Can mass be negative or not? - Answers

In classical physics, mass is considered a positive quantity, as it relates to the amount of matter in an object. However, in theoretical physics, concepts like negative mass have been proposed in certain contexts, such as in hypothetical scenarios involving exotic matter or in some interpretations of general relativity. Negative mass would behave differently, potentially repelling positive mass rather than attracting it. Nonetheless, no experimental evidence currently supports the existence of negative mass.