“An example is a thin sheet of negative mass wrapping around a wormhole to maintain cylindrical symmetry,” Lieu wrote. That’s kind of a long shot on top of a long shot, and it’s not an ...

For the first time, scientists have demonstrated that negative refraction can be achieved using atomic arrays—without the ...

“The shells in my paper consist of a thin inner layer of positive mass and a thin outer layer of negative mass; the total mass of both layers — which is all one could measure, mass-wise — is ...