Does sound have mass? Yes it does, according to researchers who make bizzare claim about “phonons”

Sound has “negative mass,” according to an article in Live Science.

[Editor’s note: This study is fascinating, but surely must be either a prank or an error. We cover it here because of its novelty, but we do not endorse its flawed conclusion. No doubt the researchers will soon discover they made a measurement error, and they will issue a retraction.]

According to the study authors, the negative mass in sound causes it to slowly but surely drift upward, instead of being pulled downward because of gravity.

Researchers from Cornell University made this assertion in a recently published study. Their discovery runs counter to the established understanding of sound and its waves.

The generally accepted understanding is that sound waves do not have mass. When they pass through matter, they exert force on molecules. However, any forward or upward movement they impose gets neutralized by an equal motion in the opposite direction.

This behavioral model accounts for the way sound behaves. However, the study brings up certain claimed exceptions to the rule.

For Cornell researcher Rafael Krichevsky, he describes the phonon as a unit of vibration that represents a very small measurement of sound. It behaves very much like a particle, but it has a minute amount of negative mass, causing sound waves to move upward very slightly. (Related: The healing power of sound: Energy fields determine how healthy you are.)

Phonons, the sound particles that fall upwards instead of downwards, claim researchers

Krichevsky explains that a phonon is different from typical particles. He notes that the passage of sound through the air will disturb the molecules. However, the movement of those molecules cannot define the vibration that set them to vibrate in the first place.

Instead, phonons resemble their similarly-named counterparts, photons. Photos are particles of light. At the same time, they can also be used to describe light waves.

Similarly, phonons can describe sound waves that are produced by the way the molecules of the fluid medium interact with each other. No physical phonon appears, but the ensuing particle movement can describe it.

The Cornell study adds that a phonon has a very small bit of mass. But because it has negative mass, when gravity acts on it, the phonon goes in the opposite direction.

“In a gravitational field phonons slowly accelerate in the opposite direction that you would expect, say, a brick to fall,” Krichevsky said.

New theory posits sound particles have negative mass that counters gravity

The study used the example of a normal fluid. Gravity imposes a downward motion on that matter. The particles in the upper layer of the fluid would also press down on their counterparts below, resulting in a denser lower layer.

The denser the matter in the medium, the faster sound goes through it. Since the upper layer is less dense than the lower layer, sound above a phonon will move slower than the one below the sound particle. Due to this fluid mechanic, the phonon ends up slowly moving upward.

Krichevsky believed this particle-level upward shift also applies to much larger sound waves. So any word you utter will move upward at a slight angle. If it lasts long enough to travel at a far enough distance, it will arc into the air.

So what does it mean for us if sound actually has mass? In this case, what does it mean if it has negative mass?

For one thing, neutron stars are stars that have collapsed into a very compact form. Their cores are so dense that sound waves can reach the speed of light inside such a star. If a sound wave possessed anti-gravitational behavior, it would affect the behavior of a star that is close to being a black hole.

Visit for more articles about the discoveries about sound waves and particles.

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