Behold the height of the stars, how high they are!
(Job 22:12)
Let's put things in perspective. That we must
Conclude the Earth is but a speck of dust
Within the cosmos cannot be escaped.
Look at the stars (each made of gases shaped
By gravity into a sphere): I'd say
That there are billions in our Milky Way,
One of the star groups we call galaxies,
And there are billions of these groups. 1 Now please
Consider next the distances: this place
The cosmos, folks, is mostly empty space.
You want to find a star? The nearest one
To our own ball of gas we call the sun
Is more than twenty trillion miles away.
Since many suns in this far-flung array
Have planets (Butler finds them, Marcy too),
Life here on Earth may well be nothing new
And little gained. 2 So, Earthlings, here we are,
Orbiting round an ordinary star
Far from the center of its galaxy,
We who once thought this orb of ours to be
The very center of the universe!
As Edwin Hubble found, 3 to make things worse,
There is no center to the thing at all.
As you well know if you've seen Annie Hall, 4
The universe expands--the galaxies
Are moving off at great velocities
From one another. There is not a one
More central than the others are. It's fun
To think that ours is at the center, but
That's more of that old geocentric rut
That we were stuck in by Ptolemy
Right up until the sixteenth century
(Where some folks still are stuck). Copernicus 5
First moved us out into the universe
And Hubble's constant keeps us moving on. 6
In case you wonder how far things have gone,
Expansion first began, it now appears,
As long ago as fourteen billion years.
The Big Bang got it going, but the gist
Of that I'll leave to our Cosmologist.Does "cosmic evolution" sound so strange?
What's evolution anyway but change?
"No one has seen a thing evolving," fuss
Creationists. 7 Well, it's too slow for us
To sit around and watch! So what to do?
We find which stage a star has gotten to,
How far it has evolved. Once we have got it,
Its chemistry and all, then we can plot it
Using a Hertzsprung-Russell diagram. 8
But why am I so certain as I am?
How in the world are we in a position
To figure out the inner composition
Of distant stars? Do we stare off and hope?
No, we use what is called a spectroscope, 9
For it's from spectral lines that we acquire
Our knowledge of what fuel is in the fire,
Which elements are being cooked within
Those stellar cores. All start with hydrogen,
Which gets converted into helium,
Then carbon, iron--stars were the medium,
The fiery furnaces in which were first
Produced these elements; by stars that burst
As supernovas, these ingredients
Were hurled out into space, and ever since
New stars have formed, some later to explode,
The elements along this starry road
Forever being born again. It's this
Process we call nucleosynthesis. 10
Now what about our sun? The stage it's in
Is called "main sequence," burning hydrogen.
When that runs low, we'll see the sun expand--
Not we exactly, we won't be on hand;
But to escape Earth's fiery end, I trust
Our species will go elsewhere as it must.
"There's still time, brother (a few billion years)!"
Then we'll look back, galactic pioneers,
At that red-giant sun that ate the Earth. 11So stars keep burning fuel for all its worth,
As they evolve through stages. As I've said,
Some stars at last explode. Then are they dead?
Not all, for such a blast can leave behind
A neutron star or pulsar--that's the kind
That spins, sends out a sweeping beam of light
Just like some E.T.'s lighthouse in the night.
But as I say, not all stars reach a stage
Where they explode, for that is just one page
From nature's book of rules on burning out.
Some simply shrivel up, they sit and pout
As what we call white dwarfs, till finally
Their light goes out completely. 12 Some will be
Too massive, they will have a weirder fate:
As they collapse, they go beyond the state
Of being white dwarfs; pulled right out of sight
By gravity, they're black holes from which light
Itself cannot escape. It's crazy stuff,
What science fiction's made of!But enough
About the stars. No, wait: I guess you've heard
Of something called a quasar, so a word
About that beast, although it's not a star
(It's "quasi-stellar," hence its name). So far
Away these brilliant objects seem to be,
How can they be as bright as what we see?
Their energy must really be prodigious,
Almost enough to make a man religious
If he's not so already. Deity,
Though, needn't be invoked. Most now agree
Quasars are galaxies distinguished by
Their centers, highly active nuclei,
Gigantic black holes; all that brightness, then,
Is energy from matter falling in. 13
(A black hole--one less active, safe to say--
Lies at the core of our own Milky Way. 14
A black hole sucks in everything that's near.
Do not go gentle as you disappear;
That black hole's glow, that strange illumination,
Is matter screaming: Squawking radiation.) 15Where was I? Ah! So much for quasars, then.
Now let's move closer home, let's zero in
On our own solar system. Can we say
That it evolved? I think we surely may! 16
The ball got rolling as the sun condensed
From gas and dust--we think that this commenced
To happen some five billion years ago.
(I'm speculating based on all we know;
I wasn't there to see this, you can trust.)
