The Supernova

A supernova is the sudden, bright flashing up of a star at the end of its life. This flashing up is actually an explosion. During the explosion the dying star can get even brighter than a whole galaxy. But not every star will end in such a gigantic light show. If there will be a supernova or not depends on the weight of the star (our sun is too light, for example).
Now, you might wonder what dying stars have to do with the topic? Well, actually quite a lot. We can compare a supernova to the two rubber balls.

First, the star collapses more and more. Due to that, the star's core gets harder and denser.

The inner hard core induces a shock wave (explosion). This wave and its pressure then hit the outer shells of the star which are still collapsing.

The moment when core and shell collide, the collision accelerates the outer shell which is finally catapulted away at an extremely high speed.

Finally the star explodes.

	First, the star collapses more and more. Due to that, the star's core gets harder and denser.
	The inner hard core induces a shock wave (explosion). This wave and its pressure then hit the outer shells of the star which are still collapsing.
	The moment when core and shell collide, the collision accelerates the outer shell which is finally catapulted away at an extremely high speed.
	Finally the star explodes.