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Surprising Discovery Hints Sonic Waves Carry Mass (scientificamerican.com)
jbmartin6 shares a report from Scientific American: In a paper published in Physical Review Letters, a group of scientists has theorized that sound waves possess mass, meaning sounds would be directly affected by gravity. They suggest phonons, particle-like collective excitations responsible for transporting sound waves across a medium, might exhibit a tiny amount of mass in a gravitational field. "You would expect classical physics results like this one to have been known for a long time by now," says Angelo Esposito from Columbia University, the lead author on the paper. "It's something we stumbled upon almost by chance."
Esposito and his colleagues built on a previous paper published last year, in which Alberto Nicolis of Columbia and Riccardo Penco from Carnegie Mellon University first suggested phonons could have mass in a superfluid. The latest study, however, shows this effect should hold true for other materials, too, including regular liquids and solids, and even air itself. And although the amount of mass carried by the phonons is expected to be tiny -- comparable with a hydrogen atom, about 10^-24 grams -- it may actually be measurable. Except, if you were to measure it, you would find something deeply counterintuitive: The mass of the phonons would be negative, meaning they would fall "up." Over time their trajectory would gradually move away from a gravitational source such as Earth. "If their gravitational mass was positive, they would fall downward," Penco says. "Because their gravitational mass is negative, phonons fall upwards." And the amount they would "fall" is equally small, varying depending on the medium the phonon is traveling through. In water, where sound moves at 1.5 kilometers per second, the negative mass of the phonon would cause it to drift at about 1 degree per second. But this corresponds to a change of 1 degree over 15 kilometers, which would be exceedingly difficult to measure.
Esposito and his colleagues built on a previous paper published last year, in which Alberto Nicolis of Columbia and Riccardo Penco from Carnegie Mellon University first suggested phonons could have mass in a superfluid. The latest study, however, shows this effect should hold true for other materials, too, including regular liquids and solids, and even air itself. And although the amount of mass carried by the phonons is expected to be tiny -- comparable with a hydrogen atom, about 10^-24 grams -- it may actually be measurable. Except, if you were to measure it, you would find something deeply counterintuitive: The mass of the phonons would be negative, meaning they would fall "up." Over time their trajectory would gradually move away from a gravitational source such as Earth. "If their gravitational mass was positive, they would fall downward," Penco says. "Because their gravitational mass is negative, phonons fall upwards." And the amount they would "fall" is equally small, varying depending on the medium the phonon is traveling through. In water, where sound moves at 1.5 kilometers per second, the negative mass of the phonon would cause it to drift at about 1 degree per second. But this corresponds to a change of 1 degree over 15 kilometers, which would be exceedingly difficult to measure.
Honestly... I call bullshit way ahead this time.
If it turns out that sound has a negative amount of mass, does this fix many of the problems with dark matter and the weight of the universe? Is dark matter just ... sounds?
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Sound is vibration = kinetic potential energy transferring off particles in a wave... mass = energy.. yadda
Wait until this has been tested, peer-reviewed, published somewhere substantial, and repeated by someone else.
Scientific American has always had a hard-on for treating all of physics as a science, but physics without experimentation is less scientific than modern art. At least the latter has review viewings.
Sound travels through matter, so consists of, well, "phonons" that are really just the slightly altered movements of the matter the sound travels through. Sound exists for as long as that extra movement exists, and for it to exist, the matter needs to be excited, ie possess energy, over and above ambient. So that means sound waves traveling perpendicular to a gravity field have a tendency to be a little less affected by that field than ambient matter. So it looks like phonons have negative mass.
So this apparent mass is an artifact of the way you look at it.
Says I, who is so very much not a physicist. Nor a patent examiner.
Wouldn't this then imply that sound should be able to pass, at least in part, through a vacuum? If sound itself has mass, then sound itself isn't a vacuum...
... like someone got his fundamentals mixed up. I'm sure mass in motion (sound) is hampered/influenced by gravity as it should, but that doesn't mean it itself has mass. I expect this guy's findings to be dismissed any time soon
We suffer more in our imagination than in reality. - Seneca
Given the idiocies all the other commenters wrote at this point, including TFS, you're the only one here who hit the nail on the head.
It seems people don't get that infomation is not a physical object (matter/energy) itself, but only the *structure* of matter/energy. So it's a meta level. In a medium. With different meta laws.
