Talk:Negative mass

Negative phlogiston
Would it be appropriate to have an historical section on the theory of negative-mass phlogiston?

Jbom1 (talk) 16:16, 9 February 2011 (UTC)

Clarification
In the last sentence: "This behavior implies that both have positive inertial mass and opposite charges; if the reverse were true, then the particle with positive inertial mass would be repelled from its antiparticle partner." ... does "the reverse" in the phrase "if the reverse were true" mean that (1.) both particles have both opposite inertial mass and opposite charges, or that (2.) both particles have opposite inertial mass and both have the same charge? --Cowlinator (talk) 00:24, 6 March 2011 (UTC)

Indeed - consider 2 scenarios:

(i) Particle and antiparticle have opposite charges but both have positive mass. They are obviously attracted to each other and (by Newton's second law) move towards each other.

(ii) Particle and antiparticle both have positive (or negative) charge and opposite mass. The positive mass particle is repelled from the negative mass particle and (again by Newton's second law) moves away from it. However, the negative mass particle is repelled from the positive mass particle, but begause of its negative mass it moves in the opposite direction to this repulsion. The particle therefore "flees away" from the antiparticle, but the antiparticle "chases after" it.

Is the latter scenario ever observed?

Another problem with negative mass antiparticles is that their masses would cancel with those of their corresponding positive-mass particles on recombination, and no net enwrgy would be released on anihilation. The explosion in Dan Brown's "Angels and Demons" would have been less of a bang than a whimper! — Preceding unsigned comment added by 141.241.199.124 (talk) 09:33, 3 June 2011 (UTC)


 * When you say 'The particle therefore "flees away" from the antiparticle, but the antiparticle "chases after" it.', I thought you were saying it "flees away" due to gravity, but "chases after" due to electromagnetism. However, obviously, electromagnetism is so much stronger than gravity in situations where antiparticles are created that the effects of gravity should be ignored. Gravity has no measurable effect. There is a symmetry (see my post "From the article, it's not clear why opposite mass but same charge would repel" below) that suggests opposite mass with like-charge should neither repel nor attract by electrostatic force.


 * I realize after writing my post below that it's the same thing you are saying. The particles would stay the same distance from each other, but would accelerate towards the positive mass. This is also what happens with gravity in this situation according to the article: "Bondi pointed out that two objects of equal and opposite mass would produce a constant acceleration of the system towards the positive mass object." So, even including gravity, this last sentence of the article is just wrong or contradictory with the rest of the article.

— Preceding unsigned comment added by Colinkeenan (talk • contribs) 05:34, 26 October 2013 (UTC)

Contradiction
Something is very wrong here. At the end of Negative mass the following is said:
 * So, as long as inertial mass and gravitational mass are always equal as required by the equivalence principle, positive active gravitational mass would be universally attractive (both negative-mass and positive-mass objects would be pulled towards an object with positive active gravitational mass), while negative active gravitational mass would be universally repulsive (both negative-mass and positive-mass objects would be pushed away).

It first says that "positive active gravitational mass would be universally attractive", that is "both negative-mass and positive-mass objects would be pulled towards" them. However, the next sentence says that objects with "negative active gravitational mass would be universally repulsive". Assuming indeed that active and passive gravitational masses are the same, this leads to a clear contradiction: A negative-mass object can't be pulled towards an object (as the first sentence says) and simultaneously repel the object that it is pulled towards. Or can it? 31.210.184.112 (talk) 18:26, 20 July 2011 (UTC)
 * It can. Negative mass would accelerate in the opposite direction of the force exerted on it. There is no contradiction. --antiXt (talk) 13:19, 30 July 2011 (UTC)
 * Given two objects with equal and opposite mass subject only to gravity, the system would accelerate from the negative mass towards the positive mass. Total mass, momentum and energy in this system remains a constant 0, despite the increase of velocity without bound. — Preceding unsigned comment added by 150.176.192.118 (talk) 16:08, 23 January 2012 (UTC)

From the article, it's not clear why opposite mass but same charge would repel.
The very last sentence of the article: "This behavior implies that both have positive inertial mass and opposite charges; if the reverse were true, then the particle with positive inertial mass would be repelled from its antiparticle partner." needs, at the very least, a reference. I am making the assumption that "if the reverse were true" means "if both have like-charge but opposite mass". There needs to be a reference or further explanation because after reading the entire article, it's not clear to me why having opposite mass but like-charge would repel as this last sentence to the article states.

