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Astronomycast Episode 204 for Monday, October 25, 2010. Temperature.

Welcome to Astronomycast, our weekly facts based journey through the cosmos.

We 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 University Day, and with me is Dr. Pamela Gaia Professor.

What's up in Illinois University?

I'm Pamela. How are you doing?

I'm doing well. How are you doing today, Fraser?

Doing great. Of course, when this is being recorded, or I guess when people listen to this,

we will have finished our presentation in Washington and I will be flying back to Vancouver.

I hope it went well.

Here's definitely to hoping for that.

We're going to answer a question that a four-year-old might ask, what is temperature?

Why are things hot and why are they cold?

Or cold can they get?

How is this all important to astronomy?

When we think about that temperature, I reach out with my hand and touch a piece of metal.

And the metal is hot or the metal is cold.

What's going on?

Well, at the most fundamental level, if you could get down and pure things at the level of electrons and atoms vibrating molecules,

what you'd see is that metal is filled with atoms and electrons that are a little bit excited to be alive

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