Zakale ndi zamakono za kilogalamu

Kodi kilogalamu imalemera bwanji? Asayansi akhala akufufuza vuto looneka ngati losavuta limeneli kwa zaka mazana ambiri.

Mu 1795, dziko la France linakhazikitsa lamulo loti “gramu” ndi “kulemera kotheratu kwa madzi mu kobe imodzi imene mphamvu yake imakhala yofanana ndi gawo limodzi mwa magawo zana a mita pa kutentha pamene ayezi asungunuka (ndiko kuti, 0°C).” Mu 1799, asayansi adapeza kuti kuchuluka kwa madzi ndikokhazikika kwambiri pamene kuchuluka kwa madzi kumakhala kwakukulu kwambiri pa 4 ° C, kotero tanthauzo la kilogalamu lasintha kukhala "kulemera kwa 1 kiyubiki decimeter yamadzi oyera pa 4 ° C. ”. Izi zinapanga kilogalamu yoyera ya platinamu, kilogalamuyo imatanthauzidwa ngati yofanana ndi kulemera kwake, komwe kumatchedwa kilogalamu yosungira zakale.

Kilogilamu yosungidwayi yakhala ikugwiritsidwa ntchito ngati chizindikiro kwa zaka 90. Mu 1889, Msonkhano Woyamba Wapadziko Lonse wa Metrology udavomereza platinamu-iridium alloy replica yomwe ili pafupi kwambiri ndi kilogalamu yosungidwa ngati kilogalamu yoyambirira yapadziko lonse lapansi. Kulemera kwa "kilogalamu" kumatanthauzidwa ndi platinamu-iridium alloy (90% platinamu, 10% iridium) yamphamvu, yomwe ili pafupifupi 39 mm kutalika ndi m'mimba mwake, ndipo panopa imasungidwa m'chipinda chapansi kunja kwa Paris.

Mayiko choyambirira kilogalamu

Kuyambira mu Age of Enlightenment, gulu lofufuza lakhala likudzipereka kukhazikitsa dongosolo la kafukufuku wapadziko lonse. Ngakhale kuti ndi njira yotheka yogwiritsira ntchito chinthu chakuthupi monga chizindikiro choyezera, chifukwa chinthu chakuthupi chimawonongeka mosavuta ndi zinthu zopangidwa ndi anthu kapena zachilengedwe, kukhazikika kumakhudzidwa, ndipo gulu la miyeso lakhala likufuna kusiya njirayi posachedwa. momwe zingathere.

Pambuyo pa kilogalamu kutengera kutanthauzira koyambirira kwa kilogalamu yapadziko lonse lapansi, pali funso lomwe akatswiri a metrologists akuda nkhawa nalo: tanthauzo ili ndi lokhazikika bwanji? Kodi idzayenda pakapita nthawi?

Ziyenera kunenedwa kuti funsoli linadzutsidwa kumayambiriro kwa tanthauzo la kilogalamu ya misa. Mwachitsanzo, pamene kilogalamu imatanthauzidwa mu 1889, bungwe la International Bureau of Weights and Measures linapanga zolemera 7 za platinamu-iridium alloy kilograms, imodzi mwa izo ndi International The kilogalamu yoyambirira imagwiritsidwa ntchito kutanthauzira kulemera kwa kilogalamu, ndipo zolemera zina 6. zopangidwa ndi zinthu zomwezo ndipo njira yomweyo imagwiritsidwa ntchito ngati zizindikiro zachiwiri kuti muwone ngati pali kusokonekera pakapita nthawi pakati pawo.

Panthawi imodzimodziyo, ndi chitukuko chaukadaulo wapamwamba kwambiri, timafunikiranso miyeso yokhazikika komanso yolondola. Chifukwa chake, dongosolo lofotokozeranso gawo lapadziko lonse lapansi lokhala ndi zosintha zakuthupi linaperekedwa. Kugwiritsa ntchito zosinthika kutanthauzira magawo oyezera kumatanthauza kuti matanthauzidwewa akwaniritsa zosowa za m'badwo wotsatira wa zomwe asayansi apeza.

Malinga ndi zidziwitso zovomerezeka za International Bureau of Weights and Measures, pazaka 100 kuyambira 1889 mpaka 2014, kusasinthika kwa ma kilogalamu ena oyambira ndi kilogalamu yapadziko lonse lapansi yapadziko lonse lapansi kudasinthidwa ndi pafupifupi ma 50 ma microgram. Izi zikuwonetsa kuti pali vuto ndi kukhazikika kwa benchmark yakuthupi yagawo labwino. Ngakhale kusintha kwa 50 micrograms kumamveka kochepa, kumakhudza kwambiri mafakitale ena apamwamba.

Ngati zoyambira zakuthupi zikugwiritsidwa ntchito m'malo mwa kilogalamu yokhazikika, kukhazikika kwa gawo lalikulu sikungakhudzidwe ndi malo ndi nthawi. Choncho, m’chaka cha 2005, bungwe la International Committee for Weights and Measures linakonza ndondomeko yogwiritsira ntchito zida zodziwikiratu kuti zifotokoze mbali zina zofunika za International System of Units. Ndikoyenera kuti Planck igwiritsidwe ntchito kutanthauzira kulemera kwa kilogalamu, ndipo ma laboratories oyenerera akulimbikitsidwa kuti agwire ntchito yokhudzana ndi kafukufuku wa sayansi.

Chifukwa chake, pa Msonkhano Wapadziko Lonse wa 2018 wa Metrology, asayansi adavota kuti athetseretu kilogalamu yapadziko lonse lapansi, ndipo adasintha mawonekedwe a Planck (chizindikiro h) ngati mulingo watsopano wofotokozeranso "kg".