Good news, Star Wars fans. Physicists from MIT and Harvard have engineered a new form of matter that behaves "just like a lightsaber," said Adam Clark Estes at Gizmodo. Scientists managed to clump together photons — massless particles of light that don't normally interact with one another — to form a molecule. When two lasers are aimed at one another, their beams typically pass through one another. But the "photonic molecules" created here "push against and deflect each other," said Harvard physicist Mikhail Lukin. "The physics of what's happening in these molecules is similar to what we see in the movies."