A trio of scientists at Columbia University have discovered new evidence that sound waves carry a lot. In his article published in the journal Physical Review Letters, Angelo Esposito, Rafael Krichevsky and Alberto Nicolis described the use of effective methods of field theory to confirm the results obtained by the team last year when they tried to measure the mass carried by sound waves.
The sound carries a lot. Why is it important?
For many years physicists were convinced that sound waves carry energy, but there was no evidence that they carry and weight. It seemed there was no reason to believe that they will generate a gravitational field. In the past year this has changed, as Nicolis and another physicist Riccardo Penco unearthed evidence that the traditional view may be wrong. They used quantum field theory to show that sound waves moving in superfluid helium, carry a small amount of weight with me. More specifically, they found that the phonons interacting with the gravitational field so that they were forced to carry the weight as you move through the environment. In the new work, scientists reported that similar results are valid for most materials.
Using effective field theory, they showed that the acoustic wave of one watt, which was moving in the water within seconds, tolerates a mass of about 0.1 milligram. They also note that this lot was part of the total mass of the system moving with the wave, as he moved from one place to another.
It is important to note that the researchers did not actually measure the mass carried by a sound wave — they used math to prove that this is happening. In the case of real measurements, they suggested experiments that can be performed with sound waves in the condensate Bose-Einstein of very cold atoms, such a system must show the portable mass to be measured. They also noted that the best approach might be to measure the mass carried by sound waves that pass through the Land, being part of the earthquake. This sound can carry billions of kilograms of mass that will be seen on devices that measure gravitational field.