Exploring the Possibility of Negative Mass in the Universe

[fedorfan]

Why is it called negative mass? I am thinking normally about it, like the mass actually is twice as small. Is this right? What is it?

 

[Rade]

Why is it called negative mass? I am thinking normally about it, like the mass actually is twice as small. Is this right? What is it?

No, the mass is not twice as small--see this link: http://www.concentric.net/~pvb/negmass.html

 

[Rade]

Please note that this is not considered as a mainstream journal (I don't even know anyone who cites this thing). I strongly suggest from now on that this source is not used.Zz.

OK, will do. But, has anyone checked the math ? Is not good math in bad journal = good science ?

 

[fedorfan]

I see what youre saying now, I was thinking like it was made of twice as less matter than positive mass. Dumb me. Thanks

 

[Andrew Mason]

http://en.wikipedia.org/wiki/Negative_mass#Negative_mass

It think this Wikipedia article has it wrong. It says:

"However, particle/antiparticle pairs are observed to electrically attract one another, often as the prelude to annihilation. This behavior implies that both have positive inertial mass and opposite charges. If the reverse were true, and antiparticles had negative inertial mass and the same charge, then the normal particle with positive inertial mass would still be repelled by its anti-particle."​

If the anti-particle has negative mass it has negative inertia so it moves opposite to the direction of the force. Thus, if the force is away from the normal particle (if the particle and anti-particle had the same charge) the anti-particle would accelerate toward the normal particle. So the result is the same as if they had opposite charges and both had positive mass.

AM

 

[Farsight]

Would they both fall down, Andrew? And would they both skitter away if I kicked them? If so it doesn't really sound like negative mass.

The only genuine negative mass I can think of is a hole. I take a rather topological view of particles, so I don't see a hole as something to be discounted. Can anybody comment on this? It seems reasonable, for example in this here paper concerning holes and superconductors:

http://arxiv.org/ftp/cond-mat/papers/0503/0503368.pdf

"The remaining hole is commonly defined as having a positive mass and charge, to avoid
complications of describing transport in terms of negative masses..."

 

[TopcatBV]

And what about the evaporation of the black holes?
Doesnt Hawkins mention very briefly about the particle with negative mass who falls in the black hole and anihilate with a normal particle? I didnt heard Hawkins saying that the particle inside the black hole anihilate with the antiparticle who fall in it and generate photons. They are vanishing, evaporating the black hole through the remaining pair-particle, no?

 

[Andrew Mason]

A recent paper that "suggests" possibility of negative mass--someone needs to verify the math:
http://www.ptep-online.com/index_files/2006/PP-06-09.PDF

Please note that this is not considered as a mainstream journal (I don't even know anyone who cites this thing). I strongly suggest from now on that this source is not used.

Zz.

Here is an http://en.wikipedia.org/wiki/Florentin_Smarandache" about the Florentin Smarandache, author of this article and the founder of this journal, PROGRESS IN PHYSICS. Definitely not mainstream, the article refers to it as a 'crank' journal. Smarandache is a professor of mathematics at University of New Mexico. I wonder what Murray Gellmann, who is also at UNM, thinks of this guy's physics...

AM

 

[Hans de Vries]

It think this Wikipedia article has it wrong. It says:

"However, particle/antiparticle pairs are observed to electrically attract one another, often as the prelude to annihilation. This behavior implies that both have positive inertial mass and opposite charges. If the reverse were true, and antiparticles had negative inertial mass and the same charge, then the normal particle with positive inertial mass would still be repelled by its anti-particle."​

If the anti-particle has negative mass it has negative inertia so it moves opposite to the direction of the force. Thus, if the force is away from the normal particle (if the particle and anti-particle had the same charge) the anti-particle would accelerate toward the normal particle. So the result is the same as if they had opposite charges and both had positive mass.

AM

The article is correct though, You are right about the anti-particle's
behavior but the statement they make is about the normal particle.



Regards, Hans

 

[Hans de Vries]

Would they both fall down, Andrew? And would they both skitter away if I kicked them? If so it doesn't really sound like negative mass.

