Ib lub tswv yim uas peb paub los ntawm thaum yau yog pawg. Thiab tseem, hauv chav kawm ntawm physics, qee qhov teeb meem cuam tshuam nrog nws txoj kev kawm. Yog li ntawd, nws yog ib qho tsim nyog yuav tsum paub meej tias qhov loj npaum li cas. Koj yuav paub nws li cas? Thiab yog vim li cas nws tsis sib npaug ntawm qhov hnyav?