Hence the whole "intellectual property" oxymoron confusion.
TL;DR: Sound does not have mass. The particles that form the medium of sound, do.
Sound is a meta level, so it can only have meta mass. Its "mass" isn't real, just as phonons aren't real. They are only a useful construct.
But this corresponds to a change of 1 degree over 15 kilometers, which would be exceedingly difficult to measure.
If the speed of light was first measured by shining light through a spinning shutter in front of a hole in a box, to a mirror on a tower miles away, I highly doubt that measuring sound over 15 kilometers is beyond the reach of scientists over a century later.
Corruption is convincing someone that the selfless ideal is the same as their selfish ideal.
Let's say you grab the end of a cable tied down at the other end, and you give it a thwap - send a pulse down that chord, that bounces as it hits the end, reducing much like a sound wave. No sound, but a propagating wave in a physical medium that can also make sound if you plucked it instead of whipping it.
Does that add mass?
If so, is there anything special about sound in this? Or would any chain reaction propagation of kinetic energy do the same?
The actual article seems to emphasize that the wave is more 'carrying' mass, rather than establishing any that wouldn't exist anyway - so really, this seems more a matter of measurement and classification of where mass is at any moment, rather than new atoms springing into existence or something.
There's no special detectable radiation from sound in our environment - just, you know, the kinetic wave we're used to.
Ryan Fenton
I always knew my guitar sound was heavy...
You know all these forces (gravity included) are all oscillating electric effects in the resonance model. I can pretty much find them all in the peasoup simulation with greater or lesser confidence.
Magnetic field is an electric oscillation, electric is a frequency 1F oscillation, magnetic is an F/2 oscillation. Every 2F cycles, magnetic effect on electric cancels out. Meaning magnetic appears to be a separate force, until you add velocity, disturb it from F/2 and then the two forces interact. The magnetic poles are the in-phase and counter-phase of this F/2 oscillation.
Big Note: In this model, electric and magnetic DIRECTLY interact. NOT via a mediating particle. This should lead to a TESTABLE experiment (see later).
I'm not sure what their Phonon is,BUT THERE ARE NO MEDIATING PARTICLES IN PEASOUP, all forces are harmonics of electric, and DIRECTLY interact. You can hypothesize a particle joining magnetic to electric (and physics currently does), but the properties of such a particle are as made up as the particle itself. QUASI PARTICLES HAVE QUASI PROPERTIES!
*******
What properties are needed for an electron to produce a magnetic field?
1. The electron must have an orientation with respect to the vector of its current flow. It is not enought to have a two-way axis, it must coordinate with the flow. This is by observation (i.e. Flemings left-hand rule).
2. The same electrons flowing with the same current in the same direction in the same material can produce differing magnetic strength fields. e.g. Superconductivity, reduces or completely eliminates the magnetic field. So there must be a property that defines this. Hypothesis: for a given material, electrons have a given orientation, this orientation is not necessarily the orentation of electron flow, the angle between this orientation and the flow angle dictates the strength of field.
********
Current quasi-particle model is not sufficient.
3. A quasi-particle, a grouping of a particle and the hole it is moving towards is not a viable solution. The physicist has grouped those two items as though they are instance specific, i.e. electron-john and hole-john acting as a single 'john' quasi-particle, electron-bob acting with hole-bob to form the quasi-bob particle. This grouping is a choice he made. It adds the missing orientation to the electron, but requires the specific corresponding hole be considered as a quasi-particle with the correct electron. It's a hack to add the missing orientation to the electron model.
4. Whatever causes an electron to interact with a 'hole' (from 3) would also apply to every hole around every electron. Even holes behind it and holes across the universe. Either the physicist
5. It also leads to 'holes' in vacuums needed to explain a vacuum as if its an electron deficient material! Which it isn't.
6. Since an electron has some orientation, it must have some structure, which means it is not a fundamental indivisible particle. So an ELECTRON IS NOT A FUNDAMENTAL PARTICLE.
7. Whatever component provides the magnetic component, must provide the same for other particles with a magentic field. (Proton electron neutron, all have a magentic component).
