved freely by computer in a three dimensional space." The program allows users and computers to interact physically through a "magnetic control system that can levitate and actuate a permanent magnet in a pre-defined 3D volume."
Columnist Mike Eglan explains it like this:
The project, called ZeroN, uses magnets, a Kinect visual system, plus special software that enables either the computer to move a steel ball around in space, or a human to just grab it and move it, essentially telling the computer where it should go.
Here' Lee shows you how it works:
Here's a bit more explanation from Lee, Rehmi Post and Hiroshi Ishii's 2011 paper:
ZeroN serves as a tangible rep- resentation of a 3D coordinate of the virtual world through which users can see, feel, and control computation. To ac- complish this we developed a magnetic control system that can levitate and actuate a permanent magnet in a pre- defined 3D volume. This is combined with an optical track- ing and display system that projects images on the levitat- ing object. We present applications that explore this new interaction modality. Users are invited to place or move the ZeroN object just as they can place objects on surfaces. For example, users can place the sun above physical objects to cast digital shadows, or place a planet that will start revolv- ing based on simulated physical conditions.
As the paper explains, tangible interfaces are meant to "bridge the gap" between the virtual and physical world. Some technology has already done this on 2D surfaces. What the group hoped to achieve with ZeroN is "a 3D space, where the computer can control the 3D position and movement of gravitationally unconstrained physical objects that represent digital information."
Read more about ZeroN here.