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Astronomycast, episode 212 from Monday, December 20, 2010. GPS Navigation.

Welcome to Astronomycast, our weekly facts-based journey through the cosmos, to really help you understand not only what we know, but how we know what we know.

My name is Fraser Cain, I'm the publisher of the universe today, and with me is Dr. Pamela Gay at Professor at Southern Illinois University.

I always feel, hi Pamela, how you doing?

I'm doing well, Fraser, how are you doing?

I'm good, we're both very well-rested. You went on a cruise in Europe, I went on a cruise in the Caribbean, and yeah.

And you are Tanner than I am, I'm guessing.

No, it was like an ice box in, well, the Caribbean was warm, but the Southern Florida was just like cold, cold.

So colder than home, so I moved back to the West Coast for warmth.

But I know the timing is all kind of messed up, we're actually recording this in January, but the date is December, because we owe you.

So, last week, we talked about the old way that navigators used to find their way around the planet,

by looking at objects in the sky and doing some tricky math.

The new navigation system, of course, is the global positioning system, or GPS, and it helps you find your spot on the planet with amazing accuracy.

Let's see where the system came from and how it works.

Let me just get this off the record, you know, just so people can know my political leanings here.

I love GPS.

Like I love it. I think GPS is the coolest thing ever.

You know, I've got an iPad, and it's got like a GPS on it, and you're like driving down the road, and you can see where you are on Earth, you can try.

Anyway, it's really awesome.

So, that said, people can keep this in mind, as we do this show, I totally love GPS.

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