Niaj hnub no tus nqi steel nyob ruaj khov. Kev ua tau zoo ntawm cov yav tom ntej dub yog qhov tsis zoo, thiab qhov chaw ua lag luam tseem nyob ruaj khov; tsis muaj zog kinetic tso tawm los ntawm kev thov txwv tus nqi los ntawm kev nce ntxiv. Cov nqi hlau yuav tsum tsis muaj zog nyob rau lub sijhawm luv.

Niaj hnub no, kev lag luam tus nqi nce siab raws li tus nqi taw qhia, kev thov stagnates, kev lag luam feem ntau yog hnub so, cov neeg siv khoom cog lus passively coj cov khoom raws li qhov pom zoo, thiab lub luag haujlwm tseem ceeb yog txo cov khoom muag thiab muag cov khoom. Nws cia siab tias tus nqi lag luam yuav ruaj khov.