Prithvi ke nirman ki kahani ko samajhne ke liye, hume prachin vaigyanik aur bhugolshastriyo ke anusar dharti ki utpatti aur uske vikas ki prakriya ko samajhna hoga. Vaigyanik manyata ke anusar, prachin samay me, lagbhag 4.6 billion varsh pahle, ek prakar ki "molecular cloud" ya anu mandalik ghumti dharati ke aas-pass tha. Is cloud me vibhinna prakar ke anu aur padarthik tatva the.
Is "molecular cloud" ke kuchh bhaag ekatrit hokar ek naye tara ke roop me suddhikaran shuru ho gaye, jise protostar kehte hain. Is protostar ke charon or ek chakravyuh ban gaya, jise accretion disk kehte hain. Accretion disk me tatva ekatr hokar chote-chote tukdon mein baante gaye aur ghane gaseous mahasagar bhi bane.
Kuchh hi lakhon varsho mein, protostar ka andruni dabao itna badh gaya ki naye nabhikiya reakshan shuru ho gaye aur usne hydrogen ko helium mein parivartit karne ka prakriya shuru ki. Is prakriya ke doran, ek mahaan urja utpann hoti hai, jise ham sooraj kahte hain. Is urja ke prakash aur dhakelne wale tej garam gas ka karan bana aur isse ek naya tara, hamari prithvi, utpann hua.
Prithvi ke nirman mein lagbhag 10 crore varsh lag gaye. Is prakriya mein, prithvi ki parat ek chikna aur garam outer core ke roop me shuruat me bani. Iske baad, dhire-dhire prithvi ke outer core aur mantle me alag-alag prakar ke tatva, jaise ki silika, iron, nikal aadi, ko alag-alag sthano par sthapit hote gaye. Aisa hone se prithvi me ek sthir nabhikiya gati ka system utpann hua, jise geologists "plate tectonics" kehte hain.
Is prakriya ke doran, prithvi ki parat alag-alag tukdo me tooti aur yeh tukde anu-mandalik activity ke antargat ghumte rahe. Kabhi-kabhi in tukdon ke takraane se pahaad, samudri trench, aur mahaan samundri tatva utpann hote rahe. Yeh prakriya aaj bhi jaari hai, aur iska parinam hai ki prithvi ke mukhya bhaugolik roop aur jalvayu samriddh aur vividh hai.
Isi tarah se, prithvi ke nirman ki kahani vaigyanik drishti se sunaye toh yeh ek lambi aur jcomplex prakriya hai jisme anek samvedansheel padartho ka sanjojana aur sanrachana ho raha tha.