8. The first 1 to 7 points do not require you accept the electric oscillating resonance universe.
*******
Resonant electric model:
9. An electron is a F2 donut / -ve monopole / F2 anti-donut sandwich. As per Postulate J3.
10. It is oriented with respect to to the local F field, which in turn is oriented with respect to the atoms around it.
11. As it moves over F field, it rotates half a spin per F (since its a 2 wavelength F2 donut).
12. Motion is a 3 axis electric oscillation, which can be re-vectored as a component in the axis of resonance, and two other components at right angles that maximize that resonance. The larger of the two forms velocity (see Postulate V1), the remnant forms a cross velocity oscillation. That cross oscillation forms the basis for magnetic field.
Actually I thought it was quite the opposite!
I figured that mass carried sound waves and the bigger the mass, the bigger the sound waves would be.
I have watched this in the field when one specimen caught my attention and led me to that discovery.
The specimen makes massive sound waves when he crawls under a desk or makes any kind of physical effort.
For reference, he lives in the Santa Clara County as he is often seen in Palo Alto. For confidentiality reasons, I can only tell you that is name end with ??eimer,
Everything is affected by gravity including light and other massless particles. That is how they first proved relativity.
What is surprising here?
And a sound wave is a movement in particles with mass, so I think relativity also says something about changing their mass.
Not real mass.
Because phonons aren't real elementary particles. They are artifacts of the structure of real elementary particles that make up the medium.
It's a nice useful construct, but don't confuse information meta-space with real space.
The problem is you have a mass of separate forces. Each force needs a binding particle to connect it to other forces, so you have a model full of mediating particles, including this phonon. Quasi particles to connect things together that somehow magically interact via force X and Y but not Z, and other particles connects Y and Z but not X....
These are not real particles, they're simply mechanisms to describe an unknown set of properties at a pinch point.
If you think of the EM Drive, it likely oscillates the electric field (directly), as each oscillation in matter is trying to stay in resonance, it might shift that field so the resonance point shifts each time creating a force. That would be an example of magnetic shifting the electric oscillation.
If you think of this sonic experiment, its likely doing exactly the same thing, but by moving oscillating matter which in turn is shifting that F oscillation field because it's moving matter that is in turn contributing to the field.
Both are likely doing the same things. Twiddling with F.
"sound can travel through what we normally think of as "vacuum", since true vacuum doesn't actually exist."
It certainly does exist. My [sandbox] model is a true vacuum, a perfect empty model with a perfect oscillating F field I use to clean up mess and play with simulated particles in isolation. Think about this sound 'speaker', it's moving matter which in turn is electric oscillating, so its adding an oscillating to the electric oscillating component. That electric oscillation CAN pass through a perfect vacuum, (it does in sandbox!).
If you recall the way I propose to change F, in my hypothetical time machine, is by a low (near zero) electric oscillation, decouple with distance, then shift that whole mechanism (the electric system and the sample) with another electric oscillation near zero. Decouple with distance, another small shift, decouple.... and on and on...
Simplified, you put in energy enough to move something W/1000 per local oscillation, i.e. 1000ths the speed of light, and you tune your frequency to local F/1000 ... does it really matter if you tweak that oscillation with electric, magnetic or even by moving plates mechanically.
If velocity is motion over an oscillating electric field, shifting the oscillation field affects velocity.
You already observed the oscillations (e.g. in electrons)
You already know everything, even neutrons have electric field.
Ergo there is an oscillating electric field everywhere.
So light must be moving over that because electro magnetic properties are all it has.
And since matter converts to light, so must matter be moving over the very same field.
ðY
An Indian-American Hindu committed to non-violent thought/speech/action alarmed by the global explosion of radical Islam
Can't believe this is a story...
this was a suprise to them?
Gravity affects things differently during acceleration/deceleration - like every fringe science experiment suggests.
Well of course sonic waves carry mass. They carry it back and forth as they propagate. That's how they propagate. Any deviation from a DC component of zero will produce a total mass flow. Try talking without breathing out.
But that's not what they're talking about.
The idea that a property of an abstract concept like phonons is, in the abstract, a bit like mass, may not be entirely unsurprising either.
However that doesn't mean there is a thing called phonons that carry mass, nor does it make actual negative mass any more possible than it was prior to this observation.
In water, where sound moves at 1.5 kilometers per second, the negative mass of the phonon would cause it to drift at about 1 degree per second. But this corresponds to a change of 1 degree over 15 kilometers, which would be exceedingly difficult to measure
Uh, if sound moves at 1.5 km/s, and drifts by 1 degree/s, then in 1 second it should have drifted by 1 degree and travelled 1.5 km, not 15km? After 10 seconds it will have travelled 15 km and drifted by 10 degrees, which surely would be measurable. (PS: I read the article, the summary quotes the article correctly.)
