Physicists create 'negative mass'

April 17, 2017 by Eric Sorensen
Experimental TOF images of the effectively 1D expanding SOC BEC for expansion times of 0, 10, and 14 ms.

Washington State University physicists have created a fluid with negative mass, which is exactly what it sounds like. Push it, and unlike every physical object in the world we know, it doesn't accelerate in the direction it was pushed. It accelerates backwards.

The phenomenon is rarely created in laboratory conditions and can be used to explore some of the more challenging concepts of the cosmos, said Michael Forbes, a WSU assistant professor of physics and astronomy and an affiliate assistant professor at the University of Washington. The research appears today in the journal Physical Review Letters, where it is featured as an "Editor's Suggestion."

Hypothetically, matter can have negative in the same sense that an electric charge can be either negative or positive. People rarely think in these terms, and our everyday world sees only the positive aspects of Isaac Newton's Second Law of Motion, in which a force is equal to the mass of an object times its acceleration, or F=ma.In other words, if you push an object, it will accelerate in the direction you're pushing it. Mass will accelerate in the direction of the force.

"That's what most things that we're used to do," said Forbes, hinting at the bizarreness to come. "With negative mass, if you push something, it accelerates toward you."

Conditions for negative mass

He and his colleagues created the conditions for negative mass by cooling to just a hair above absolute zero, creating what is known as a Bose-Einstein condensate. In this state, predicted by Satyendra Nath Bose and Albert Einstein, particles move extremely slowly and, following the principles of quantum mechanics, behave like waves. They also synchronize and move in unison as what is known as a superfluid, which flows without losing energy.

Led by Peter Engels, WSU professor of physics and astronomy, researchers on the sixth floor of Webster Hall created these conditions by using lasers to slow the particles, making them colder, and allowing hot, high energy particles to escape like steam, cooling the material further.

The lasers trapped the atoms as if they were in a bowl measuring less than a hundred microns across. At this point, the rubidium superfluid has regular mass. Breaking the bowl will allow the rubidium to rush out, expanding as the rubidium in the center pushes outward.

To create negative mass, the researchers applied a second set of lasers that kicked the atoms back and forth and changed the way they spin. Now when the rubidium rushes out fast enough, if behaves as if it has negative mass."Once you push, it accelerates backwards," said Forbes, who acted as a theorist analyzing the system. "It looks like the hits an invisible wall."

Avoiding underlying defects

The technique used by the WSU researchers avoids some of the underlying defects encountered in previous attempts to understand negative mass.

"What's a first here is the exquisite control we have over the nature of this negative mass, without any other complications" said Forbes. Their research clarifies, in terms of negative mass, similar behavior seen in other systems.This heightened control gives researchers a new tool to engineer experiments to study analogous physics in astrophysics, like neutron stars, and cosmological phenomena like black holes and dark energy, where experiments are impossible."It provides another environment to study a fundamental phenomenon that is very peculiar," Forbes said.

Explore further: Destabilized solitons perform a disappearing act

More information: M. A. Khamehchi et al, Negative-Mass Hydrodynamics in a Spin-Orbit–coupled Bose-Einstein Condensate, Physical Review Letters (2017). DOI: 10.1103/PhysRevLett.118.155301

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61 comments

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JongDan
4.8 / 5 (4) Apr 17, 2017
To me it sounds like a phenomenon related to negative temperature. By applying those lasers, the atoms were confined, which also bounded the energy upwards, and at the same time excited by those lasers. When you pump in more energy than it takes for maximum entropy state, the whole system starts behaving as a negative-temperature system – microstates with higher energy are favoured, as the total energy is too high anyway.
Apply a force – a potential field, and atoms will flow towards higher energy states – towards the direction the force was applied from.
Cave_Man
2.3 / 5 (6) Apr 17, 2017
WARP DRIVE HERE WE COME! Get me the f$% away from this planet full of insane monkeys!
nkalanaga
4.2 / 5 (5) Apr 17, 2017
I doubt that this will be enough for a warp drive, as it's strictly a local, temporary effect. But the fact that negative mass has been observed is a good sign that there may be more practical ways of achieving the same effect.
ulao
1 / 5 (1) Apr 17, 2017
Would there be a gravitational repulsion here?
Hyperfuzzy
Apr 17, 2017
This comment has been removed by a moderator.
IronhorseA
5 / 5 (3) Apr 17, 2017
The quantum nature of the system may be generating a negative acceleration rather than a negative mass. Question is how to determine which of the two terms on the right side of the equation is negative.
Mimath224
not rated yet Apr 17, 2017
The quantum nature of the system may be generating a negative acceleration rather than a negative mass. Question is how to determine which of the two terms on the right side of the equation is negative.

