▁his ▁assistant , ▁the ▁tale ' s ▁narr ator , ▁that ▁he ▁has ▁discovered ▁that ▁the ▁visible ▁universe ▁at ▁the ▁largest ▁scales ▁corresponds ▁to ▁the ▁micro scop ic ▁universe ▁at ▁the ▁smallest ▁observed ▁scales , ▁the ▁relations ▁between ▁universe ' s ▁plan ets ▁sun s , ▁and ▁star ▁cluster ▁being ▁identical ▁to ▁the ▁relations ▁of ▁electrons , ▁atomic ▁nuc lei , ▁and ▁mole cules . ▁R ather ▁than ▁explore ▁the ▁universe ▁at ▁their ▁own ▁scale , ▁the ▁professor ▁int ends ▁to ▁explore ▁the ▁world s ▁end lessly ▁nested ▁within ▁matter ▁itself , ▁which ▁he ▁arg ues ▁by ▁induction , ▁must ▁go ▁on ▁to ▁ever ▁smaller ▁levels , ▁and ▁claims ▁to ▁have ▁invent ed ▁a ▁subst ance , ▁that ▁once - app lied ▁will ▁cause ▁an ▁individual ▁to ▁perpet ually ▁shr ink . ▁His ▁assistant ▁thinks ▁him ▁ins ane , ▁but ▁the ▁professor , ▁surprising ▁the ▁assistant , ▁inject s ▁him ▁with ▁the ▁subst ance , ▁tempor arily ▁par al yz ing ▁the ▁assistant ▁and ▁do oming ▁him ▁to ▁et ern ally ▁shr ink ▁ever ▁smaller , ▁through ▁success ively ▁smaller ▁world s , ▁each ▁a ▁sub atomic ▁particle ▁of ▁the ▁previous ▁one . ▁( The ▁inject ed ▁subst ance , ▁" S hr inx ", ▁has ▁engine ered ▁secondary ▁properties ▁such ▁as ▁o xygen ating ▁the ▁blood ▁and ▁protect ing ▁against ▁heat ▁loss ▁in ▁space .) ▁The ▁professor ▁will ▁monitor ▁the ▁assistant ' s ▁fate ▁through ▁a ▁device ▁that ▁receives ▁his ▁sense ▁of ▁sight ▁and ▁sound , ▁and ▁int ends ▁to ▁eventually ▁follow