Yintoni imitha?

Bekuya Kubonakala ukuba oko kube lula ngaphezu unit inyathelo, ngayo wonke umntu ejongene ngokoqobo ukusuka ezalwa. Imitha, kilogram, ilitha ... Noko ke, maxa wambi ubomi ubeka imibuzo omtsha phambi le "kubefundisi". Enye mizekelo - yintoni na lo manzi. Eneneni, xa izifundo geometry yesikolo beeyunithi na ubukhulu nje kulinganiswa. Ngoko ke, mhlawumbi ke musa khona, njengoko kwenza iimitha eziqalayo - fiction esulungekileyo? Ke kaloku, ukuba Internet iyafikeleleka kubo bonke, ngethiyori, unako lula ukufumana impendulo phantse nawuphi na umbuzo. Eyona nto ibalulekileyo - ukuba banelungelo lokwenza oko. Benelungelo ngokuthi uchwetheza kwi bar ekhangela isicelo umkhangeli zincwadi 'ukuba imitha "Ngokuqinisekileyo wamangaliswa kukuba la mazwi idityaniswe ekhitshini umxholo. Kuthetha ntoni oku?

standard

Mhlawumbi, emva konke, ngokucokisekileyo kufuneka aphande umbuzo we into semitha. Licacile elokuba, ekubeni sithetha iiyunithi zomlinganiselo, ukufuna impendulo kufuneka ibe eFransi, kwi-Bureau of nobuNzima Measures, leyo igcina zonke iisampuli reference SI. Kodwa ukuba sithe khangela kwiziganga, ngoko akukho manzi wasentsomini yomgama akukho ayifumanekanga. Oku kubonisa ukuba imitha langoku umlinganiselo ofunekayo ubude kunxulumene ngokungangqalanga kuphela.

Ekuqaleni, omnye ezilishumi-inxalenye lonke ixesha esiqu ezisentlabathini, ezidibanayo eParis kuthathwe njengokubhekisa. amanyathelo ayimfuneko zaphunyezwa-1795, yaye emva kokuba ukuqaliswa ezongeziweyo okulungisa 1799, ngokususela kumgca data ye yenziwe ubungakanani platinum stainless. Emva koko, ke, ukuchaneka kweemitha enjalo ibizwa ngokuba ngakumbi athandabuze, kuba ukumila kweli hlabathi sikude sphere egqibeleleyo, kodwa geodesy lwamandulo ukufumana ukuchana ibonwe ngaphandle engenayo yesathelayithi nzima. Ukuba ngexesha original "umgangatho" Ukuchaneka wakhe kwanele ngayo yonke imisebenzi ixesha, isimo ukutshintsha ngonyaka ngamnye. Ngenxa yoko, ngowe-1960, oko yaphakanyiswa ukusebenzisa njenge imitha inxalenye ethile ye ngamaza yinguqu atom in Interface. Kunye engama-23 kuphela emva umgangatho omiselwe nentsingiselo yalo mihla, ebotshelelwe ubude umendo umqadi ukukhanya cleaner.

Yintoni imitha?

Eli gama lisetyenziswa kwi-nokuthengiswa iziveliso liqengqiwe. Enkosi kuye, abakwazi ukuba lula kakhulu izibalo. Ngokomzekelo, umntu kufuneka athenge 10 yesikwere seemitha ilinoliyam. La majelo izinto esebenzayo yaqaphela imiqulu, ububanzi leyo invariable ibe nganye. Ngenxa yoko, ukuba bafumane i efunekayo macala-10. m 2 m roll ububanzi, kuyimfuneko ukuba umlinganiselo kuphela 5 m. Ukususela 2 m * 5 m = 10 macala onke. M. Nazi ezi-5 - uze ube manzi. Ngamanye amazwi, imitha elingana nexabiso reference, kodwa ngenxa naluphi na olunye Ixabiso rhoqo (kule meko ububanzi).

Noko ke, le nkcazelo kufuna ukucaciswa, njengoko rhoqo ibinzana elithi "yomgama imitha ekhitshini," akusoloko kucacile. Ngapha koko, xa mfanekiso, kunye ukuthenga ifanitshala ikhitshi, kwakuthiwa, ukuba ucelwe ukuba siphumle ukusuka kuluhlu inani elithile nekhabhathi. isenzeko ukudideka ngenxa yokuba kubathengisi yeemveliso ifanitshala enjalo ngaphambili zikhankanywe amaxabiso rhoqo zithathwa nje ngokubanzi, kwaye iindleko eziphathekayo kunye nabasebenzi. Ukuba siyazi ixabiso kwemitha, yaye ngalinye ziyahluka kuphela zoqwalaselo lwesithuba (lo gama kugcinwe inani elifanayo material), kunokuba lula kakhulu ukuba ukusebenzisa ingqiqo yobalo luqikelelo metre nganye. Kubathengi ezinomdla iindleko "imodeli ikhitshi efanayo, kodwa ubude enoba kukancinane okanye kakhulu," ngokulula ukubala nto, nkqu bebodwa.