Update to Monty Python post

Whether or not you are a scientist, it’s important to allow new information to change your mind.  Yesterday I realized that I needed to revise my post about Monty Python’s Galaxy Song.  This is the song from The Meaning Of Life in which Eric Idle sings a bunch of astronomical facts. 

Someone was trying to explain the change of seasons to a bunch of little kids, including Little Rock, who is 3 1/2.  She wanted to explain that the northern hemisphere is a little farther away from the sun in winter.  She only had about four minutes to do it so she quickly told the kids that the earth rotates, it revolves around the sun, and the entire solar system moves around the galaxy.  She also gave the speed at which all these things happened.  I can’t imagine that many of these kids had a clue what she was talking about. 

Little Rock must have realized she was making it all up.  He told her that he shot down the moon.  Apparently he put a stick in some poison berries and put the thing there and the thing there and then he shot down the moon.

Anyway, the way she was rattling off those facts reminded me of The Galaxy Song.  I remembered the lyrics and realized that I misunderstood the first line.

Just remember that you’re standing on a planet that’s evolving

In my initial post about the song, I interpreted “evolving” narrowly and assumed Idle was thinking of natural selection.  Life evolves, but planets don’t evolve.  Yesterday I remembered that geologists use the word differently.  When they say the earth evolves, they just mean that it changes over time.  It wasn’t always the way it is now.  Mountains and oceans form and disappear.  Continents merge and separate.   It takes a long time, but the world is always changing.  That’s what Monty Python was singing about.  I updated my views (and my blog post.)

I’ll give myself four Lemmys for learning something new.

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Can we trust Monty Python’s science?

Monty Python did a nice job of melding music and science near the end of The Meaning Of Life

The other day, I told you to be like Rock Dad and check things out.  You can’t check everything out, so one handy trick is to consider the source.  We shouldn’t have been surprised that Airborne turned out to be bogus.  It was created by a school teacher, after all.  We trust school teachers, but we shouldn’t expect them to invent medicines.

I like Monty Python a lot.  A weakness of mine is to assume that people I like are also intelligent.  Motorhead’s lyrics are ironic, whereas Kiss’ songs are kind of dumb.  Even if I think Monty Python’s Eric Idle is smart, is it safe to assume that he bothered to get his facts straight when he wrote “The Galaxy Song?”  Good question. Let’s take a look.

Just remember that you’re standing on a planet that’s evolving

[They don’t mean evolving in the Scopes’ Monkey trial sense. They mean evolving as in changing.  Mountains are pushed up and later eroded. Continents move around.  Oceans open and close.  That sort of thing.]

And revolving at 900 miles an hour

[Actually 1056 miles an hour – 1700 kr/hr * 0.62 mi/km]

That’s orbiting at 19 miles a second, so it’s reckoned

[Yes. 30 km/sec * 0.62 km/mi = 18.6]

A sun that is the source of all our power

[Not quite. Radioactive decay of elements inside the earth sends some heat to the surface.]

The sun and you and me, and all the stars that we can see
Are moving at a million miles a day
In an outer spiral arm at 40,000 miles an hour

[Pretty much.  1.2 million miles a day or 49,000 miles an hour.  The solar system’s orbital speed is 220 km/sec.  (220 km/sec * 0.62 km/mi * 360 sec/hr = 49,104 mi/hr.  49,104 mi/hr * 24 hr/day = 1,178,496 mi/day.)  We are in an outer spiral arm.]

Of the galaxy we call the Milky Way

[True.]

Our galaxy itself contains 100 billion stars

It’s 100,000 light years side-to-side

[Yes, if you are only referring to the stellar disc.]

It bulges in the middle, 16,000 light years thick

[12,000 light years, but they thought it was 6,000 when this song was written.]

But out by us it’s just 3,000 light years wide

[Probably 2,000 – 2,500]

We’re 30,000 light years from galactic central point

[This was believed when the song was written, but now we think it is 26,000 ± 1400.]

We go round every 200 million years

And our galaxy is only one of millions of billions

In this amazing and expanding universe.

[It is exapnding.  Whether it amazes of not is a matter of opinion.]

The universe itself keeps on expanding and expanding
In all of the directions it can whiz

[True.]

As fast as it can, go at the speed of light, you know

[No. Rate of expansion depends on how far apart two objects are.]

Twelve million miles a minute

[Eleven miles a minute.  (186,000 mi/sec * 60 sec/min)]

And that’s the fastest speed there is.

[True.]

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
Because there’s bugger all down here on Earth.

[Wrong: Dolphins.]

Not bad. Not bad at all. 4 Lemmys.

Keep on keeping on,
Rock Dad