Relativistic Entities

First, a disclaimer: This may sound correct or obvious, but if so, it is because that is the way I write.  Nothing should be taken as either factual or as representing the opinions of educated physicists.

This is the fifth of my crank ideas.

So, a previousbit of nonsense was about how relativistic objects might not be viable at long ranges.  This bit of nonsense is about how they might be.

There is an idea that antimatter has negative mass - which, to take one relevant piece of information out of this, implies that it emits antigravity.  (It still falls down, not up.  Gravity is a distortion in space, not a force, as we usually think of forces.  Instead, objects fall away from antimatter at gravitationally relevant distances.)

This implies an interesting possibility: A braided material of matter and antimatter might be able to cancel out the gravitational wave, meaning it may be possible to build a relativistic missile this way.  It wouldn't be terribly effective as a relativistic missile, however, as it wouldn't have much energy - if antimatter has negative inertial mass, the total inertial energy would be close to nil.

(It would still be a fast-moving antimatter bomb, granted.)

This particular technique wouldn't work for interstellar travel, however - at close range the gravitational turbulence would probably rip just about anything apart.  (Maybe even the braided material itself.)

If all of this is accurate, such a braided material would have some strange properties; because it has zero inertial mass, the slightest bit of unbalanced kinetic energy would send it zipping away at relativistic speeds.  When it collides with something, even a hydrogen atom floating in space, it would come to an abrupt stop.

Oh, and depending on the configuration of the braided material, it might move on its own without any external energy, because if that model of antimatter is correct, antimatter chases matter - pulled in by matter's gravity, while matter is pushed away by antimatter's gravity.