Sound waves can levitate and move objects through space, according to the three researchers and coauthors of a recent study, Jun Rekimoto, Takayuki Hoshi and Yoichi Ochiai — but, they’re not wizards, no — they are scientists from the University of Tokyo. Their study is called “Three-dimensional Mid-air Acoustic Manipulation by Ultrasonic Phased Arrays.”
It’s been claimed and might some day be proven that sound waves brought the walls of Jericho tumbling down. These three scientists, however, weren’t examining the potential of using sound as a WMD, but were trying to use a levitation rig and ultrasonic standing waves to move objects in and through space, and essentially, time, if Einstein was right.
The technical term for what the scientists are doing with sound waves is acoustic levitation. The idea and dream of being able to levitate objects acoustically has been around for thousands of years, but it is now becoming a reality.
The paper that the three researchers wrote was submitted just this past month to the Arxiv science site at Cornell University. While objects, and even live frogs, have been levitated using magnetism, and some objects have previously been levitated using sound waves, this is the first time that researchers have figured out how to also move the levitated objects.
Did the researchers attempt to levitate an elephant using sound waves?
The researchers are starting off modestly, as far as size goes — they have no plans to levitate anything the size of an elephant, at least not until they can work up to something that size, gradually.
The study is based on the scientists using high-frequency sound waves to levitate objects which are extremely light. Then, after they levitate or suspend the objects in the air, the researchers have discovered how to move the objects through space by manipulating the sonic waves, something that they couldn’t do with their earlier experiments where they tried bouncing sound waves off of solid surfaces.
Past experiments involving sound waves to levitate objects in mid-air used in-line speakers and utilized sound reflected, or bounced off of, a sound-reflecting surface. The method that the three scientists from Tokyo detail in their study is very different, though.
They didn’t use speakers lined up in a row. Instead, they used four arrays of speakers, facing towards each other, so that they sound emanating from all of the speakers converged into a single focal point where the ultrasonic waves met and merged together. Where the sonic waves converged at this focal point was, the researchers found, an ideal place to levitate small objects.
Then, the scientists discovered that if they moved the focal point up or down or from the left to the right, they could also get the suspended, or levitated, objects to move. To do this, they experimented by varying the output of each of the speaker arrays until they were successful and got the objects to move.
With the recent study, the researchers “levitated and moved” particles that were “millimetre-sized.” These “particles” were drops of water and small beads. By using opposed phased speaker arrays, they created what the study refers to as an “ultrasound beam.” The scientists were then able to move the “localised standing wave” they generated using the opposed phase array of speakers, and move the levitated objects, as a result.
Though the objects the research team moved were very small, their study has provided crucial groundwork that will likely lead, eventually, to levitating and moving larger objects through the use of ultrasonic waves concentrated, not into “solid walls of sound” like in the Elton John/Bernie Taupin song Bennie and the Jets, but into beams of sound. Check out the video below of some of the objects the researchers used levitating and moving through space!
Written by: Douglas Cobb
Video of Levitating and Moving Objects