Homogeneity of space is fundamental to quantum field theory (QFT) where the wave function of any object propagates along all available unobstructed paths. When integrated along all possible paths, with a phase factor proportional to the action, the interference of the wave-functions correctly predicts observable phenomena. Every point on the wavefront acts as the source of secondary wavelets that spread out in the light cone with the same speed as the wave. The new wavefront is found by constructing the surface tangent to the secondary wavelets.
homOGeneity oF SpACE is fundAmental to QuanTum FIELD tHeorY (qFt) wherE THE wave fUnctIoN of Any ObJECT PropagaTEs alonG ALl aVAilaBLe unObsTRucTEd paTHS. WhEn inTegRAted aLoNg alL pOSsibLE patHS, WiTh A PHase factor prOPORtionAl to The ActiOn, tHe intErFerence oF the wAve-fuNCTiONS CorRectLy preDIcts Observable pHenOmena. Every Point on The wAvEfRont acTs as the sourcE Of SeconDaRy WavElets That SPrEad OUt iN the lIgHt CoNe witH the Same speeD as THe wAVe. The neW WAvefront is foUNd by constructinG the surFace TANgenT TO tHE Secondary waVelETS.