Did someone confirm negative mass? I wouldn't hold your breath on trying to understand negative mass. It is akin to time travel. I'm not saying it isn't possible to understand it, there are probably better things to waste your time with.

When I was an undergraduate I tried to develop a coordinate system for mass, where the center of mass of the universe was the origin, and the axes where the three fundamental forces. Then I found out from a professor that John Wheeler, who was very much alive at that time, had attempted it and I kinda gave up after that.

Later, in graduate school I learned about Wheelers geometrodynamics ("mass without mass"). Talk about paradoxes. I don't know how you resolve all of those paradoxes. I'm guessing that is why he gave up.

If negative mass were confirmed it would be a seismic shift in physics. I'm getting old, and don't keep up anymore. Let me know if it was confirmed, or what other research has been done to substantiate the idea.