is there negative mass?

Answer 1

princess is exactly right. mass is not a function of anything but simply a fact of the amount of particles making up a specific thing or person. thus, it can not be negative because sero mass would mean nothing and negaitve would mean less than nothing. that is not possible, however, in theory, there may be mass which is not attracted by gravity and thus undergoes repulsive acceleration....the definition of such matter can not be worked out as there is no empirical evidence for such. again, there is no negative mass.

Answer 2

No, we haven't found such a thing. Even antiparticles have positive mass. If something did have a negative mass, it would move in the opposite direction of an applied force. This would violate the conservation of momentum. Imagine a collison between something of normal mass with something of negative mass. The negative mass object would accelerate into the other object, increasing the force between them, causing both objects to accelerate off in some direction. This violates conservation of energy. So it seems unlikely that negative mass is something that we will find.

Answer 3

Classically, No, a real particle cannot have negative mass. Such a particle would have to be an imaginary or a virtual particle.

There may be some new radical theory's that suggest it is a possibility. But when you ask: Is there such thing as negative mass? the answer is no because we haven't seen any evidence for such.

Answer 4

Well, it has been proposed that there may be gravity that is repulsive rather than attractive. Since gravity is caused by mass, maybe repulsive gravity is caused by negative mass. Everything else in the Universe has it's antithesis why not gravity.

Answer 5

mass can never be negative as it does not depend upon gravity but weight can be negative

Answer 6

Perhaps, as a Theorecical Concept, see Link