Light sabers are now a reality, ScienceDaily reports:
A group at the Harvard-MIT Center for Ultracold Atoms have managed to coax light photons into binding together to form molecules — a state of matter that, until recently, had been purely theoretical.
The discovery runs contrary to accepted wisdom about the nature of light. Photons have long been described as massless particles which don’t interact with each other. “Photonic molecules,” however, behave more like something in science fiction — the light saber.
“What we have done is create a special type of medium in which photons interact with each other so strongly that they begin to act as though they have mass, and they bind together to form molecules,” Lukin said.
The system could be useful in classical computing, considering the power-dissipation challenges chip-makers now face. It might one day even be used to create complex three-dimensional structures wholly out of light.