From the brains behind brains on, this is the Moment of Um.

Um, um, um, um, um, um, um, um, moment of um comes to you from APM Studios. I'm Ruby Guthrie.

Um, I don't know about you, but I'm always trying my best to reduce the amount of garbage I produce.

I compost my food scraps.

I buy dry goods in bulk from the co-op and then put them in glass jars.

I try to bike or take the bus instead of drive.

I carry my reusable water bottle, so I don't have to rely on plastic ones.

In fact, the less plastic I can use, the better. It's wild how much plastic we produce,

and then toss away. And I'm trying everything I can do to cut down on that. In fact, I don't even

really understand what plastic is. And neither does Julian, who asked this question.

Hi, my name is Julian, and I'm from Winnipeg, Canada.

And my question is, what is plastic made of?

It's a good question, but it's a pretty complicated one.

Plastic is made out of many different kinds of plastic.

That's like asking, what is food made at it?

I'm Frank Bates, and I'm a regents professor at the University of Minnesota. There are different categories of plastic.

The big ones are polyethylene, polypropylene, polystyrene, polyvinyl chloride, polyvinyl chloride, polyethylene-terophthalate. Those are the five big ones. That's about

90% of all plastics. And they're made from relatively simple chemical compounds, but they each have

their own unique properties.

So a water bottle made out of P.E.T, which is a big plastic, has properties that you appreciate

are different than the properties of the tuppelware that goes in your, maybe your refrigerator. And the P.E.T.

is a particularly interesting one because you can take those plastic bottles and you can actually

...