Class 7 Science Chapter 12: Earth, Moon, and the Sun (Hinglish Notes)

Ye chapter kis baare mein hai?

Kanniyakumari mein Rashmika dekhti hai ki school jaate samay naariyal ke pedon ki parchhaaiyan lambi hoti hain aur ghar lautte samay chhoti. Kya Sun aasmaan mein chalta hai, ya Earth chalti hai? Book ka ye aakhri chapter uske sawaal ka jawab deta hai. Ye dikhata hai ki Earth kaise ghoomti aur chakkar lagaati hai, aur ye do chaalein din aur raat, taaron ka ghoomna, seasons aur grahan kaise samjhaati hain.

Earth rotate karti hai

Anti-clockwise ghoomte merry-go-round pe aas paas ki duniya clockwise ghoomti dikhti hai. Earth ke saath bhi aisa hi hai. Wo apni axis pe, jo North aur South Pole se guzarti hai, lagbhag 24 ghante mein ek baar rotate karti hai, North Pole ke upar se dekhne pe anti-clockwise, yaani West se East. Sun ki taraf waale aadhe hisse mein din hota hai aur baaki aadhe mein raat, aur har jagah pe sunrise tab hota hai jab wo roshni mein ghoomti hai. Hum West se East ghoomte hain, isliye Sun, Moon aur taare East mein ugte aur West mein doobte dikhte hain. Aur padho rotation aur revolution mein.

Aasmaan ghoomta dikhta hai

Raat mein taare bhi aasmaan mein chalte dikhte hain, sivaay Pole Star (Dhruva Tara) ke, jo lagbhag ruka rehta hai kyunki Earth ki axis lagbhag usi ki taraf hai. Saptarishi, yaani Big Dipper, raat bhar uske chaaron taraf ghoomta hai. Der tak khule camera se li gayi tasveeron mein taare gol lakeerein banaate hain, jinhe star trails kehte hain. Aryabhata ne 5th sadi CE ke aas paas ise samjhaaya: aage badhti naav se kinaare ki cheezein peechhe jaati dikhti hain, aur waise hi sthir taare West ki taraf chalte dikhte hain. India ki nayi Parliament imaarat mein laga 22 metre ka Foucault pendulum bhi Earth ka rotation dikhata hai.

Earth revolve karti hai

Ghoomte hue Earth Sun ke chaaron taraf lagbhag gol orbit mein revolve bhi karti hai, aur ise lagbhag 365 din 6 ghante lagte hain. Mahine beetne ke saath uska raat waala hissa antariksh ke alag hisse ki taraf hota hai, isliye sunset pe ugne waale taare saal bhar badalte rehte hain. Tapi ghaati ke Bhil aur Pawara samudaay kuch khaas taaron ke dikhne se jaan lete the ki monsoon aane waala hai.

Seasons kyun hote hain

Earth ki axis jhuki hui hai, aur poori orbit mein wo yahi jhukaav banaaye rakhti hai. June mein Northern Hemisphere Sun ki taraf jhuka hota hai, isliye wahan dhoop zyaada ghani hoti hai aur din 12 ghante se lambe hote hain: wahan garmi hoti hai, aur Southern Hemisphere mein sardi. December mein ulta hota hai. Uttar ka sabse lamba din, lagbhag 21 June, summer solstice hai; March aur September ke equinox pe din aur raat barabar hote hain. Sun se doori iski wajah nahi hai: Earth January mein Sun ke sabse paas hoti hai. Dekho seasons kyun badalte hain?

Grahan

Mercury aur Venus hamare aur Sun ke beech se guzarte hain par itne chhote dikhte hain ki Sun ko chhupa nahi sakte. Moon chhota hai par paas hai, isliye Sun jitna bada dikhta hai aur use dhak sakta hai. Surya grahan mein Moon Earth ke ek chhote hisse tak Sun ki roshni rok deta hai, jahan total grahan dikhta hai, jabki aas paas ke bade hisse mein partial grahan dikhta hai. Ise kabhi seedhe mat dekho. Chandra grahan mein Earth ki parchhaai poore chaand pe padti hai, jo gehra laal ho sakta hai, aur ise dekhna surakshit hai. Padho surya grahan aur chandra grahan, aur har sawaal ka jawab Chapter 12 ke NCERT solutions mein dekho.