Streams of sound are now all you need to make objects dance in the air and combine. A levitation device is the first to use high-frequency sound waves to bring together floating particles and liquid droplets. In principle, the technique could even levitate a person or animal – although it’s not strong enough yet.
For now, such hands-free control could be used to study chemical reactions in extreme environments, to move hazardous materials and to simulate the low-gravity environment of space. At 24 kilohertz, the waves are too high-pitched to be audible to humans – but can be heard by some animals, including cats, bats and mice.
Other levitation methods use magnets or electrical fields, making mag-lev trains – and even levitating frogs – possible. But in these cases, the levitated objects must have particular magnetic or electrical properties.
Acoustic levitation imposes no such constraints. It can, in principle, float anything, says Dimos Poulikakos of the Swiss Federal Institute of Technology (ETH) in Zurich, Switzerland.
A sound wave is a pressure wave that produces a force and so has the potential to counteract gravity. To float things using sound, you need to ensure the force remains constant in a particular point in space.
This has been done previously, by using speakers or other resonators to fire pressure waves upwards and bounce them off a reflector. The original waves and their reflections then combine to create a standing wave, with a series of stationary "nodes" that stay put even as the wave oscillates.
If the standing wave has the right frequency, the force at these nodes exactly cancels gravity – and anything trapped there hovers in place.
"Scientists at Argonne National Laboratory have discovered a way to use sound waves to levitate individual droplets of solutions containing different pharmaceuticals. While the connection between levitation and drug development may not be immediately apparent, a special relationship emerges at the molecular level."
Pressure from the United Patriots Front Stops Mosque Plan 2016-04-28 20:10
Pressure from the United Patriots Front appears to have killed off a mosque development in Narre Warren North.
The City of Casey council now looks likely to withhold planning approval for the development in a special meeting set for Tuesday night.
A council report, to be considered by councillors on Tuesday, recommends that the approval be blocked.
The mosque opponents’ cause has been helped by councillor ...
Police face questions over the influence of the Freemasons 2016-04-28 20:48
South Yorkshire Police today face questions over whether powerful 'secret society' the Freemasons held sway over the force at the time of Hillsborough.
Families of victims say that officers who were Masons were promoted into powerful positions despite being ill-equipped, including match commander David Duckenfield.
Duckenfield told the fresh inquests he had been a Freemason since 1975 and became head of his ...
England Bans its Own Flag to Avoid Offending Muslims 2016-04-27 2:23 St. George's Cross "racist" towards immigrants
Government officials said their city was ‘too multicultural’ to celebrate St George’s Day, England’s version of the 4th of July.
The council said that displaying the English flag may have been seen as “racist” towards immigrants.
Half of Western European men descended from one Bronze Age ‘king’ 2016-04-27 2:09
Half of Western European men are descended from one Bronze Age ‘king’ who sired a dynasty of elite nobles which spread throughout Europe, a new study has shown.
The monarch, who lived around 4,000 years ago, is likely to have been one of the earliest chieftains to take power in the continent.
He was part of a new order which emerged in ...
"Local Residents" Are Filmed Stealing Dozens of Bottles of Water at London Marathon Stop 2016-04-25 23:10
Editor's Comment: "Local" residents? Why bother blurring their faces? We know who they are.
London marathon runners were robbed of dozens of bottled waters when thieves raided a refreshment area armed with trolleys during today's race.
Nearby residents - including parents with children - were captured on camera piling up crates of free water handed out by volunteers during the 26-mile event.