My thoughts too. Moving in the opposite direction to the one expected MIGHT be ONE of the properties of 'negative mass' but what would be the others for a sufficient definition of negative mass.
richdiggins
3 / 5 (2) Apr 18, 2017
"Now when the rubidium rushes out fast enough, if behaves as if it has negative mass"

Looks like they are just simulating negative mass.
Jayded
Apr 18, 2017
This comment has been removed by a moderator.
antialias_physorg
5 / 5 (5) Apr 18, 2017
This is the start of anti gravity.

Erm, no. Not even close. Go to the linked abstract and look at the distribution given in the first image. The whole BEC still behaves like a positive mass. There is just a certain region that *behaves* like negative mass.
(If all of it were to behave like negative mass you'd break all kinds of conservation laws, which isn't the case here)
AmritSorli
1 / 5 (1) Apr 18, 2017
Phenomena described here fas nothing to do with phenomena of mass. See my article in AJMP Energy Mass Gravity Theory. Yours Amrit Sorli
swordsman
1 / 5 (4) Apr 18, 2017
This has the characteristics that fit electronic interactions and electromagnetic fields. Another example of the electric properties of atoms and molecules. Much more complex than presented here.
Hyperfuzzy
3.7 / 5 (3) Apr 18, 2017
Hmm, wonder why my reference to reversing gravity was deleted. I cannot think of any other issue as more pertinence. Effectively, if "this" is true, negative mass, then negative inertia, zero gravity. Juz say'n We really, really require a better paper, negative mass? And to think the moderator removes a ref to zero gravity, seems like trying to control information, this is the biggest conjecture ever! essentially the fields would have to defy charge, i.e. like fields repel, so how do you create a substance where only the like fields are in play for other matter.
antialias_physorg
5 / 5 (1) Apr 18, 2017
Hmm, wonder why my reference to reversing gravity was deleted.

Maybe because it's
a) not relevant to the article
and
b) pseudo-science
(both counts are against PO guidelines, ya know? So I can see the mods insta-deleting it when they actually get around to policing the site)
Dingbone
Apr 18, 2017
This comment has been removed by a moderator.
Dingbone
Apr 18, 2017
This comment has been removed by a moderator.
donjoseph
not rated yet Apr 18, 2017
And this is all you require to prove you "created" negative mass? And (????)yeah right
Hyperfuzzy
1 / 5 (2) Apr 19, 2017
Okay, not a "funny" force but a "negative" mass. Mass, an experimental constant defining the quantity of a substance to have a measured amount of the unknown, experimental constant, i.e. quantized; but, not defined substantially in terms of method of field production that can define the field of gravity!! Now we have charge and no mass, i.e. a defined measure. The constant, "mass" may be negative, or decreasing, or increasing; however, typically the force is defined with causality. Negative mass infers a force as applied is negative of expectations. Suggest a new process, but not negative mass. Else your measure must demonstrate anti-gravity to show definitively a negative mass, i.e. definition of mass!
Hyperfuzzy
1 / 5 (1) Apr 19, 2017
Elese you are playing with the E field! All forms, time & spatial variation/magnetics, i.e. mass is undefined. Only charge exists.
antialias_physorg
5 / 5 (2) Apr 19, 2017
I do agree - it seems the laser cooling violates equivalence principle

