# Sound Waves carry Mass

#### Yaakov

Joined Jan 27, 2019
1,612
I think the mass is from the medium through which they move, not the transducer.

On the other hand, if you wait long enough, I am sure your speakers will disappear, one way or another.

#### pmd34

Joined Feb 22, 2014
518
Haha I love this bit: "Importantly, the researchers did not actually measure mass being carried by a sound wave—they used math to prove it happens"

#### Tonyr1084

Joined Sep 24, 2015
5,031
PHONONS ? ? ? LMAO!

Sound will not travel through a vacuum. If there WERE mass then sound WOULD travel through a vacuum.

Measuring (not using math to justify your findings) measuring the gravity fluctuation of a sound wave only means that as a sound wave compresses the air molecules - it stands to reason the increased density of air molecules would hold a higher gravitational equivalency.

Sorry, I just don't see how sound can carry mass. Otherwise by now the back window of my car should be coated with sublime'd speaker cone material.

#### wayneh

Joined Sep 9, 2010
16,399
I call BS. I was thinking it could be reasonable that a small mass was displaced by sound traveling through a medium, slightly analogous to the small flow of electrons in an electric field.

But then I considered a thought experiment of a speaker inside a balloon, floating at neutral buoyancy. As sound is produced and leaves the balloon, there’s no flow of mass across the walls of the balloon. The balloon neither sinks nor rises.

#### Tonyr1084

Joined Sep 24, 2015
5,031
The balloon neither sinks nor rises.
I - too - call BS on this. However, your balloon analogy - sound as it seems - the buoyancy may be ever so slightly altered that it would be nearly impossible to perceive (from a human vision point of view) where the balloon would gain or lose mass.

There was an experiment done many years ago attempting to prove humans had a soul that left the body at the time of death. They put dying patients on a bed and carefully set a scale to neutrally balance out his weight. IF a soul should leave his body then the scale should become unbalanced and trip a signal. Recording the moment of the scale tipping was supposed to identify both that a soul had left the person AND register the time of his spiritual death. Results were never conclusive. Interesting theory though. But it's as likely as growing spaghetti on a tree.

#### mvas

Joined Jun 19, 2017
537
PHONONS ? ? ? LMAO!

Sound will not travel through a vacuum. If there WERE mass then sound WOULD travel through a vacuum.

Measuring (not using math to justify your findings) measuring the gravity fluctuation of a sound wave only means that as a sound wave compresses the air molecules - it stands to reason the increased density of air molecules would hold a higher gravitational equivalency.

Sorry, I just don't see how sound can carry mass. Otherwise by now the back window of my car should be coated with sublime'd speaker cone material.
In physics, a PHONON is a collective excitation in a periodic, elastic arrangement of atoms or molecules in condensed matter, specifically in solids and some liquids.

"condensed matter" is the opposite of a vacuum.

#### Tonyr1084

Joined Sep 24, 2015
5,031
Sorry, I've never heard of "Phonons" before. It just struck me silly - non-seriousness.

Remember the movie "Avitar"? Scientists were in search of the rarest element of all, known as "Unobtainium". Now THAT is just plain silly!

 Now THIS is a good morning for sure!

#### wayneh

Joined Sep 9, 2010
16,399
I - too - call BS on this. However, your balloon analogy - sound as it seems - the buoyancy may be ever so slightly altered that it would be nearly impossible to perceive (from a human vision point of view) where the balloon would gain or lose mass.

There was an experiment done many years ago attempting to prove humans had a soul that left the body at the time of death. They put dying patients on a bed and carefully set a scale to neutrally balance out his weight. IF a soul should leave his body then the scale should become unbalanced and trip a signal. Recording the moment of the scale tipping was supposed to identify both that a soul had left the person AND register the time of his spiritual death. Results were never conclusive. Interesting theory though. But it's as likely as growing spaghetti on a tree.
In any closed system, detecting an outflow of mass might be challenging but is very doable. Of course that would prove it wasn’t as closed as was thought. But these guys seem to be claiming that for sound to leave the closed system, a little mass has to go with it. That’s not a hard hypothesis to test. Maybe I’m misreading the implications of their claim.

#### Tonyr1084

Joined Sep 24, 2015
5,031
Well, physics is not my strongest suit. I can't logically or intelligently refute their claim. However, I CAN say that I find it hard to believe. And that I won't be, anytime soon, putting stock in their hypothesis. Or "Spaghetti trees".