Negative mass particles would behave the same in a gravitational field if
both their inertial and gravitational mass are negative. It just an extension
of Galileo’s observation that the acceleration of objects doesn't depend
on their mass.

The reaction on kicking them would also be the same if the actual Force
is electrostatic, however the reaction of the normal particles would
reveal them as "negative mass, same charge" as the Wikipedia article
mentions.Regards, Hans

 

[Andrew Mason]

The article is correct though, You are right about the anti-particle's
behavior but the statement they make is about the normal particle.

Ok. The normal particle is repelled by the negative mass so it will accelerate away from it, while the negative mass accelerates toward the positive mass. But this does not mean that the separation would always increase if one of the masses is negative, which is what the article seems to say.

If they have masses of equal magnitude (opposite direction), whether the separation increases or decreases depends on which is initially approaching/moving away faster. Slight differences in initial kinetic energy will determine whether they approach or separate. It's like a wolf chasing a deer. Slight differences in initial kinetic energy make all the difference.

AM

 

[Farsight]

The normal particle is repelled by the negative mass so it will accelerate away from it, while the negative mass accelerates toward the positive mass.

That doesn't sound right Andy. Did I misunderstand, or will these two masses accelerate away forever?

It just an extension of Galileo’s observation that the acceleration of objects doesn't depend on their mass.

Thanks Hans. Now that is really interesting.

 

[rbj]

The normal particle is repelled by the negative mass so it will accelerate away from it, while the negative mass accelerates toward the positive mass.

That doesn't sound right Andy. Did I misunderstand, or will these two masses accelerate away forever?

It just an extension of Galileo’s observation that the acceleration of objects doesn't depend on their mass.

Thanks Hans. Now that is really interesting.

take a look at the other thread, guys (in the Classical phyisics forum). this was the observation 3 or 4 days ago.

in my opinion (but since I'm just an EE, i will also say the opinion of a couple of heavyweights on sci.physics.research) is that the consequences of this observation bodes very poorly for the reality of negative mass. if you can construct two blobs of equal mass except one blob negative and the other blob positive, you can make yourself a perpetual motion machine or a space drive mechanism that you don't have to feed fuel or propellent into (not sure how you would turn it on or off).

 

[Farsight]

Thanks rbj. It rather makes me think negative mass makes as much sense as negative red. There seem to be a lot of threads on it at the moment.

 

[TopcatBV]

So, in the Hawkins radiation explanation is envolved negative mass or I misunderstood somethink?

 

[Haelfix]

Guys this isn't very complicated.. Eqns of motion of a negative mass particle (-m)

F = (-m) a = G (-m) m /r^2 ==> a = GM/r^2. It accelerates towards a positive mass particle, just as normal mass does.

Whats the difference?

the positive mass charge

F = ma = g m (-m) /r^2 ==> a = -gm/r^2. The positive charge runs away.

So the situation is highly asymetric, the negative mass charge chases the positive mass charge. Gauss's law no longer holds, and the system is unstable, no equilibrium can ever be reached. That is why, in a nutshell, the situation cannot exist in a world of both positive and negative mass.

 

[Rade]

Guys this isn't very complicated.. Eqns of motion of a negative mass particle (-m)F = (-m) a = G (-m) m /r^2 ==> a = GM/r^2. It accelerates towards a positive mass particle, just as normal mass does.Whats the difference?the positive mass chargeF = ma = g m (-m) /r^2 ==> a = -gm/r^2. The positive charge runs away.So the situation is highly asymetric, the negative mass charge chases the positive mass charge. Gauss's law no longer holds, and the system is unstable, no equilibrium can ever be reached. That is why, in a nutshell, the situation cannot exist in a world of both positive and negative mass.

But, is this not only the case when the positive and negative masses are identical ? -- more interesting, IMO, is when masses are not identical--in that case the two should meet, but whether or not they form stable union is unclear--is this not correct ?