Please. Look up how laser coolimg works before making such ludicrous statements. There's nothing being violated, here. (Next you'll be telling us that your fridge violates the laws of thermodynamics?)
https://en.wikipe..._cooling
nikola_milovic_378
not rated yet Apr 19, 2017
What are these experimenters do? Maybe they themselves do not know !. They are using a laser focused beam of electrons to an atomic nucleus and surrounding electrons forced to move closer to the core or to enter into a proton and thus form the neutrons, a neutron made anti protons and plus gluons, which are connected antiprotons into a unit, and so is currently formed somewhat as antimatter. As soon as the laser is turned off, it was all back to normal.
Moth
not rated yet Apr 19, 2017
The lack of "antigravity" that people seem to be expecting might come from a slight oversight in how gravitic attraction is calculated. Instead of accounting for just "mass", the proper equation might posit that this attraction accounts for the absolute value of the mass, not whatever state the mass might be in.

Of course, given that we haven't experienced "negative mass" before, it requires more study.
Hyperfuzzy
not rated yet Apr 19, 2017
The lack of "antigravity" that people seem to be expecting might come from a slight oversight in how gravitic attraction is calculated. Instead of accounting for just "mass", the proper equation might posit that this attraction accounts for the absolute value of the mass, not whatever state the mass might be in.

Of course, given that we haven't experienced "negative mass" before, it requires more study.

It's the result of superposition. There exist 2 diametrical spherical fields, the superimposed centers occupy a quasi point. The average distance between these 2 quasi points define gravity, for the earth, using the erroneous epsilon sublimated by the number of charge pairs/ kg , one gets 10^-13 meters or so. But we can only imply this from a measure of g.
Hyperfuzzy
not rated yet Apr 19, 2017
So, gravitational mass on a quantum scale is undefined.
luxorion
not rated yet Apr 20, 2017
Great! We will soon (or late) be able to propel our cars and rockets with negative mass as soon as we were able to transform this observation from an effective mass to real one ! Also, better to place the future dashboard upside down to avoid some surprises, oops ! By the way, what do we seen in the picture, what kinf of appartus ?
idjyit
not rated yet Apr 20, 2017
Interesting the "wall" was only on one side, a spacial effect or third party field effect ?
antialias_physorg
5 / 5 (3) Apr 20, 2017
By the way, what do we seen in the picture

Go to the link at the bottom of the above article. There you can click on the image and get a full text description.
In short: You are seeing the expansion of a Bose-Einstein Condensate. The right side does not expand as expected and hence has a negative effective mass.

(Note that having an 'effective negative mass' is about the same as saying a photon has 'effective mass' via E= mc^2. We are not talking *real* negative mass, here. And most definitely we are not talking anti-gravity. We are talking "behaves as if it has negative mass", not "has negative mass". That's an important distinction)

From the diagram above the image of the expanding cloud I surmise that the momentum is captured in spin transitions. But without access to the full article that is just a guess.
Hyperfuzzy
not rated yet Apr 20, 2017
By the way, what do we seen in the picture

Go to the link at the bottom of the above article. There you can click on the image and get a full text description.
In short: You are seeing the expansion of a Bose-Einstein Condensate. The right side does not expand as expected and hence has a negative effective mass.

(Note that having an 'effective negative mass' is about the same as saying a photon has 'effective mass' via E= mc^2. We are not talking *real* negative mass, here. And most definitely we are not talking anti-gravity. We are talking "behaves as if it has negative mass", not "has negative mass". That's an important distinction)

From the diagram above the image of the expanding cloud I surmise that the momentum is captured in spin transitions. But without access to the full article that is just a guess.

