Physics

Stars go through many stages in their lives - just like teenagers.

1) Stars form from clouds of DUST AND GAS. The force of gravirty makes the gas and dust spiral in together to form a protostar.

2) The gravitational forces inside the star cause it to get really hot. When the temperature gets high enough, hydrogen nuclei undergoes nuclear fusion to form helium nuclei. Smaller masses of gas and dust may also pull together to make planets that orbit the star.

3) The star enters a long stable period. The heat created by the nuclear fusion peovides an outward pressure to balance the force of gravity pulling everything inwards. The forces within the star are balanced. In this …