Question

Light requires about 8 minutes to travel from the sun to the earth. Is it delayed appreciably by the earth’s atmosphere? Explain.

Short answer

Yes, it is delayed appreciably by the earth’s atmosphere majorly due to the denser medium of earth’s atmosphere and refraction of light.

Step-by-step solution

Speed of light in a vacuum and speed of light in a medium having a refractive index n

$$\begin{gathered} c=3*{10}^{8}m/s \\ v=c/n \end{gathered}$$

Consider the speed of light in a denser medium

The light travels at a speed of $c=3*{10}^{8}m/s$in a vacuum. But this speed gets reduced when light has to travel in a denser medium.

The speed of light in a medium having a refractive n index is: v = c/n

Where v = speed of light in medium,

c = speed of light in a vacuum

n = the refractive index of the medium

Since the atmosphere of the earth is having a denser medium and having a refractive index greater than 1 , the speed of the light will be reduced significantly. In addition to that since light will refract in the atmosphere and travel more to reach the grounds of the earth, it will increase the time.

Hence, it is delayed appreciably by the earth’s atmosphere majorly due to the denser medium of earth’s atmosphere and refraction of light.