Day 346 (New Year’s Eve)
Let’s end the year with a song about the stars. Carl Sagan said that we are all stardust. Here’s how that works. You can sing it to O, Holy Night, if you have a good voice.
THE STARS AT NIGHT
All through the night the stars are brightly shining.
We see their light and we ask what it’s from.
Four hydrogens together are combining
With such great force that they form helium.
As gravity compresses stellar gases;
Their fusion yields enormous energy.
And, while they fuse, they lose some of their masses
And radiate out the difference, visibly.
That’s why the sky is bright with at night.
Deep in a star the pressure is astounding.
The density makes the temperature soar.
Atoms are built, complexity compounding,
Until it stops at a dense iron core.
Their fuel gone, the stars begin imploding
And temperatures again begin to rise.
Shock waves compound, rebounding, then exploding.
The flash of a nova foretells the star’s demise.
Whose light, so bright, soon dies from midnight skies.
After the blast all synthesis is ended.
New elements will be blown into space.
Once more the core, its energy expended,
Collapses down leaving hardly a trace.
The cores collapse to remnants of three classes:
White dwarfs and neutron stars well-recognized.
In remnant cores, more than two solar masses,
A black hole may form; at least it’s theorized.
Where light, once bright, falls right in out of sight.
So we can say good night to all the stars at night.
Stephen Baird, 2012