CBSE Class 10 Answered

HI dear,

Twinkling basically depends on the temperature difference. When light enters a transparent medium, it generally changes direction or gets bent or scattered. But, by how much it chnages depends on the temperature. Warm air bends light less. while cool air bends more. Now any star is practically is so far away, that it sends only a ingle ray towards us. As that enters the atmosphere, it gets scattered in different ways as it crosses air medium at different temperatures. When it is scattered away from us, the star seems to disappear, when is scattered into our eyes, it looks it is appeared resulting in a twinkle.

Regarding the sun, there are so many light rays coming our way,  that dosen't matter, some of them are scattered away, and the remaining are scattered to us. Hence, the image looks steady.

Hope this helped.

Regards

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