A recursive sig
Can impart wisdom and truth
Call proc signature()
Everyone knows that mass and energy are interchangeable. Sound waves are carrying energy, and therefore they are carrying mass. Duh.
We already knew light has mass, why wouldn't sound?
In how far can this be deducted from 'classical' physics? Because phonons are not real, but quasiparticles, only quantised because of the geometrical setup.
Meaning: sonic waves have differences in pressure in them. Something of low pressure tends to go up (helium balloons) in a material, and vice versa.
What if these do not eliminate each other exactly within one wavelength?
Imagining that something may be true is not a discovery. If experimental work showed the speculation to be true then there would be support. If a number of convincing observations failed to disprove then there would be a discovery. But imagining possibilities in Physics is not a discovery at all.
It doesn't explain dark matter. But I'm sure this is somehow related to Superman's ability to fly.
If sound waves carry mass (as opposed to moving mass) the should move through vacuum. That should be easy enough to test (if, against all odds, someone has not experimented with it before)
I'll bet if you applied lorentz and electrostatic forces to the equations, you'd find the rapidly-changing velocities of air particles do allow for particles to be moved in this manner. The effect should increase severalfold when the entire apparatus is surrounded in a larger static magnetic field.
If there is a 1 degree per 15 mile rise in sound underwater, I would imagine that the Navy would have some evidence of it already, due to the use of sonar. I'm pretty sure they would notice a systematic error in position like that. Now whether they recognized it as an artifact of negative mass who knows, but they should have data that shows the deflection.
I'm quite sure that the geniuses at Monster Cable have already patented some gravity cancelling cables with gold plated connectors, which will allow the sound to reach your ears at the proper angle.
I read their paper. They have discovered the Stokes drift. This has been known since the nineteeth century.
Wouldn't this then imply that sound should be able to pass, at least in part, through a vacuum?
No. By definition sound cannot pass through a vacuum. Oversimplifying here but sound is defined as a pressure wave through a medium. No medium = no sound.
If sound itself has mass, then sound itself isn't a vacuum..
Probably an imprecise statement. It's not that sound has mass so much as that it carries energy which has an effect on mass of the medium through which it travels. I've never really thought about it explicitly but it makes some sense that sound and mass would have some relationship. (E=mc^2 and all that)
If you get into the weeds of it, mass doesn't actually mean what your intuition probably tells you. Particles don't actually have a mass that is a single value. What we think of as mass is really just the expected value but at any given time it can vary according to a probability distribution. Also there is the fact that if you add up the weight of the particles in a molecule it's common for the weight of the molecule to be different from the weight of it's constituent particles. Energy into our out of a system can often affect mass in some subtle and not so subtle ways.
Yes. It seems many readers skipped "particle-like collective excitations" in the summary.
If the waves have what they are referring to as "negative gravity", could it not be that the waves are simply exhibiting movement based upon the friction with the material through which the wave is traveling? Since that material is seeking gravity (positive gravity), it should seek to flow under said wave, hence raising the wave, perhaps causing the illusion of negative gravity.
Ok, so since phonons aren't a real phenomenon and are just mathematical placeholders like gravitons, can we all just admit that this is saying in the mathematical framework of quantum theory, this may be possible? Just because the theory allows for it, doesn't mean it exists.
"The Alcubierre drive is a speculative idea based on a solution of Einstein's field equations in general relativity as proposed by Mexican theoretical physicist Miguel Alcubierre, by which a spacecraft could achieve apparent faster-than-light travel if a configurable energy-density field lower than that of vacuum (that is, negative mass) could be created."
https://en.wikipedia.org/wiki/Alcubierre_drive
"Thus, in a very physical sense, the phonon carries (negative) mass."
https://arxiv.org/pdf/1807.08771.pdf
Big apple, new Yorik, undig it, something's unrotting in Edenmark.
Anything that stores energy has mass doesn't it? So a sound wave which is a melange of oscillations of kinetic and potential energy has mass. So this is already known.
Additionally, if it's like a photon, then it is not going to have any additional mass on top of that I believe though I might be wrong.
Some drink at the fountain of knowledge. Others just gargle.
oops... accidentally deleted half my post when I submitted it.