My doubt comes from looking at an earlier statement in the article about negative mass and the electrostatic force: "Geoffrey A. Landis pointed out other implications of Forward's analysis,[2] including noting that although negative mass particles would repel each other gravitationally, the electrostatic force would be attractive for like-charges and repulsive for opposite charges." Given that if both particles are positive mass then the electrostatic force is repulsive for like-charges, and that if both particles have negative mass then the electrostatic force is attractive for like-charges, it's not obvious that if one particle has positive mass and the other has negative mass then like-charges would produce a repulsive electrostatic force no different than if both masses were positive.

The symmetry of the situation almost seems to suggest they would not be attracted or repulsed by the electrostatic force because

positive/negative is to positive/positive

as

negative/positive is to negative/negative

So, if positive/positive masses repel like-charges and negative/negative masses attract like-charges, then positive/negative masses would neither attract nor repel like-charges according to this symmetry. The article needs to explain why it is instead expected that the positive/negative masses would actually behave the same as positive/positive masses as far as electromagnetism goes. Or, at least provide a reference. So, the very last sentence of the article: "This behavior implies that both have positive inertial mass and opposite charges; if the reverse were true, then the particle with positive inertial mass would be repelled from its antiparticle partner." needs, at the very least, a reference.

As noted in the first section of this Talk page, there would seem to be less confusing reasons to rule out negative mass for antiparticles. After re-reading the first section of this talk page titled "Clarification", I realize that comment is similar to mine. In that comment, it is concluded that the negative mass particle would chase after the positive mass particle because the positive mass would be repelled by the like-charge while the negative mass would be attracted to the like-charge. So, overall, there's no net attraction or repulsion but the system accelerates towards the positive mass. --Colinkeenan (talk) 05:15, 26 October 2013 (UTC)

Pair of equal positive/negative mass
Cite from the paper: 'Negative masses in general relativity and the Dirac equation - F. Winterberg'


 * More detailed analysis of the positive-negative mass two body problem first carried out by Bondi, does not lead to a self acceleration.
 * It rather leads to the finding that the Dirac spinors can be thought of as being composed of positive and negative mass particles, and rather than leading to a self-acceleration, it leads to the “Zitterbewegung,” which for the Dirac particle was discover ed by Schrödinger. It definitely does not lead to an unstable vacuum composed of positive and negative masses as claimed by Cavalleri and Tonni [7].


 * Replacing supersymmetry by the assumption that the vacuum is made up by an equal number of positive and negative masses, and replacing the Higgs field by the Einsteinian gravitational field of positive masses interacting with likewise negative masses, it can be seen as a model replacing the standard supersymmetric model of elementary particles and cosmology [8, 9]

So, clearly, a body of positive/negative mass (equal in absolute magnitude) would not chase each other and accelerate indefinately.

Robheus (talk) 13:37, 20 June 2014 (UTC)

Cancelation of a positive mass and a negative mass
The following was stated: ''Forward also coined a term, "nullification" to describe what happens when ordinary matter and negative matter meet: they are expected to be able to "cancel-out" or "nullify" each other's existence. An interaction between equal quantities of positive mass matter (hence of positive energy E = m c^2) and negative mass matter (of negative energy -E = -m c^2) would release no energy,''

Taking that at face value, doesn't that violate the principle of the Conservation of energy? It's destroying matter and even though the net energy of the system is zero, it just doesn't sit right with me. It sounds like a magical way to get rid of stuff that you don't want and not have it create any side reactions. Thoughts? Kedamono (talk) 04:46, 19 January 2015 (UTC)

ok, so I know I'm 7 years late to this but the short answer is: no, it doesn't violate the law as nothing is destroyed, 2 values were just added together when the 2 masses collided, the net mass adding to 0 Aldguton (talk) — Preceding undated comment added 11:40, 5 October 2022 (UTC)

Black Holes Big Bang
Stephen Hawking explains this retarded religious concept is a necessary component of the Big Bang and Black Holes

https://www.youtube.com/watch?v=D6lFGJdwRyo

Why don't we put this article, and also the big bang and black hole articles into the religious category? — Preceding unsigned comment added by 112.198.30.121 (talk) 03:15, 17 February 2015 (UTC)


 * No idea what religious concept you are talking about, but it would be ridiculous to put this article into a religious category. SpinningSpark 09:00, 17 February 2015 (UTC)

Changed the end of the lead to make it clearer
The end of the lead had read as follows: Although general relativity well describes the laws of motion for both positive and negative energy particles, hence negative mass, it does not include the fundamental forces other than gravitation. Whereas the Standard Model which describes elementary particles does not encompass gravitation, which is yet intimately involved in the origin of mass and inertia. Thus a correct particle model should explicitly include gravity.

