Yuav ua li cas yog cov roj siab, kua thiab khoom

Twb tau nyob rau hauv lub ancient ntiaj teb no, cov neeg xav tias hais tias xws li siab ntawm huab cua thiab cov kua ua tau. Ib co ntawm cov tswv yim hais txog cov atomic qauv ntawm qhov teeb meem tuaj rau peb nyob rau hauv cov paj huam Lucretius 'Nyob rau Xwm yam ", thiab qhov no yog lub sij hawm ntawm antiquity, thaum lub siab ntawm lub zog twb tau zoo siv nyob rau hauv ancient Egypt. Pov thawj nyob rau hauv ib tug rhuab thiab nthuav roj "magically" qhib qhov rooj tuam tsev, thiab builders siv hydraulic nqa hnyav pob zeb blocks.

Niaj hnub no, cov lus nug zoo li cas ntawm siab li lub cev muaj nuj nqis, teb: nws yog tus piv ntawm kev quab yuam ib chav tsev cheeb tsam. Yog li ntawd, lub cua siab, lub siab ntawm lub kua nyob rau hauv cov hlab thiab lub siab ntawm lub txhav lub cev rau yug - yog hais txog phenomena. Vim hais tias lawv muab kev koom tes rau hauv lub dag zog yuam, lub siab yuav ua tau rau ua hauj lwm (lub enterprising thiab enjoyed lub ancient Iyiv pov thawj).

Nrog lub siab ntawm cov khoom cev rau ib tug them nyiaj yug, nyob rau hauv tus, nws tus kheej-explanatory. Lub cev hnyav - yog lub hwj chim, thiab nws yog muab faib mus rau hauv ib tug txhawb lub cev hu cheeb tsam. Txawm li cas los, nyob rau hauv cov kua thiab gas hais yog tsis nyob rau hauv so. Lawv yeej ib txwm ua ib tug tsab ntawv tsa suab los yog Brownian random los yog tsom tus me nyuam ntawm tej yam ntawm sab nraud rog los nrog tej yam kev mob ntawm lub system. Siab yog tsim los raug tus hais ntawm cov hlab phab ntsa.

Lub dag zog yuam uas yog muab kev koom tes nyob rau hauv cov creation ntawm siab nyob rau hauv cov ntaub ntawv no - nws yog ib qho impulse uas muab txhua particle ib chav tsev lub sij hawm. Qhov twg puas lub zog thiab lub zog, peb to taub hais tias peb nco ntsoov cov mis kinematics qhia txog cov elastic kev sib tsoo ntawm lub cev. Ib tug qauv los yog atom ntawm cov kua thiab gas yog ntshai ua ib elastic kheej. Hauv tu ncua tsoo nrog txhua lwm yam cov kua thiab cov gaseous tshuaj hais, lub zog thiab momentum pauv. Yog li ntawd, lub siab kuj tshwm sim tsis tau tsuas yog nrog rau kev hwm mus cov hlab phab ntsa, tab sis kuj nyob rau hauv tej substance.
Txawm nyob rau hauv lub tshuab nqus tsev nws yog ib txwm ib qhov nqi ntawm hais tias tsim tau ib tug me ntsis siab therein. Nws yog qhov tseeb hais tias qhov no zoo ntawm siab nyob rau hauv ib lub tshuab nqus tshwm sim, nws qhia ib zaug. Chiv nws twb xav hais tias ib lub tshuab nqus - nws tsis yog emptiness, thiab nws tsim tau ib tug pes tsawg siab. lub tsev kawm ntawv physics Hoob no siv no assumption tam sim no.

Rov qab mus rau cov lus tsa suab hais. Nws yuav pab kom peb to taub dab tsi yog qhov kev tig tau thiab zoo li qub siab. Thaum tus hais yog nyob rau hauv random thermal tsab ntawv tsa suab, uas yog qhov, muaj ib tug zoo li qub siab. Thaum ua ntawv thov mus rau lub system tej lwm cawv, thiab cov lus tsa suab hais muaj predominant kev taw qhia, cov tib hais pib muaj ib kinetic siab.

Zoo li qub siab yuav tsum muaj cai, piv txwv li, nyob rau hauv qab ntawm lub tub sau nrog dej. Yog hais tias peb qhib tus kais, shooting ib lub dav hlau ntawm dej yuav tsim ib tug ntxiv kinetic siab. Simplistically nws yog ua tau los xam, raws li nyob rau hauv tib xav txog kev teem raws li tau piav saum toj no nrog rau kev hwm mus elastic collisions ntawm tus hais. Lub dav hlau muaj ib tug measured tshaj tawm thiab momentum yog exchanged nrog da dej hauv qab nyob rau hauv ib tug kev sib tsoo. Tag nrho cov system siab (cov dej da dej) yuav tsum tau sib npaug zos rau cov sum ntawm cov kev tig tau thiab zoo li qub pressures.