Photons — those fundamental particles of light — have a slew of interesting properties, including the fact they don’t tend to crash into one another. That hasn’t stopped physicists from trying, though.

University of Chicago physicists have now come up with a new, highly flexible way to make photons behave more like the particles that make up matter. It might not give us lightsabers, but making photons collide could still lead to some fantastic technologies.

The trick to getting particles of light — which have no mass — to acknowledge one another’s existence is to have them meet in the quiet confines of an atom, and combine their properties with those of an electron.