Chapter 16, Problem 37A

In 2004 when Mercury passed between the sun and Earth, light was not appreciably bent as it passed Mercury. Why?

To determine

To explain: The reason for no light bent as the planet Mercury is passed between the sun and Earth.

Answer to Problem 37A

Light bent over the planet mercury is very small and negligible which was not observed as Mercury do not possess the very high gravitational fields as of like the sun and the stars.

Explanation of Solution

Introduction:

All the celestial bodies possess gravitational fields to some measurable extent. The gravitational fields have the enough strength to pull the objects in its vicinity even it also affects the light.

The mass of the Mercury is $3.285\times {10}^{23}\text{kg}$ is lesser than the mass of the Earth $5.972\times {10}^{24}\text{kg}$ and the Sun $1.989\times {10}^{30}\text{kg}$ .

The gravitational field capacity of Mercury is only about $3.8\text{N}\text{/}\text{kg}$ which is small compared to Earth’s gravitational field of $9.8\mathrm{N}/kg$ , the sun light is not hindered.

The gravitational field strength of sun is $293.0\mathrm{N}/kg$ , which is very high when compared to the planets. So, all the objects around sun are kept held by its gravity.

Hence, when the planet Mercury passes by Sun and Earth the light is not appreciably bent.

Conclusion:

Thus, when the planet Mercury passes by Sun and Earth, the light is not appreciably bent.