Anyhow, so how do we get to negative mass? I think there are two ways that are essentially realted.
in a nutshell, this is like an airbubble in water. The air bubble is made of air so it has mass. But it floats up like it has negative mass.
Consider the mass defect effect. That's the reason why isoptopes weigh less than they should. the reason is that the attractiv forces in the nucleous create abinding energy well the neutrons are in. So they have less not more energy than a free neutron. As a result they also have less mass than a free neurtron.
If you were to imagine (incorrectly but a sufficient picture) a neutron as oscillating electrons and protons (or quarks), and you would describe what you saw as much like a sound field or a pendulum in which energy flowed back and forth from potential to kinetic energy in the oscillations. And so you would say hey, those oscillations seem to be creating negative mass. But that's backwards. What's happening is the binding forced are what cause the oscillation ust as gravity causes a pendulum. So the binding field has created a lower mass for the particle like the mass defect.
THe other way is to analogize this to the "holes" in semiconductors. We often refer to the "holes" (missing electrons) as having a mass. THey don't but if you model then that way they act like they do. In reality, in a classical picture, they are just missing electrons in a sea of electons. But when we switch to quantum model they become particles and we give them a mass. But this is just subtracting a constant surrounding mass whose inertia is what makes the holes appear to have inertia. If you ejected a hole into free space it would not even exist!
thus you get negative mass when you are subtracting a background.
Some drink at the fountain of knowledge. Others just gargle.
The way you say it still is confusing. We need to be very clear: The
actual particles of the actual medium have of course mass.
But that is a different layer of meaning from the meta layer of phonon "particles". Which do *not* have real mass. The medium particles have real mass. The meta particles have meta mass, if any.
Just like information in the information meta space can be copied at zero cost, taken without the original holder losing it, and is hence infinitely abundant. So there, the concepts of "ownership", " theft", or "property" make no sense, like "north of here" at the north pole.
Only the medium itself takes matter/energy to make, can get stolen, and be owned.
(So a reality-based business model for creating information [like software, art, data] would be a service business model. And nonsense like "intellectual property" or fear of "theft" would not even exist.)
"a change of 1 degree over 15 kilometers, which would be exceedingly difficult to measure."
What? The? Fuck?
Gravitational wave detectors measure changes in length of a thousandth part the diameter of a proton over many kilometers. How can ANYONE possibly say that measuring an arc-degree is exceedingly difficult?
Fucking idiots.
I thought we already figured out that waves have energy and thus can be treated as having mass?
Like, 100 years ago or something like that.
Am I missing something?
Lookup what a "standing wave" can do (which is 'levitate' objects with mass) folks - it's pretty amazing what sound can do...
APK
P.S.=> I thought it was amazing... apk
Sonic waves carry energy. Energy is mass. We've known this for about a century.
So if we know sound is formed during compression / rapid changes in pressure, and there is plenty enough matter going into a black hole, couldn't we then map the interior of a black hole based on the sound waves, since if they have negative mass they should be repulsed out of a black hole? Granted, we probably can't measure it from here as the sound wound wouldn't be able to travel past the matter directly flowing into and around the black hole. But if we could build a series of satellites that circle the most outer expanse of matter available, we should be able to map the refractions of the known large pieces of matter (prior to the event horizon) and develop a baseline by which to then determine the relative shape past the event horizon. Right?
For this reason, God sends them a powerful delusion(operation of wandering)(planet) so that they will believe the lie.
Mystery Red of the Great American Eclipse
It has blood on it!
ABCNews: Eclipse makes pendulum wander
Sun researchers find strange eclipse reading
We've discovered the key to anti-gravity, but to have flying cars, they all have to turn the bass up to eleven.
And that it's just an emergent property of other forces. There is less pressure in the medium at further distances from the "gravity" source making it easier to move, so of course it would tend towards that.
My sound waves do travel up. That's why I have to talk down to people.
Yet your "complex mind" (not) can't do better than I have & GOOD engineering? Does the job & is SIMPLE - complexity's its enemy leading to points of failure/breakdown/exploit.
* BIG TALKER you & nothing to show for yourself, being the DO-NOTHING "ne'er-do-well" you are, lol...
