Matsalar siffar Duniya tana damun mutane shekaru da yawa. Wannan shine ɗayan mahimman tambayoyin ba kawai don labarin ƙasa da ilimin ɗabi'a ba, har ma don ilimin taurari, falsafa, kimiyyar lissafi, tarihi har ma da adabi. Yawancin ayyukan masana kimiyya na kowane zamani, musamman na Zamani da Haskakawa, an keɓe su ga wannan batun.
Hujjojin masana kimiyya game da surar Duniya
Don haka Pythagoras a cikin ƙarni na VI na BC ya riga ya yi imani cewa duniyarmu tana da siffar ƙwallo. Bayaninsa ya raba ne daga Parmenides, Anaximander na Miletus, Eratosthenes da sauransu. Aristotle ya gudanar da gwaje-gwaje iri-iri kuma ya iya tabbatar da cewa Duniya tana da siffar zagaye, tunda a lokacin kusufin Wata, inuwar a koyaushe tana cikin da'irar. La'akari da cewa a wancan lokacin akwai tattaunawa tsakanin masu goyan bayan ra'ayoyi biyu mabambanta, wasu daga cikinsu sunyi jayayya cewa ƙasa madaidaiciya ce, wasu kuma cewa tana da zagaye, ka'idar sphericity, kodayake masu tunani da yawa sun yarda da ita, yana buƙatar mahimmin bita.
Kasancewar fasalin duniyarmu daban da kwallon, Newton yace. Ya kasance ya yi imani da cewa yafi na ellipsoid, kuma don tabbatar da hakan, ya gudanar da gwaje-gwaje iri-iri. Bugu da ari, ayyukan Poincaré da Clairaud, Huygens da d'Alembert sun sadaukar da surar duniya.
Tunanin zamani game da yanayin duniya
Yawancin ƙarni na masana kimiyya sun gudanar da bincike na asali don tabbatar da yanayin duniya. Sai kawai bayan jirgin farko zuwa sararin samaniya ya sami damar kawar da duk tatsuniyoyin. Yanzu ra'ayi ya yarda cewa duniyar tamu tana da suran ellipsoid, kuma tayi nesa da surar da ta dace, an daidaita ta daga sandunan.
Don bincike daban-daban da shirye-shiryen ilimantarwa, an halicci samfurin duniya - duniya, wacce ke da sifar kwallan, amma wannan duk babu tsari. A saman sa, yana da wahalar zanawa a sikeli da kimantawa gaba dayan abubuwan wuri na duniyar mu. Amma radius, ana amfani da ƙimar kilomita 6371.3 don ayyuka daban-daban.
Don ayyukan sararin samaniya da geodesy, don bayyana fasalin duniyar, ana amfani da manufar ellipsoid na juyi ko geoid. Koyaya, a wurare daban-daban duniya ta bambanta da geoid. Don magance matsaloli daban-daban, ana amfani da samfuran samfuran ƙasa ellipsoids, alal misali, mai nuni ellipsoid.
Don haka, surar duniyar tambaya ce mai wahala, hatta ga ilimin kimiyyar zamani, wanda ke damun mutane tun zamanin da. Haka ne, zamu iya tashi zuwa sararin samaniya mu ga sifar Duniya, amma har yanzu babu wadatar lissafi da sauran lissafi da za su iya nuna adadi daidai, tunda duniyar tamu ta musamman ce, kuma ba ta da wani fasali mai sauki kamar jikin jiometric.
