The Large Hadron Collider plays with Albert Einstein's famous equation, E = mc2, to transform matter into energy and then back into different forms of matter. But on rare occasions, it can skip the first step and collide pure energy - in the form of electromagnetic waves. Last year, the ATLAS experiment at the LHC observed two photons, particles of light, ricocheting off one another and producing two new photons. This year, they've taken that research a step further and discovered photons merging and transforming into something even more interesting: W bosons, particles that carry the weak force, which governs nuclear decay. This research doesn't just illustrate the central concept governing processes inside the LHC: that energy and matter are two sides of the same coin. It also confirms that at high enough energies, forces that seem separate in our everyday lives - electromagnetism and the weak force - are united.