APK
P.S.=> Lastly - & such "courage & conviction" not even standing BEHIND YOUR WORDS as you STALK me by UNIDENTIFIABLE anonymous like the JEALOUS "Lil' Jowie" (lol) you are, hahahaha... apk
Does that mean that the noisier the plane engines the better the plane flies? :P
Witches should fly on vacuum cleaners, not brooms.
You get the idea.
"Everybody's naked underneath" -- The Doctor
The rest mass of an electron is pretty much a single value... in fact it's a fundamental constant you could say.
Not what I'm talking about. PBS Space Time has a very good video which explains what I'm talking about far more eloquently than I probably could. Totally worth watching.
Phonons are an artificial construct. Mass in motion has energy. This energy is transmitted between atoms through collision or transmitted vibration. E=mc^2. So if mass is negative, the energy contained in that mass must also be negative. Since sound waves have a positive effect on mass, and do not STOP motion of an object but add to the motion of the object, this should be a red flag that the mass of phonons cannot be negative. Sound when applied is positive energy. Therefore, any mass must also be positive. If you are getting negative mass, from first principles, an error has been made.
Someone should have realized there was a problem in the calculations instead of justifying the result.
Quantum fields do not exist in exclusion of the particle state of matter. They both exist simultaneously. It's a matter of your frame of reference.
the ratio of the sines of the angles of incidence and refraction of a wave are constant when it passes between two given media.
So basically the sound kind of bounces off the pressure gradient caused by gravity, lifting the mass of the medium with it (slightly). The authors themselves discuss how it is equivalent to sourcing gravity, how to measure the effect in the conclusion, and mention how the same effect could cause two parallel sound save packets to experience a very slight attractive force.
Is about 250 meters, following the 1:60 rule used in navigation. I would've thought a 250m offset is large enough to measure, but maybe not with sound in water.
Does this mean you could theoretically vibrate an object out of orbit? The article suggests the effect could change the ticking of an atomic clock, so this effect apparently isn’t just imaginary for the phonons themselves. I’m assuming this effect is only gravitational and not inertial? Any actual physicists around who can speak to this?
"In water, where sound moves at 1.5 kilometers per second, the negative mass of the phonon would cause it to drift at about 1 degree per second. But this corresponds to a change of 1 degree over 15 kilometers, which would be exceedingly difficult to measure."
Wow....it would also correspond to a change of 1 degree over 1 millimetre. And a change of 1 degree over 1 billion parsecs.
The rest of this pathetic post is similarly utter ignorant nonsense babble from someone who doesn't understand the most basic concepts.
yes, photons affect phonons too.
big solar powered speakers instead of ion propulsion
For the correct delivery of phonons to your eardrums, use Siltech Royal Signature Emperor Double Crown Loudspeaker cables. The have elegant self-shielding topology.
When they came for the communists, I said "He's next door. Take him away. Goddam commies."
I'm glad you guys have finally realized the Aether is REAL. You can call it a QM Field, a Higgs Field, Dark Matter, Dark Energy, or whatever you like but it IS Aether physics. See how much of Einstein's work you've had to scrap or modify until unrecognizable when you would have been better off listening to Tesla in the first fucking place?
Viva la Aether!
Is it possible that the Earth is not flat, and is curved? And the sound is moving in a straight line, but appears to be going up as the Earth drops away from it?
How's life in the hypocrite lane?
Mass and weight are not the same. Mass is the net amount of matter. Weight is the force exerted by gravity. The bouyant force is exerted on a bubble by the displaced air, equal to the MASS of air displaced. But the MASS of the bubble is not negative. Negative matter is an antiparticle.
No - mass is NOT a resistance to acceleration. Mass is the AMOUNT of MATTER. There is no other definition.
MASS is the amount of matter. If there is a negative mass, the matter itself must be negative - an antiparticle. This cannot happen. So what is the cause? An unaccounted for EM interaction similar to the bouyant force in air. Gravity cannot magically reverse without an antiparticle.
"The Alcubierre drive is a speculative idea based on a solution of Einstein's field equations in general relativity as proposed by Mexican theoretical physicist Miguel Alcubierre, by which a spacecraft could achieve apparent faster-than-light travel if a configurable energy-density field lower than that of vacuum (that is, negative mass) could be created."
https://en.wikipedia.org/wiki/Alcubierre_drive
"Thus, in a very physical sense, the phonon carries (negative) mass."
https://arxiv.org/pdf/1807.08771.pdf
Big apple, new Yorik, undig it, something's unrotting in Edenmark.