The second of these three sentences was not actually a sentence; it was a dependent clause. Therefore, I rewrote the end of the lead, to make it both grammatical and clearer, as follows:

Although general relativity well describes gravity and the laws of motion for both positive and negative energy particles, hence negative mass, it does not include the other fundamental forces. On the other hand, although the Standard Model well describes elementary particles and the other fundamental forces, it does not include gravity, even though gravity is intimately involved in the origin of mass and inertia. A model that explicitly includes gravity along with the other fundamental forces may be needed for a better understanding of the concept of negative mass. --Wikifan2744 (talk) 01:04, 10 August 2015 (UTC)

Update needed
An update to the article is called for it seems: http://www.bbc.co.uk/news/science-environment-39642992 86.132.220.111 (talk) 15:33, 19 April 2017 (UTC).


 * I agree. It seems this has been removed a few times for "incorrectly portrayed as evidence" of negative mass. I think people should explain how "effective mass" is different from "real mass" here--Sparkyscience (talk) 18:04, 20 April 2017 (UTC)


 * Read this wikipedia article Effective mass (solid-state physics). The important sentence is: "The effective mass is a quantity that is used to simplify band structures by constructing an analogy to the behavior of a free particle with that mass.". Please remove the mentioned experimental evidence of negative mass since there is none. — Preceding unsigned comment added by 185.50.213.248 (talk) 11:20, 21 April 2017 (UTC)


 * Its not an 'analogy' lol...The issue seems largely over semantics...that "effective mass" is somehow artificial. Well... artificial light is still real light, artificial insemination is still real insemination... but artifical flowers are not real flowers. effective mass is real mass. Before you say "it is not a property of the fundamental particles!"...where does most mass inside atoms actually come from?--Sparkyscience (talk) 13:15, 21 April 2017 (UTC)


 * The manmade origin of the phenomena isn't important. Your 'Artificial light' is not an effective thing in that you're managing to force something to behave as though it is light, even though it really isn't, just by flashing a lightbulb. Only light is light. In the same way, a baby made via IVF isn't something that's only like a baby in a sense above and beyond what it actually is. A picture of a baby created by randomly throwing marbles onto a table would only be an effective baby, because the marbles aren't innately baby parts and can only take on some of a real baby's properties. There should be a clue in the fact that the WSU study made use of rubidium atoms rather than some kind of newly discovered exotic matter. Nothing in the Standard Model occurs with negative inertial mass whether it's made in a star or a particle accelerator. All atoms (mattter or antimatter) have intrinsically positive mass. The ions were only made to behave as though their mass was negative, but nothing so fundamental as their actual mass was tampered with. It's like a wave on a guitar string, the molecules in the string don't move with the wave, the wave is just an emergent property of the energy moving through the string. The wave itself has no substance, and if you reduce the wave to the motion of the molecules you will learn nothing new about it. It only makes sense to regard the wave as a wave. In the same way, the 'negative mass' in this study was referencing an emergent 'simulated' property of the rubidium’s collective behaviour in the experimental system, not a property of the rubidium atoms themselves. That means that there was no literal negative mass matter discovered. It is misleading to put a section labelled "Discovery" in the main article because it implies that negative mass matter has been discovered when it really hasn't.Mrpersonman0 (talk) 13:23, 3 May 2017 (UTC)

Another article that feels the distinction is critical. — Preceding unsigned comment added by 75.61.71.17 (talk) 07:27, 22 April 2017 (UTC)


 * The Gizmodo article gets its scoop from a blog post here This blog is not written by a condensed matter physicist and the basic premise of her argument is they use the word ""effective" to indicate something that is not fundamental but emergent". She obviously doesn't know much about what she's talking about since most, if not all, mass in the universe is emergent . So the argument basically boils down to subjective semantics and ideological reductionism. Effective mass is still real mass... it is not some synthetic illusion.--Sparkyscience (talk) 12:40, 22 April 2017 (UTC)


 * "Not a condensed matter physicist" is an argument from authority fallacy (and a hypocritical one I reckon). The emergence of "mass in the universe" isn't comparable to matter that already exists. They did not create the rubidium from fields and subatomic particles before the experiment began, and its 'negative mass' properties only appeared after they ejected it from the Bose-Einstein condensate in the ion trap. If you took the ions back out again you'd find that they would all be back to normal. That's because they didn't change at all. What exactly could electromagnetism and low temperatures do to an atom that would invert the sign of its mass without altering the internal makeup of the atom in any way? That'd be some impressive new science right there if you could explain it to everyone. Mrpersonman0 (talk) 13:23, 3 May 2017 (UTC)

