# QM = Positive Mass / GR = Negative Mass **URL:** \ **Category:** Great Debates\ **Created:** [February 6, 2013, 8:28am UTC](https://boards.straightdope.com/t/qm-positive-mass-gr-negative-mass/649471 "2013-02-06T08:28:00Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![cmyk](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cmyk/32/3353_2.png) [@cmyk](https://boards.straightdope.com/u/cmyk)\ **Post date:** [February 6, 2013, 8:28am UTC](https://boards.straightdope.com/t/qm-positive-mass-gr-negative-mass/649471/1 "2013-02-06T08:28:00Z")
We show mass and energy being equivalent, and the same for space and time. We can break it down even further and find dualities and symmetries all over the place: electricity/magnetism; matter/antimatter; wave/particles; position/momentum; etc. But we not only suspect, yet have astoundingly strong evidence to believe all manifestations of nature, along with our mathematical descriptions of it, can be (and actually once was) unified. Matter attracts matter by a function of what we observe and describe as gravity. At the same time, space is becoming ever more evident that there’s just as much _something_ in the fabric we call the vacuum as there is typical matter within it\* — virtually sizzling with energy/particles popping in and out of existence — as it’s not only expanding, but _accelerating_ as far as we can tell. Is there any reason to not look at space-time as a true opposite of mass-energy? If positive mass attracts to itself, and negative mass would repel itself, does it make sense to look at space-time as “negative mass”? Could gravity be less a “force” as it appears to be, and more of a consequence of what we perceive as “tangible” mass-energy, and “intangible” space-time interacting with each other if seen as being opposites of the same _thing_? Or have I flown completely off my ontological rocker again? \*leaving aside dark energy/matter for now ---
**Author:** ![cmyk](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cmyk/32/3353_2.png) [@cmyk](https://boards.straightdope.com/u/cmyk)\ **Post date:** [February 6, 2013, 8:55am UTC](https://boards.straightdope.com/t/qm-positive-mass-gr-negative-mass/649471/2 "2013-02-06T08:55:39Z")
Hrmmm… or is this more or less Quantum Field Theory? ---
**Author:** ![Der\_Trihs](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/der_trihs/32/233_2.png) [@Der\_Trihs](https://boards.straightdope.com/u/Der_Trihs)\ **Post date:** [February 6, 2013, 9:21am UTC](https://boards.straightdope.com/t/qm-positive-mass-gr-negative-mass/649471/3 "2013-02-06T09:21:12Z")
> [@cmyk](#): > > If positive mass attracts to itself, and negative mass would repel itself, does it make sense to look at space-time as “negative mass”? Actually, it’s my understanding that positive matter attracts everything, and negative mass repels everything. And I understand that the expansion of space can be looked at as possessing negative mass/energy; I recall reading of theories that used that as an explanation for the origin of matter. The idea being that the rapid expansion of space counting as negative energy, and the appearance of positive mass/energy cancel it out so the universe has net zero energy. I’m not a physicist, so I’m probably butchering the explanation though. ---
**Author:** ![FinnAgain](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/finnagain/32/12500_2.png) [@FinnAgain](https://boards.straightdope.com/u/FinnAgain)\ **Post date:** [February 6, 2013, 9:45am UTC](https://boards.straightdope.com/t/qm-positive-mass-gr-negative-mass/649471/4 "2013-02-06T09:45:56Z")
Everything is nothing, yes. ---
**Author:** ![cmyk](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cmyk/32/3353_2.png) [@cmyk](https://boards.straightdope.com/u/cmyk)\ **Post date:** [February 6, 2013, 5:33pm UTC](https://boards.straightdope.com/t/qm-positive-mass-gr-negative-mass/649471/5 "2013-02-06T17:33:52Z")
The universe is like my bank account: A frothy, carbonated activity of credits and debts. ---
