Activity 1: Modelling the formation of a black hole
This activity will demonstrate to students how a black hole is formed through the collapse of a massive star, once the core of the star is unable to support the weight of the outer layers of gas surrounding it. The time needed should be about one hour.
Materials
Each working group will need:
A balloon
A few sheets of aluminium foil, each approximately 30 cm square
A pin for popping the balloon.
Method
Have the students inflate the balloon and tie it closed. They should then wrap the balloon in several layers of aluminium foil to create the model star.
Explain that the layers of foil represent the different gas layers of the star, and the balloon that gives them their shape is analogous to the hot burning core of the star. Inside the core, the heat created by thermonuclear fusion exerts a pressure on the gas layers of the star, which keeps them from collapsing.
Have the students simulate the effect of gravity by trying to lightly compress the balloon. The pressure of the core is such that the star cannot collapse from gravity.
When a star reaches the end of its life, it runs out of fuel in the core and is no longer able to hold up the gas layers. Have the students pop the balloon with the pin, which simulates this process.
Again, they should try to compress the balloon with their hands to mimic the effect of gravity. This time, they will be able to compress the foil into a small ball, which simulates the formation of a black hole. Note that the mass of the small ball is the same as that of the model star, but their sizes are quite different.