This is CBS Eye on the World with John Bachelor. Here's John Bachelor.

This is CBS Eye on the World. I'm John Bachelor. I welcome Dr. Ken Croswell, author of the

Alchemy of the Heavens, searching for meaning in the Milky Way, to take us to the Milky

Way. A galactic enterprise can as long admired as beautiful, and he now writes in the proceedings

of the National Academy of Sciences. A revelation about the Milky Way, about our place in it,

our solar system, can a very good evening to you. And the Milky Way is a spiral galaxy,

but to do some history, the revelations of spiral galaxy, you date to the mid-19th century,

the Whirlpool galaxy. And that was sometime before we could perceive our own galaxy because we're

inside that spill of stars across the sky. What did the Whirlpool galaxy teach us? What does it

mean to be a spiral galaxy? Good evening to you. Good evening, John. The Whirlpool galaxy is a

stunning spiral galaxy. It's still one of the most beautiful galaxies we know. And there's a

picture of a great picture from Hubble that appears in my article in the proceedings of the

National Academy of Sciences. We discovered a spiral structure in 1845, where I should say Lord

Ross in Ireland was the first to make out the spiral structure of that galaxy. And soon after

we discovered a number of other spiral nebulaes, that's what they were called, that bed. We now

know that those are other galaxies that resemble our own, located well beyond the Milky Way. And

almost from the start, a lot of astronomers speculated that the Milky Way might be a spiral galaxy,

but it was only a century later that they were able to prove that in the early 1950s. As I

tell the story in my book, The Alchemy of the Heavens, William Morgan at Eurichese Observatory,

in Wisconsin, and his colleagues plotted the positions of young stars and the gas clouds that

give birth to those stars. And he was able to make out the three nearest spiral arms. Now,

let me explain something. The spiral arms give birth to new stars. So if you want to trace out

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