**Author:** ![cmyk](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cmyk/32/3353_2.png) [@cmyk](https://boards.straightdope.com/u/cmyk)\ **Post date:** [February 6, 2013, 5:36pm UTC](https://boards.straightdope.com/t/qm-positive-mass-gr-negative-mass/649471/6 "2013-02-06T17:36:16Z")
So, does this lead to the conclusion, gravity and the cosmological constant arise from this dichotomy? Gravity is positive / CC is negative. ---
**Author:** ![FinnAgain](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/finnagain/32/12500_2.png) [@FinnAgain](https://boards.straightdope.com/u/FinnAgain)\ **Post date:** [February 6, 2013, 5:38pm UTC](https://boards.straightdope.com/t/qm-positive-mass-gr-negative-mass/649471/7 "2013-02-06T17:38:04Z")
Not exactly… but there is evidence for the idea that the Graviational Constant on our brane is particularly weak and ‘should’ be equal to Coloumb’s Constant. There’re suggestions, however, that gravity can somehow ‘cross branes’ and serve as a means of communication between universes in the multiverse. ---
**Author:** ![cmyk](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cmyk/32/3353_2.png) [@cmyk](https://boards.straightdope.com/u/cmyk)\ **Post date:** [February 6, 2013, 5:39pm UTC](https://boards.straightdope.com/t/qm-positive-mass-gr-negative-mass/649471/8 "2013-02-06T17:39:41Z")
Assuming that interpretation correct, yes? ---
**Author:** ![Sailboat](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/sailboat/32/461_2.png) [@Sailboat](https://boards.straightdope.com/u/Sailboat)\ **Post date:** [February 6, 2013, 5:39pm UTC](https://boards.straightdope.com/t/qm-positive-mass-gr-negative-mass/649471/9 "2013-02-06T17:39:58Z")
> [@FinnAgain](#): > > There’re suggestions, however, that gravity can somehow ‘cross branes’ and serve as a means of communication between universes in the multiverse. I’m getting a crossed brane just thinking about it. ---
**Author:** ![Half\_Man\_Half\_Wit](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/half_man_half_wit/32/21766_2.png) [@Half\_Man\_Half\_Wit](https://boards.straightdope.com/u/Half_Man_Half_Wit)\ **Post date:** [February 6, 2013, 5:43pm UTC](https://boards.straightdope.com/t/qm-positive-mass-gr-negative-mass/649471/10 "2013-02-06T17:43:44Z")
> [@cmyk](#): > > So, does this lead to the conclusion, gravity and the cosmological constant arise from this dichotomy? Gravity is positive / CC is negative. No. The gravitational field has stress-energy (and is thus a source of the gravitational field) just like the other forces do. And the expansion of space is due to it having a _positive_ energy density (via the cosmological constant), leading to a _negative_ pressure. ---
**Author:** ![Asympotically\_fat](https://avatars.discourse-cdn.com/v4/letter/a/e47c2d/32.png) [@Asympotically\_fat](https://boards.straightdope.com/u/Asympotically_fat)\ **Post date:** [February 6, 2013, 5:48pm UTC](https://boards.straightdope.com/t/qm-positive-mass-gr-negative-mass/649471/11 "2013-02-06T17:48:45Z")
> [@Der\_Trihs](#): > > And I understand that the expansion of space can be looked at as possessing negative mass/energy; I recall reading of theories that used that as an explanation for the origin of matter. The idea being that the rapid expansion of space counting as negative energy, and the appearance of positive mass/energy cancel it out so the universe has net zero energy. I’m not a physicist, so I’m probably butchering the explanation though. Negative pressure I think is what you mean to say. - see HMHW (simulpost) ---
**Author:** ![BrainGlutton](https://avatars.discourse-cdn.com/v4/letter/b/82dd89/32.png) [@BrainGlutton](https://boards.straightdope.com/u/BrainGlutton)\ **Post date:** [February 6, 2013, 5:57pm UTC](https://boards.straightdope.com/t/qm-positive-mass-gr-negative-mass/649471/12 "2013-02-06T17:57:33Z")
> [@Der\_Trihs](#): > > Actually, it’s my understanding that positive matter attracts everything, and negative mass repels everything. Including other negative matter? Then, would negative matter ever be found in accretions larger than a single atom? ---
