Photons mediate electromagnetic interactions between particles in quantum electrodynamics. Electromagnetism's QFT is quantum electrodynamics (QED). Experimental tests of quantum electrodynamics are typically scattering experiments. The first gauge theory quantized was quantum electrodynamics (QED). For example, quantizing classical electrodynamics gives quantum electrodynamics. Maxwell's equations have been superseded by quantum electrodynamics (QED). After the success of quantum electrodynamics, Feynman turned to quantum gravity. This holds throughout the quantum theory, including electrodynamics. Its detection is important for quantum electrodynamics. This comes from the formula for the propagation of a photon in quantum electrodynamics. Also, cavity quantum electrodynamics (Cavity QED) is one possible method of doing this. It is also related to the field of cavity quantum electrodynamics. Fermilab measured a somewhat different cross section, in agreement with predictions of quantum electrodynamics. Such comparisons are a test of quantum electrodynamics (QED). This is exactly the case of quantum electrodynamics displaying just three diverging diagrams.