#### mvas

Joined Jun 19, 2017
537
Haha I love this bit: "Importantly, the researchers did not actually measure mass being carried by a sound wave—they used math to prove it happens"
This is exactly how many theories begin.

#### Tonyr1084

Joined Sep 24, 2015
5,031
On the notion of Phonic Mass, if it is true then wouldn't the same be (or similar to) true of electromagnetic waves?

#### Tonyr1084

Joined Sep 24, 2015
5,031
In THIS thread, we're discussing how sound waves can be used to detect fluid levels in containers. A point I've made as a trained UT Technician is that sound waves travel and reflect off the first and last surfaces of a particular material. In this case we're talking about a steel tank that appears to be stainless steel. If there's an imperfection within the wall of the container it too will reflect a portion of a sound wave. If PM (Phonic Mass) theory is true then are we suggesting we're sending mass through another mass? Honestly that's a question I'm not qualified to answer; but I suspect it doesn't. Nevertheless, discussing such matters can sometimes lead to a greater understanding of things. Whether PM is true or just a calculated error on someone's part remains to be seen. There's another theory of the speed of light - that it's unchanging. Yet we KNOW it slows down when passing through a lens or through a glass of water. So light speed DOES change. So I have to ask: If PM carries mass then wouldn't it pass through space? If so, shouldn't we be able to hear the sun? Assuming any sound it may make is within the audible range of human hearing. Nevertheless, sensitive microphones should be able to pick up the infrasonic or ultrasonic sound waves transmitted by the sun. I'd have to imagine that if the sun were making noise at all it would be pretty darn loud.

#### bogosort

Joined Sep 24, 2011
484
On the notion of Phonic Mass, if it is true then wouldn't the same be (or similar to) true of electromagnetic waves?
The physics of sound waves is quite different from that of light waves, but -- as both carry energy in their respective fields -- there must be an associated mass with each.

#### bogosort

Joined Sep 24, 2011
484
IThere's another theory of the speed of light - that it's unchanging. Yet we KNOW it slows down when passing through a lens or through a glass of water. So light speed DOES change.
The speed of light isn't invariant; the speed limit is.

So I have to ask: If PM carries mass then wouldn't it pass through space?
Like all waves, sound needs a field -- physical "stuff" with certain properties -- in which to travel. Space is mostly devoid of the stuff sound needs, though it does have the electromagnetic field for light to travel.

#### OBW0549

Joined Mar 2, 2015
3,545
Haha I love this bit: "Importantly, the researchers did not actually measure mass being carried by a sound wave—they used math to prove it happens"
Yup. That's the point at which I stopped reading the article. If they'd said, instead, that "their mathematical models suggested it should happen" I would have gone on; but they didn't.

#### Tonyr1084

Joined Sep 24, 2015
5,031
I only read all the way through because it was a short enough read. And I was interested to see if they said anything else that might have made me laugh.

#### OBW0549

Joined Mar 2, 2015
3,545
I only read all the way through because it was a short enough read. And I was interested to see if they said anything else that might have made me laugh.
Well, I did also get a laugh out of this bit:
Using effective field theory, they showed that a single-watt sound wave that moved for one second in water would carry with it a mass of approximately 0.1 milligrams.
And using grade-school math and common sense, according to their theory that same 1 watt sound wave would therefore move about 8.6 grams over the course of a day (1 day = 86,400 seconds)-- more than enough mass to measure.

But they didn't.

#### BobTPH

Joined Jun 5, 2013
2,534
I think you are all reading this wrong. I don't think the claim is that mass is moved from one place to another by sound waves. I think what he is saying is the the wave itself is affected by gravity, that is, it create a gravitational field and interacts with a gravitational field.

This interpretation would make the balloon argument and the 8.6 gm of mass argument moot.

Bob

Joined Mar 10, 2018
4,057
Sorry, I've never heard of "Phonons" before. It just struck me silly - non-seriousness.

Remember the movie "Avitar"? Scientists were in search of the rarest element of all, known as "Unobtainium". Now THAT is just plain silly!

 Now THIS is a good morning for sure!
https://en.wikipedia.org/wiki/Phonon

Regards, Dana.