I've no idea what your trying to say...I think an analogy to what your saying is this: An object that accelerates to the close the speed of light doesn't really gain more mass, because afterwards when it slows down to the same speed it is still has the same mass as it had before. Therefore it didn't change at all and relativity is an illusion. In this experiment we are dealing with quantum effects, a gentle reminder we don't have a full formal quantum theory of mass...and that the best theories we do have say that the universe is comprised of continuous fields not divisible parts, atoms and particles. It seems that you have unfortunately fallen into the trap of reductionism, believing the world can only be understood linearly, via additive parts and that therefore there are some fundamental units from which all truth in the universe is derived e.g. If you understand the properties of the parts or particles, you understand the full functioning of the system. Nope. This negative effective mass stuff is a nonlinear effect - it doesn't fit that atomistic linear paradigm that has restricted Western thinking for centuries  - that does not mean it is not real. It isn't fake, it isn't a trick, it is not a simulation. In the words of Poincaré (who was perhaps the first to know about nonlinear effects via the three body problem) :

We seek reality, but what is reality? The physiologists tell us that organisms are formed of cells; the chemists add that cells themselves are formed of atoms. Does this mean that these atoms or these cells constitute reality, or rather the sole reality? The way in which these cells are arranged and from which results the unity of the individual, is not it also a reality much more interesting than that of the isolated elements, and should a naturalist who had never studied the elephant except by means of the microscope think himself sufficiently acquainted with that animal?

Or perhaps a more modern version of this point in the words of a string theorist:

I could go on and on, taking you on a tour of the space of string theories, and show you how everything is mutable, nothing being more elementary than anything else. Personally, I would bet that this kind of anti-reductionist behavior is true in any consistent synthesis of quantum mechanics and gravity.

This is the essence of duality - point particles in one perspective or theory are field solitons in another and vice versa etc. Anyway I digress...This really is a lot more simple then a philosophical debate about the true nature of reality. If you can find a reliable source (preferably in a standard textbook or peer reviewed journal article) that says that this experiment which claims to break Galilean covariance is in fact wrong in asserting as such then you are more then welcome to discuss it here and I'm sure we can amend the article. The opinion offered in the blog post comes under WP:OR. The negative mass claim comes from multiple reliable sources and is peer reviewed. --Sparkyscience (talk) 15:39, 3 May 2017 (UTC)


 * That's not what I was trying to say, at all. I'm saying that the mass of the rubidium is unchanged by the process of the experiment at all times, and it is. I also agree with your anti-reductionist philosophy (I could've sworn I tried to explain what emergence was to you earlier) which is why I'm surprised that you don't seem to understand how you can't reduce the negative mass beyond the level of the jet of ions from the laser trap, and not the rubidium atoms themselves, which is required for them to have true negative mass. They are still made of particles from the standard model with +ve mass, which distinguishes them from exotic matter. When you say "reliable sources" do you mean the popular press or do you mean press realeases from actual academic institutions, research laboratories or papers publised in a peer reviewed journal? As I understand it there's only the original paper, and if you could quote for me where it says that the rubidium atoms themselves represent a new kind of matter after what they did to it, that'd be great. Mrpersonman0 (talk) 16:16, 3 May 2017 (UTC)

We have no idea what happens to the mass of the rubidium atom during spin-orbit coupling, a process which Wilczek showed can be used to create gauge fields "out of nowhere": Spin-orbit coupling can be used to change the topology of the EM field in the atom. A change in topology means a change in mass in GR - the Mass in general relativity article illustrates quite nicely the fact you cannot isolate the mass from the field under nonlinear conditions. The thing and the environment are one and the same. You are still treating the field and the atom as two separate things. The exact same cold atom set up is being used to test general relativity today because we just don't know what will happen under these conditions:

    

GR in cold atoms is very open question. Note that cold atom set up is also being used as a "gravity sensor" How do you think they amplify the sensitivity? So many exciting unanswered questions in this area and you seem to think you know all about it..--Sparkyscience (talk) 16:55, 3 May 2017 (UTC)


 * I'm still waiting for the part of the original paper that explicitly states that the rubidium became negative matter. For all of your hand waving about reductionism, fields vs particles, general relativity, and citing wikipedia's original research policy you haven't shown that this negative mass is an intrinsic property of the matter. It is only negative in the context of this experiment and in a limited sense. At any rate if this is such a new and poorly understood field of science then how can you already be making any definitive claims about it? How can you make the positive statement that these people have created negative inertial mass in a lab and explain it with such vague terms? Were you hoping the words 'quantum' and 'relativity' would throw people off or do you honestly believe that if you throw those words in there then someone will eventually figure out how they fit and you'll get your exotic matter? It is, you must admit, too early to talk about what's possible here before we have a ToE. You yourself told me we haven't got a quantum theory of mass yet but you're still appealing to one. Mrpersonman0 (talk) 19:34, 3 May 2017 (UTC)