 

[Haelfix]

You can conspire them to get close (to at least epsilon) if you want, just tune the initial conditions. A mass difference would affect the eqns of motion as well, same difference.

The situation would not be stable classically though, as I mentioned. I don't know what the quantum behaviour would look like, short of doing the calculation, but I'd venture to guess it would be a mess, likely with states violating SR and so forth, tachyons all over the place etc.

 

[rbj]

Guys this isn't very complicated.. Eqns of motion of a negative mass particle (-m)

F = (-m) a = G (-m) m /r^2 ==> a = GM/r^2. It accelerates towards a positive mass particle, just as normal mass does.

Whats the difference?

the positive mass charge

F = ma = g m (-m) /r^2 ==> a = -gm/r^2. The positive charge runs away.

So the situation is highly asymetric, the negative mass charge chases the positive mass charge. Gauss's law no longer holds, and the system is unstable, no equilibrium can ever be reached. That is why, in a nutshell, the situation cannot exist in a world of both positive and negative mass.

i've been trying to tell them that a zillion times in the other thread (in the Classical Physics forum) with a similar, but not exactly the same title. I'm not sure why they don't get it. it's like they allow the EP to hold for some cases, but then insist on an absolute value function to convert inertial mass to graviational mass in some other context.

in the nutshell, the reality of negative mass (in our universe) is akin to the reality of a perpetual motion machine and the obsolecense of the conservation of energy and the end of any energy crisis that humans may experience.

 

[Rade]

Any thoughts on the use of (+ -) in the equation number (5) [F(r) = +-Gm1m2/r^2] in this paper on negative mass ?:http://arxiv.org/PS_cache/physics/pdf/0308/0308038.pdf

 

[Andrew Mason]

i've been trying to tell them that a zillion times in the other thread (in the Classical Physics forum) with a similar, but not exactly the same title. I'm not sure why they don't get it. it's like they allow the EP to hold for some cases, but then insist on an absolute value function to convert inertial mass to graviational mass in some other context.

in the nutshell, the reality of negative mass (in our universe) is akin to the reality of a perpetual motion machine and the obsolecense of the conservation of energy and the end of any energy crisis that humans may experience.

Your concerns about energy are certainly well taken but I am not sure that it leads to a violation of conservation of energy since negative mass would have negative energy. What that means in the real world is not clear to me at this point.

Just a thought: The idea that normal matter can be pushed outward forever by negative matter is interesting. Perhaps it is negative mass that is causing the universe to expand at an ever increasing rate!

AM

 

[rbj]

Any thoughts on the use of (+ -) in the equation number (5) [F(r) = +-Gm1m2/r^2] in this paper on negative mass ?:http://arxiv.org/PS_cache/physics/pdf/0308/0308038.pdf

well, i disagree with adding $\pm$ to it and that matter and "antimatter" (i would use the term "negative mass") both repel each other. positive mass attracts the negative mass (as it attracts any mass), but negative mass repels the positive mass (as it repels any mass).

but i got to read the rest of the paper.

 

[rbj]

Your concerns about energy are certainly well taken but I am not sure that it leads to a violation of conservation of energy since negative mass would have negative energy. What that means in the real world is not clear to me at this point.

Just a thought: The idea that normal matter can be pushed outward forever by negative matter is interesting. Perhaps it is negative mass that is causing the universe to expand at an ever increasing rate!

that's what that arxiv paper that was just brought to our attention is about.

my belief that two equal sized balls of mass, but one of them positive and the other negative, will together accelerate indefinitely is what i think leads to a violation of conservation of energy (what that paper calls the "negative-mass paradox"), but so does the accelerating expanding universe except if there is that "dark energy" that's stored up somewhere that's doing it.

i don't think anti-particles are supposed to be negative mass. they have positive mass (and opposite charge) of their normal counterparts and when a particle and anti-particle annihilate each other, the two positive masses are converted to a net positive energy. ain't that the way it's supposed to go?

 

[advitiyas]

IS anTI-MATTER SIMILAR TO NEGATIVE MASS, WHAT ABT BLACK MATTER.

