EntityQ5249638· pop 5· linked from 23 articlesdecouplingSign in to saveperiod in the development of the universe when different types of particles fall out of thermal equilibrium with each otherConnectionsredshiftEntityHubble–Lemaître lawEntityexpansion of the universeEntitychronology of the universeEntityscale factorEntityAlbert EinsteinPersonIsaac NewtonPersonGalileo GalileiEntityatomEntityhydrogenEntityuniverseEntityNicolaus CopernicusEntityStephen HawkingPersonJohannes KeplerEntityBig BangEntityInternational Standard Book NumberEntityspeed of light in vacuumEntityplasmaEntitymass densityEntityphotonEntityCategoriesPhysical cosmology