Imagine first a cloud of gas and dust,
A nebula, rotating. Now nearby
A star explodes, the shock wave from it why
Our cloud begins contracting. 17 Now its spin
Speeds up as gravity keeps pulling in,
Till in the center there is so much heat
That nuclear reactions start--now meet
The sun, a star is born! 18 But what about
The cloud surrounding it? It flattens out
Into a disk, caused by the solar spin,
And all the particles of dust within
The inner disk begin colliding, soon
To aggregate, compact, till here a moon
And there a planet; in the outer disk,
Far from the sun, form gassy giants; whisk
Hard rocks about, stray planetesimals,
Bombarders who with unheard decibels
Impact and crater; other such debris
Includes the asteroids (that belt we see
Twixt Mars and Jupiter); the solar wind
(Charged particles) comes sweeping out, to send
To interstellar space what's left of gas
And dust.
That's how we think it came to pass. 19
The radiometric age of meteorites--
Mementos (like those celebrated lights
The comets) of the solar system's birth,
Like long-lost brothers dropping in on Earth--
Is over four and one-half billion years. 20
Material our space-age pioneers
Brought with them from the moon is just as old. 21
The oldest Earth rocks man has yet to hold
Were formed four billion years ago. 22 Right now
I won't go into dating methods, how
It's done, I'll leave that for our Physicist.
My point is this, and I don't want it missed:
Among creationists a leading group
Is called young-Earthers, people who will stoop
To anything to "prove" the Earth is young.
This song of theirs continually is sung
In books and churches and I'm sure they'll sing
It here. Not just the Earth but everything,
The universe, has only been around,
They claim, about ten thousand years. They found
This out by adding up all those begats
In Genesis--some pretty sexy stats. 23
Can they explain this little gap to us,
Between ten thousand and four billion plus?
Of course! Forget a date, it is maintained,
That's been radiometrically obtained,
Because it's unreliable. Well, folks,
They're saying physicists are walking jokes,
Atomic theory must be tommyrot, 24
And we're tomfools ignoring truth we've got
In ancient lists of who did what to whom.
They�ve also said we�re misled to assume
That starlight we now see began its flight
Billions of years ago (the speed of light
Means it would take that long). 25 They claim that we
Just think arriving starlight that we see
Has come that far, for God created it
En route--Yes, sir! as they have stated it,
God gave all that we see "apparent age," 26
So time elapsed is something we can't gauge,
We only think we've got it right. How sweet
To say that God would practice such deceit! 27Now let me tell you why creationists
Say what they do. They're fundamentalists 28
Who think the Bible's very clear to speak
Of everything created in a week 29--
The sun, the moon, the planets, stars, the works--
And all who wish to share in heaven's perks
Had best believe the Bible doesn't lie.
Well, I respect the Bible, written by
Men learned for their time, not fools or dopes;
I also know they had no telescopes
Or lots of other things we have today
To see in a more scientific way.
I'll read the Bible for its moral view
And not because I think it's really true
That Joshua once made the sun stand still. 30
He didn't then and no one ever will
And that's a fact. If that is what he did,
All that was on the Earth then must have slid
Right off! I'm sorry, I don't mean to holler.
I'll leave this subject to our Bible Scholar.From what I've said, then, I hope you agree
That cosmic evolution's plain to see.
"God made us," you can say and never doubt,
But scientific method's not about
What you believe but have no way to test
Or falsify. It's therefore always best
That science and religion not be mixed.
That's why "creation science" should be nixed,
There's really no such thing. That's not to say
That God did not create, there's just no way
To prove it, while the evidence is strong
That things evolve--so God must go along
If he exists. That's why the best solution
For theists is theistic evolution. 31
But that's not really science; I'll defer
That subject to our good Philosopher.
Epilogue to the Astronomer's Tale
As soon as the Astronomer was done,
The Physicist spoke up, though not the one
Whose tale was next. He said, "My goodness gracious,
We've started well, sir, you are quite sagacious
About the cosmos! Just one thing I'll add,
If I'm allowed, for those who haven't had
Much science training, since it's pretty clear
It's for such people that this fellow here
Is taking notes--I judge he'll write a book.
One thing you said deserves a longer look.
You mentioned falsifying. 32 How could I
Prove God did not create? I can't, that's why
We say the notion can't be falsified.
If we can't prove a thing, for all we've tried,
Then why not try disproving it instead?
Where do we start, though, if it's simply said
That 'God created us'? For that's a call
We can't make, we can't falsify at all,
The statement has no scientific meaning.
What's science anyhow? It is a screening
Of theories based on how well they may fit
The facts observed. A theory we submit
To tests, and passing tests will make it strong;
A theory can't be 'right,' though, only wrong, 33
For science doesn't deal in certainty.
No, that's a critter we will never see; 34
We tell you this and that, but only when
It's understood that we are dealing in
What's probable based on a lot of facts. 35
That thing about the sun stopped in its tracks?
Well, based on all our science, trust in me,
There is no lower probability!""And that's for sure," said the Astronomer.
"Now let's keep comments short, if you concur,
As each one tells his tale. Proceeding now,
Our Biochemist here will tell us how
Life started. What's the probability?
My guess is, all by natural chemistry."