What Do You Mean By "Negative Mass?"

I just saw this in Science Daily:

Quote:

Physicists have created a fluid with negative mass, which is exactly what it sounds like. Push it, and unlike every physical object in the world we know, it doesn't accelerate in the direction it was pushed. It accelerates backwards.

Intrigued, I thought to my Trekkie self, "negative mass implies negative energy, thought that was impossible, but hooray, I need it for my spiffy Alcubierre Drive." Then I kept reading:

Quote:

To create negative mass, the researchers applied a second set of lasers that kicked the atoms back and forth and changed the way they spin. Now when the rubidium rushes out fast enough, if behaves as if it has negative mass. "Once you push, it accelerates backwards," said Forbes, who acted as a theorist analyzing the system. "It looks like the rubidium hits an invisible wall."

So, to you labcoats: Would you please quit jerking me off making cool announcements with loose language? That, or tell me this is for realskis.

via International Skeptics Forum http://ift.tt/2oIzAF5