People who saw the 1984 film 2010: The Year We Make Contact might remember a scene in which Roy Scheider, while describing the orientation of the spaceship that he’s aboard, picks up a pen and places it in mid-air in front of himself. While that effect was actually accomplished using a sticky-sided pen and a very clear plate of glass, the same sort of thing is now actually possible – if you’re in the right place, and positioning the right object. The place is MIT’s Media Lab, and the object is a small plastic-coated spherical magnet called ZeroN. Users can physically place it anywhere within a specified three-dimensional block of “anti-gravity space,” then watch as it stays in place when they let it go. It can also move through the air on its own, and even function as a virtual movie camera.
The ZeroN system was created by Media Lab research assistant Jinha Lee in collaboration with Dr. Rehmi Post of the MIT Center for Bits and Atoms, and the Media Lab's Prof. Hiroshi Ishii.
Above its open-air anti-gravity space sits an electromagnet, that can be moved vertically and horizontally via a three-axis motor controller. To the side is a stereo infrared motion-tracking system made with two stock Sony PS3 Eyecam cameras, along with a video projector. A second projector and third camera sit beneath a horizontal translucent screen, that is located on a tabletop underneath the anti-gravity space.
As the user reaches into the space with the ZeroN ball in their hand, the motion-tracking system keeps track of where it is. It relays this information to the motor controller, which moves the electromagnet accordingly. When the user lets go, the magnet will be in such a position that its magnetic field holds the ball in place, right where the user left it. If they then reach in and reposition it, the electromagnet will move with it, to keep it hovering in its new location.
Along with simply keeping the ZeroN where it was left, however, the system can also record its movements and then play them back. This means that the ball could be guided through an aerial routine by hand, let go, and then proceed to repeat that routine on its own.
While these may sound like fascinating parlor tricks, the technology has many potential applications. Using the side-mounted projector, for instance, images can be projected onto the surface of the ZeroN. They will not only stay with it through 3D space, but will also rotate with it as it spins in place. This feature could allow it to be labelled, then used to help visualize physics problems – instead of simply thinking the problems through or looking at two-dimensional computer models, physicists could actually reach in and manipulate models of objects such as electrons by hand.
It could also be used in the field of astronomy to act as a rotating model of a planet, orbiting around a static model Sun.
In fact, it could even play the part of the Sun. If an object is placed on the translucent bottom screen, the bottom projector can be instructed to create a digital virtual shadow for that object on the screen. As the ZeroN is moved above the object, the direction and length of its shadow will change, as if the ZeroN is the Sun.
Additionally, the ZeroN can be assigned the role of a movie camera. In this case, after it has been moved over a grouping of physical models placed below it, a 3D fly-over animation of those objects can be generated, “shot” as if the ZeroN were the camera. This could prove particularly useful to architects, who want to record virtual aerial shots of their hand-built models.
Lee goes into more detail of the possibilities, in the video below.