Star is very far away from our Earth. The distance is so big that the star appears as a single point of light. Our eyes or telescopes do not resolved the star beyond a pinpoint-sized object. We observe the Light coming from a single point.
Light waves are refracted in the atmosphere. The density as well as the temperature of atmosphere are not uniformly distributed. Number of light waves coming to our eyes are also changing continuously due to refraction. Some rays bend much and do not come to our eyes while some rays strike our eyes. Hence we see a quick dimming and brightening of light called twinkling of star.
There will be more twinkling if the star is situated at far distance.
On the other hand planet is near to the Earth comparing to a star's distance. It is seen bigger in size and can be considered as collections of many pin-point sized sources.
When light waves enter the atmosphere they are also refracted but due to the bigger size of planet, we can not see it twinkling. If light from one point- source get refracted and dimmed, the light waves of other sources may nullifying the effect of dimmed light. Hence on an average we can perceive the planet having constant brightness.
Light waves are refracted in the atmosphere. The density as well as the temperature of atmosphere are not uniformly distributed. Number of light waves coming to our eyes are also changing continuously due to refraction. Some rays bend much and do not come to our eyes while some rays strike our eyes. Hence we see a quick dimming and brightening of light called twinkling of star.
There will be more twinkling if the star is situated at far distance.
On the other hand planet is near to the Earth comparing to a star's distance. It is seen bigger in size and can be considered as collections of many pin-point sized sources.
When light waves enter the atmosphere they are also refracted but due to the bigger size of planet, we can not see it twinkling. If light from one point- source get refracted and dimmed, the light waves of other sources may nullifying the effect of dimmed light. Hence on an average we can perceive the planet having constant brightness.
Post a Comment