‘Negative mass’ clarified

A FLEET study led by University of Queensland’s David Colas clarifies recent studies of negative mass, investigating the strange phenomenon of self-interference.

NEGATIVE MASS??

When we think of ‘mass’, we usually consider the ‘inertial’ mass – the resistance of a body to acceleration due to an applied force.

For a moving object, its mass is then a simple relationship between momentum applied to it, and the velocity it acquires.

However, in some situations, this relationship is not simply proportional and can depend on the impulse applied to the object. Physicists then talk about effective mass, which can even be negative.