Seven Ages of Starlight

00:00:05 Each night, after the sun sets, sit back

00:04:32 And then we have a pattern here

00:08:37 will fall into the centre and they will become denser and denser

00:12:04 in full bloom - this is probably about 30 million degrees right now.

00:15:26 scientists have discovered

00:19:03 in the disc of dust that surrounds the star.

00:22:38 but it's not at all quiet and boring

00:26:00 scientists have discovered that the sun's active, changeable nature is

00:30:03 that's so important, that without it, the...life would cease to exist.

00:34:15 and move into the next phase of its life

00:38:15 Their story starts the day the hydrogen in their core runs out.

00:42:17 A story of creation that is about us, as well as about the stars.

00:46:43 They start off with hydrogen and they make helium

00:50:06 between the gravity which is trying to squeeze it together

00:54:03 that you need to peer much, much further to find many more.

00:57:48 and down here, in the violet part of the spectrum, is calcium.

01:01:28 that triggers the supernova

01:05:45 It seemed so preposterous that Zwicky's ideas were dismissed.

01:09:21 It showed Swiss astronomer Zwicky was correct all along.

01:13:12 the suggestion is that, in the future

01:16:43 Doug and his team realised that they had an unprecedented opportunity.

01:20:52 the elements, even of us.

01:24:35 had to have been made in space in some environment

01:28:17 Subtitles by Red Bee Media Ltd