 

[ambresh]

the existence of an antiparticle is a reality eg positron the antiparticle of electron. So far we don't have any experimental evidence for the existense of -ve mass but the property that like masses would attract and opposite would repel is similar to the fact that two wires with the current in the same direction attract and repel each other if the direction of current in them is in the opposite direction. I have heard that masses can be represented in terms of charges (probably in string theory) may be from there we may conclude something.

 

[arivero]

Guys this isn't very complicated.. Eqns of motion of a negative mass particle (-m)

F = (-m) a = G (-m) m /r^2 ==> a = GM/r^2. It accelerates towards a positive mass particle, just as normal mass does.

What about a negative length too?


it would change the sign of the aceleration. you can postulate that negative mass sees negative leghts and save the day

 

[Severian]

I am afraid I don't have the stamina to read the whole thread, but I thought I would make a comment anyway.

In Quantum Field Theories negative mass doesn't make much difference. For a scalar (spinless) object, the expression in the Lagrangian (ie. the physical description) is alway m^2, so if m<0 you get the same thing. Therefore whether or not the mass is positive or negative is just a matter of definition.

For a fermion, the mass in the Lagrangian is linear but you can just redefine your fermion field to make it positive.

As for GR, the important quantity is the energy, not the mass, so the appropriate question would be, 'are there negative energy states?'

In other words, I don't think there is any reason why you couldn't have negative mass, but it would behave exactly the same as what we already see, and would just be a definition. A more interesting question is 'are there imaginary masses'?

 

[Rade]

...A more interesting question is 'are there imaginary masses'?

By imaginary do you mean masses that mathematically can only be described by (i) as a type of complex number superposition between real + imaginary, where i = the square root of -1 ?

 

[Severian]

By imaginary do you mean masses that mathematically can only be described by (i) as a type of complex number superposition between real + imaginary, where i = the square root of -1 ?

Yes, so that the square of the mass is negative, and the particle is a tachyon.

 

[Norman]

Yes, so that the square of the mass is negative, and the particle is a tachyon.

Not really all that interesting since it has been rigorously proven that you cannot send a "message" with a tachyon. Check out john baez's site for a great explanation of it.

 

[selfAdjoint]

Not really all that interesting since it has been rigorously proven that you cannot send a "message" with a tachyon. Check out john baez's site for a great explanation of it.

WIth all respect to Professor Baez, the history of "rigorous no-go theorems" in physics is not too magnificent.

 

[Norman]

WIth all respect to Professor Baez, the history of "rigorous no-go theorems" in physics is not too magnificent.

A very good point that made me smile a little also at how cavalier my statement was. But the experimental search for the tachyon has not been too magnificent either... so I suppose we will wait.

 

[Severian]

Not really all that interesting since it has been rigorously proven that you cannot send a "message" with a tachyon. Check out john baez's site for a great explanation of it.

It is interesting because of the consequences the presence of a tachyon would have for the stability of the vacuum.

 

[actionintegral]

Do not loose track of reality. According to David Gross (Nobel Luareate) We are in a state of confussion...these equations tell us nothing about where space and time come from and describe nothing we would recognize. We are missing something fundamental.
What we know is a collection of mathematical short cuts which predict. we know not why or how.

I came across this post out-of-context. I would like to know more about it.

 

[Nexus555]

Here's something interesting to think about. If negative mass did exist, it would probably be nearly impossible to identify in the lab. Think about it, negative mass means negative gravity, which means something with negative mass wouldn't attract matter, it would repel it... To me that means that we won't be able to find it anytime soon, because it's repel away from positive gravity...

I'm very doubtful and unsure about dark energy/matter at this point, but a good idea would be that the dark energy and matter is actually the negative mass/energy in the universe, and it may cause the universe to expand because it's reactions with positive mass and energy. Maybe that's why it "spreads" too, because when it comes on contact with new space, it attracts the NEGATIVE mass and energy and continues to repel positive mass and energy...

Just an assumption.