'Anti-Gravity' Ball Floats in Mid-Air
MIT students created an 'anti-gravity' space with a ball people can move and play with.
Hasn't everyone always wished for a small anti-gravity portal of his own? Jinha Lee, a doctoral student in media arts at MIT, and his lab-mates have created a small "anti-gravity" space for people to play with. Within it, people can move a special magnetic ball, record loops for the ball to bounce along. With the aid of a hidden projecter, users can also project images onto the ball, to make it look like a planet for example.
What Lee calls the ZeroN ball stays in the air with magnetic levitation, the same technology that keeps anti-gravity toys and Japan's maglev trains aloft. Above the ball, a magnetic coil provides the levitation. Below the ball, a tabletop with a projector hidden inside beams images onto the table for scenes. And all around, cameras track the position of the ball and of people's hands. The anti-gravity effect works in the middle of all these instruments, in a space that's 15 inches by 15 inches by 3.5 inches (38 centimeters by 38 centimeters by 9 centimeters).
When people put the ball somewhere in the anti-gravity space or move it from one place to another, the cameras track what's happening and the magnetic coil moves to keep the ball suspended in its new position. The user's hands and other non-magnetic materials don't affect the magnetic levitation, according to a paper Lee wrote for an Association for Computing Machinery conference held in October.
The cameras can also detect when someone grabs the ball for longer than two and a half seconds. They automatically switch to a mode that records what the ball does as long as the person is holding it. When the person lets go, the ZeroN system moves the ball along the same path, bouncing through the air in an endless loop.
Besides looking cool, ZeroN can work as a teaching aid. People can enter commands, such as planetary orbits, into the ZeroN's computer for the ball to follow. Users can put a plastic "sun" in the middle of the table for the ZeroN ball to orbit, while a projector beams images on the ball to make it look like Mars or any other planet. Place a second plastic planet on the table, and the system will detect it an alter ZeroN's orbit accordingly.
The ZeroN ball can act like a sun itself, too. In an "architecture" mode, users put buildings on the table and put the ZeroN ball above. The projector inside the table will create light and shadows as if the ball were the sun. People can move the ball around to see how shadows change, helping artists and urban planners predict what shadows would fall in a particular city layout.
Next, Lee wants to reduce the ZeroN ball's slight wobbling movement in the air, he wrote in his paper. He'd also like to create a space that can suspend more than one ZeroN ball, but that's a challenge as the balls' magnetic fields would interfere with each other. In the future, perhaps people will be able to move and place objects anywhere they want in the air, he wrote.