A collision of light

One of the latest discoveries from the LHC takes the properties of photons beyond what your electrodynamics teacher will tell you in class. Professor Anne Sickles is currently teaching a laboratory class at the University of Illinois in which her students will measure what happens when two photons meet. What they will find is that the overlapping waves of light get brighter when two peaks align and dimmer when a peak meets a trough. She tells her students that this is process called interference...