Thread: Possible to simulate negative matter.

1. That's right.. "NEGATIVE MATTER"
I know it sounds farfetched but would it not be possible to simulate it?  2.

3. Originally Posted by Brian
That's right.. "NEGATIVE MATTER"
I know it sounds farfetched but would it not be possible to simulate it?
Simulate it how ?

What is it supposed to be ?

To simulate something you need a cogent theory of how it behaves.  4. Well, there do exist anti matter. Take some of this and combine it with normal matter, and they cancel each other out  Without breaking the laws of physics though. Their mass is converted into light, with an energy E = mc^2. Thats the closest I can think of, when it comes to negative matter.  5. Anti matter is not "negative matter". A positron still has positive rest mass, equal to the rest mass of an electron.

As for what negative matter would mean...

Well, as I see it, such a particle's rest frame momentum vector would be pointed in the opposite direction as an ordinary particle's. And since the momentum vector of a massive particle in any frame is simply the lorentz transform of the rest frame one, the particle's 4-momentum will always point in the opposite direction as the 4-momentum vector of a particle with positive mass of equal magnitude.

Now this sounds like the kind of thing that could happen in the creation of a particle-antiparticle pair. But the only problem with this is that particle-antiparticle creation, to my knowledge, isn't quite that simple. For example, the Feynman diagram for electron-positron creation requires two incoming photons, the exchange of a virtual electron/positron, and then the outgoing electron and positron. I don't know of any situation in which two particles can just propagate outwards from the same spot, like this:

<------*------->

But if you could find particles that behaved that way, I suppose one of them would have negative mass. It seems to me like such a particle would violate cause and effect, so I wouldn't look to hard for something like this.  I concluded earlier that if you could come up with a particle with the following Feynman diagram (time going left to right), then the one going right to left would have negative mass:

<-----*------>

But then I asked myself: how could you ever produce such a Feynman diagram? You'd need a field term of the form or perhaps if the particle is charged. Either way, these are MASS terms (i.e., not interaction terms). So if those are the only higher power terms that appear in the Lagrangian, then what you have is a non-interacting particle. In which case, I believe that the physics cannot distinguish between positive and negative mass--I think the only thing that matters in terms of describing how the particle behaves is the absolute value of the mass. If I'm wrong about this, anyone feel free to correct me.  7. Originally Posted by salsaonline

I concluded earlier that if you could come up with a particle with the following Feynman diagram (time going left to right), then the one going right to left would have negative mass:

<-----*------>

But then I asked myself: how could you ever produce such a Feynman diagram? You'd need a field term of the form or perhaps if the particle is charged. Either way, these are MASS terms (i.e., not interaction terms). So if those are the only higher power terms that appear in the Lagrangian, then what you have is a non-interacting particle. In which case, I believe that the physics cannot distinguish between positive and negative mass--I think the only thing that matters in terms of describing how the particle behaves is the absolute value of the mass. If I'm wrong about this, anyone feel free to correct me.
If you simply play the Newtonian game with F=ma, then negative mass ought to result in something that moves to the left when you push it to the right. I think I can distinguish that from the normal behavior of an object with positive mass. Think about a solid cube that is divided between positive and negative mass. You couldn't move it since under application of a force part wants to go hither and the other part wants to go yonder.

Gravitationally it ought to behave the same way, near a positive mass. The gravitational force on it would be reversed, but the acceleration would be in opposite direction to the force, so the net is no difference. But on impact the behavior would be pretty weird. The high contact forces at impact would result in a downward rather than upward acceleration -- it would not bounce. The military could make some pretty impressive penetrators out of this stuff.

On the other hand if two bodies had negative mass then the force would be directed towards the other body, but the acceleration would be away from it -- effectively anti-gravity.  8. Originally Posted by DrRocket

If you simply play the Newtonian game with F=ma, then negative mass ought to result in something that moves to the left when you push it to the right. I think I can distinguish that from the normal behavior of an object with positive mass. Think about a solid cube that is divided between positive and negative mass. You couldn't move it since under application of a force part wants to go hither and the other part wants to go yonder.

Gravitationally it ought to behave the same way, near a positive mass. The gravitational force on it would be reversed, but the acceleration would be in opposite direction to the force, so the net is no difference. But on impact the behavior would be pretty weird. The high contact forces at impact would result in a downward rather than upward acceleration -- it would not bounce. The military could make some pretty impressive penetrators out of this stuff.

On the other hand if two bodies had negative mass then the force would be directed towards the other body, but the acceleration would be away from it -- effectively anti-gravity.
Actually gravitationally, with a positive mass the results can be very interesting. As you said, the negative mass would still accelerate towards the positive mass, since the gravitational force is would be negative as it is result of the product of the two masses (+, -). The positive also feels this negative gravitational force and would be pushed away from the negative mass. It would accelerate away from the negative mass.

As a result, conservation of momentum takes a holiday. This alone makes the existence of negative matter of this type suspect in my opinion.  9. negative mass, I wonder how that type of matter would behave in the first place.

Gravitationally, the force both objects would experience being would be the same, the acceleration opossite due to the whole F=ma deal. What would happen if you had two bodies of equal magnitude mass? I mean, both accelerating in the same direction, they would experience a weird relationship that definitely breaks some physical laws.

Hmm... I think this just showed that anti-gravity is a fundamental impossibility due to conservation laws.  10. Originally Posted by salsaonline
Anti matter is not "negative matter". A positron still has positive rest mass, equal to the rest mass of an electron.
Has this ever been verified? Or just predicted?  11. Originally Posted by drowsy turtle Originally Posted by salsaonline
Anti matter is not "negative matter". A positron still has positive rest mass, equal to the rest mass of an electron.
Has this ever been verified? Or just predicted?
It was pretty much verified the first time the postitron was detected. It was slowed by passing through a lead plate. If the positron had had a negative rest mass, the forces acting on it as it passed thorugh the plate would have sped it up.

Also, If the positron had a negative mass, it would be impossible to form positronium, Which is a electron-positron orbiting pair.  12. Originally Posted by drowsy turtle Originally Posted by salsaonline
Anti matter is not "negative matter". A positron still has positive rest mass, equal to the rest mass of an electron.
Has this ever been verified? Or just predicted?
Antimatter is made on a regular basis in particle accelerators.  13. All I can say is.. "Damn.." You guys are smart? I understand it up to the words that I have never seen before.. Lol.  Posting Permissions
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