Breaking news here claim researchers at Washington State University have created negative mass by the characteristic that if you push it, it accelerates in the opposite direction.
The so called negative mass is a collection of rubidium atoms forming an Einstein Bose Condensate.
My question is can one claim they have negative mass by this one characteristic? Doesn't the material at least need to be checked against gravitational forces to see if it 'falls' up?
What is the 'acid test' that indeed these experimenters have negative mass? Perhaps they are just seeing some other mechanism of the system that makes things appear as though they have negative mass.