**Author:** ![FinnAgain](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/finnagain/32/12500_2.png) [@FinnAgain](https://boards.straightdope.com/u/FinnAgain)\ **Post date:** [February 6, 2013, 6:06pm UTC](https://boards.straightdope.com/t/qm-positive-mass-gr-negative-mass/649471/13 "2013-02-06T18:06:07Z")
> [@cmyk](#): > > Assuming that interpretation correct, yes? It depends on what you mean by ‘interpretation’. That we live in a multiverse is rock solid, as the mathematics behind the Inflation (think big bang) show that it wasn’t an isolated event. That various 'verses are essentially holographs on branes, that’s much more conjecture. And that gravitation can ‘leak’ between branes, of course, relies on branes being real in the first place, and then that hypothesis being falsifiable. ---
**Author:** ![Half\_Man\_Half\_Wit](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/half_man_half_wit/32/21766_2.png) [@Half\_Man\_Half\_Wit](https://boards.straightdope.com/u/Half_Man_Half_Wit)\ **Post date:** [February 6, 2013, 6:16pm UTC](https://boards.straightdope.com/t/qm-positive-mass-gr-negative-mass/649471/14 "2013-02-06T18:16:28Z")
> [@FinnAgain](#): > > That we live in a multiverse is rock solid, as the mathematics behind the Inflation (think big bang) show that it wasn’t an isolated event. Nah, inflation is perfectly consistent with there just being one universe. The multiverse gets started with eternal inflation/bubble universe model, which is much less well supported observationally (certainly far from ‘rock solid’). ---
**Author:** ![FinnAgain](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/finnagain/32/12500_2.png) [@FinnAgain](https://boards.straightdope.com/u/FinnAgain)\ **Post date:** [February 6, 2013, 6:24pm UTC](https://boards.straightdope.com/t/qm-positive-mass-gr-negative-mass/649471/15 "2013-02-06T18:24:35Z")
> [@Half\_Man\_Half\_Wit](#): > > Nah, inflation is perfectly consistent with there just being one universe. [Nope.](http://scienceblogs.com/startswithabang/2011/10/28/why-we-think-theres-a-multiver/) > [@](#): > > Although inflation will end in more than 50% of the Universe at any given time, enough of it will spread back up the hill that inflation lasts an eternity. And this is true for every model of slow-roll inflation we’ve concocted! > > In other words, there are regions of the Universe where it inflated in the past, that false-vacuum energy got turned into radiation and matter, and those parts of the Universe had a history very much like our own. But in between those regions, there are other parts that keep on inflating, and so on, and so on, and so on… > > And that’s why there’s a multiverse, and not just our Universe! > > Now, the story I’ve told you is a conservative one. In this version of the story, the fundamental constants are the same in all the different regions of the multiverse, and the other Universes have the same laws of physics — with the same quantum vacuum and all — as our own. But most of what you hear about the multiverse these days are from people who have speculated much farther than that. > > The ideas that you hear — multiple false vacua, the landscape, connections to quantum gravity, etc. — are ones that people have speculated upon in recent years. These are mostly driven by including connections to string theory, and they present a whole host of difficulties as well as a great many interesting avenues to investigate. I will not touch upon them here, but when you hear those words, this is the basic story that they all take for granted. > > So this basic concept, while it likely isn’t the entire story, is just simple quantum mechanics applied to our best working model of the Early Universe. And what we get out of it is a Universe that, in most regions of it, will continue to inflate for all eternity: our Multiverse. ---
**Author:** ![Half\_Man\_Half\_Wit](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/half_man_half_wit/32/21766_2.png) [@Half\_Man\_Half\_Wit](https://boards.straightdope.com/u/Half_Man_Half_Wit)\ **Post date:** [February 6, 2013, 7:17pm UTC](https://boards.straightdope.com/t/qm-positive-mass-gr-negative-mass/649471/16 "2013-02-06T19:17:08Z")
He’s talking about slow roll inflation, which is not the only, nor to my knowledge the only viable, model of inflation we have. [ > [@](#): > > In standard inflation, inflationary expansion occurred while the universe was in a false vacuum state, halting when the universe decayed to a true vacuum state and became a general and inclusive phenomenon with homogeneity throughout, yielding a single expanding universe which is “our general reality” wherein the laws of physics are consistent throughout. In this case, the physical laws “just happen” to be compatible with the evolution of life. ]([Eternal inflation - Wikipedia](http://en.wikipedia.org/wiki/Eternal_inflation#Differential_decay)) ---
