In February 2019, a group of researchers from Columbia University published the results of an experiment that showed that sound waves can carry gravitational mass. During the experiment, scientists discovered that sound waves can generate a small gravitational field.
“Calculations show that sound waves carry a tiny negative mass, which means that in the presence of a gravitational field, such as that of the Earth, their trajectory will bend upward.” Scientists have found that sound waves also generate a small gravitational field,” the study said.
For many years, physicists believed that sound waves could carry energy, but they did not think that waves could carry mass. However, the researchers found evidence that their earlier findings were wrong, Phys.org reports.
The team of scientists found that sound waves passing through superfluid helium have a small mass. They proved this mathematically, but did not measure the mass carried by the sound wave.
They found that phonons (quasiparticles) interact with the gravitational field in such a way that they transfer mass as they move through the material. In their new work, scientists report evidence that the same results hold for most materials.
Researchers have suggested ways to test their discovery in the real world. One option is to use gravity-sensing devices to study earthquakes. When an earthquake sends sound across the planet, the devices can detect “billions of kilograms of mass” carried by the sound.
In 2020, scientists created an algorithm to detect earthquake signals that deform gravity, changing the density of rocks for a short time. These changes in gravity send signals at the speed of light, allowing earthquakes to be detected even before destruction begins.
How earthquakes create waves inside the planet:
A year before this study, the same group of scientists put forward the theory that phonons have negative mass and, therefore, negative gravity.
Co-founder of string theory Michio Kaku says:
“It turns out that under certain conditions, sound waves can start to rise rather than descend. And this anomaly seems to be consistent with the laws of physics, so that some vibrations, instead of falling down, may actually fall up.”
Researchers of ancient civilizations believe this study suggests how ancient humans managed to move massive stones. Perhaps they used sound waves and vibrations for this.
According to ancient legends, sound was part of the process, and people built giant structures like the pyramids in Egypt using sounds of a specific frequency.
Scientists hope that perhaps someday they will unravel the mystery of sound waves and, on their basis, create a technology for moving objects of large mass.