Na te whakakore i te whanaungatanga motuhake o te aiter luminiferous, i kii a Einstein ko te roa o te waa me te roa o te waa e whangangahia ana i roto i tetahi mea e neke ana te nekehanga - ara, he tere tonu te whakaatu mai o te mea, he tere me te ahunga, ina ka meangahia e te kaimanaaki.