Wednesday, August 31, 2011

The Galaxy Song (with metric conversions)

This morning at the breakfast table we were having a conversation about astronomy, moon phases and the like (as you do), and Yarrow wanted to know at what speed the Earth revolved. So I sang her Monty Python's "The Galaxy Song". The astronomical facts and figures in the song are tolerably accurate, but as they are not in metric, Yarrow couldn't get a 'feel' for the distances and speeds. So I promised her I'd convert the figures to metric.

Just remember that you're standing on a planet that's evolving
And revolving at nine hundred [MW1] miles an hour,
That's orbiting at nineteen miles a second[MW2] , so it's reckoned,
A sun that is the source of all our power.
The sun and you and me and all the stars that we can see
Are moving at a million miles a day[MW3] 
In an outer spiral arm, at forty thousand miles an hour[MW4] ,
Of the galaxy we call the 'Milky Way'.
Our galaxy itself contains a hundred billion stars.
It's a hundred thousand light years [MW5] side to side.
It bulges in the middle, sixteen thousand light years thick[MW6] ,
But out by us, it's just three thousand light years wide.
We're thirty thousand light years from galactic central point.
We go 'round every two hundred million years,
And our galaxy is only one of millions of billions
In this amazing and expanding universe.

The universe itself keeps on expanding and expanding
In all of the directions it can whizz
As fast as it can go, at the speed of light, you know,
Twelve million miles a minute[MW7] , and that's the fastest speed there is.
So remember, when you're feeling very small and insecure,
How amazingly unlikely is your birth,
And pray that there's intelligent life somewhere up in space,
'Cause there's bugger all down here on Earth.

 [MW1]1448 kph
 [MW2]30 km / sec
 [MW3]1,609,344 km / day
 [MW4]64,374 km / hour
 [MW6]Australian astrophysicist Bryan Gaensler has even stated that Eric's estimation of the thickness of the Milky Way, at 16,000 light years, is more accurate than the official 'textbook' figure of 6,000 light years :-)
 [MW7]By conversion, it’s 19,312,128 km/min, but according to google research, it’s 17, 987, 547.5 km/min


Mateo said...

Hi. That is wonderful. I am Mateo Esteban on facebook. I like my galaxy, so much better than M91.

Dr. Mieke said...

Why thank you Mateo. I'm guessing you mean Messier 91, the barred spiral galaxy about 63 million light-years away in the constellation Coma Berenices, not Route M91, Hurstville to Parramatta via Padstow, Bankstown & Lidcombe ... Mind you it might be interesting to write a song about either of those, too.