The opposite of pair production is pair destruction or pair annihilation. Analogously, this seems to jibe with the marital principle “till death do us part” to which modern marriages rarely adhere to. But since the death of an electron colliding with a positron is the creation of two photons, the sorrow of material dying is more than justified by the happiness of living forever as two quanta of light. It is experimentally verified that at low energies, say around a few MeV, the result of electron-positron collision is always a pair of photons. Hence, the phrase “matter down to light.”

However, at high energies several interesting things begin to happen. The e-e+ collisions begin to produce three photons. At higher energies still, the phrase “matter up to matter” starts to make sense. Electron-positron annihilations produce pairs of up quark-antiquark or heavier lepton-antilepton pairs. However, the quarks never existed as free particles. They could simply produce and became other types of hadrons as detected by experiments. As the available energy increases quarks and leptons of larger rest mass begin to appear. Moreover, striking resonances appear at energies of tangent rate angle greater than unity. At about 3 GeV (billions electron volts) the resonance of charm-anticharm quark pair appears producing abundant supplies of charmed hadrons seen in particle accelerators. At 10 GeV, bottom quark-antiquark pairs appear. At 90 GeV the Z-zero intermediate vector gauge boson appears. Nonetheless, between 100 GeV and the Planck energy of 10 000 000 000 000 000 000 GeV nothing can be predicted to appear either by theory or experiment although at the lower end of this elementary particle desert are supposedly the rest energies of scalar Higgs boson, the magnetic monopoles, and the supersymmetric partners of every particle of matter and energy. None of these can be detected. Why matter down reality is limited below 100 GeV is truly a great mystery of nature?