You are conflating matter with mass. Most mass in an atom comes from matter which has no intrinsic mass - gluons (see Quantum chromodynamics binding energy). Nearly all mass in the universe is not intrinsic to so called elementary particles. This article is titled negative mass - not negative matter - which redirects here. Negative mass is obtained from complex interactions of matter + field, just like most normal mass.--Sparkyscience (talk) 08:56, 4 May 2017 (UTC)


 * An update in terms of prior work is needed. E.g. Banesh Hoffmann pioneered the notion of negative mass and there is no mention of his work. Also Rupert W. Anderson has a whole chapter on negative mass in his book "The Cosmic Compendium: Interstellar Travel". This website needs an overhaul in view of what has been done .TonyMath (talk) 10:05, 4 September 2017 (UTC)

Experimentation
I think it should be made more clear that the things mentioned in the experimentation section have precisely nothing at all to do with the negative mass that is discussed in the rest of the article. As it is now it is possible to read this section and think it is relevant. 2001:1458:204:1:0:0:101:E51C (talk) 03:01, 7 July 2018 (UTC)
 * I removed this section, something that I and others have done many times on this article. To any bright-eyed editors coming along: please do not re-add these links, pop-science misinterpretations of unrelated studies are not welcome here. SirCmpwn (talk) 04:30, 27 June 2019 (UTC)

To follow-up on this - the suggestion that metamaterials comprising superconductors & dielectrics can somehow have negative mass, seems to be a misunderstanding of the term mass, as used in the referenced articles. Whilst Cooper Pairs might exhibit negative EFFECTIVE mass for a certain range in dispersion - there is no indication that the overall inertial / gravitational mass of the sample is negative. It seems that the writer could (or would) not distinguish between the two. Neither ignorance nor sensationalism contribute to Wiki. — Preceding unsigned comment added by 59.102.83.174 (talk) 02:02, 8 February 2020 (UTC)

Dark energy, dark matter
A statement has been added "since no observation of these objects (dark energy and dark matter) have only been made in 30 years of research". It seems dubious since these subjects have been studied extensively over the past few years. Probably a slight provocation and a way to promote a theory. By the way, the whole paragraph should be removed (not sourced, irrelevant).--92.152.232.147 (talk) 15:11, 13 August 2020 (UTC)

Misrepresentation of Damour's analysis
User:Mîkhâ'êlusticia wrote that Mr Damour's analysis was based on 2014 articles, whereas he says in his article that various documents were used (including one from 2016). She tries to denigrate the analysis by making people believe his analysis was "out of date". I don't know if User:Mîkhâ'êlusticia made a good faith edit, or if she's trying to push her POV. I leave that to more experienced wikipedians. Anyway, what a waste of (precious) time.--82.126.202.171 (talk) 18:54, 15 August 2020 (UTC)

Bimetric solution for the runaway motion paradox
I'm not happy with this section. I have done my best, as of 15 August, to flag, with relevant templates, the issues. The result does not look good. I am aware that this is an ongoing 'discussion' in physics, but this topic emerged from WP:FRINGE, and our job is to ensure that elements do not descend back into WP:FRINGE. Consequently, I am flagging that I will get the hatchet out on this section and WP:BOLD start deleting stuff that only has primary, self-published, or potentially unreliable citations. Thank you. Johncdraper (talk) 20:44, 15 August 2020 (UTC)

Clarification on "attract", "repel", "pull", and "push"
I think it should be clarified what "attract" means in this article. From my understanding, it is being used as "to cause to approach" (create an acceleration toward), but not "to exert a force toward". Similarly, and less intuitively, "pull" seems to be used as a synonym for "attract" ("to exert force upon so as to cause or tend to cause motion toward the force"); this definition is more confusing because it mentions force; however, force in objects of negative mass causes them to accelerate or tend to accelerate in the opposite direction.

This distinction is important, because (if my understanding is correct) two negative masses actually feel gravitational force toward each other, just like two positive masses; nevertheless, this causes them to accelerate away from each other, since a force applied to a negative mass will accelerate it in the opposite direction.

Should this be clarified in a footnote?

—Cousteau (talk) 21:51, 26 August 2023 (UTC)