Side face rub hit make photons beeline speed converted to spin speed. When photons beeline speed about reduced to 3km/s, it become low-speed-photon. Low-speed-photon only a very small beeline kinetic energy and mass, therefore, low-speed-photon become mankind currently undetectable micro-substance. Electromagnetic force make low-speed-photon maintain three-dimensional reseau orderly arrangement, form electromagnetic field. Photon pass through between three-dimensional reseau, excite low-speed-photon fluctuation, form electromagnetic waves. This situation makes photon show wave-particle duality. Positive collision make low-speed-photons spin speed converted to beeline speed. Low-speed-photons beeline speed acceleration to light speed, it become photon. Side face rub hit make low-speed-photons beeline speed converted to spin speed. When low-speed-photons beeline speed about reduced to 3cm/s, it become micro-speed-photon. Micro-speed-photons beeline speed is very small. So, magnetic force make micro-speed-photons orderly bond into electron or positron. Electron and positron orderly bond into atom. Atoms orderly bond into molecule. Molecules orderly bond into cosmic dust. Photon flying to cosmic every corner. Therefore, low-speed-photon, micro-speed-photon, electron positron, atom, molecule, cosmic dust, floating in cosmic every corner.