Fly Away

Lenny Kravitz’s album 5 has been out for a few years now. I remember especially enjoying its hit single “Fly Away” which had an energetic video to go with it. You can hear “Fly Away” on Lenny Kravitz’s MySpace page (you’ll have to click the song yourself, I can’t figure out how to link to it).

Meanwhile, however, I’d like to discuss these lyrics:

Oh I want to get away.
I want to fly away.
Yeah, yeah, yeah.

Let’s go and see the stars,
The milky way, or even Mars.
Where it could just be ours.

Is anybody else bothered by the cosmology implied by those lyrics?

For one thing, the Sun is a star. It’s just really, really close. The next nearest star is called Alpha Centauri, and it’s about 265,000 times further away. That isn’t what bothers me about the song, though. After all, Lenny obviously means he wants to go and see the other stars. Let’s talk about those.

All the stars we can see in the sky, including Alpha Centauri, are part of a large group of about 100 billion stars that are organized into a thin disk called a galaxy. It’s a big disk: From one edge to the other is about 24 thousand times greater than the distance between the Earth and Alpha Centauri, or 6.3 billion times the distance from the Earth to the Sun. Our Sun, and therefore our planet, is also in this disk, somewhere around half way between the center and the rim.

If you go out at night someplace far enough from a big city so that the sky is truly black, you can see this disk. You’ll have to wait for your eyes to adapt. We’re embedded in the disk, so we see it edge-on. It appears as a faint uneven band of light stretching across the night sky.

If you travel the earth following that band, you’d see that it stretches around the entire sky of our planet. We’re in the middle of a glowing ring of light. The ring is patchy and uneven, and appears to wander around between the stars. Our ancestors staring up at the sky during the late hours gave it a descriptive name: The Milky Way.

The stars are part of the Milky Way, and so are we. So Welcome to the Milky Way, Lenny. Make sure you try some of the food here, it’s really good.

Actually, that’s not what really bothers me either. I’m bothered by the reference to Mars, specifically to the implication that Mars is something special. It’s not.

With apologies to all those who study Mars, it’s a cold, nearly-airless jerkwater little planet that’s practically right next door. Many nearby stars will have planets just like it, or far more interesting.

So when Lenny Kravitz sings

Let’s go and see the stars,
The milky way, or even Mars.

it’s a lot like someone earthbound in Chicago singing

Let’s go and see Paris,
The World, or even Joliet.

Addendum: Actually, if you do the math, if the nearest star is as far as Paris, then Mars is the corner bar. On the other hand, if the Milky Way is the size of the Earth, then Mars is like a speck of dust on your skin.