But I wonder if photon molecules would really create anything like a light saber. The researchers at Harvard and MIT passed single photons through a rarified, super chilled gas of rubidium. They found as the photons passed through the gas, the gas drew energy from the photons, slowing them down and adding spin that allows them to bond in the same way that other elements bond as molecules. Here are two looks at the story: The Press Release on EurekAlert — Science World Report article.
Now, I am not a theoretical physicist or quantum mechanic, but I have my doubts about photon molecules and light sabers. The process of producing the photon molecule must rob the photon of some of its energy. Additionally, as photon molecules bind, the photon itself must be stripped of its carrier wave. The heat energy of light is not the massless photon. It is the wave that it travels on. The wave creates vibration. It is the wave that generates the energy we associate with heat. As such, I have my doubts that a photon molecule structure would have any heat energy associated with it. You might generate something that looks like a light saber but would not burn like one.
That said, photon molecules would be an awesome thing if they could be bound into large scale structures. The process the researchers developed makes the photons behave as if they have mass, but that does not mean that the photons have acquired mass. A photon molecule structure may be massless, like the photon itself. Think about that for a moment. It would be possible to construct a solid structure the size of a football stadium that would weight nothing. It would interact on the Earth’s surface as if it was in a weightless environment, as gravity requires mass for attraction.
It is doubtful that photon molecule structures will be created anytime in the foreseeable future. It is a distant dream at best, but what a cool idea. Sheet material that could be built to any size and thickness, and have no weight. But light sabers? Nah.