Yes, we understand, it's just kind of funny. Mass? Gravitational mass or Quanta? OK, Maxwell, expansion? Not, GR?
murraylo9
not rated yet Apr 20, 2017
So, gravitational mass on a quantum scale is undefined.
Dingbone
Apr 20, 2017
This comment has been removed by a moderator.
Hyperfuzzy
not rated yet Apr 21, 2017
Yes - it can be interpreted in the way, the vacuum fluctuations are wiggling with tiny particles - so that they cannot attract itself properly. This also gives them minute intrinsic acceleration, which doesn't require any apparent inertial force for to manifest itself - thus violating Newton inertial law. In MOND theory this acceleration is utilized for explanation of dark matter and its value https://ned.ipac....om3.html would lead into expansion and spreading of wave packet instead of its collapse with gravity. It also means, that if we divide and spread the matter in sufficient fine way, it will never collapse again, until its total mass will remain lower than so-called Planck mass. It's not very small value: for example the body mass of a flea is roughly 4000 - 5000 Planck masses.

This is an unreconcilable misunderstanding, collapse is correction, mathematically, to reality. QM is "almost right" not causal; hence, your stated err.
Dingbone
Apr 21, 2017
This comment has been removed by a moderator.
idjyit
not rated yet Apr 22, 2017
Urgelt
5 / 5 (1) Apr 24, 2017
Bleh. I really hate it when explanations of scientific experiments are dumbed down by throwing around terms like 'negative mass.' It does the public no favors.

The researchers were able to elicit a specific behavior *as if* the atoms had negative mass. But by no means have they shown that those atoms display negative mass across all observable behaviors.

It's an interesting bit of research, but why is it necessary to hype it by throwing around incendiary nonsense terms?
antialias_physorg
5 / 5 (3) Apr 24, 2017
It's an interesting bit of research, but why is it necessary to hype it by throwing around incendiary nonsense terms?

The problem comes when scientists come in contact with science journalists. Science journalists usually have some background in science but not particularly deep (which is OK, as the have to report on all kinds of science, so a broad approach is necessary). The downside is that when you get into the nitty gritty details of explaining your work to them they become lost or latch upon some label in a wrong way - but before you figure out they misunderstood the article is already printed (yeah, I've had that happen to me in the past).

In this case they (and a lot of posters on here) got mixed up between "negative mass" and "effective negative mass". The "effective" being a crucial qualifier.
antialias_physorg
5 / 5 (4) Apr 24, 2017
A general note:

In scientific papers it's important to read what is actually there - and not to infer anything on your own. The point of a paper is to be precise. It's not a journalistic piece. A paper describes everything you did and describes NOTHING you did not.
Remember that the people who wrote the actual paper have spent at least half a decade (or maybe more than a decade) studying this stuff.

Then ask yourself: If anti-gravity were in the cards, wouldn't they have mentioned it? Rest assured - they would have ('cause it would be an insta-Nobel-Prize).

So if you then go off and post about this being the "key to anti-gravity" or somesuch - where they didn't - you can be 100% sure that you're wrong before your mouse cursor even hits the 'submit' button.
Da Schneib
5 / 5 (1) Apr 24, 2017
I am reminded of the search for Majorana fermions, and the confusion engendered when detection of Majorana bound states was announced. We still have never detected a free Majorana particle, though we are still looking; the most promising sector is neutrino physics, but we've pushed the possibilities down pretty far and not found anything. And this was ignored in the popular treatment of the bound Majorana states.
Hyperfuzzy
not rated yet Apr 24, 2017
I am reminded of the search for Majorana fermions, and the confusion engendered when detection of Majorana bound states was announced. We still have never detected a free Majorana particle, though we are still looking; the most promising sector is neutrino physics, but we've pushed the possibilities down pretty far and not found anything. And this was ignored in the popular treatment of the bound Majorana states.

Excuse, what boundary conditions?
swordsman
not rated yet Apr 24, 2017
These scientists are not seeing what they think they are seeing. The atoms are reacting to the laser beams. The rotating electrons change course when illuminated. The direction of this force depends upon the electron velocity vector and the polarity of the laser light beam. Positive polarity attracts, while negative polarity repels
antialias_physorg
5 / 5 (2) Apr 24, 2017
Positive polarity attracts, while negative polarity repels

Erm...whut? What does positive/negative polarity of a laser beam even mean? Care to explain?
OceanDeep
5 / 5 (1) Apr 24, 2017
I am confused. If F = ma, then if the mass (m) is negative, then either F or a has to be negative**. But if the mass accelerates towards the push, then is that negative or positive acceleration? Would seem to have to be positive acceleration.

