2015-02-27 BBC:星光七纪元-12（在线收听）

What most of us have learnt is that the Sun's reliable, dependable, unchanging, but its serene outward appearance that we take for granted belies a truth about all middle age stars, beneath the surface, there is a battle raging, uncovered by the scientists who know it better.

The Sun is in the prime of its life, it's a middle age star, that it's actually very dynamic, very full of life, I regard the Sun as a sort of personal friend of mine, i like to know what's happening on the Sun each day, and i look at the satellite pictures to find out, it's almost as if the Sun sometimes doesn't want you to know what's happening on it though, because sometimes the data links could be down, or something you can't actually see it, and that's quite frustrating because you want to know how your friend is getting on each day.

Doctor Helen M's intimate relationship with the Sun has turned her into one of the world's leading solar physicists.

People think of it as quiet and boring, but it's not at all quiet and boring, and that makes it really interesting to study.

The work of scientists like Helen has revealed that inside the Sun there is a fight between two of nature's fundamental forces, that's key to the star's entire life history, the gravity that created a star is pulling it inwards trying to crush it, and the nuclear fusion that brought it to life is pushing outwards, ready to blow it apart.