According to an article published in the science journal Nature, scientists from MIT and Harvard have managed to observe light photons as particles. That means that while light doesn’t really have matter or mass in the way we normally understand it, it can still be made to “stick together” to form light molecules.
Now, if we can just get three or four feet worth of these light molecules to stick together and add whatever properties let it deflect lasers and slice through flesh, we’ll have ourselves our very own lightsabers.