** What I mean is that a negative times a negative is a positive, so I don't understand if that means the force F is still positive even though the mass and acceleration are both negative.
Hyperfuzzy
not rated yet Apr 24, 2017
These scientists are not seeing what they think they are seeing. The atoms are reacting to the laser beams. The rotating electrons change course when illuminated. The direction of this force depends upon the electron velocity vector and the polarity of the laser light beam. Positive polarity attracts, while negative polarity repels

Wow! Give the Prof. and apple! Are there many ready to actually define a wave front, uniquely, individually, separately, in unison without giving names to harmonics but construct the charge motion? It can be done, optics! Amplitude analysis, polarity, among multiple sources, multiple spectra, yeah, we see creation, and it never started from empty space, we are but a semi-steady state. i.e. charge has no mass!

The light will scatter with a different velocity vector, the speed of light in the relative to the center of the charge, the wrinkle in the charges field moves away at the speed of light relative that center
Hyperfuzzy
not rated yet Apr 24, 2017
Can the motion of a charge be restrained, i.e. contained in a nucleus, I prefer, stable self assembly This way we do not get confused with relative velocities, so we can move through a field from it's center, or in any direction, so it's not can this point exist; but, what would be the minimum distance, possible, using the proper interpretation of the redshift and amplitude over the distribution.

OOps, got lost in my own head.

Oh yeah they only see a charge response they can't explain.
antialias_physorg
5 / 5 (3) Apr 24, 2017
OOps, got lost in my own head.


That...explains a thing or two.
Hyperfuzzy
not rated yet Apr 24, 2017
OOps, got lost in my own head.


That...explains a thing or two.

I dare you to follow.
antialias_physorg
5 / 5 (2) Apr 24, 2017
Sorry, I don't do 'crazy'.
Hyperfuzzy
not rated yet Apr 24, 2017
Sorry, I don't do 'crazy'.

OK, negative mass! LOL
Hyperfuzzy
not rated yet Apr 24, 2017
I think if all you had to work with is charge, then we would not invent mass. It's unnecessary and insufficient; charge, however is both necessary and sufficient. I do not support a science that suggest we are created from nothing; unless the nothing is defined as this Maxwellian space. The field is continuous from its center to infinity, True. The field is updated relative to its center at the speed of light, True. The speed of the WaveFront of any charge relative to any other charge is the emitted wave length by the measured time. All possible configurations satisfy Maxwell and Coulomb. Charge is empirical. Therefore axiom: There exist only diametrical spherical fields, QED.
Hyperfuzzy
not rated yet Apr 24, 2017
There's the summation of the individual changes in the fields, spectral; and the force derived by the superimposed charge centers, and the center dynamics, structure of the mass, surrounding fields, etc..

And each measure is defined temporally relative to us. However, with great distance, one must understand the flow of information, vectorially. Not sure it this vector is defined completely, i.e. the Poynting vector, and let us not forget our universal constants. Think we can do better, i.e. more definitive reality.
Hyperfuzzy
not rated yet Apr 24, 2017
I'm thinking stay with Maxwell, even atomically, the field reflects the motion, juz say'n
Da Schneib
5 / 5 (1) Apr 24, 2017
I am confused. If F = ma, then if the mass (m) is negative, then either F or a has to be negative**. But if the mass accelerates towards the push, then is that negative or positive acceleration? Would seem to have to be positive acceleration.
Traditionally, Newtonian mechanics (which is where F=ma comes from) doesn't differentiate; it's only when you start to talk about momentum that you need to start paying attention to signs. Force and acceleration aren't conserved; momentum is.

