Thaum xyoo 1820, tus kws tshawb fawb Duster Auster tau tshawb pom cov nyhuv ntawm cov dej ntws, thiab thawj zaug tau qhia tias muaj qhov txuas ntawm cov nplhaib thiab hluav taws xob, yog li sib txuas nrog hluav taws xob.
Yuav kom piav qhia txog qhov tshwm sim ntawm cov hlau nplaum thiab cov hlau nplaum, Ampere npaj tau lub tswvyim qub molecular. Ampere ntseeg hais tias muaj ib qho tam sim no hauv cov khoom siv khoom, hu ua molecular tamsis no, thiab molecular tamsim no yog sib npaug rau cov txheej thaum ub. Thaum cov khoom tsis muaj nyob hauv lub tshuab nqus hlau macroscopic, qhov kev taw qhia ntawm cov molecular currents yog lus, thiab lawv qhov teeb meem sib nqus ntawm sab nraud tshem tawm txhua qhov, kom tag nrho cov khoom tsis yog sib nqus. Nyob hauv qhov kev txiav txim ntawm ib sab nraud magnetic teb, txhua molecular sib npaug tam sim no rau qib elementary magnet yuav raug oriented hauv cov kev taw qhia ntawm cov sab nraud magnetic teb, thiab cov khoom yuav ua rau sib nqus.
Muaj ib qho tseem ceeb ntawm qhov sib txawv ntawm qhov tshwm sim ntawm qhov sib txawv thiab qhov muaj hluav taws xob tshwm sim. Cov khoom sib nqus ntawm cov teeb meem muaj kev sib raug zoo nrog cov qauv ntawm lub zog ntawm electrons. Lub tswv yim ntawm electron spin thawj npaj siab los ntawm Uhlenbeck thiab Goldschmidt yog xav txog cov electron raws li lub pob. Lawv xav hais tias, zoo ib yam li lub zog ntawm lub ntiaj teb ib ncig lub hnub, electrons khiav ntawm ib sab ntawm cov keeb kwm ntawm cov keeb kwm thiab muaj qhov sib txawv orbits. Lub sij hawm ntawm lub zeem muag thiab lub zeem muag ntawm lub zeem muag, ntawm qhov tod tes, tig ib ncig ntawm lawv tus kheej lub cev, nrog qhov tig qhov siab thiab qhov sib txig sib cav sib nqus. Lub sib nqus magnetic ntsuas los ntawm Stern-Gellach ntawm cov nyiaj atom atom txoj kev sim yog qhov nraim no tig hlau magnetic lub sij hawm.
