In quantum physics, coincidence counting is used in experiments testing particle non-locality and quantum entanglement. In these experiments two or more particles are created from the same initial packet of energy, inexorably linking/ entangling their physical properties. Separate particle detectors measure the quantum states of each particle and send the resulting signal to a coincidence counter. In any experiment studying entanglement, the entangled particles are vastly outnumbered by non-entangled particles which are also detected; patternless noise that drowns out the entangled signal. In a two detector system, a coincidence counter alleviates this problem by only recording detection signals that strike both detectors simultaneously (or more accurately, recording only signals that arrive at both detectors and correlate to the same emission time). This ensures that the data represents only entangled particles.