That said, if you do elect to consider signs, then you can either choose to talk about positive and negative accelerations, OR talk about positive and negative forces, but not both. If you talk about both, then those two negatives would cancel.

Good question; for more information you should look into vectors, which you will find holds the answer to your question in detail rather than broad strokes as I have given here.
Hyperfuzzy
not rated yet Apr 25, 2017
I am confused. If F = ma, then if the mass (m) is negative, then either F or a has to be negative**. But if the mass accelerates towards the push, then is that negative or positive acceleration? Would seem to have to be positive acceleration.
Traditionally, Newtonian mechanics (which is where F=ma comes from) doesn't differentiate; it's only when you start to talk about momentum that you need to start paying attention to signs. Force and acceleration aren't conserved; momentum is.

That said, if you do elect to consider signs, then you can either choose to talk about positive and negative accelerations, OR talk about positive and negative forces, but not both. If you talk about both, then those two negatives would cancel.

Good question; for more information you should look into vectors, which you will find holds the answer to your question in detail rather than broad strokes as I have given here.

It's bipolar! Charge!
Hyperfuzzy
not rated yet Apr 25, 2017
Conservation? 'pends on how ya look at it. Arbitrary reference frame with some Mad or rapid changes, based upon nothing but the controls, far from things, might see a different world, so i'm guessing it's all a matter of scale and how the measure is made.
Hyperfuzzy
not rated yet Apr 25, 2017
The nucleus of the atom at very low temperatures is a state where all the charges are locked within the tightest stable condition. One must simulate the energy states geometrically. I prefer a space without units by assigning each access the same magnitude. Let time be defined c = 1. Then space-time is measured in lambda, any lambda.

As you can see, if we are discussing energy, oscillatory freedom, direction, wobble all within a negative charge shield at minimum energy? So what's mass got to do with it?
Hyperfuzzy
not rated yet Apr 25, 2017
Note, that lambda at any scale, also defines the measure of the sphere about each charge for that space time. So each point is defined by a mathematical expansion, Fourier. This gives QM, causality, an axiomatic structure. The ability to define charge motion and the field continuously. Simple 3D continuous space, i.e 3D[f(t)];

So if you use smart memory and a large universal register, I think you can define the Object space with ease.
Hyperfuzzy
not rated yet Apr 25, 2017
In other words, the only way to create a minimal energy state, regardless of how you name it, will be by simulation, not realizable. The space we want to observe, is the containment space, so the lowest state would be a function over the possible assemblies. Hence simulation over lambda! Anyway, we presently only have an idea, based upon a false premise.
theprocessionist
not rated yet May 01, 2017
It's not negative mass. That is a misinterpretation. I would like to see a video rather than still shots,, though, as I might be able to fine tune aspects of my own model, by comparison.
theprocessionist
not rated yet May 01, 2017
In the published pdf, the carefully chosen phrase, "negative effective mass," is used. That, I'm ok with. :)
theprocessionist
not rated yet May 01, 2017
I'm reading the pdf and find that many of the statements in it offer direct support for my string theory variant. :)
Hyperfuzzy
not rated yet May 01, 2017
I'm reading the pdf and find that many of the statements in it offer direct support for my string theory variant. :)

ST? Nice try. Start with a given truth. Charge exist, both negative and positive. OK, it's an isomorphic mathematical representation; however, with logic one sees that E is portional to the surface area of the sphere about the charge. Charge is Bipolar and is contained in "all" things. Therefore the idea, no matter what the representation, negative mass, and not a bipolar response has no defense. juz say'n
Hyperfuzzy
not rated yet May 01, 2017
I'm reading the pdf and find that many of the statements in it offer direct support for my string theory variant. :)

ST? Nice try. Start with a given truth. Charge exist, both negative and positive. OK, it's an isomorphic mathematical representation; however, with logic one sees that E is portional to the surface area of the sphere about the charge. Charge is Bipolar and is contained in "all" things. Therefore the idea, no matter what the representation, negative mass, and not a bipolar response has no defense. juz say'n

yeah, yeah, inversely proportional

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