Scientists have been able to levitate objects with sound waves for some time, though the process has typically suffered from a lack of precision and control.
Now, researchers at the Swiss Federal Institute of Technology (ETH) have developed an "acoustic levitator" that allows them to suspend and then carefully move small substances, like water droplets, between two reflective panels.
Transmitters arranged in a row beneath one of the panels do the heavy lifting. When sound waves emitted by those transmitters echo back off the opposite panel, the two competing, overlapping forces cancel each other out, trapping particles in space.
By upping the power on an adjacent transmitter, particles can be coaxed into moving laterally. That's what you see in the video above, in which a sodium particle is thrust into a water droplet, triggering a suspended chemical reaction.
The trick requires an extreme amount of acoustical force, so the team had to use a frequency beyond what the human ear can detect — think a really powerful dog whistle.
THE WEEK'S AUDIOPHILE PODCASTS: LISTEN SMARTER
- What the collapse of the Ming Dynasty can tell us about American decline
- Colorado’s new ‘drive high, get a DUI’ commercials are actually pretty clever
- Why is American internet so slow?
- 7 ways to be the most interesting person in any room
- Ukraine's fraught relationship with Russia: A brief history
- The GOP must try to win over African-Americans
- 10 things you need to know today: March 10, 2014
- Sandy Hook shooter Adam Lanza's dad: 'I wish he'd never been born'
- Why is it so expensive to build a bridge in America?
- What would a U.S.-Russia war look like?
Subscribe to the Week