Francois Arago

Ba da daɗewa ba bayan farkon ƙarni na 19,ƙwazo na aƙalla masana falsafa uku suna tsara koyaswar ka’idar haske mara kyau.Hujjojin Fresnel da ke goyon bayan waccan ka'idar sun sami ƙaramin tagomashi ga Laplace,Poisson da Biot, zakaran ka'idar watsi;amma Humboldt da Arago,waɗanda Makarantar ta nada su ba da rahoto a kan takarda sun yarda da su sosai.Wannan shi ne ginshikin abota ta kud-da-kud tsakanin Arago da Fresnel,da kuma ƙudirin ci gaba tare da ƙarin ƙa'idodi masu mahimmanci na polarization na haske da aka sani ta hanyarsu.A sakamakon wannan aiki,Arago ya gina wani polariscope,wanda ya yi amfani da shi don wasu abubuwa masu ban sha'awa game da polarization na hasken sararin sama.Ya kuma gano ikon jujjuyawar polarization wanda ma'adini ke nunawa.