OnthebasisofPlanckquantumhypothesisandEinsteinphotonquantumhypothesis,Zhongjizi(anewelementaryparticle)hypothesiswasproposedtorevealtheessenceofphoton,theoriginofmass,thequantumpropertyofgravitation,andthenatureofdarkmatter.TheresultsshowthatphotonisessentiallyasetofZhongjizi,lightiscomposedupofZhongjizi,thenatureoflightisparticleproperty,thepropertyoflightisdeterminedbythepropertyofZhongjizi,andthequantumpropertyoflightisessentiallyZhongjizipropertyoflight.Zhongjiziisthemostbasicparticleintheuniverseandtheoriginofmass,whichgivesmasstootherparticles.Zhongjiziisparticletransmittingthegravitation;gravitationtransmissionspeedisequaltothespeedoflight.ThequantumpropertyofgravitationisthepropertythatgravitationistransmittedbyZhongjizi.Theso-calleddarkmatterisessentiallyZhongjizifulloftheuniverseandtransmittinggravitation,soZhongjiziistheso-calleddarkmatterparticle.
