Why isn't the Sun shrinking or expanding?
A) Because the Sun is spinning so fast, the centrifugal forces keep the surface of the Sun supported against collapse
B) Because the Sun has lived for billions of years
C) Because the Sun is solid
D) Because gas pressure balances gravity in the Sun

Question

Quizplus · Accepted Answer

The reason why the Sun isn't shrinking or expanding is that gas pressure balances gravity in the Sun. The inward force of gravity on the Sun tries to collapse it, but the outward force of gas pressure prevents this collapse. This balance between gravity and gas pressure is what makes the Sun stable and maintain its size over time.

Why Isn't the Sun Shrinking or Expanding