Nawa ne nauyin kilogram? Masana kimiyya sun binciko wannan matsala mai sauƙi na ɗaruruwan shekaru.
A shekara ta 1795, Faransa ta fitar da wata doka da ta ayyana “gram” a matsayin “cikakkiyar nauyin ruwa a cikin cube wanda girmansa ya yi daidai da ɗari na mita a yanayin zafi lokacin da ƙanƙara ta narke (wato, 0°C).” A shekara ta 1799, masana kimiyya sun gano cewa yawan ruwa ya fi kwanciyar hankali lokacin da yawan ruwa ya kasance mafi girma a 4 ° C, don haka ma'anar kilogram ya canza zuwa "ma'auni na 1 cubic decimeter na ruwa mai tsabta a 4 ° C. ". Wannan ya samar da kilogiram na asali na platinum mai tsafta, ana siffanta kilogiram daidai da girmansa, wanda ake kira kilogiram na ajiya.
An yi amfani da wannan kilogiram na tarihin a matsayin ma'auni tsawon shekaru 90. A shekara ta 1889, taron farko na kasa da kasa kan ilimin kimiya da fasaha ya amince da wani nau'in alloy na platinum-iridium mafi kusa da kilogram na kayan tarihi a matsayin kilogram na asali na duniya. Nauyin “kilogram” an bayyana shi ta hanyar silinda na platinum-iridium (90% platinum, 10% iridium) Silinda, wanda tsayinsa ya kai 39 mm tsayi da diamita, kuma a halin yanzu ana adana shi a wani ginshiki a wajen birnin Paris.
Kilogi na asali na duniya
Tun zamanin wayewa, al'ummar binciken sun himmatu wajen kafa tsarin binciken duniya. Duk da cewa abu ne mai yuwuwa a yi amfani da abu na zahiri a matsayin ma'aunin ma'auni, domin abu na zahiri yana samun sauki ta hanyar abubuwan da mutum ya yi ko muhalli ya lalace, kwanciyar hankali za ta yi tasiri, kuma al'ummar ma'aunin a kodayaushe suna son yin watsi da wannan hanya da zarar an yi amfani da shi. kamar yadda zai yiwu.
Bayan kilogiram ya karbi ma'anar kilogiram na asali na kasa da kasa, akwai wata tambaya da masana kimiyyar yanayi suka damu da ita: yaya wannan ma'anar ta tabbata? Shin zai yi tafiya a kan lokaci?
Ya kamata a ce an taso wannan tambayar a farkon ma'anar ma'anar ma'aunin kilogram. Misali, lokacin da aka bayyana kilogiram a shekara ta 1889, Hukumar Kula da Ma'auni da Ma'auni ta Duniya ta samar da ma'aunin nau'in platinum-iridium alloy kilogram 7, daya daga cikinsu shi ne na kasa da kasa An yi amfani da kilogram na asali wajen ayyana ma'aunin kilogiram, sauran kuma 6 ma'aunin nauyi. Anyi amfani da abu iri ɗaya kuma ana amfani da tsari iri ɗaya azaman ma'auni na biyu don bincika ko akwai ɓata lokaci tsakanin juna.
A lokaci guda, tare da haɓaka fasaha mai mahimmanci, muna kuma buƙatar ƙarin ma'auni masu tsayi da daidaito. Saboda haka, an gabatar da wani shiri na sake fasalta sashin asali na ƙasa da ƙasa tare da madaidaicin jiki. Yin amfani da ma'auni don ayyana raka'o'in ma'auni yana nufin cewa waɗannan ma'anar za su dace da buƙatun binciken kimiyya na gaba na gaba.
Bisa kididdigar da hukumar kula da ma'aunin nauyi ta kasa da kasa ta fitar, a cikin shekaru 100 daga 1889 zuwa 2014, daidaiton ingancin sauran kilogiram na asali da na kilogiram na asali na kasa da kasa ya canza da kusan 50 micrograms. Wannan yana nuna cewa akwai matsala tare da kwanciyar hankali na ma'auni na jiki na naúrar inganci. Kodayake canjin 50 micrograms yana ƙara ƙarami, yana da tasiri mai girma akan wasu manyan masana'antu.
Idan ana amfani da madaidaicin madaurin jiki don maye gurbin ma'auni na jiki na kilogram, kwanciyar hankali na rukunin taro ba zai shafi sararin samaniya da lokaci ba. Sabili da haka, a cikin 2005, Kwamitin Kula da Ma'auni da Ma'auni na Ƙasashen Duniya ya tsara tsarin yin amfani da ainihin ma'auni na zahiri don ayyana wasu mahimman raka'a na Tsarin Raka'a na Duniya. Ana ba da shawarar cewa a yi amfani da ma'aunin Planck akai-akai don ayyana ma'aunin kilogram, kuma ana ƙarfafa ƙwararrun dakunan gwaje-gwaje na matakin ƙasa don aiwatar da aikin binciken kimiyya mai alaƙa.
Saboda haka, a taron kasa da kasa na 2018 kan ilimin kimiyyar halittu, masana kimiyya sun kada kuri'a don soke samfurin kilogram na kasa da kasa a hukumance, kuma sun canza tsarin Planck (alama h) a matsayin sabon ma'auni don sake fasalin "kg".
Lokacin aikawa: Maris-05-2021