Interesting. Notice (by the total energy equation ...

2010-01-11T10:01:59.211-05:00

Interesting. Notice (by the total energy equation you wrote down) that invariant rest-energy (i.e., vanishing 3-velocity p) is mc^2, which is indeed negative when m is negative. So I don't think negative mass would be a problem for energy conservation in SR.

In GR things get trickier, because it's harder to say what you mean by energy -- and hence by energy conservation. But I don't see any prima facie problem with negative mass for the existing conservation laws. Nice idea though, I'll have to think about it.

What what happens to the positive mass in the pres...

2010-01-10T19:59:34.213-05:00

What what happens to the positive mass in the presence of a negative mass? Why from the looks of it, the acceleration will be in the same direction as the negative mass's. While this isn't mathematically a problem for the conservation of momentum, since the momentum of a negative mass moving in some direction is in the opposite direction, it does seem exceedingly strange. I mean, the very thought of sitting two things next to each other and having them accelerate off, forever going faster, is a bit strange, no? Classically, there's no conservation of energy problem because the kinetic energy of a negative mass object is negative. It would seem to be a problem for special relativity, though, because the energy takes the form: sqrt( (m * c^2 )^2 + ( p * c )^2 ), and that's positive whether or not the mass is positive.

I'm less familiar with the situation in GR, but I would imagine that the unbounded increase in the energy can be compensated for by the release of gravitational waves that adjust space-time's curvature appropriately.

Comments on Soul Physics: How would negative mass behave in a gravitational ...

Interesting. Notice (by the total energy equation ...

What what happens to the positive mass in the pres...