**Author:** ![Der\_Trihs](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/der_trihs/32/233_2.png) [@Der\_Trihs](https://boards.straightdope.com/u/Der_Trihs)\ **Post date:** [February 6, 2013, 7:50pm UTC](https://boards.straightdope.com/t/qm-positive-mass-gr-negative-mass/649471/17 "2013-02-06T19:50:48Z")
> [@BrainGlutton](#): > > Including other negative matter? Then, would negative matter ever be found in accretions larger than a single atom? It could still be held together by electromagnetic forces much like positive matter, although the details would be different since it would react in an opposite fashion to electrical charge (like charges would attract, opposite charges repel). And for that matter in an opposite fashion to force; pushing negative matter away would make it move towards you, while pulling on it would make it move away from you. There’s a Wikipedia [article](http://en.wikipedia.org/wiki/Negative_matter#Negative_mass) or [two](http://en.wikipedia.org/wiki/Negative_mass) about it. ---
**Author:** ![cmyk](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cmyk/32/3353_2.png) [@cmyk](https://boards.straightdope.com/u/cmyk)\ **Post date:** [February 7, 2013, 4:52am UTC](https://boards.straightdope.com/t/qm-positive-mass-gr-negative-mass/649471/18 "2013-02-07T04:52:48Z")
Some good food for thought. Thanks all, so far. > [@FinnAgain](#): > > Everything is nothing, yes. Actually, this idea is what inspired the OP. I know it’s been around for a while, I just was curious if thinking about space-time as “anti-mass”, in the same vein as anti-matter or electrical charge, was accurate. ---
**Author:** ![cmyk](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cmyk/32/3353_2.png) [@cmyk](https://boards.straightdope.com/u/cmyk)\ **Post date:** [February 7, 2013, 10:11am UTC](https://boards.straightdope.com/t/qm-positive-mass-gr-negative-mass/649471/19 "2013-02-07T10:11:12Z")
Upon further thought, I suppose I’d like to argue here (my admittedly half-baked proposition) that space-time is “anti mass-energy” (or the equivalence that mass-energy is “anti space-time”). Where mass-energy gives rise to matter, space-time gives rise to the vacuum; at the smallest scales, matter and the vacuum are a stochastic, quantum fluctuation between space-time and mass-energy. But, on the largest scales, matter and the vacuum likewise clump and diffuse, respectively. From this perspective, I see “gravity” arising from mass-energy, and the “vacuum” expanding from space-time (assuming it being “anti mass-energy”). From here, looking at something like a singularity where the “pull” of mass-energy, and the “push” of space-time cancel each other out, yet the equal and opposite signs of positive mass and negative mass would still favor an acceleration toward the positive mass, forming an unintuitively enigmatic region of space-time that now “pulls”, and the converse of mass-energy which now “pushes.” Momentum and energy would remain conserved, but the resultant black hole could be seen as a physical manifest of the reversal of attraction/repulsion of matter-energy/space-time respectively. Gravity then is a consequence of the interaction of +/- mass as they interact with each other; a dance of mass-energy informing space-time how to curve and space-time informing mass-energy how to move. ---
**Author:** ![cmyk](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cmyk/32/3353_2.png) [@cmyk](https://boards.straightdope.com/u/cmyk)\ **Post date:** [February 7, 2013, 10:25am UTC](https://boards.straightdope.com/t/qm-positive-mass-gr-negative-mass/649471/20 "2013-02-07T10:25:04Z")
Or something. [Next page](https://boards.straightdope.com/t/qm-positive-mass-gr-negative-mass/649471.md?page=2)