Dark matter is mysterious because it doesn't interact with light. How remarkable it would be if we made it in the lab by colliding light. Using the LHC as a photon collider opens supersymmetry and dark matter searches with the full missing momentum 4-vector via proton tagging. Furthermore, the enormous photon flux surrounding heavy ions could be used to measure tau g–2, which is barely constrained but can be 280 times more sensitive to new physics than muon g–2. Tantalisingly, these new and important energy frontier tests of QED could be realised today.