Question

Why planets can't twinkle?


Answer this ques on the basis of ch - 11th *Human Eye and colourful world* Class 10th


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Answer 1

$\bf{\Huge{\underline{\boxed{\bf{\orange{ANSWER\::}}}}}}$

Planets are much closer to the earth and are extended source of light. As planets are large number of point-sized sources of light, the total variation in the amount of light entering our eyes will average out to zero. Hence, planets do not twinkle.

$\bf{\large{\underline{\sf{Important\:question\::}}}}}$

Explain the scattering of light. Which colour ray is scattered maximum and which one minimum?

$\bf{\large{\underline{\sf{Answer\::}}}}}$

• $\bf{\Large{\underline{\sf{\red{Scattering\:of\:light\::}}}}}}$

As sunlight travels through the atmosphere, it gets scattered. When size of scattering particles is very small as compared to the wavelength of light, then the amount of scattering is inversely proportional to the fourth power of wavelength. This is known as Rayleigh scattering.

$\bf{\large{\sf{\pink{Amount\:of\:scattering\propto\frac{1}{\lambda^{4} } }}}}$

Since the wavelength of blue colour is approximately half of the wavelength of red colour, therefore scattering of blue light is about $2^{4}$ times more than that of red light. Due to this reason the sky appears blue and at sunrise or sunset, the sun looks almost red.

Larger particles like dust and water droplets present in the atmosphere scatter light of all colours almost equally and hence clouds are generally white.

It is well known by experiment that scattering of red light is minimum and  violet light is maximum.

Answer 2

HEY MATE!!!

The planets are much closer to the earth, and are thus seen as extended sources. If we consider a planet as a collection of a large number of point -sized sources of light, the total variation in the amount of light entering our eye from all the individual point-sized sources will average out to zero, thereby nullifying the twinkling effect.

HOPE IT HELPS YOU!