Chapter 32, Problem 5RQ

According to nebular theory, did the planets start before or after Sun ignited?

To determine

Whether the planets starts forming before or after the ignition of Sun.

Answer to Problem 5RQ

The planets starts forming before the Sun ignited because the formation of Sun occurred due to the high temperature of the central portion and it happened after more time.

Explanation of Solution

The formation of planets occurs due to the rotation of nebula. The nebula changes its disk shape from spherical shape due to faster rotation. The central portion of the nebula becomes hot and nuclear fission ignited.

The central portion of the nebula changes to Sun and planets are formed by the surrounding material of the nebula around the Sun. The nebula begins hot due to the radiated energy of the Sun.

The more dense surrounding material in the vicinity of the Sun forms the inner planets and less dense material away from the Sun forms the outer planets. The formation of the planets starts before the ignition of the Sun.

Conclusion:

Therefore, the planets starts forming before the Sun ignited because the formation of Sun occurred due to the high temperature of the central portion and it happened after more time.