Using a simple set of loudspeakers, scientists have figured out a way to levitate and rotate objects in midair. If perfected, this "sonic tractor beam" could find uses ranging from treating kidney stones to creating artificial gravity on the International Space Station.
Scientists have used sound to levitate objects before. That feat isn't surprising, as sound is a wave of pressure strong enough to move your eardrum. However, instead of audible sound, sonic levitation utilizes higher ultrasonic frequencies that are beyond the range of human hearing. When blared from loudspeakers in the right configuration, these sound waves can combine to form a sonic scaffolding called an interference pattern—a sort of a force field that can hold a small object aloft.
[...] The algorithm works by constructing the best possible interference patterns, one that not only keeps the bead floating, but lets it twist and move with some freedom. The interference pattern comes about by adjusting the precise synchronization, or "phases," of the waves leaving the various speakers. By setting the phase differences just right, the researchers make the waves combine to reinforce one another in some places and cancel out one another in other places. In that way they create a complex 3D pattern of high and low pressure regions, which the authors call an "acoustic hologram," that can support the bead against the pull of gravity. As the algorithm tunes the phases, the interference pattern and resulting hologram change, enabling researchers to move the bead around.
(Score: 0) by Anonymous Coward on Thursday October 29 2015, @11:53PM
It is a repulser beam. It moves the object above it... Up, down and around and around. Gravity drops it back to surface when it is powered of.
Now if they placed the array above the obejct and pulled into the air vs. pushing then that is different story.
PS: another bad title.
(Score: 0) by Anonymous Coward on Friday October 30 2015, @02:48PM
Maybe a sonic screwdriver?
(Score: 0) by Anonymous Coward on Friday October 30 2015, @11:15PM
"As the algorithm tunes the phases, the interference pattern and resulting hologram change, enabling researchers to move the bead around."
The fact it happens to support it against gravity is incidental to the tractor-beam ability of moving it laterally, which could include "pulling" an object in microgravity towards a unit using a sufficiently advanced implementation (within a sound-propagating medium of course).
The really big question is: can these complex structures of low and high pressure regions be analogously created as charged regions with an electromagnetic version? Such charge structure is what gives matter its solidity… if it can be efficiently synthesized without the heft of nuclear mass, the implications would be profound.