Duba wurin da ke ƙasa sannan ka amsa tambayar daga baya a cikin harshe ɗaya kamar yadda wurin yake:  Ta hanyar dokarsa Stefan ya kuma ƙayyade zafin jiki na farfajiyar rana. Ya yanke shawara daga bayanan Jacques-Louis Soret (1827<unk>1890) cewa yawan kuzarin kuzari daga Rana ya ninka sau 29 fiye da yawan kuzarin kuzari na wani lamella na ƙarfe mai zafi (wani faranti mai laushi). An sanya lamella mai zagaye a irin wannan nesa daga na'urar auna cewa za'a gan shi a daidai kusurwar da Rana. Soret ya kiyasta yawan zafin jiki na lamella ya kasance kusan 1900 ° C zuwa 2000 ° C. Stefan ya yi hasashen cewa 1⁄3 na kwararar makamashi daga Rana yana sha da yanayin Duniya, don haka ya ɗauki madaidaicin kwararar makamashi na Rana darajar 3/2 sau mafi girma fiye da darajar Soret, wato 29 × 3/2 = 43.5.  Tambaya: Menene Stefan ya sanya kusa da na'urar auna zafin rana?
Zagaye lamella