• H2 molecules break apart into H atoms
• H atoms loose their electrons
• He atoms lose their electrons
• He nuclei break apart into protons, neutrons
• Protons and neutrons break apart into quarks
• More exotic massive unstable particles are created
• You get more and shorter wavelength photons
• You get a quasi-equilibrium between photons and matter
               High energy photons (particles + antiparticles)