“Mummmmm”,”yes”. “I have a question”. “Go on then, tell me about it”. “Brian Cox says the sun is a star, why is it bigger than other stars?” “Because it is” is not a viable option.
Before I started to look for an answer I became sidetracked reading about Professor Brian Cox. One of his inspirer’s had been Carl Sagan. So, I thought who is Carl Sagan.