Eric Idle, Monty Python player extraordinaire, wrote the Galaxy Song for the movie The Meaning of Life. I was quite curious to see how it has withstood 20 years of astronomical leaps in our understanding of the universe. My references can be found at http://www.softwarerepair.com/astro/ReferencesforGalaxySong.htm.
Just remember that you're standing on a planet that's evolving
While still controversial in some areas, evolution seems pretty well established.
And revolving at nine hundred miles an hour,
The speed of the earth's revolution is once per day (duh) but at the equator the circumference of the earth is 25,000 miles so that makes the speed just over 1,000 miles per hour. However, by the time you get as far north as the UK (Eric Idle's country) the speed is actually less than 700 miles per hour. The 900 figure might be good enough for our purposes.
That's orbiting at nineteen miles a second, so it's reckoned,
The earth orbits the sun at 29km/second and there is roughly a 3:2 ratio between kilometers and miles so 19 miles per second is pretty close.
A sun that is the source of all our power.
This may be a bit of hyperbole. The sun is responsible for all wind and solar power and because our weather depends on the sun we would include hydroelectric power as well. Oil and coal formed as a result of sun-driven processes on earth so that's okay. But this particular sun did not create uranium so it could be argued that it doesn't supply all of our power. IMHO.
The sun and you and me and all the stars that we can see
Are moving at a million miles a day
The sun (and therefore the earth and at least all the stars that you can see with the naked eye) are moving through the galaxy at 225km/sec. This comes out to more than 6 million miles per day.
In an outer spiral arm, at forty thousand miles an hour,
We are indeed in an outer spiral arm of the galaxy. If we were moving at a million miles per day that would come out to 40,000 miles an hour. If the number is closer to 6 million miles per day that makes it close to 250,000 MPH.
Of the galaxy we call the 'Milky Way'.
Our galaxy itself contains a hundred billion stars.
While there have been some estimates that are a bit higher than 100 billion stars, this is still a pretty good estimate.
It's a hundred thousand light years side to side.
Give or take 20,000 light years, this is close to the current estimate.
It bulges in the middle, sixteen thousand light years thick,
Estimates vary quite a bit but 10-30 thousand light years is at least one estimate for the middle of the galaxy
But out by us, it's just three thousand light years wide.
And in the outer arms it is anywhere from 1 to 10 thousand light years wide.
We're thirty thousand light years from galactic central point.
A very good estimate.
We go 'round every two hundred million years,
Rounding down to the nearest hundred million, this will do nicely.
And our galaxy is only one of millions of billions
Millions of billions would be quite a lot. Some estimates are in excess of 1 trillion galaxies but that's only thousands of billions. But we aren't done counting yet.
In this amazing and expanding universe.
And probably expanding at a faster rate than before.
The universe itself keeps on expanding and expanding
In all of the directions it can whiz
We have pretty solid proof of that these days
As fast as it can go, at the speed of light, you know,
But matter cannot generally move at the speed of light so the speed of the expansion is somewhat less. On the other hand, there was a time in the early universe where it seems it did expand at a speed greater than the speed of light.
Twelve million miles a minute, and that's the fastest speed there is.
The speed of light is about 186,000 miles per second or just a bit shy of 12 million miles a minute. There are claims for things that can go faster but it is still speculation.
So remember, when you're feeling very small and insecure,
How amazingly unlikely is your birth,
The human genome project has found 30,000 genes. It would take only 33 genes to make every living person unique.
And pray that there's intelligent life somewhere up in space,
Hence my membership in Team SETI.
'Cause there's bugger all down here on Earth.
An unassailable truth.
[Editor's note: Enjoy more great missives from new editors Paul and Mary Kohlmiller in the coming months.]