Question

You and a friend are looking at the stars and your friend says, "Stars must be shrinking because gravity is constantly pulling their particles together." Explain what is wrong with this reasoning.

Please answer within a paragraph. I promise you can't get it wrong. :)

Answer 1

 Technically? It's not wrong. A star is a ball of gas that is held together by it's own gravity of which it constantly struggles against. Gravity constantly works to try and make the star collapse. However, stars are extremely hot at their cores which help the star push against it's own gravity creating a sort of equilibrium. So long as the star continues to push against gravity, it will not collapse, however eventually a star will lose its energy and eventually collapse into a black hole. 

Answer 2

Answer:

The shrinking of the star due to gravitational forces internal to the core is counterbalanced by the pressure of the photons seeking to get out.

Inside stars nuclear fission happens that is like hundreds of nuclear bombs going off. That creates pressure that presses out to keep the star at a constant size. Gravity presses in, explosions press out.

(Novas occur when these forces become out of balance and the core collapses, and the star blows off the outer shells of gas.)

Explanation: