Kodi kilogalamu imodzi imalemera zingati? Asayansi akhala akufufuza vutoli looneka ngati losavuta kwa zaka mazana ambiri.
Mu 1795, France idakhazikitsa lamulo lomwe linkanena kuti "gramu" ndi "kulemera kwathunthu kwa madzi mu kyubiki yomwe voliyumu yake ndi yofanana ndi gawo limodzi mwa zana la mita kutentha pamene ayezi asungunuka (ndiko kuti, 0°C)." Mu 1799, asayansi adapeza kuti voliyumu ya madzi ndi yokhazikika kwambiri pamene kuchuluka kwa madzi kuli kwakukulu pa 4°C, kotero tanthauzo la kilogalamu lasintha kukhala "kulemera kwa 1 cubic decimeter ya madzi oyera pa 4°C". Izi zinapanga kilogalamu yoyambirira ya platinamu yoyera, kilogalamuyo imafotokozedwa ngati yofanana ndi kulemera kwake, komwe kumatchedwa kilogalamu yosungiramo zinthu zakale.
Kilogiramu iyi yakhala ikugwiritsidwa ntchito ngati muyezo kwa zaka 90. Mu 1889, Msonkhano Woyamba Wapadziko Lonse pa Metrology unavomereza kopi ya aloyi ya platinum-iridium yomwe ili pafupi kwambiri ndi kilogiramu ya archival ngati kilogiramu yoyambirira yapadziko lonse. Kulemera kwa "kilogiramu" kumatanthauzidwa ndi silinda ya platinum-iridium (90% platinum, 10% iridium), yomwe ili pafupifupi 39 mm kutalika ndi m'mimba mwake, ndipo pakadali pano imasungidwa m'chipinda chapansi kunja kwa mzinda wa Paris.
Kilogalamu yoyambirira yapadziko lonse lapansi
Kuyambira mu Nthawi ya Chidziwitso, gulu lofufuza lakhala likudzipereka kukhazikitsa njira yofufuzira yapadziko lonse. Ngakhale kuti ndi njira yotheka kugwiritsa ntchito chinthu chenicheni ngati muyezo woyezera, chifukwa chinthu chenichenicho chimawonongeka mosavuta ndi zinthu zopangidwa ndi anthu kapena zachilengedwe, kukhazikika kwake kudzakhudzidwa, ndipo gulu loyesa nthawi zonse lakhala likufuna kusiya njira iyi mwachangu momwe zingathere.
Pambuyo poti kilogalamu yayamba kugwiritsa ntchito tanthauzo la kilogalamu yoyambirira yapadziko lonse lapansi, pali funso lomwe akatswiri a za metro amalidera nkhawa kwambiri: kodi tanthauzoli ndi lokhazikika bwanji? Kodi lidzapitirira pakapita nthawi?
Tiyenera kunena kuti funsoli linafunsidwa pachiyambi cha tanthauzo la kulemera kwa kilogalamu imodzi. Mwachitsanzo, pamene kilogalamu inafotokozedwa mu 1889, Bungwe Loona za Kulemera ndi Kuyeza Padziko Lonse linapanga kulemera kwa kilogalamu 7 za platinum-iridium alloy, chimodzi mwa izo ndi International The original kilogalamu imagwiritsidwa ntchito kufotokoza kulemera kwa kilogalamu imodzi, ndipo zolemera zina 6 zopangidwa ndi chinthu chomwecho ndi njira yomweyo zimagwiritsidwa ntchito ngati zizindikiro zachiwiri kuti ziwone ngati pali kusinthana pakati pa wina ndi mnzake pakapita nthawi.
Pa nthawi yomweyo, ndi chitukuko cha ukadaulo wolondola kwambiri, tikufunikanso miyeso yokhazikika komanso yolondola. Chifukwa chake, dongosolo lokonzanso gawo loyambira lapadziko lonse lapansi ndi zokhazikika zakuthupi linaperekedwa. Kugwiritsa ntchito zokhazikika pofotokoza mayunitsi oyesera kumatanthauza kuti matanthauzidwe awa adzakwaniritsa zosowa za mbadwo wotsatira wa zomwe asayansi apeza.
Malinga ndi deta yovomerezeka ya International Bureau of Weights and Measures, m'zaka 100 kuyambira 1889 mpaka 2014, kusinthasintha kwa ma kilogalamu ena oyambirira ndi kilogalamu yoyambirira yapadziko lonse lapansi kunasintha ndi pafupifupi ma microgram 50. Izi zikusonyeza kuti pali vuto ndi kukhazikika kwa muyezo weniweni wa unit ya khalidwe. Ngakhale kusintha kwa ma microgram 50 kumamveka kochepa, kumakhudza kwambiri mafakitale ena apamwamba.
Ngati zinthu zoyambira zokhazikika zimagwiritsidwa ntchito m'malo mwa kilogalamu yoyezera thupi, kukhazikika kwa gawo la kulemera sikudzakhudzidwa ndi malo ndi nthawi. Chifukwa chake, mu 2005, Komiti Yapadziko Lonse Yoona za Kulemera ndi Kuyeza idalemba dongosolo logwiritsira ntchito zinthu zoyambira zokhazikika zokhazikika pofotokoza mayunitsi ena oyambira a International System of Units. Ndikofunikira kuti Planck igwiritsidwe ntchito pofotokoza kulemera kwa gawo la kilogalamu, ndipo ma laboratories oyenerera adziko lonse akulimbikitsidwa kuchita ntchito yofufuza yasayansi yokhudzana nayo.
Chifukwa chake, pa Msonkhano Wapadziko Lonse wa 2018 pa Metrology, asayansi adavota kuti achotse mwalamulo chiŵerengero cha prototype chapadziko lonse lapansi, ndipo adasintha chizindikiro cha Planck (chizindikiro h) kukhala muyezo watsopano wofotokozeranso "kg".
Nthawi yotumizira: Marichi-05-2021